- Email: [email protected]
Readmissions after acute type B aortic dissection
Readmissions after acute type B aortic dissection Brett J. Carroll, MD,a Marc Schermerhorn, MD,b Kevin F. Kennedy, MS,c Nicholas Swerdlow, MD,b Kevin M. Soriano, MD,d Robert W. Yeh, MD, MSc,a and Eric A. Secemsky, MD, MSc,a Boston, Mass; and Kansas City, Mo
ABSTRACT Objective: Acute type B aortic dissection can be treated with medical management alone, open surgical repair, or thoracic endovascular aortic repair (TEVAR). The nationwide burden of readmissions after acute type B aortic dissection has not been comprehensively assessed. Methods: We analyzed adults with a hospitalization due to acute type B aortic dissection between January 1, 2010, and December 31, 2014, in the Nationwide Readmissions Database. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify hospitalizations with a primary diagnosis code for thoracic or thoracoabdominal aortic dissection. The primary outcome was nonelective 90-day readmission. Predictors of readmission were determined using hierarchical logistic regression. Results: The study population consisted of 6937 patients with unplanned admissions for type B aortic dissections from 2010 through 2014. Medical management alone was the treatment for 62.6% of patients, 21.0% had open surgical repair, and 16.4% underwent TEVAR. Nonelective 90-day readmission rate was 25.1% (23.6% with medical management alone, 26.9% with open repair, and 28.7% with TEVAR; P < .001). An additional 4.7% of patients were electively readmitted. The most common cause for nonelective readmission was new or recurrent arterial aneurysm or dissection (24.8%). Of those with unplanned readmissions, 5.2% underwent an aortic procedure. The mortality rate during nonelective readmission was 5.0%, and the mean cost of the rehospitalization was $22,572 6 $41,598. Conclusions: More than one in four patients have a nonelective readmission 90 days after hospitalization for acute type B aortic dissection. Absolute rates of readmission varied by initial treatment received but were high irrespective of the initial treatment. The most common cause of readmission was aortic disease, particularly among those treated with medication alone. Further research is required to determine potential interventions to decrease these costly and morbid readmissions, including the role of multidisciplinary aortic teams. (J Vasc Surg 2019;-:1-11.) Keywords: Thoracic aortic dissection; Thoracic endovascular repair; Readmissions
Acute type B aortic dissection is associated with high morbidity and mortality.1 Medical management with blood pressure and heart rate control is the guidelinerecommended treatment for uncomplicated patients, whereas intervention in the acute setting with open surgical repair or thoracic endovascular aortic repair (TEVAR) is generally reserved for patients with persistent symptoms, evidence of malperfusion, or concerning aortic morphologic features including rupture or rapid aneurysm expansion.2 During the last 20 years, there has been an increased rate of intervention that parallels
the introduction of TEVAR. In addition, there has been a reduction in medical management alone, from 75% to 57% between 1995 and 2013 in the International Registry of Acute Aortic Dissection (IRAD).1 In-hospital mortality, however, has remained unchanged in this time (12%-14%). In those who survive the initial event, intervention-free survival is low for medically managed patients, reported at 41% during 6 years at a single center.3 In those who have TEVAR, regular interval follow-up to monitor for the development of endoleaks is indicated as there is a
From the Division of Cardiovascular Medicine, Department of Medicine,a Divi-
Additional material for this article may be found online at www.jvascsurg.org.
sion of Vascular Surgery, Department of Surgery,b and Department of Medi-
Correspondence: Brett J. Carroll, MD, Division of Cardiovascular Medicine, Beth
cine,d Beth Israel Deaconess Medical Center, Harvard Medical School,
Israel Deaconess Medical Center, 185 Pilgrim Rd, Boston, MA 02215 (e-mail:
Boston; and the Department of Cardiovascular Research, Saint Luke’s MidAmerica Heart Institute, Kansas City.c The study was internally funded by the Smith Center for Outcomes Research in Cardiology at Beth Israel Deaconess Medical Center (Boston, Mass). Author conflict of interest: M.S. has received consulting fees from Cook Medical,
[email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214
Medtronic, and Endologix. R.W.Y. has received research grants and consulting
Copyright Ó 2019 by the Society for Vascular Surgery. Published by Elsevier Inc.
fees from Abbott Vascular and Boston Scientific and consulting fees from
https://doi.org/10.1016/j.jvs.2019.08.280
Medtronic and Teleflex. Presented as an oral presentation at the Sixty-eighth Annual Scientific Session & Expo of the American College of Cardiology, New Orleans, La, March 16-18, 2019.
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reintervention rate of 16% at a median follow-up of 31 months as reported by a systematic review in patients treated for chronic type B dissection.4 Data regarding readmissions after acute type B dissection and subsequent interventions during rehospitalization are limited to single-center reports, Medicare beneficiaries, or those receiving TEVAR alone.5-7 In this study, we evaluate readmissions after type B aortic dissection among a nationwide cohort of adult patients from all insurer types and undergoing various treatment strategies.
ARTICLE HIGHLIGHTS d
d
METHODS Data source. We obtained data from the Nationwide Readmissions Database (NRD) from 2010 to 2014. The Agency for Healthcare Research and Quality sponsors the NRD as part of the Healthcare Cost and Utilization Project. The NRD collects discharge data from 18 to 22 geographically dispersed U.S. states, accounting for >40% of all U.S. hospitalizations. The database includes data from all payers and uninsured persons and contains >100 clinical and nonclinical variables for each hospitalization. The data include diagnosis and procedure codes from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and Clinical Classifications Software diagnosis and procedure classifications. The Institutional Review Board at Beth Israel Deaconess Medical Center evaluated this study and deemed it not to qualify as human subjects research. Study population. We identified all adult hospitalizations (aged $18 years) that were associated with a diagnosis code of dissection of the thoracic aorta (ICD-9-CM 441.01) or dissection of the thoracoabdominal aorta (ICD9-CM 441.03; n ¼ 36,157) and included only those with a primary diagnosis code (21,213; Fig 1). Because the NRD does not track readmissions between years, admissions from October 1 through December 31 of each year were excluded (n ¼ 5861) to allow 90-day follow-up for every patient. Patients were also excluded if they died during index hospitalization (n ¼ 2109), underwent a short-term transfer (n ¼ 491), left the hospital against medical advice (n ¼ 127), were electively admitted for the index hospitalization (n ¼ 1848), or had undergone an aortic procedure within the preceding 90 days of the index admission (n ¼ 367). A second admission that occurred within 90 days was counted only as one readmission. In addition, as there is no diagnosis code for acute aortic dissection, only patients with a primary diagnosis code of aortic dissection and a nonelective admission were included to discriminate against chronic dissection. Furthermore, ICD-9-CM codes do not differentiate ascending and descending aortic dissection. Thus, we used the following approach to identify patients with potential ascending aortic dissection, similar to previous studies (Supplementary Table I, online only).6,8 Those who had received cardioplegia (n ¼ 405) or had cardiac
2019
d
Type of Research: Multicenter retrospective cohort study from the Nationwide Readmissions Database Key Findings: Of 6937 patients with type B aortic dissections, 62.6% received medical management alone, 21.0% had open surgical repair, and 16.4% underwent thoracic endovascular aortic repair. Nonelective 90-day readmission rate was 25.1%, 23.6% with initial medical management alone, 26.9% after open repair, and 28.7% after thoracic endovascular aortic repair. The most common cause for nonelective readmission was new or recurrent arterial aneurysm or dissection (24.8%). Take Home Message: Readmissions after acute type B aortic dissection are high regardless of initial treatment received. Interventions to reduce readmissions should be further evaluated.
valve surgery (n ¼ 1923), operation on vessels of the heart (n ¼ 373), dissection (coronary, carotid, or vertebral artery; n ¼ 97), pericardial effusion (n ¼ 271), or aortic regurgitation (n ¼ 404) were excluded as they were presumed to have had an ascending aortic dissection. Patient, hospitalization, and institutional characteristics. Patients’ sociodemographics included age, sex, primary insurer, quartile of median household income by ZIP code, and residency categorized by county population. Chronic conditions were determined by the 29 Elixhauser comorbidities provided by the Agency for Healthcare Research and Quality.9 Characteristics of the index hospitalization included procedure code for open repair and TEVAR (Supplementary Table I, online only). Those with procedure codes for both open repair and TEVAR were considered to have TEVAR as we were unable to differentiate planned hybrid procedure from planned TEVAR with subsequent conversion to open repair. The remainder of patients without procedure codes for repair were considered to have been managed medically. Additional characteristics of the index hospitalization included length of stay, discharge destination, and costcharge ratios. Institutional characteristics included hospital bed volume, ownership, and teaching status. In addition, ICD-9 codes were used to identify patients with Marfan syndrome, patients with Ehlers-Danlos syndrome, and those with an ischemic complication during index hospitalization (Supplementary Table I, online only). Study outcomes. The primary outcome was the rate of nonelective all-cause 90-day readmissions, defined as hospitalization for any cause within 90 days of discharge after an index hospitalization. Secondary end points included costs of readmission, in-hospital mortality during readmission, and the need for a repeated aortic
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Fig 1. Flow diagram of exclusion criteria and final analytic cohort. TEVAR, Thoracic endovascular aortic repair.
procedure during readmission. We also identified reasons for unplanned 90-day readmissions determined by the Clinical Classifications Software coding system, a diagnosis and procedure categorization scheme that clusters patient diagnoses and procedures into meaningful clinical categories.9 We used primary ICD-9 codes associated with the readmission to obtain further granularity of specific causes. Statistical analysis. The Healthcare Cost and Utilization Project does not allow reporting of values of <10; thus, such values were reported as <10. We report categorical variables as counts and percentages and continuous variables as medians and ranges or means and standard deviations. Between-group differences were assessed using linear trend test for continuous variables and MantelHaenszel trend test for categorical variables. To derive predictors of 90-day readmission, hierarchical modified Poisson models were developed. All analysis was performed with SAS version 9.4 (SAS Institute, Cary, NC), with a P value of .05 marking statistical significance.
RESULTS Index hospitalization. During the study period, there were 21,213 patients hospitalized with a primary diagnosis code of thoracic aortic dissection. In-hospital
death occurred in 2109 hospitalizations (9.9%). After the remainder of exclusion criteria were implemented, the final cohort analyzed included 6937 hospitalizations of patients with acute type B aortic dissection who survived to discharge (Fig 1). Mean age at index admission was 63.1 6 15.1 years, and the majority were male (59.0%; Table I). Prevalent comorbidities included hypertension (88.1%), fluid and electrolyte disorders (34.2%), chronic pulmonary disease (21.2%), anemia (20.3%), diabetes (15.4%), renal failure (17.8%), and peripheral vascular disorders (12.6%). A small proportion had Marfan syndrome (2.2%) or Ehlers-Danlos syndrome (0.1%). An ischemic complication during the index hospitalization occurred in 4.2%: 1.9% with ischemic kidney injury, 1.0% with gastrointestinal ischemia, and 1.4% with thrombosis or embolization of abdominal aorta or iliac artery (Table II). The majority of patients received medical management alone (62.3%). Open repair was performed in 21.0% and TEVAR in 16.4% of patients. The specific claims codes for an open repair are noted in Supplementary Table II (online only). Among TEVAR patients, 14.2% also had a procedure code for open repair. Patients who received medical management alone were older (64.8 years in medical management group vs 59.2 years in open repair group vs 61.6 years in TEVAR group). The number of chronic comorbidities was similar between groups. Length of stay was shorter
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Table I. Patient demographics, clinical characteristics, and treatment received Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
TEVAR (n ¼ 1141)
Age, years
63.1 6 15.1
64.8 6 15.2
59.2 6 13.9
61.6 6 15.0
<.001
Female
2843 (41.0)
1885 (43.4)
500 (34.3)
458 (40.1)
<.001
2010
1306 (18.8)
889 (20.5)
233 (16.0)
184 (16.1)
2011
1286 (18.5)
798 (18.4)
294 (20.2)
194 (17.0)
2012
1272 (18.3)
779 (17.9)
284 (19.5)
209 (18.3)
2013
1439 (20.7)
885 (20.4)
297 (20.4)
257 (22.5)
2014
1634 (23.6)
989 (22.8)
348 (23.9)
297 (26.0)
2255 (52.1)
530 (36.5)
516 (45.3)
Variable
<.001
Calendar year
<.001
Primary insurance Medicare Medicaid Private insurance Self-pay No charge Other
P value
3301 (47.7) 877 (12.7)
524 (12.1)
203 (14.0)
150 (13.2)
1839 (26.6)
1011 (23.3)
518 (35.7)
310 (27.2)
554 (8.0)
342 (7.9)
48 (0.7)
31 (0.7)
303 (4.4)
167 (3.9)
116 (8.0)
96 (8.4)
<10 (<0.6)
<10 (<0.8)
78 (5.4)
58 (5.1)
Median household income quartile by residential ZIP code
.449
Lowest quartile
1922 (28.3)
1237 (29.0)
370 (26.0)
315 (28.3)
Middle lowest quartile
1682 (24.7)
1064 (25.0)
333 (23.4)
285 (25.6)
Middle highest quartile
1632 (24.0)
996 (23.4)
353 (24.8)
283 (25.4)
Highest quartile
1562 (23.0)
965 (22.6)
366 (25.7)
231 (20.7)
No. of chronic conditions
6.3 6 2.8
6.3 6 2.8
6.4 6 2.8
6.3 6 2.8
.467
Hypertension (combined uncomplicated and complicated)
6114 (88.1)
3967 (91.4)
1184 (81.3)
963 (84.4)
<.001
Congestive heart failure
575 (8.3)
45 (3.1)
19 (1.7)
<.001
Peripheral vascular disorders
873 (12.6)
227 (5.2)
280 (19.2)
366 (32.1)
<.001
Valvular disease
461 (6.6)
410 (9.4)
34 (2.3)
17 (1.5)
<.001
Pulmonary circulation disorders Fluid and electrolyte disorders
511 (11.8)
160 (2.3)
139 (3.2)
17 (1.2)
<10 (<0.8)
<.001
2375 (34.2)
1216 (28.0)
688 (47.3)
471 (41.3)
<.001
Paralysis
314 (4.5)
124 (2.9)
113 (7.8)
77 (6.7)
<.001
Other neurologic disorders
432 (6.2)
259 (6.0)
113 (7.8)
60 (5.3)
.988
Chronic pulmonary disease
1471 (21.2)
936 (21.6)
278 (19.1)
257 (22.5)
.980
Diabetes, uncomplicated
953 (13.7)
609 (14.0)
185 (12.7)
159 (13.9)
.629
Diabetes with chronic complications
112 (1.6)
72 (1.7)
20 (1.4)
20 (1.8)
.964
Hypothyroidism
641 (9.2)
431 (9.9)
111 (7.6)
99 (8.7)
.047
Renal failure
1233 (17.8)
822 (18.9)
225 (15.5)
186 (16.3)
.005
Liver disease
158 (2.3)
106 (2.4)
28 (1.9)
24 (2.1)
.333
Metastatic cancer
50 (0.7)
43 (1.0)
<10 (<0.6)
<10 (<0.8)
.002
Solid tumor without metastasis
82 (1.2)
57 (1.3)
10 (0.7)
15 (1.3)
.540
216 (3.1)
158 (3.6)
21 (1.4)
37 (3.2)
.051
878 (12.7)
Rheumatoid arthritis/ collagen vascular diseases Coagulopathy Obesity Weight loss Chronic blood loss anemia Deficiency anemias
<.001
278 (6.4)
453 (31.1)
147 (12.9)
1050 (15.1)
615 (14.2)
253 (17.4)
182 (16.0)
445 (6.4)
195 (4.5)
140 (9.6)
110 (9.6)
<.001
69 (1.0)
29 (0.7)
23 (1.6)
17 (1.5)
.001
1411 (20.3)
864 (19.9)
284 (19.5)
263 (23.0)
.051
.023
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Table I. Continued. Variable
Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
TEVAR (n ¼ 1141)
P value
Alcohol abuse
402 (5.8)
241 (5.6)
84 (5.8)
77 (6.7)
.148
Drug abuse
472 (6.8)
303 (7.0)
94 (6.5)
75 (6.6)
.516
Psychoses
274 (3.9)
177 (4.1)
58 (4.0)
39 (3.4)
.344
Depression
545 (7.9)
344 (7.9)
102 (7.0)
99 (8.7)
.710
Marfan syndrome Ehlers-Danlos syndrome
153 (2.2)
108 (2.5)
31 (2.1)
14 (1.2)
.011
<10 (<0.1)
<10 (0.2)
<10 (0.6)
<10 (<0.8)
.682
TEVAR, Thoracic endovascular aortic repair. Categorical variables are presented as number (%). Continuous variables are presented as mean 6 standard deviation. Percentages may not sum to 100 because of rounding. Most variables had 0% to 2.0% of data missing unless otherwise noted.
Table II. Hospitalization and institutional characteristics Variable
Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
TEVAR (n ¼ 1141)
P value
Length of stay, days
10.8 6 12.1
7.6 6 8.9
16.8 6 15.2
15.0 6 13.9
<.001
239 (3.4)
170 (3.9)
45 (3.1)
24 (2.1)
<.001
Bed size of hospital Small Medium
1045 (15.1)
729 (16.8)
171 (11.7)
145 (12.7)
Large
5653 (81.5)
3441 (79.3)
1240 (85.2)
972 (85.2)
1155 (16.6)
659 (15.2)
241 (16.6)
255 (22.3)
5105 (73.6)
3223 (74.3)
1112 (76.4)
770 (67.5)
677 (9.8)
458 (10.6)
103 (7.1)
Metro nonteaching
1584 (22.8)
1096 (25.3)
268 (18.4)
220 (19.3)
Metro teaching
5266 (75.9)
3181 (73.3)
1176 (80.8)
909 (79.7)
87 (1.3)
63 (1.5)
12 (0.8)
45,332 6 52,997
23,644 6 34,264
85,210 6 62,719
74,885 6 52,919
<.001
297 (4.2)
149 (3.4)
52 (3.6)
96 (8.4)
<.001
Ischemic kidney
134 (1.9)
83 (1.9)
38 (3.3)
.053
Gastrointestinal ischemia
68 (1.0)
25 (0.05)
13 (0.9)
30 (2.6)
<.001
Embolism or thrombosis of abdominal aorta or iliac artery
95 (1.4)
41 (0.9)
26 (1.8)
28 (2.5)
<.001
3032 (69.9)
562 (38.6)
621 (54.5)
<.001
Ownership of hospital Government Private not-profit Private invest-own
116 (10.2) <.001
Teaching status of urban hospitals
Non metro Index cost (U.S. dollars) Ischemic complication
13 (0.9)
12 (1.1)
<.001
Disposition of patient Routine
4215 (60.8)
Transfer SNF or ICF
1223 (17.6)
573 (13.2)
406 (27.9)
244 (21.4)
HHC
1491 (21.5)
729 (16.8)
487 (33.4)
275 (24.1)
HHC, Home health care; ICF, intermediate care facility; SNF, skilled nursing facility; TEVAR, thoracic endovascular aortic repair. Categorical variables are presented as number (%). Continuous variables are presented as mean 6 standard deviation. Most variables had 0% to 3.8% of data missing unless otherwise noted.
and costs were lower in those with medical management alone (7.6 days, $23,644) compared with open repair (16.8 days, $85,210) and TEVAR (15.0 days, $74,885; Table II). Readmissions. Nonelective 90-day readmission occurred in 1744 (25.1%; Table III; Figs 2 and 3). The nonelective readmission rate was lowest in those who received medical management alone (16.4% at 30 days, 23.6% at 90 days) compared with those who had open
repair (20.2% at 30 days, 26.9% at 90 days) and those who had TEVAR (20.1% at 30 days, 28.7% at 90 days). Predictors of 90-day nonelective readmission included TEVAR vs medical management (relative risk [RR], 1.21; confidence interval [CI], 1.03-1.42), discharge to a nursing facility compared with home (RR, 1.44; CI, 1.22-1.69), greater number of chronic comorbidities (RR, 1.06 for every additional comorbidity; CI, 1.03-1.09), chronic kidney disease (RR, 1.31; CI, 1.13-1.52), fluid and electrolyte
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Table III. Readmission rates and outcomes during readmission Variable
Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
Overall 90-day readmission
2073 (29.9)
1255 (28.9)
440 (30.2)
378 (33.1)
<.001
30-Day nonelective readmission
1023 (14.7)
710 (16.4)
294 (20.2)
229 (20.1)
<.001
90-Day nonelective readmission
1744 (25.1)
1024 (23.6)
392 (26.9)
328 (28.7)
<.001
<.001
TEVAR (n ¼ 1141)
P value
Aortic intervention during 90-day nonelective readmission (% of those nonelectively readmitted) 100 (5.2)
76 (7.4)
<10 (<2.6)
20 (6.1)
Open repair
21 (1.2)
14 (1.4)
<10 (<2.6)
<10 (<3.0)
.286
TEVAR
79 (4.5)
62 (6.1)
<10 (<2.6)
13 (3.9)
.010
22,572 6 41,598
23,603 6 42,644
Total
Cost of 90-day nonelective readmission (U.S. dollars)a 90-Day nonelective readmission mortality 90-Day elective readmission
87 (5.0) 329 (4.7)
54 (5.3) 231 (5.3)
20,804 6 46,800
21,545 6 30,327
.441
20 (5.1)
13 (4.0)
.378
48 (3.3)
50 (4.4)
.006
Aortic intervention during 90-day elective readmission (% of those electively readmitted) 105 (31.9)
91 (39.4)
<10 (<20.8)
<10 (<20.0)
<.001
Open repair
29 (8.8)
26 (11.2)
<10 (<20.8)
<10 (<20.0)
.053
TEVAR
76 (23.1)
65 (28.1)
<10 (<20.8)
<10 (<20.0)
.004
47,211 6 46,371
21,551 6 26,914
40,173 6 109,600
.446
<10 (<3.0)
<10 (<4.3)
<10 (<20.8)
Total
Cost of 90-day elective readmission 42,233 6 59,433 (U.S. dollars)b 90-Day elective readmission mortality
<10 (20.0)
.665
Aortic intervention during 90-day readmission (% of all readmitted patients) 205 (9.9)
167 (13.3)
<10 (<2.3)
29 (7.7)
Open repair
50 (2.4)
40 (3.2)
<10 (<2.3)
<10 (<2.6)
TEVAR
155 (2.2)
127 (10.1)
<10 (<2.3)
20 (5.3)
<.001
96 (4.6)
60 (4.8)
21 (4.7)
15 (4.0)
.795
Total
Overall 90-day readmission mortality
<.001 .064
TEVAR, Thoracic endovascular aortic repair. Categorical variables are presented as number (%). Continuous variables are presented as mean 6 standard deviation. a Missing data for 3.7%. b Missing data for 3.3%.
disorders (RR, 1.21; CI, 1.08-1.37), hypertension (RR, 1.21; CI, 1.01-1.46), and ischemic complication (RR, 1.52; CI, 1.032.24; Fig 4). The 90-day nonelective readmission was higher among those who had an ischemic complication at index admission (31.4% vs 24.9%; P ¼ .01). In those with an ischemic complication, the readmission rate was highest if TEVAR was the initial treatment (medical management, 25.3%; open repair, 30.6%; TEVAR, 42.0%; P ¼ .028). Factors protective against readmission included private insurance (vs Medicare; RR, 0.72; CI, 0.610.85) and obesity (RR, 0.78; CI, 0.66-0.91). The rate of elective readmission at 90 days was 4.7% (Table II; Fig 3), occurring in 5.3% of the medical management group, 3.3% of the open repair group, and 4.4% of the TEVAR group.
Causes of readmission. The most frequent cause of nonelective 90-day readmission was an arterial aneurysm or dissection (24.8%; Fig 5; Supplementary Table III, online only). Complications of surgical procedures or medical care, the second most common reason for readmission, accounted for a substantially lower proportion of rehospitalizations (4.8%). This was followed by hypertension with complications (4.1%), congestive heart failure (3.7%), and complication of device, implant, or graft (3.6%). Residual arterial aneurysm or dissection accounted for a larger proportion of readmissions in the medical management alone group (35.4%) compared with the open repair group (7.1%) and TEVAR group (12.8%). The most common cause for readmission in the open repair group
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0.8 0.6 0.4
Medical Open TEVAR
0.0
0.2
Freedom from Readmission
7
-
1.0
Volume
0
60
30
90
Days
Fig 2. Freedom from readmission 90 days after hospitalization. TEVAR, Thoracic endovascular aortic repair.
Open vs Medical
1.08 (0.93, 1.27)
TEVAR vs Medical
1.21 (1.03, 1.42)
Age +10
0.92 (0.87, 0.97)
Female
1.06 (0.94, 1.19)
Disp: Txfer Other vs Routine
1.44 (1.22, 1.69)
Disp: HHC vs Routine
1.17 (1.01, 1.36)
Chronic Conditions +1
1.06 (1.03, 1.09)
Ins: Medicaid vs Medicare
1.19 (0.97, 1.45)
Ins: Private vs Medicare
0.72 (0.61, 0.85)
Teaching Hosp
1.08 (0.95, 1.24)
CHF
1.07 (0.87, 1.31)
Valvular heart disease
1.01 (0.80, 1.27)
PVD
1.08 (0.91, 1.29)
Paralysis
0.99 (0.76, 1.28)
Chronic pulmonary disorders
1.06 (0.92, 1.22)
Renal failure
1.31 (1.13, 1.52)
Coagulopathy
0.96 (0.81, 1.15)
Obesity
0.78 (0.66, 0.91)
Fluid and electrolyte disorders
1.21 (1.08, 1.37)
Alcohol use
0.93 (0.73, 1.18)
Drug use
1.12 (0.90, 1.40)
Hypertension
1.22 (1.01, 1.46)
Marfan syndrome
1.26 (0.86, 1.84)
Ischemic kidney
0.69 (0.40, 1.18)
Ischemic complication
1.52 (1.03, 2.24)
90-Day Readmission Rates TEVAR
0.25
0.5
1
2
4
Odds Ratio
Open Repair
<<
Fig 4. Predictors of 90-day nonelective readmission. CHF, Congestive heart failure; HHC, home health care; Ins, insurance; PVD, peripheral vascular disease; TEVAR, thoracic endovascular aortic repair; Txfer, transfer.
Medical Management
All Paents 0%
More Likely 90Day Readmission >>>
5%
10%
Nonelecve
15%
20%
25%
30%
35%
Elecve
Fig 3. Rates of 90-day readmission. TEVAR, Thoracic endovascular aortic repair.
was complications of surgical procedures or medical care (11.2%). The most common cause of readmission in those who had TEVAR was residual arterial aneurysm or dissection (12.8%), followed by complication of device, implant, or graft (9.5%) and complication of surgical procedures or medical care (7%). Top reasons for readmission by ICD-9 are listed in Table IV. The most common cause of readmission in those with an elective readmission was residual arterial aneurysm or dissection (61%). Procedures, costs, and mortality of readmission. The rate of aortic procedures performed during nonelective readmission was 5.7%, with the majority of interventions being TEVAR in those initially medically managed (62% of total interventions during nonelective readmission; Table III). The mean cost of nonelective readmission was $22,572. In-hospital mortality during readmission was 5.0% and was similar between groups.
An aortic procedure occurred in 31.9% of patients during elective readmissions. The rate of intervention was highest in those who were electively readmitted after initial medical management alone (39.4%). TEVAR in the initially medically managed group accounted for the majority of all elective interventions (61.9%). The mean cost of readmission was higher in those with an elective readmission than in those with a nonelective readmission ($42,233).
DISCUSSION Our analysis of patients hospitalized with an acute type B aortic dissection demonstrated that one in four patients had a nonelective readmission within 90 days, with an additional 4.7% of patients electively readmitted within 90 days. Readmission rates were highest among those who had received TEVAR and lowest among those who received medical management alone; however, patients medically managed were more likely to receive an aortic intervention on readmission. The most common driver of readmission was residual aortic disease, whereas complications from procedures were frequent among those who underwent open repair and TEVAR. Mortality
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Causes of 90-Day Nonelective Readmission Acute and unspecified renal failure Cardiac dysrhythmias Nonspecific chest pain Pneumonia Septicemia Complication of device; implant or graft Congestive heart failre; nonhypertensive Hypertension with complications and secondary hypertension Complications of surgical procedures or medical care Aortic; peripheral; and visceral artery aneurysm/dissection 0% TEVAR
5% Open Repair
10%
15%
Medical Management
20%
25%
30%
35%
40%
Total
Fig 5. Causes of 90-day nonelective readmission as defined by Clinical Classifications Software. TEVAR, Thoracic endovascular aortic repair.
Table IV. Top 10 causes of 90-day nonelective readmission by International Classification of Diseases, Ninth Revision (ICD-9) code for all patients Cause of readmission
Medical management (n ¼ 1023)
441.01
Dissection of thoracic aorta
208 (20.3)
441.03
Dissection of thoracoabdominal aorta
75 (7.3)
ICD-9 code
Open repair (n ¼ 392)
TEVAR (n ¼ 328)
Total (N ¼ 1743)
15 (3.8)
22 (6.7)
245 (14.1)
<10 (<2.6)
<10 (<3.0)
86 (4.9) 45 (2.6)
486
Pneumonia, organism NOS
24 (2.3)
13 (3.3)
<10 (<3.0)
38.9
Puncture of vessel
20 (2.0)
12 (3.1)
<10 (<3.0)
41 (2.4)
415.19
Pulmonary emboli/infarct
18 (1.8)
10 (2.6)
<10 (<3.0)
36 (2.1)
584.9
Acute kidney failure NOS
25 (2.40)
<10 (<2.6)
<10 (<3.0)
34 (2.0)
441.02
Dissection of abdominal aorta
29 (2.8)
<10 (<2.6)
<10 (<3.0)
33 (1.9)
401.9
Hypertension NOS
16 (1.6)
11 (2.8)
<10 (<3.0)
32 (1.8)
786.59
Chest pain NEC
16 (1.6)
<10 (<2.6)
<10 (<3.0)
29 (1.7)
998.59
Other postoperative infection
<10 (<1.0)
15 (3.8)
<10 (<3.0)
23 (1.3)
NEC, Not elsewhere classified; NOS, not otherwise specified; TEVAR, thoracic endovascular aortic repair. Values are reported as number (%).
and costs during readmission were overall high irrespective of initial treatment strategy. Acute type B aortic dissection is associated with a high mortality during initial presentation, with 10.7% in-hospital mortality in IRAD.1 There has been little change in mortality despite advances in surgical management. IRAD data also demonstrate that additional
mortality is relatively low from 7 days to 60 days after symptom onset.10 Survival is higher in those who receive medical management alone at initial presentation compared with those who undergo TEVAR or open repair as patients who require intervention in the acute period often have high-risk features to warrant such procedures.1,10
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The rate of readmissions after type B dissection has not been well studied in large cohorts of adult patients and inclusive of all insurer types. We demonstrated a high rate of readmission regardless of the initial treatment received. Mody et al6 evaluated 30-day readmission in the Medicare beneficiary Denominator File and found slightly higher rates of 30-day readmission in 2011 (19.8% for medical management, 25.5% for open repair, 22.3% for TEVAR) compared with our findings. This comparably higher rate may reflect the older population in the Medicare cohort. Kalesan et al7 investigated 90day readmission rate for TEVAR in the setting of dissection using the NRD in 2013 and found a readmission rate of 21%; however, this included patients with both a primary and secondary code for dissection and therefore may have included a larger proportion of patients who did not have an acute dissection, possibly explaining the lower rate than observed in our study. Patients with an ischemic complication were deemed a “complicated” aortic dissection. An ischemic complication was associated with a 1.5-fold increased risk of readmission, although the absolute rate of 4.2% is likely an underestimate, and uncomplicated dissections may have an even lower rate of readmission than reported here. Patients who have an ischemic complication related to an acute aortic dissection are known to have worse outcomes in the acute setting.11 We found that such patients are also at higher risk for readmission, although we could not differentiate whether the complication was related to the dissection or a possible intervention. TEVAR had the highest rate of nonelective 90day readmission; this may in part be due to higher risk features of the dissection that warranted TEVAR during the index hospitalization, such as mesenteric, renal, or lower extremity ischemia. In conjunction, the rate of an ischemic complication was more than double in the TEVAR group. The most frequent cause for readmission was related to aortic disease, although the contribution of this complication varied by initial treatment received. An aortarelated etiology accounted for more than one-third of readmissions in the medical management group, whereas the rates were 7% in the open repair group and 13% in the TEVAR group. Although aorta-specific diagnosis codes for readmission were lower in the open repair and TEVAR groups, the most common cause of readmission was related to an intervention performed on index admission, accounting for an additional 14% of readmissions for the open repair group and 18% for the TEVAR group. The reported rates of complications and reinterventions after TEVAR vary widely and depend on indication for TEVAR and duration of follow-up.4,12,13 The rate of repeated intervention in patients with TEVAR for aneurysm or dissection at 90 days has been reported at 2.4%, two-thirds of which was repeated TEVAR.7 We
demonstrated similar findings with a low rate of reintervention at 90 days of 2.5% in those initially managed with TEVAR, 69.0% of which was repeated TEVAR. The overall rate of aortic intervention in 90-day follow-up for those initially managed medically was low at 3.8%, the majority of which occurred electively (54.4%). Costs during readmission were substantial with a mean above $20,000 and above $40,000 for those admitted electively. Mortality during nonelective readmission was high at 5.0% and comparable to that of patients readmitted after revascularization for peripheral artery disease and ST elevation myocardial infarction.14,15 Mortality was lower in those with an elective readmission (2.7%). Aortic centers and networks have recently been developed and demonstrated improved short-term outcomes and are recommended in guidelines.2,16,17 Given the high rate of readmissions and associated costs and mortality, the development of aortic centers and multidisciplinary teams to manage aortic dissection may aid in decreasing the rate of readmission to allow close coordination of care, follow-up, and optimal medical management. Further study is warranted to evaluate whether such approaches decrease readmissions as well. Limitations. We analyzed data from a large administrative database and relied on billing codes, which can be susceptible to misclassification, lack more granular patient- and procedure-level data, and do not include adjudicated outcomes. The database also does not capture out-of-hospital deaths and thus does not account for the competing risk for readmission and postdischarge death. In addition, the rate of malperfusion or “complicated” dissection may be underestimated if it is not appropriately coded for at the time of index admission as it would be expected to be higher in those who require open repair than in the medical therapy group alone. There is no ICD-9 code for acute type B dissection, and some patients may have been misclassified. However, we employed an algorithm to identify those with acute type B dissections based on previous studies and limited inclusion to only those patients with a primary diagnosis of dissection. A recent study adjudicated acute aortic dissection and management based on billing codes at a single center.18 The study included both primary and secondary billing codes and demonstrated specificity of 99.0% for TEVAR, 99.0% for open repair, and 80.3% for medical management, with low sensitivity. In our analysis, when including those with a primary and secondary diagnosis of aortic dissection, only 40% of patients in the medical management group had a primary diagnosis compared with 91% in the open repair group and 87% in the TEVAR group. Given that the goal of our study was to evaluate readmissions after acute type B aortic dissection rather than to explore epidemiologic trends
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over time, which would be more susceptible to error with low sensitivity, we chose to limit our cohort to only those with a primary diagnosis to increase the specificity of patients included with an acute dissection. In so doing, we decreased the size of the cohort and may have biased the cohort to a sicker population. This is evidenced by a higher than expected rate of open repair in our cohort at 20.9% compared with 7.6% in IRAD; the rate of open repair in our cohort when including primary and secondary diagnosis code was 11.3%. The rate of open repair in our final analysis was similar to prior administrative data reports. An analysis of the Nationwide Inpatient Sample from 2012 demonstrated an open repair rate of 22.8% and TEVAR rate of 16.8%.19 Evaluation of interventions for acute type B dissection using data from Medicare in 2010 demonstrated that 73% received open repair and 27% TEVAR.20 It is possible that some of the patients included in the open repair group had type A dissection or a chronic type B dissection despite exclusion of patients with billing codes associated with type A open surgical repair and those who were electively admitted. However, it is reassuring that in the recent single-center study that adjudicated acute aortic dissections against billing code assessment, no patients who were categorized as an open repair of a type B dissection were found to have actually had a type A dissection.18 In our algorithm, it was presumed that all patients with type A dissection were managed with surgical intervention; thus, it is possible that some patients with type A dissection were managed medically and included in our study. To limit the inclusion of medically managed type A dissection patients (which is estimated at 8% based on IRAD data),1 we additionally excluded patients with findings often associated with type A dissection, which had not been done in previous studies including patients with aortic regurgitation, pericardial effusion, and artery (coronary, carotid, or vertebral) dissection. Adherence to medical therapy following aortic dissection is poor.21 Medication data are not available in the NRD; thus, we were unable to assess the medical therapy prescribed or adherence to medication. However, our findings are likely representative of “real-world” adherence to medications and the associated outcomes after medical therapy alone.
CONCLUSIONS Acute type B aortic dissection is associated with a high rate of nonelective readmission at 90 days regardless of initial treatment received. Readmissions are most commonly related to aortic disease or complications from initial interventions and are associated with a high rate of mortality and costs. Patients with type B aortic dissection should be closely monitored after discharge, and identification of measures to reduce readmissions is warranted, given the high associated readmission rates and costs.
2019
AUTHOR CONTRIBUTIONS Conception and design: BC, MS, NS, RY, ES Analysis and interpretation: BC, MS, KK, NS, KS, RY, ES Data collection: KK, KS Writing the article: BC, ES Critical revision of the article: BC, MS, KK, NS, KS, RY, ES Final approval of the article: BC, MS, KK, NS, KS, RY, ES Statistical analysis: KK Obtained funding: Not applicable Overall responsibility: BC
REFERENCES 1. Pape LA, Awais M, Woznicki EM, Suzuki T, Trimarchi S, Evangelista A, et al. Presentation, diagnosis, and outcomes of acute aortic dissection: 17-year trends from the International Registry of Acute Aortic Dissection. J Am Coll Cardiol 2015;66:350-8. 2. Erbel R, Aboyans V, Boileau C, Bossone E, Di Bartoloea R, Eggerbrect H, et al. 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC). Eur Heart J 2014;35: 2873-926. 3. Durham CA, Cambria RP, Wang LJ, Ergul EA, Arason NJ, Patel V, et al. The natural history of medically managed acute type B aortic dissection. J Vasc Surg 2015;61:1192-8. 4. Thrumurthy SG, Karthikesalingam A, Patterson BO, Holt PJ, Hinchliffe RJ, Loftus IM, et al. A systematic review of midterm outcomes of thoracic endovascular repair (TEVAR) of chronic type B aortic dissection. Eur J Vasc Endovasc Surg 2011;42:632-47. 5. Afifi RO, Sandhu HK, Leake SS, Boutrous ML, Kumar V, Azizzadeh A, et al. Outcomes of patients with acute type B (DeBakey III) aortic dissection: a 13-year, single-center experience. Circulation 2015;132:748-54. 6. Mody SM, Wang Y, Geirsson A, Kim N, Desai MM, Gupta A, et al. Trends in aortic dissection hospitalizations, interventions, and outcomes among Medicare beneficiaries in the United States, 2000-2011. Circ Cardiovasc Qual Outcomes 2014;7:920-8. 7. Kalesan B, Cheng TW, Farber A, Zuo Y, Kalish J, Jones DW, et al. Readmissions after thoracic endovascular aortic repair. J Vasc Surg 2018;68:372-82. 8. Sachs T, Pomposelli F, Hagberg R, Hamdan A, Wyers M, Giles K, et al. Open and endovascular repair of type B aortic dissection in the Nationwide Inpatient Sample. J Vasc Surg 2010;52:860-6. 9. HCUP Clinical Classifications Software (CCS) for ICD-9-CM. Rockville, Md: Agency for Healthcare Research and Quality; March 2017. Available at: www.hcup-us.ahrq.gov/ toolssoftware/ccs/ccs.jsp. Accessed June 29, 2018. 10. Booher AM, Isselbacher EM, Nienaber CA, Trimarchi S, Evangelista A, Montgomery DG, et al. The IRAD classification system for characterizing survival after aortic dissection. Am J Med 2013;126:730.e19-24. 11. Tolenaar JL, Froehlich W, Jonker FH, Upchurch GR, Rampoldi V, Tsai TT, et al. Predicting in-hospital mortality in acute type B aortic dissection: evidence from International Registry of Acute Aortic Dissection. Circulation 2014;130(Suppl 1):S45-50. 12. Andersen ND, Keenan JE, Ganapathi AM, Gaca JG, McCann RL, Hughes GC. Current management and
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13.
14.
15.
16.
17.
-,
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outcome of chronic type B aortic dissection: results with open and endovascular repair since the advent of thoracic endografting. Ann Cardiothorac Surg 2014;3:264-74. Cambria RP, Crawford RS, Cho JS, Bavaria J, Farber M, Lee WA, et al. A multicenter clinical trial of endovascular stent graft repair of acute catastrophes of the descending thoracic aorta. J Vasc Surg 2009;50:1255-64. Secemsky EA, Schermerhorn M, Carroll BJ, Kennedy KF, Shen C, Valsdottir LR, et al. Readmissions after revascularization procedures for peripheral arterial disease: a nationwide cohort study. Ann Intern Med 2018;168:93-9. Kim LK, Yeo I, Cheung JW, Swaminathan RV, Wong SC, Charitakis K, et al. Thirty-day readmission rates, timing, causes, and costs after ST-segment-elevation myocardial infarction in the United States: a National Readmission Database analysis 2010-2014. J Am Heart Assoc 2018;7:e009863. Duceau B, Alsac JM, Bellenfant F, Mailloux A, Chhor V, Lagrange A, et al. Improved survival after implementation of a large-scale regional dedicated aortic network. J Am Coll Cardiol 2017;70:3068-9. Andersen ND, Ganapathi AM, Hanna JM, Williams JB, Gaca JG, Hughes GC. Outcomes of acute type A dissection repair before and after implementation of a
18.
19.
20.
21.
multidisciplinary thoracic aortic surgery program. J Am Coll Cardiol 2014;63:1796-803. Finnesgard EJ, Weiss S, Kalra M, Johnston JK, Oderich GS, Shuja F, et al. Performance of current claims-based approaches to identify aortic dissection hospitalizations. J Vasc Surg 2018;67:e93. Zimmerman KP, Oderich G, Pochettino A, Hanson KT, Habermann EB, Bower TC, et al. Improving mortality trends for hospitalization of aortic dissection in the National Inpatient Sample. J Vasc Surg 2016;64:606-15. Jones DW, Goodney PP, Nolan BW, Brooke BS, Fillinger MF, Powell RJ, et al. National trends in utilization, mortality, and survival after repair of type B aortic dissection in the Medicare population. J Vasc Surg 2014;60:11-9. Chaddha A, Erickson S, Kline-Rogers E, Montgomery D, Woznicki E, Jabara J, et al. Medication adherence patterns in aortic dissection survivors. Indian J Med Res 2018;147:183-8.
Submitted May 7, 2019; accepted Aug 20, 2019.
Additional material for this article may be found online at www.jvascsurg.org.
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Supplementary Table I (online only). Diagnostic and procedure billing codes Diagnosis
ICD-9 code
Dissecting thoracic aortic aneurysm
441.01
Dissecting thoracoabdominal aneurysm
441.03
Cardioplegia
39.63
Valve repair
35.00-35.99
Operations on vessels of the heart Dissection, artery, carotid
36.00-36.99, 37.0, 37.2, 37.31-37.90, 37.93-37.99 443.21
Dissection, artery, coronary
414.12
Dissection, artery, vertebral
443.24
Pericardial effusion
423.9
Aortic regurgitation
424.1
TEVAR Endovascular implantation of graft in thoracic aorta
39.73
Open repair Resection of vessel with anastomosis, aorta
38.34
Resection of vessel with anastomosis, thoracic vessels
38.35
Resection of vessel with replacement, thoracic vessels
38.45
Repair of a vessel with a tissue patch graft
39.57
Repair of a vessel with a synthetic patch graft
39.58
Marfan syndrome
759.82
Ehlers-Danlos
756.83
Ischemic complication Ischemia, kidney
593.81
Acute bowel ischemia
557.9
Ischemic colon
557.0
Embolism and thrombosis of abdominal aorta
444.0
Arterial embolism and thrombosis of iliac artery
444.22
Embolism and thrombosis of iliac artery
444.81
ICD-9, International Classification of Diseases, Ninth Revision; TEVAR, thoracic endovascular aortic repair.
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Supplementary Table II (online only). Billing codes for patients with open repair Total (N ¼ 1495)
Open repair billing codes
Open repair only (n ¼ 1456)
TEVAR þ open repair (n ¼ 39) <10 (<25.6)
Resection of vessel with anastomosis, aorta
<10 (<0.7)
<10 (<0.7)
Resection of vessel with anastomosis, thoracic vessels
<10 (<0.7)
<10 (<0.7)
18 (46.1)
Resection of vessel with replacement, thoracic vessels
1395 (93.3)
1377 (94.6)
18 (46.1)
88 (5.9)
70 (4.8)
<10 (<25.6)
<10 (<0.7)
<10 (<0.7)
<10 (<25.6)
Repair of a vessel with a tissue patch graft Repair of a vessel with a synthetic patch graft TEVAR, Thoracic endovascular aortic repair. Values are reported as number (%).
Supplementary Table III (online only). Top 10 causes of 30-day nonelective readmission by Clinical Classifications Software (CCS) classification CCS classification No.
Cause of readmission
Medical management (n ¼ 1023)
Open repair (n ¼ 392)
TEVAR (n ¼ 328)
Total (N ¼ 1743)
363 (35.5)
28 (7.1)
42 (12.8)
433 (24.8)
115
Aortic, peripheral, and visceral artery aneurysms
238
Complications of surgical procedures or medical care
16 (1.6)
44 (11.2)
23 (7.0)
83 (4.8)
99
Hypertension with complications and secondary hypertension
53 (5.2)
<10 (<2.6)
13 (4.0)
73 (4.2)
108
Congestive heart failure, nonhypertensive
37 (3.6)
23 (5.9)
<10 (<3.0)
65 (3.7)
237
Complication of device, implant, or graft
18 (1.8)
13 (3.3)
31 (9.5)
62 (3.6)
2
Septicemia (except in labor)
34 (3.3)
16 (4.1)
11 (3.4)
61 (3.5)
122
Pneumonia (except that caused by tuberculosis or sexually transmitted disease)
26 (2.5)
17 (4.3)
<10 (<3.0)
52 (3.0)
102
Nonspecific chest pain
30 (2.9)
13 (3.3)
<10 (<3.0)
51 (2.9)
106
Cardiac dysrhythmias
20 (2.0)
18 (4.6)
<10 (<3.0)
45 (2.6)
157
Acute and unspecified renal failure
31 (3.0)
<10 (<2.6)
<10 (<3.0)
43 (2.5)
TEVAR, Thoracic endovascular aortic repair. Values are reported as number (%).
ABSTRACT Objective: Acute type B aortic dissection can be treated with medical management alone, open surgical repair, or thoracic endovascular aortic repair (TEVAR). The nationwide burden of readmissions after acute type B aortic dissection has not been comprehensively assessed. Methods: We analyzed adults with a hospitalization due to acute type B aortic dissection between January 1, 2010, and December 31, 2014, in the Nationwide Readmissions Database. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify hospitalizations with a primary diagnosis code for thoracic or thoracoabdominal aortic dissection. The primary outcome was nonelective 90-day readmission. Predictors of readmission were determined using hierarchical logistic regression. Results: The study population consisted of 6937 patients with unplanned admissions for type B aortic dissections from 2010 through 2014. Medical management alone was the treatment for 62.6% of patients, 21.0% had open surgical repair, and 16.4% underwent TEVAR. Nonelective 90-day readmission rate was 25.1% (23.6% with medical management alone, 26.9% with open repair, and 28.7% with TEVAR; P < .001). An additional 4.7% of patients were electively readmitted. The most common cause for nonelective readmission was new or recurrent arterial aneurysm or dissection (24.8%). Of those with unplanned readmissions, 5.2% underwent an aortic procedure. The mortality rate during nonelective readmission was 5.0%, and the mean cost of the rehospitalization was $22,572 6 $41,598. Conclusions: More than one in four patients have a nonelective readmission 90 days after hospitalization for acute type B aortic dissection. Absolute rates of readmission varied by initial treatment received but were high irrespective of the initial treatment. The most common cause of readmission was aortic disease, particularly among those treated with medication alone. Further research is required to determine potential interventions to decrease these costly and morbid readmissions, including the role of multidisciplinary aortic teams. (J Vasc Surg 2019;-:1-11.) Keywords: Thoracic aortic dissection; Thoracic endovascular repair; Readmissions
Acute type B aortic dissection is associated with high morbidity and mortality.1 Medical management with blood pressure and heart rate control is the guidelinerecommended treatment for uncomplicated patients, whereas intervention in the acute setting with open surgical repair or thoracic endovascular aortic repair (TEVAR) is generally reserved for patients with persistent symptoms, evidence of malperfusion, or concerning aortic morphologic features including rupture or rapid aneurysm expansion.2 During the last 20 years, there has been an increased rate of intervention that parallels
the introduction of TEVAR. In addition, there has been a reduction in medical management alone, from 75% to 57% between 1995 and 2013 in the International Registry of Acute Aortic Dissection (IRAD).1 In-hospital mortality, however, has remained unchanged in this time (12%-14%). In those who survive the initial event, intervention-free survival is low for medically managed patients, reported at 41% during 6 years at a single center.3 In those who have TEVAR, regular interval follow-up to monitor for the development of endoleaks is indicated as there is a
From the Division of Cardiovascular Medicine, Department of Medicine,a Divi-
Additional material for this article may be found online at www.jvascsurg.org.
sion of Vascular Surgery, Department of Surgery,b and Department of Medi-
Correspondence: Brett J. Carroll, MD, Division of Cardiovascular Medicine, Beth
cine,d Beth Israel Deaconess Medical Center, Harvard Medical School,
Israel Deaconess Medical Center, 185 Pilgrim Rd, Boston, MA 02215 (e-mail:
Boston; and the Department of Cardiovascular Research, Saint Luke’s MidAmerica Heart Institute, Kansas City.c The study was internally funded by the Smith Center for Outcomes Research in Cardiology at Beth Israel Deaconess Medical Center (Boston, Mass). Author conflict of interest: M.S. has received consulting fees from Cook Medical,
[email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214
Medtronic, and Endologix. R.W.Y. has received research grants and consulting
Copyright Ó 2019 by the Society for Vascular Surgery. Published by Elsevier Inc.
fees from Abbott Vascular and Boston Scientific and consulting fees from
https://doi.org/10.1016/j.jvs.2019.08.280
Medtronic and Teleflex. Presented as an oral presentation at the Sixty-eighth Annual Scientific Session & Expo of the American College of Cardiology, New Orleans, La, March 16-18, 2019.
1
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reintervention rate of 16% at a median follow-up of 31 months as reported by a systematic review in patients treated for chronic type B dissection.4 Data regarding readmissions after acute type B dissection and subsequent interventions during rehospitalization are limited to single-center reports, Medicare beneficiaries, or those receiving TEVAR alone.5-7 In this study, we evaluate readmissions after type B aortic dissection among a nationwide cohort of adult patients from all insurer types and undergoing various treatment strategies.
ARTICLE HIGHLIGHTS d
d
METHODS Data source. We obtained data from the Nationwide Readmissions Database (NRD) from 2010 to 2014. The Agency for Healthcare Research and Quality sponsors the NRD as part of the Healthcare Cost and Utilization Project. The NRD collects discharge data from 18 to 22 geographically dispersed U.S. states, accounting for >40% of all U.S. hospitalizations. The database includes data from all payers and uninsured persons and contains >100 clinical and nonclinical variables for each hospitalization. The data include diagnosis and procedure codes from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and Clinical Classifications Software diagnosis and procedure classifications. The Institutional Review Board at Beth Israel Deaconess Medical Center evaluated this study and deemed it not to qualify as human subjects research. Study population. We identified all adult hospitalizations (aged $18 years) that were associated with a diagnosis code of dissection of the thoracic aorta (ICD-9-CM 441.01) or dissection of the thoracoabdominal aorta (ICD9-CM 441.03; n ¼ 36,157) and included only those with a primary diagnosis code (21,213; Fig 1). Because the NRD does not track readmissions between years, admissions from October 1 through December 31 of each year were excluded (n ¼ 5861) to allow 90-day follow-up for every patient. Patients were also excluded if they died during index hospitalization (n ¼ 2109), underwent a short-term transfer (n ¼ 491), left the hospital against medical advice (n ¼ 127), were electively admitted for the index hospitalization (n ¼ 1848), or had undergone an aortic procedure within the preceding 90 days of the index admission (n ¼ 367). A second admission that occurred within 90 days was counted only as one readmission. In addition, as there is no diagnosis code for acute aortic dissection, only patients with a primary diagnosis code of aortic dissection and a nonelective admission were included to discriminate against chronic dissection. Furthermore, ICD-9-CM codes do not differentiate ascending and descending aortic dissection. Thus, we used the following approach to identify patients with potential ascending aortic dissection, similar to previous studies (Supplementary Table I, online only).6,8 Those who had received cardioplegia (n ¼ 405) or had cardiac
2019
d
Type of Research: Multicenter retrospective cohort study from the Nationwide Readmissions Database Key Findings: Of 6937 patients with type B aortic dissections, 62.6% received medical management alone, 21.0% had open surgical repair, and 16.4% underwent thoracic endovascular aortic repair. Nonelective 90-day readmission rate was 25.1%, 23.6% with initial medical management alone, 26.9% after open repair, and 28.7% after thoracic endovascular aortic repair. The most common cause for nonelective readmission was new or recurrent arterial aneurysm or dissection (24.8%). Take Home Message: Readmissions after acute type B aortic dissection are high regardless of initial treatment received. Interventions to reduce readmissions should be further evaluated.
valve surgery (n ¼ 1923), operation on vessels of the heart (n ¼ 373), dissection (coronary, carotid, or vertebral artery; n ¼ 97), pericardial effusion (n ¼ 271), or aortic regurgitation (n ¼ 404) were excluded as they were presumed to have had an ascending aortic dissection. Patient, hospitalization, and institutional characteristics. Patients’ sociodemographics included age, sex, primary insurer, quartile of median household income by ZIP code, and residency categorized by county population. Chronic conditions were determined by the 29 Elixhauser comorbidities provided by the Agency for Healthcare Research and Quality.9 Characteristics of the index hospitalization included procedure code for open repair and TEVAR (Supplementary Table I, online only). Those with procedure codes for both open repair and TEVAR were considered to have TEVAR as we were unable to differentiate planned hybrid procedure from planned TEVAR with subsequent conversion to open repair. The remainder of patients without procedure codes for repair were considered to have been managed medically. Additional characteristics of the index hospitalization included length of stay, discharge destination, and costcharge ratios. Institutional characteristics included hospital bed volume, ownership, and teaching status. In addition, ICD-9 codes were used to identify patients with Marfan syndrome, patients with Ehlers-Danlos syndrome, and those with an ischemic complication during index hospitalization (Supplementary Table I, online only). Study outcomes. The primary outcome was the rate of nonelective all-cause 90-day readmissions, defined as hospitalization for any cause within 90 days of discharge after an index hospitalization. Secondary end points included costs of readmission, in-hospital mortality during readmission, and the need for a repeated aortic
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Fig 1. Flow diagram of exclusion criteria and final analytic cohort. TEVAR, Thoracic endovascular aortic repair.
procedure during readmission. We also identified reasons for unplanned 90-day readmissions determined by the Clinical Classifications Software coding system, a diagnosis and procedure categorization scheme that clusters patient diagnoses and procedures into meaningful clinical categories.9 We used primary ICD-9 codes associated with the readmission to obtain further granularity of specific causes. Statistical analysis. The Healthcare Cost and Utilization Project does not allow reporting of values of <10; thus, such values were reported as <10. We report categorical variables as counts and percentages and continuous variables as medians and ranges or means and standard deviations. Between-group differences were assessed using linear trend test for continuous variables and MantelHaenszel trend test for categorical variables. To derive predictors of 90-day readmission, hierarchical modified Poisson models were developed. All analysis was performed with SAS version 9.4 (SAS Institute, Cary, NC), with a P value of .05 marking statistical significance.
RESULTS Index hospitalization. During the study period, there were 21,213 patients hospitalized with a primary diagnosis code of thoracic aortic dissection. In-hospital
death occurred in 2109 hospitalizations (9.9%). After the remainder of exclusion criteria were implemented, the final cohort analyzed included 6937 hospitalizations of patients with acute type B aortic dissection who survived to discharge (Fig 1). Mean age at index admission was 63.1 6 15.1 years, and the majority were male (59.0%; Table I). Prevalent comorbidities included hypertension (88.1%), fluid and electrolyte disorders (34.2%), chronic pulmonary disease (21.2%), anemia (20.3%), diabetes (15.4%), renal failure (17.8%), and peripheral vascular disorders (12.6%). A small proportion had Marfan syndrome (2.2%) or Ehlers-Danlos syndrome (0.1%). An ischemic complication during the index hospitalization occurred in 4.2%: 1.9% with ischemic kidney injury, 1.0% with gastrointestinal ischemia, and 1.4% with thrombosis or embolization of abdominal aorta or iliac artery (Table II). The majority of patients received medical management alone (62.3%). Open repair was performed in 21.0% and TEVAR in 16.4% of patients. The specific claims codes for an open repair are noted in Supplementary Table II (online only). Among TEVAR patients, 14.2% also had a procedure code for open repair. Patients who received medical management alone were older (64.8 years in medical management group vs 59.2 years in open repair group vs 61.6 years in TEVAR group). The number of chronic comorbidities was similar between groups. Length of stay was shorter
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Table I. Patient demographics, clinical characteristics, and treatment received Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
TEVAR (n ¼ 1141)
Age, years
63.1 6 15.1
64.8 6 15.2
59.2 6 13.9
61.6 6 15.0
<.001
Female
2843 (41.0)
1885 (43.4)
500 (34.3)
458 (40.1)
<.001
2010
1306 (18.8)
889 (20.5)
233 (16.0)
184 (16.1)
2011
1286 (18.5)
798 (18.4)
294 (20.2)
194 (17.0)
2012
1272 (18.3)
779 (17.9)
284 (19.5)
209 (18.3)
2013
1439 (20.7)
885 (20.4)
297 (20.4)
257 (22.5)
2014
1634 (23.6)
989 (22.8)
348 (23.9)
297 (26.0)
2255 (52.1)
530 (36.5)
516 (45.3)
Variable
<.001
Calendar year
<.001
Primary insurance Medicare Medicaid Private insurance Self-pay No charge Other
P value
3301 (47.7) 877 (12.7)
524 (12.1)
203 (14.0)
150 (13.2)
1839 (26.6)
1011 (23.3)
518 (35.7)
310 (27.2)
554 (8.0)
342 (7.9)
48 (0.7)
31 (0.7)
303 (4.4)
167 (3.9)
116 (8.0)
96 (8.4)
<10 (<0.6)
<10 (<0.8)
78 (5.4)
58 (5.1)
Median household income quartile by residential ZIP code
.449
Lowest quartile
1922 (28.3)
1237 (29.0)
370 (26.0)
315 (28.3)
Middle lowest quartile
1682 (24.7)
1064 (25.0)
333 (23.4)
285 (25.6)
Middle highest quartile
1632 (24.0)
996 (23.4)
353 (24.8)
283 (25.4)
Highest quartile
1562 (23.0)
965 (22.6)
366 (25.7)
231 (20.7)
No. of chronic conditions
6.3 6 2.8
6.3 6 2.8
6.4 6 2.8
6.3 6 2.8
.467
Hypertension (combined uncomplicated and complicated)
6114 (88.1)
3967 (91.4)
1184 (81.3)
963 (84.4)
<.001
Congestive heart failure
575 (8.3)
45 (3.1)
19 (1.7)
<.001
Peripheral vascular disorders
873 (12.6)
227 (5.2)
280 (19.2)
366 (32.1)
<.001
Valvular disease
461 (6.6)
410 (9.4)
34 (2.3)
17 (1.5)
<.001
Pulmonary circulation disorders Fluid and electrolyte disorders
511 (11.8)
160 (2.3)
139 (3.2)
17 (1.2)
<10 (<0.8)
<.001
2375 (34.2)
1216 (28.0)
688 (47.3)
471 (41.3)
<.001
Paralysis
314 (4.5)
124 (2.9)
113 (7.8)
77 (6.7)
<.001
Other neurologic disorders
432 (6.2)
259 (6.0)
113 (7.8)
60 (5.3)
.988
Chronic pulmonary disease
1471 (21.2)
936 (21.6)
278 (19.1)
257 (22.5)
.980
Diabetes, uncomplicated
953 (13.7)
609 (14.0)
185 (12.7)
159 (13.9)
.629
Diabetes with chronic complications
112 (1.6)
72 (1.7)
20 (1.4)
20 (1.8)
.964
Hypothyroidism
641 (9.2)
431 (9.9)
111 (7.6)
99 (8.7)
.047
Renal failure
1233 (17.8)
822 (18.9)
225 (15.5)
186 (16.3)
.005
Liver disease
158 (2.3)
106 (2.4)
28 (1.9)
24 (2.1)
.333
Metastatic cancer
50 (0.7)
43 (1.0)
<10 (<0.6)
<10 (<0.8)
.002
Solid tumor without metastasis
82 (1.2)
57 (1.3)
10 (0.7)
15 (1.3)
.540
216 (3.1)
158 (3.6)
21 (1.4)
37 (3.2)
.051
878 (12.7)
Rheumatoid arthritis/ collagen vascular diseases Coagulopathy Obesity Weight loss Chronic blood loss anemia Deficiency anemias
<.001
278 (6.4)
453 (31.1)
147 (12.9)
1050 (15.1)
615 (14.2)
253 (17.4)
182 (16.0)
445 (6.4)
195 (4.5)
140 (9.6)
110 (9.6)
<.001
69 (1.0)
29 (0.7)
23 (1.6)
17 (1.5)
.001
1411 (20.3)
864 (19.9)
284 (19.5)
263 (23.0)
.051
.023
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Table I. Continued. Variable
Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
TEVAR (n ¼ 1141)
P value
Alcohol abuse
402 (5.8)
241 (5.6)
84 (5.8)
77 (6.7)
.148
Drug abuse
472 (6.8)
303 (7.0)
94 (6.5)
75 (6.6)
.516
Psychoses
274 (3.9)
177 (4.1)
58 (4.0)
39 (3.4)
.344
Depression
545 (7.9)
344 (7.9)
102 (7.0)
99 (8.7)
.710
Marfan syndrome Ehlers-Danlos syndrome
153 (2.2)
108 (2.5)
31 (2.1)
14 (1.2)
.011
<10 (<0.1)
<10 (0.2)
<10 (0.6)
<10 (<0.8)
.682
TEVAR, Thoracic endovascular aortic repair. Categorical variables are presented as number (%). Continuous variables are presented as mean 6 standard deviation. Percentages may not sum to 100 because of rounding. Most variables had 0% to 2.0% of data missing unless otherwise noted.
Table II. Hospitalization and institutional characteristics Variable
Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
TEVAR (n ¼ 1141)
P value
Length of stay, days
10.8 6 12.1
7.6 6 8.9
16.8 6 15.2
15.0 6 13.9
<.001
239 (3.4)
170 (3.9)
45 (3.1)
24 (2.1)
<.001
Bed size of hospital Small Medium
1045 (15.1)
729 (16.8)
171 (11.7)
145 (12.7)
Large
5653 (81.5)
3441 (79.3)
1240 (85.2)
972 (85.2)
1155 (16.6)
659 (15.2)
241 (16.6)
255 (22.3)
5105 (73.6)
3223 (74.3)
1112 (76.4)
770 (67.5)
677 (9.8)
458 (10.6)
103 (7.1)
Metro nonteaching
1584 (22.8)
1096 (25.3)
268 (18.4)
220 (19.3)
Metro teaching
5266 (75.9)
3181 (73.3)
1176 (80.8)
909 (79.7)
87 (1.3)
63 (1.5)
12 (0.8)
45,332 6 52,997
23,644 6 34,264
85,210 6 62,719
74,885 6 52,919
<.001
297 (4.2)
149 (3.4)
52 (3.6)
96 (8.4)
<.001
Ischemic kidney
134 (1.9)
83 (1.9)
38 (3.3)
.053
Gastrointestinal ischemia
68 (1.0)
25 (0.05)
13 (0.9)
30 (2.6)
<.001
Embolism or thrombosis of abdominal aorta or iliac artery
95 (1.4)
41 (0.9)
26 (1.8)
28 (2.5)
<.001
3032 (69.9)
562 (38.6)
621 (54.5)
<.001
Ownership of hospital Government Private not-profit Private invest-own
116 (10.2) <.001
Teaching status of urban hospitals
Non metro Index cost (U.S. dollars) Ischemic complication
13 (0.9)
12 (1.1)
<.001
Disposition of patient Routine
4215 (60.8)
Transfer SNF or ICF
1223 (17.6)
573 (13.2)
406 (27.9)
244 (21.4)
HHC
1491 (21.5)
729 (16.8)
487 (33.4)
275 (24.1)
HHC, Home health care; ICF, intermediate care facility; SNF, skilled nursing facility; TEVAR, thoracic endovascular aortic repair. Categorical variables are presented as number (%). Continuous variables are presented as mean 6 standard deviation. Most variables had 0% to 3.8% of data missing unless otherwise noted.
and costs were lower in those with medical management alone (7.6 days, $23,644) compared with open repair (16.8 days, $85,210) and TEVAR (15.0 days, $74,885; Table II). Readmissions. Nonelective 90-day readmission occurred in 1744 (25.1%; Table III; Figs 2 and 3). The nonelective readmission rate was lowest in those who received medical management alone (16.4% at 30 days, 23.6% at 90 days) compared with those who had open
repair (20.2% at 30 days, 26.9% at 90 days) and those who had TEVAR (20.1% at 30 days, 28.7% at 90 days). Predictors of 90-day nonelective readmission included TEVAR vs medical management (relative risk [RR], 1.21; confidence interval [CI], 1.03-1.42), discharge to a nursing facility compared with home (RR, 1.44; CI, 1.22-1.69), greater number of chronic comorbidities (RR, 1.06 for every additional comorbidity; CI, 1.03-1.09), chronic kidney disease (RR, 1.31; CI, 1.13-1.52), fluid and electrolyte
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Table III. Readmission rates and outcomes during readmission Variable
Total (N ¼ 6937)
Medical management (n ¼ 4340)
Open repair (n ¼ 1456)
Overall 90-day readmission
2073 (29.9)
1255 (28.9)
440 (30.2)
378 (33.1)
<.001
30-Day nonelective readmission
1023 (14.7)
710 (16.4)
294 (20.2)
229 (20.1)
<.001
90-Day nonelective readmission
1744 (25.1)
1024 (23.6)
392 (26.9)
328 (28.7)
<.001
<.001
TEVAR (n ¼ 1141)
P value
Aortic intervention during 90-day nonelective readmission (% of those nonelectively readmitted) 100 (5.2)
76 (7.4)
<10 (<2.6)
20 (6.1)
Open repair
21 (1.2)
14 (1.4)
<10 (<2.6)
<10 (<3.0)
.286
TEVAR
79 (4.5)
62 (6.1)
<10 (<2.6)
13 (3.9)
.010
22,572 6 41,598
23,603 6 42,644
Total
Cost of 90-day nonelective readmission (U.S. dollars)a 90-Day nonelective readmission mortality 90-Day elective readmission
87 (5.0) 329 (4.7)
54 (5.3) 231 (5.3)
20,804 6 46,800
21,545 6 30,327
.441
20 (5.1)
13 (4.0)
.378
48 (3.3)
50 (4.4)
.006
Aortic intervention during 90-day elective readmission (% of those electively readmitted) 105 (31.9)
91 (39.4)
<10 (<20.8)
<10 (<20.0)
<.001
Open repair
29 (8.8)
26 (11.2)
<10 (<20.8)
<10 (<20.0)
.053
TEVAR
76 (23.1)
65 (28.1)
<10 (<20.8)
<10 (<20.0)
.004
47,211 6 46,371
21,551 6 26,914
40,173 6 109,600
.446
<10 (<3.0)
<10 (<4.3)
<10 (<20.8)
Total
Cost of 90-day elective readmission 42,233 6 59,433 (U.S. dollars)b 90-Day elective readmission mortality
<10 (20.0)
.665
Aortic intervention during 90-day readmission (% of all readmitted patients) 205 (9.9)
167 (13.3)
<10 (<2.3)
29 (7.7)
Open repair
50 (2.4)
40 (3.2)
<10 (<2.3)
<10 (<2.6)
TEVAR
155 (2.2)
127 (10.1)
<10 (<2.3)
20 (5.3)
<.001
96 (4.6)
60 (4.8)
21 (4.7)
15 (4.0)
.795
Total
Overall 90-day readmission mortality
<.001 .064
TEVAR, Thoracic endovascular aortic repair. Categorical variables are presented as number (%). Continuous variables are presented as mean 6 standard deviation. a Missing data for 3.7%. b Missing data for 3.3%.
disorders (RR, 1.21; CI, 1.08-1.37), hypertension (RR, 1.21; CI, 1.01-1.46), and ischemic complication (RR, 1.52; CI, 1.032.24; Fig 4). The 90-day nonelective readmission was higher among those who had an ischemic complication at index admission (31.4% vs 24.9%; P ¼ .01). In those with an ischemic complication, the readmission rate was highest if TEVAR was the initial treatment (medical management, 25.3%; open repair, 30.6%; TEVAR, 42.0%; P ¼ .028). Factors protective against readmission included private insurance (vs Medicare; RR, 0.72; CI, 0.610.85) and obesity (RR, 0.78; CI, 0.66-0.91). The rate of elective readmission at 90 days was 4.7% (Table II; Fig 3), occurring in 5.3% of the medical management group, 3.3% of the open repair group, and 4.4% of the TEVAR group.
Causes of readmission. The most frequent cause of nonelective 90-day readmission was an arterial aneurysm or dissection (24.8%; Fig 5; Supplementary Table III, online only). Complications of surgical procedures or medical care, the second most common reason for readmission, accounted for a substantially lower proportion of rehospitalizations (4.8%). This was followed by hypertension with complications (4.1%), congestive heart failure (3.7%), and complication of device, implant, or graft (3.6%). Residual arterial aneurysm or dissection accounted for a larger proportion of readmissions in the medical management alone group (35.4%) compared with the open repair group (7.1%) and TEVAR group (12.8%). The most common cause for readmission in the open repair group
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0.8 0.6 0.4
Medical Open TEVAR
0.0
0.2
Freedom from Readmission
7
-
1.0
Volume
0
60
30
90
Days
Fig 2. Freedom from readmission 90 days after hospitalization. TEVAR, Thoracic endovascular aortic repair.
Open vs Medical
1.08 (0.93, 1.27)
TEVAR vs Medical
1.21 (1.03, 1.42)
Age +10
0.92 (0.87, 0.97)
Female
1.06 (0.94, 1.19)
Disp: Txfer Other vs Routine
1.44 (1.22, 1.69)
Disp: HHC vs Routine
1.17 (1.01, 1.36)
Chronic Conditions +1
1.06 (1.03, 1.09)
Ins: Medicaid vs Medicare
1.19 (0.97, 1.45)
Ins: Private vs Medicare
0.72 (0.61, 0.85)
Teaching Hosp
1.08 (0.95, 1.24)
CHF
1.07 (0.87, 1.31)
Valvular heart disease
1.01 (0.80, 1.27)
PVD
1.08 (0.91, 1.29)
Paralysis
0.99 (0.76, 1.28)
Chronic pulmonary disorders
1.06 (0.92, 1.22)
Renal failure
1.31 (1.13, 1.52)
Coagulopathy
0.96 (0.81, 1.15)
Obesity
0.78 (0.66, 0.91)
Fluid and electrolyte disorders
1.21 (1.08, 1.37)
Alcohol use
0.93 (0.73, 1.18)
Drug use
1.12 (0.90, 1.40)
Hypertension
1.22 (1.01, 1.46)
Marfan syndrome
1.26 (0.86, 1.84)
Ischemic kidney
0.69 (0.40, 1.18)
Ischemic complication
1.52 (1.03, 2.24)
90-Day Readmission Rates TEVAR
0.25
0.5
1
2
4
Odds Ratio
Open Repair
<<
Fig 4. Predictors of 90-day nonelective readmission. CHF, Congestive heart failure; HHC, home health care; Ins, insurance; PVD, peripheral vascular disease; TEVAR, thoracic endovascular aortic repair; Txfer, transfer.
Medical Management
All Paents 0%
More Likely 90Day Readmission >>>
5%
10%
Nonelecve
15%
20%
25%
30%
35%
Elecve
Fig 3. Rates of 90-day readmission. TEVAR, Thoracic endovascular aortic repair.
was complications of surgical procedures or medical care (11.2%). The most common cause of readmission in those who had TEVAR was residual arterial aneurysm or dissection (12.8%), followed by complication of device, implant, or graft (9.5%) and complication of surgical procedures or medical care (7%). Top reasons for readmission by ICD-9 are listed in Table IV. The most common cause of readmission in those with an elective readmission was residual arterial aneurysm or dissection (61%). Procedures, costs, and mortality of readmission. The rate of aortic procedures performed during nonelective readmission was 5.7%, with the majority of interventions being TEVAR in those initially medically managed (62% of total interventions during nonelective readmission; Table III). The mean cost of nonelective readmission was $22,572. In-hospital mortality during readmission was 5.0% and was similar between groups.
An aortic procedure occurred in 31.9% of patients during elective readmissions. The rate of intervention was highest in those who were electively readmitted after initial medical management alone (39.4%). TEVAR in the initially medically managed group accounted for the majority of all elective interventions (61.9%). The mean cost of readmission was higher in those with an elective readmission than in those with a nonelective readmission ($42,233).
DISCUSSION Our analysis of patients hospitalized with an acute type B aortic dissection demonstrated that one in four patients had a nonelective readmission within 90 days, with an additional 4.7% of patients electively readmitted within 90 days. Readmission rates were highest among those who had received TEVAR and lowest among those who received medical management alone; however, patients medically managed were more likely to receive an aortic intervention on readmission. The most common driver of readmission was residual aortic disease, whereas complications from procedures were frequent among those who underwent open repair and TEVAR. Mortality
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Causes of 90-Day Nonelective Readmission Acute and unspecified renal failure Cardiac dysrhythmias Nonspecific chest pain Pneumonia Septicemia Complication of device; implant or graft Congestive heart failre; nonhypertensive Hypertension with complications and secondary hypertension Complications of surgical procedures or medical care Aortic; peripheral; and visceral artery aneurysm/dissection 0% TEVAR
5% Open Repair
10%
15%
Medical Management
20%
25%
30%
35%
40%
Total
Fig 5. Causes of 90-day nonelective readmission as defined by Clinical Classifications Software. TEVAR, Thoracic endovascular aortic repair.
Table IV. Top 10 causes of 90-day nonelective readmission by International Classification of Diseases, Ninth Revision (ICD-9) code for all patients Cause of readmission
Medical management (n ¼ 1023)
441.01
Dissection of thoracic aorta
208 (20.3)
441.03
Dissection of thoracoabdominal aorta
75 (7.3)
ICD-9 code
Open repair (n ¼ 392)
TEVAR (n ¼ 328)
Total (N ¼ 1743)
15 (3.8)
22 (6.7)
245 (14.1)
<10 (<2.6)
<10 (<3.0)
86 (4.9) 45 (2.6)
486
Pneumonia, organism NOS
24 (2.3)
13 (3.3)
<10 (<3.0)
38.9
Puncture of vessel
20 (2.0)
12 (3.1)
<10 (<3.0)
41 (2.4)
415.19
Pulmonary emboli/infarct
18 (1.8)
10 (2.6)
<10 (<3.0)
36 (2.1)
584.9
Acute kidney failure NOS
25 (2.40)
<10 (<2.6)
<10 (<3.0)
34 (2.0)
441.02
Dissection of abdominal aorta
29 (2.8)
<10 (<2.6)
<10 (<3.0)
33 (1.9)
401.9
Hypertension NOS
16 (1.6)
11 (2.8)
<10 (<3.0)
32 (1.8)
786.59
Chest pain NEC
16 (1.6)
<10 (<2.6)
<10 (<3.0)
29 (1.7)
998.59
Other postoperative infection
<10 (<1.0)
15 (3.8)
<10 (<3.0)
23 (1.3)
NEC, Not elsewhere classified; NOS, not otherwise specified; TEVAR, thoracic endovascular aortic repair. Values are reported as number (%).
and costs during readmission were overall high irrespective of initial treatment strategy. Acute type B aortic dissection is associated with a high mortality during initial presentation, with 10.7% in-hospital mortality in IRAD.1 There has been little change in mortality despite advances in surgical management. IRAD data also demonstrate that additional
mortality is relatively low from 7 days to 60 days after symptom onset.10 Survival is higher in those who receive medical management alone at initial presentation compared with those who undergo TEVAR or open repair as patients who require intervention in the acute period often have high-risk features to warrant such procedures.1,10
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The rate of readmissions after type B dissection has not been well studied in large cohorts of adult patients and inclusive of all insurer types. We demonstrated a high rate of readmission regardless of the initial treatment received. Mody et al6 evaluated 30-day readmission in the Medicare beneficiary Denominator File and found slightly higher rates of 30-day readmission in 2011 (19.8% for medical management, 25.5% for open repair, 22.3% for TEVAR) compared with our findings. This comparably higher rate may reflect the older population in the Medicare cohort. Kalesan et al7 investigated 90day readmission rate for TEVAR in the setting of dissection using the NRD in 2013 and found a readmission rate of 21%; however, this included patients with both a primary and secondary code for dissection and therefore may have included a larger proportion of patients who did not have an acute dissection, possibly explaining the lower rate than observed in our study. Patients with an ischemic complication were deemed a “complicated” aortic dissection. An ischemic complication was associated with a 1.5-fold increased risk of readmission, although the absolute rate of 4.2% is likely an underestimate, and uncomplicated dissections may have an even lower rate of readmission than reported here. Patients who have an ischemic complication related to an acute aortic dissection are known to have worse outcomes in the acute setting.11 We found that such patients are also at higher risk for readmission, although we could not differentiate whether the complication was related to the dissection or a possible intervention. TEVAR had the highest rate of nonelective 90day readmission; this may in part be due to higher risk features of the dissection that warranted TEVAR during the index hospitalization, such as mesenteric, renal, or lower extremity ischemia. In conjunction, the rate of an ischemic complication was more than double in the TEVAR group. The most frequent cause for readmission was related to aortic disease, although the contribution of this complication varied by initial treatment received. An aortarelated etiology accounted for more than one-third of readmissions in the medical management group, whereas the rates were 7% in the open repair group and 13% in the TEVAR group. Although aorta-specific diagnosis codes for readmission were lower in the open repair and TEVAR groups, the most common cause of readmission was related to an intervention performed on index admission, accounting for an additional 14% of readmissions for the open repair group and 18% for the TEVAR group. The reported rates of complications and reinterventions after TEVAR vary widely and depend on indication for TEVAR and duration of follow-up.4,12,13 The rate of repeated intervention in patients with TEVAR for aneurysm or dissection at 90 days has been reported at 2.4%, two-thirds of which was repeated TEVAR.7 We
demonstrated similar findings with a low rate of reintervention at 90 days of 2.5% in those initially managed with TEVAR, 69.0% of which was repeated TEVAR. The overall rate of aortic intervention in 90-day follow-up for those initially managed medically was low at 3.8%, the majority of which occurred electively (54.4%). Costs during readmission were substantial with a mean above $20,000 and above $40,000 for those admitted electively. Mortality during nonelective readmission was high at 5.0% and comparable to that of patients readmitted after revascularization for peripheral artery disease and ST elevation myocardial infarction.14,15 Mortality was lower in those with an elective readmission (2.7%). Aortic centers and networks have recently been developed and demonstrated improved short-term outcomes and are recommended in guidelines.2,16,17 Given the high rate of readmissions and associated costs and mortality, the development of aortic centers and multidisciplinary teams to manage aortic dissection may aid in decreasing the rate of readmission to allow close coordination of care, follow-up, and optimal medical management. Further study is warranted to evaluate whether such approaches decrease readmissions as well. Limitations. We analyzed data from a large administrative database and relied on billing codes, which can be susceptible to misclassification, lack more granular patient- and procedure-level data, and do not include adjudicated outcomes. The database also does not capture out-of-hospital deaths and thus does not account for the competing risk for readmission and postdischarge death. In addition, the rate of malperfusion or “complicated” dissection may be underestimated if it is not appropriately coded for at the time of index admission as it would be expected to be higher in those who require open repair than in the medical therapy group alone. There is no ICD-9 code for acute type B dissection, and some patients may have been misclassified. However, we employed an algorithm to identify those with acute type B dissections based on previous studies and limited inclusion to only those patients with a primary diagnosis of dissection. A recent study adjudicated acute aortic dissection and management based on billing codes at a single center.18 The study included both primary and secondary billing codes and demonstrated specificity of 99.0% for TEVAR, 99.0% for open repair, and 80.3% for medical management, with low sensitivity. In our analysis, when including those with a primary and secondary diagnosis of aortic dissection, only 40% of patients in the medical management group had a primary diagnosis compared with 91% in the open repair group and 87% in the TEVAR group. Given that the goal of our study was to evaluate readmissions after acute type B aortic dissection rather than to explore epidemiologic trends
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over time, which would be more susceptible to error with low sensitivity, we chose to limit our cohort to only those with a primary diagnosis to increase the specificity of patients included with an acute dissection. In so doing, we decreased the size of the cohort and may have biased the cohort to a sicker population. This is evidenced by a higher than expected rate of open repair in our cohort at 20.9% compared with 7.6% in IRAD; the rate of open repair in our cohort when including primary and secondary diagnosis code was 11.3%. The rate of open repair in our final analysis was similar to prior administrative data reports. An analysis of the Nationwide Inpatient Sample from 2012 demonstrated an open repair rate of 22.8% and TEVAR rate of 16.8%.19 Evaluation of interventions for acute type B dissection using data from Medicare in 2010 demonstrated that 73% received open repair and 27% TEVAR.20 It is possible that some of the patients included in the open repair group had type A dissection or a chronic type B dissection despite exclusion of patients with billing codes associated with type A open surgical repair and those who were electively admitted. However, it is reassuring that in the recent single-center study that adjudicated acute aortic dissections against billing code assessment, no patients who were categorized as an open repair of a type B dissection were found to have actually had a type A dissection.18 In our algorithm, it was presumed that all patients with type A dissection were managed with surgical intervention; thus, it is possible that some patients with type A dissection were managed medically and included in our study. To limit the inclusion of medically managed type A dissection patients (which is estimated at 8% based on IRAD data),1 we additionally excluded patients with findings often associated with type A dissection, which had not been done in previous studies including patients with aortic regurgitation, pericardial effusion, and artery (coronary, carotid, or vertebral) dissection. Adherence to medical therapy following aortic dissection is poor.21 Medication data are not available in the NRD; thus, we were unable to assess the medical therapy prescribed or adherence to medication. However, our findings are likely representative of “real-world” adherence to medications and the associated outcomes after medical therapy alone.
CONCLUSIONS Acute type B aortic dissection is associated with a high rate of nonelective readmission at 90 days regardless of initial treatment received. Readmissions are most commonly related to aortic disease or complications from initial interventions and are associated with a high rate of mortality and costs. Patients with type B aortic dissection should be closely monitored after discharge, and identification of measures to reduce readmissions is warranted, given the high associated readmission rates and costs.
2019
AUTHOR CONTRIBUTIONS Conception and design: BC, MS, NS, RY, ES Analysis and interpretation: BC, MS, KK, NS, KS, RY, ES Data collection: KK, KS Writing the article: BC, ES Critical revision of the article: BC, MS, KK, NS, KS, RY, ES Final approval of the article: BC, MS, KK, NS, KS, RY, ES Statistical analysis: KK Obtained funding: Not applicable Overall responsibility: BC
REFERENCES 1. Pape LA, Awais M, Woznicki EM, Suzuki T, Trimarchi S, Evangelista A, et al. Presentation, diagnosis, and outcomes of acute aortic dissection: 17-year trends from the International Registry of Acute Aortic Dissection. J Am Coll Cardiol 2015;66:350-8. 2. Erbel R, Aboyans V, Boileau C, Bossone E, Di Bartoloea R, Eggerbrect H, et al. 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC). Eur Heart J 2014;35: 2873-926. 3. Durham CA, Cambria RP, Wang LJ, Ergul EA, Arason NJ, Patel V, et al. The natural history of medically managed acute type B aortic dissection. J Vasc Surg 2015;61:1192-8. 4. Thrumurthy SG, Karthikesalingam A, Patterson BO, Holt PJ, Hinchliffe RJ, Loftus IM, et al. A systematic review of midterm outcomes of thoracic endovascular repair (TEVAR) of chronic type B aortic dissection. Eur J Vasc Endovasc Surg 2011;42:632-47. 5. Afifi RO, Sandhu HK, Leake SS, Boutrous ML, Kumar V, Azizzadeh A, et al. Outcomes of patients with acute type B (DeBakey III) aortic dissection: a 13-year, single-center experience. Circulation 2015;132:748-54. 6. Mody SM, Wang Y, Geirsson A, Kim N, Desai MM, Gupta A, et al. Trends in aortic dissection hospitalizations, interventions, and outcomes among Medicare beneficiaries in the United States, 2000-2011. Circ Cardiovasc Qual Outcomes 2014;7:920-8. 7. Kalesan B, Cheng TW, Farber A, Zuo Y, Kalish J, Jones DW, et al. Readmissions after thoracic endovascular aortic repair. J Vasc Surg 2018;68:372-82. 8. Sachs T, Pomposelli F, Hagberg R, Hamdan A, Wyers M, Giles K, et al. Open and endovascular repair of type B aortic dissection in the Nationwide Inpatient Sample. J Vasc Surg 2010;52:860-6. 9. HCUP Clinical Classifications Software (CCS) for ICD-9-CM. Rockville, Md: Agency for Healthcare Research and Quality; March 2017. Available at: www.hcup-us.ahrq.gov/ toolssoftware/ccs/ccs.jsp. Accessed June 29, 2018. 10. Booher AM, Isselbacher EM, Nienaber CA, Trimarchi S, Evangelista A, Montgomery DG, et al. The IRAD classification system for characterizing survival after aortic dissection. Am J Med 2013;126:730.e19-24. 11. Tolenaar JL, Froehlich W, Jonker FH, Upchurch GR, Rampoldi V, Tsai TT, et al. Predicting in-hospital mortality in acute type B aortic dissection: evidence from International Registry of Acute Aortic Dissection. Circulation 2014;130(Suppl 1):S45-50. 12. Andersen ND, Keenan JE, Ganapathi AM, Gaca JG, McCann RL, Hughes GC. Current management and
Journal of Vascular Surgery Volume
13.
14.
15.
16.
17.
-,
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outcome of chronic type B aortic dissection: results with open and endovascular repair since the advent of thoracic endografting. Ann Cardiothorac Surg 2014;3:264-74. Cambria RP, Crawford RS, Cho JS, Bavaria J, Farber M, Lee WA, et al. A multicenter clinical trial of endovascular stent graft repair of acute catastrophes of the descending thoracic aorta. J Vasc Surg 2009;50:1255-64. Secemsky EA, Schermerhorn M, Carroll BJ, Kennedy KF, Shen C, Valsdottir LR, et al. Readmissions after revascularization procedures for peripheral arterial disease: a nationwide cohort study. Ann Intern Med 2018;168:93-9. Kim LK, Yeo I, Cheung JW, Swaminathan RV, Wong SC, Charitakis K, et al. Thirty-day readmission rates, timing, causes, and costs after ST-segment-elevation myocardial infarction in the United States: a National Readmission Database analysis 2010-2014. J Am Heart Assoc 2018;7:e009863. Duceau B, Alsac JM, Bellenfant F, Mailloux A, Chhor V, Lagrange A, et al. Improved survival after implementation of a large-scale regional dedicated aortic network. J Am Coll Cardiol 2017;70:3068-9. Andersen ND, Ganapathi AM, Hanna JM, Williams JB, Gaca JG, Hughes GC. Outcomes of acute type A dissection repair before and after implementation of a
18.
19.
20.
21.
multidisciplinary thoracic aortic surgery program. J Am Coll Cardiol 2014;63:1796-803. Finnesgard EJ, Weiss S, Kalra M, Johnston JK, Oderich GS, Shuja F, et al. Performance of current claims-based approaches to identify aortic dissection hospitalizations. J Vasc Surg 2018;67:e93. Zimmerman KP, Oderich G, Pochettino A, Hanson KT, Habermann EB, Bower TC, et al. Improving mortality trends for hospitalization of aortic dissection in the National Inpatient Sample. J Vasc Surg 2016;64:606-15. Jones DW, Goodney PP, Nolan BW, Brooke BS, Fillinger MF, Powell RJ, et al. National trends in utilization, mortality, and survival after repair of type B aortic dissection in the Medicare population. J Vasc Surg 2014;60:11-9. Chaddha A, Erickson S, Kline-Rogers E, Montgomery D, Woznicki E, Jabara J, et al. Medication adherence patterns in aortic dissection survivors. Indian J Med Res 2018;147:183-8.
Submitted May 7, 2019; accepted Aug 20, 2019.
Additional material for this article may be found online at www.jvascsurg.org.
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Supplementary Table I (online only). Diagnostic and procedure billing codes Diagnosis
ICD-9 code
Dissecting thoracic aortic aneurysm
441.01
Dissecting thoracoabdominal aneurysm
441.03
Cardioplegia
39.63
Valve repair
35.00-35.99
Operations on vessels of the heart Dissection, artery, carotid
36.00-36.99, 37.0, 37.2, 37.31-37.90, 37.93-37.99 443.21
Dissection, artery, coronary
414.12
Dissection, artery, vertebral
443.24
Pericardial effusion
423.9
Aortic regurgitation
424.1
TEVAR Endovascular implantation of graft in thoracic aorta
39.73
Open repair Resection of vessel with anastomosis, aorta
38.34
Resection of vessel with anastomosis, thoracic vessels
38.35
Resection of vessel with replacement, thoracic vessels
38.45
Repair of a vessel with a tissue patch graft
39.57
Repair of a vessel with a synthetic patch graft
39.58
Marfan syndrome
759.82
Ehlers-Danlos
756.83
Ischemic complication Ischemia, kidney
593.81
Acute bowel ischemia
557.9
Ischemic colon
557.0
Embolism and thrombosis of abdominal aorta
444.0
Arterial embolism and thrombosis of iliac artery
444.22
Embolism and thrombosis of iliac artery
444.81
ICD-9, International Classification of Diseases, Ninth Revision; TEVAR, thoracic endovascular aortic repair.
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Supplementary Table II (online only). Billing codes for patients with open repair Total (N ¼ 1495)
Open repair billing codes
Open repair only (n ¼ 1456)
TEVAR þ open repair (n ¼ 39) <10 (<25.6)
Resection of vessel with anastomosis, aorta
<10 (<0.7)
<10 (<0.7)
Resection of vessel with anastomosis, thoracic vessels
<10 (<0.7)
<10 (<0.7)
18 (46.1)
Resection of vessel with replacement, thoracic vessels
1395 (93.3)
1377 (94.6)
18 (46.1)
88 (5.9)
70 (4.8)
<10 (<25.6)
<10 (<0.7)
<10 (<0.7)
<10 (<25.6)
Repair of a vessel with a tissue patch graft Repair of a vessel with a synthetic patch graft TEVAR, Thoracic endovascular aortic repair. Values are reported as number (%).
Supplementary Table III (online only). Top 10 causes of 30-day nonelective readmission by Clinical Classifications Software (CCS) classification CCS classification No.
Cause of readmission
Medical management (n ¼ 1023)
Open repair (n ¼ 392)
TEVAR (n ¼ 328)
Total (N ¼ 1743)
363 (35.5)
28 (7.1)
42 (12.8)
433 (24.8)
115
Aortic, peripheral, and visceral artery aneurysms
238
Complications of surgical procedures or medical care
16 (1.6)
44 (11.2)
23 (7.0)
83 (4.8)
99
Hypertension with complications and secondary hypertension
53 (5.2)
<10 (<2.6)
13 (4.0)
73 (4.2)
108
Congestive heart failure, nonhypertensive
37 (3.6)
23 (5.9)
<10 (<3.0)
65 (3.7)
237
Complication of device, implant, or graft
18 (1.8)
13 (3.3)
31 (9.5)
62 (3.6)
2
Septicemia (except in labor)
34 (3.3)
16 (4.1)
11 (3.4)
61 (3.5)
122
Pneumonia (except that caused by tuberculosis or sexually transmitted disease)
26 (2.5)
17 (4.3)
<10 (<3.0)
52 (3.0)
102
Nonspecific chest pain
30 (2.9)
13 (3.3)
<10 (<3.0)
51 (2.9)
106
Cardiac dysrhythmias
20 (2.0)
18 (4.6)
<10 (<3.0)
45 (2.6)
157
Acute and unspecified renal failure
31 (3.0)
<10 (<2.6)
<10 (<3.0)
43 (2.5)
TEVAR, Thoracic endovascular aortic repair. Values are reported as number (%).