In-Hospital Outcomes of Atherectomy During Endovascular Lower Extremity Revascularization

In-Hospital Outcomes of Atherectomy During Endovascular Lower Extremity Revascularization Sidakpal S. Panaich, MDa, Shilpkumar Arora, MDb, Nilay Patel, MDc, Nileshkumar J. Patel, MDd, Samir V. Patel, MDe, Chirag Savani, MDf, Vikas Singh, MDd, Sunny Jhamnani, MDg, Rajesh Sonani, MDh, Sopan Lahewala, MDi, Badal Thakkar, MDj, Achint Patel, MDk, Abhishek Dave, MDl, Harshil Shah, MDm, Parth Bhatt, MDj, Radhika Jaiswal, MDn, Abhijit Ghatak, MDo, Vishal Gupta, MDa, Abhishek Deshmukh, MDp, Ashok Kondur, MDq, Theodore Schreiber, MDq, Cindy Grines, MDq, and Apurva O. Badheka, MDr,* Contemporary data on clinical outcomes after utilization of atherectomy in lower extremity endovascular revascularization are sparse. The study cohort was derived from Healthcare Cost and Utilization Project nationwide inpatient sample database from the year 2012. Peripheral endovascular interventions including atherectomy were identified using appropriate International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic and procedural codes. The subjects were divided and compared in 2 groups: atherectomy versus no atherectomy. Two-level hierarchical multivariate mixed models were created. The coprimary outcomes were in-hospital mortality and amputation; secondary outcome was a composite of in-hospital mortality and periprocedural complications. Hospitalization costs were also assessed. Atherectomy utilization (odds ratio, 95% CI, p value) was independently predictive of lower in-hospital mortality (0.46, 0.28 to 0.75, 0.002) and lower amputation rates (0.83, 0.71 to 0.97, 0.020). Atherectomy use was also predictive of significantly lower secondary composite outcome of in-hospital mortality and complications (0.79, 0.69 to 0.90, 0.001). In the propensity-matched cohort, atherectomy utilization was again associated with a lower rate of amputation (11.18% vs 12.92%, p [ 0.029), inhospital mortality (0.71% vs 1.53%, p 0.001), and any complication (13.24% vs 16.09%, p 0.001). However, atherectomy use was also associated with higher costs ($24,790 – 397 vs $22635 – 251, p <0.001). Atherectomy use in conjunction with angioplasty (with or without stenting) was associated with improved in-hospital outcomes in terms of lower amputation rates, mortality, and postprocedural complications. Ó 2016 Elsevier Inc. All rights reserved. (Am J Cardiol 2016;117:676e684) Peripheral arterial disease (PAD) accounts for significant morbidity and mortality and subsequent financial implications.1e3 Nearly 20% of the patients undergoing a revascularization procedure for PAD need a repeat procedure or amputation within 2 years, whereas 1/3 of these patients undergo amputation of contralateral leg in the next 2 years.4,5 The endovascular approach for revascularization of lower extremity PAD is associated with high rates of restenosis and need for recurrent procedures especially in

the infrainguinal vessels. Attempts to improve clinical outcomes of endovascular procedures have included the development of various stents and drug eluting balloons (DEBs).6 Atherectomy also serves as an important adjunct in peripheral revascularization especially in heavily calcified lesions.7 The Tissue Removal by Ultrasound Evaluation study showed an 11.8% reduction in plaque volume with atherectomy primarily involving the fibrous and fibrofatty plaque with resultant luminal volume expansion without

a Cardiology Department, Borgess Medical Center, Kalamazoo, Michigan; bInternal Medicine Department, Mount Sinai St. Luke’s Roosevelt Hospital, New York, New York; cInternal Medicine Department, Saint Peter’s University Hospital, New Brunswick, New Jersey; dCardiology Department, University of Miami Miller School of Medicine, Miami, Florida; eInternal Medicine Department, Western Reserve Health System, Youngstown, Ohio; fEpidemiology Department, New York Medical College, New York; gCardiology Department, Yale School of Medicine, New Haven, Connecticut; hInternal Medicine Department, Emory University School of Medicine; iInternal Medicine Department, Jersey City Medical Center, New Jersey, New Jersey; jEpidemiology Department, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana; k Public Health Department, Icahn School of Medicine at Mount Sinai, New York, New York; lPublic Health Department, Texas A&M Health Science

Center, School of Public Health, College Station, Texas; mCardiology Department, St. Anthony’s Hospital, Oklahoma City, Oklahoma; nCardiology Department, John H. Stroger, Jr. Hospital of Cook County, Chicago, Illinois; oCardiology Department, Southwest Heart, Las Cruces, New Mexico; pCardiology Department, Mayo Clinic, Rochester, Minnesota; q Cardiology Department, Detroit Medical Center, Detroit, Michigan; and r Cardiology Department, The Everett Clinic, Everett, Washington. Manuscript received October 4, 2015; revised manuscript received and accepted November 18, 2015. The authors Panaich and Arora share equal contribution to this manuscript. See page 683 for disclosure information. *Corresponding author: Tel: (408) 324-4516; fax: (203) 737-2437. E-mail address: [email protected] (A.O. Badheka).

0002-9149/15/$ - see front matter Ó 2016 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjcard.2015.11.025

www.ajconline.org

Miscellaneous/In-Hospital Outcomes of Peripheral Atherectomy

Figure 1. Data extraction.

concomitant vessel expansion.8 Previous studies evaluating the clinical efficacy of various atherectomy devices have had inherent limitations including single arm designs, small sample sizes, restrictive patient populations and lack of clinical end points, and so forth.7 The primary objective of our study was to evaluate postprocedural outcomes in terms of in-hospital mortality, amputation, complications, and hospitalization costs after utilization of atherectomy in lower extremity peripheral revascularization. Methods The study cohort was derived from the Nationwide Inpatient Sample (NIS) database from the year 2012, a subset of the Healthcare Cost and Utilization Project sponsored by the Agency for Healthcare Research and Quality. The NIS is the largest publicly available all-payer inpatient care database in the United States, including data on approximately 7 to 8 million discharges per year and is a stratified 20% sample of discharges from US community hospitals, excluding rehabilitation and long-term acute care hospitals.6 The details regarding the NIS data have been previously published.9 Annual data quality assessments of the NIS are performed, which guarantee the internal validity of the database. Ascertainment of all diagnoses and procedures was made using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9CM) codes. Peripheral vascular disease was identified by all diagnoses codes mentioned in Supplementary Table 1 as primary diagnosis codes. Patients aged <18 years were excluded and peripheral endovascular interventions were identified using ICD-9 procedural codes 39.90, 39.50, 00.55, 17.56 (Figure 1; Supplementary Table 1). Peripheral

677

atherectomy was identified using the ICD-9 code 17.56 (percutaneous atherectomy of other noncoronary vessels) introduced in October 2011. The subjects were divided into 2 groups on the basis of whether they underwent peripheral atherectomy or not. The coprimary outcomes were in-hospital mortality and amputation; secondary outcome was a composite of in-hospital mortality and periprocedural complications. Preventable procedural complications were identified by patient safety indicators (PSIs), version 4.4, March 2012. These indicators are based on ICD-9-CM codes and medicare severity diagnosiserelated groups, and each PSI has specific inclusion and exclusion criteria.10 Amputation and other procedureerelated complications, which included postprocedure hemorrhage requiring blood transfusion, other iatrogenic respiratory complications (which included ventilatoreassociated pneumonia, postprocedure aspiration pneumonia, and other respiratory complications not elsewhere classified), postprocedural stroke, or transient ischemic attack, and other vascular complications were identified using ICD-9-CM codes (listed in Supplementary Table 2) in any secondary diagnosis field. Vascular complications were defined as PSI code for accidental puncture or ICD-9-CM codes for injury to blood vessels, creation of arteriovenous fistula, vascular complications requiring surgery, vascular device/graft/implant complications, and other vascular complications not elsewhere classified. “Any complications” were defined as occurrence of one or more postprocedural complications listed in Supplementary Table 2. NIS variables were used to identify patients demographic characteristics including age, gender, and race (Table 1). We defined severity of co-morbid conditions using Deyo’s modification of Charlson co-morbidity index (CCI; Supplementary Table 3).11 The Healthcare Cost and Utilization Project NIS contains data on total charges that hospitals billed for services. These data were merged with the cost to-charge ratio files to get actual cost per hospital visit. Stata 11.0 (StataCorp, College Station, Texas) and SAS 9.4 (SAS Institute Inc., Cary, North Carolina) were used for analyses. Weighted values of patient-level observations were generated to produce nationally representative estimates. Differences between categorical variables were tested using the chi-square test, and differences between continuous variables were tested using the Student t test. Hierarchical mixed effects logistic regression models were used for categoricaldependent variables like primary and secondary outcomes and hierarchical mixed effects linear regression models were used for continuous dependent variables like the cost of care. p Value <0.05 was considered significant. In all multivariate models, we included hospital level variables such as location/teaching status of hospital, hospital region, hospital bed size and patient level variables such as age, gender, Deyo modification of CCI, admission over the weekend, primary payer (with Medicare/ Medicaid considered as referent), admission type (elective admission as referent), and intervention type (no atherectomy group as referent). To control for imbalances in baseline characteristics between the 2 study (atherectomy use and no atherectomy use) groups that might influence treatment outcome, we used

678

The American Journal of Cardiology (www.ajconline.org)

Table 1 Baseline table Variable

Table 1 (continued) Atherectomy NO

Overall

p-value

YES

Overall (unweighted) 10138 (76.77) 3068(23.23) Overall (weighted) 50690(76.77) 15340 (23.23) Overall Age (Years) 18-34 0.31% 0.16% 35-49 5.44% 3.59% 50-64 30.92% 26.27% 65-79 41.85% 44.75% >¼80 21.47% 25.23% Gender Male 56.23% 56.03% Female 43.77% 43.97% Race White 66.82% 60.95% Non-white 27.9% 35.07% Missing 5.28% 3.98% Charlson/ Deyo comorbidity index 0 23.86% 20.24% 1 27.81% 28.94% >¼2 48.33% 50.81% Comorbidities Obesity* 8.63% 9.78% Hypertension (by 78.11% 79.14% History) Diabetes Mellitus 44.17% 53.75% Heart failure (By 1.84% 1.27% History) History of chronic 23.48% 20.89% pulmonary disease Renal failure 26.02% 27.57% Neurological 6.93% 6.88% disorder or paralysis Anemia or 22.64% 25.68% coagulopathy Hematological or 1.95% 2.09% oncological malignancy Weight loss 4.54% 3.59% Rheumatoid 2.98% 2.9% arthritis or other collagen vascular disease Depression, 12.72% 10.5% psychosis or substance abuse Fluid and 16.01% 14.05% electrolyte disorders Pulmonary 0.37% 0.07% circulation disorders Valvular disease 0.48% 0.29% Acute Myocardial 1.87% 1.11% Infarction

Variable

Atherectomy NO

13206 66030 <0.001 0.27% 5.01% 29.84% 42.53% 22.35% 0.656 56.19% 43.81% <0.001 65.46% 29.57% 4.98% <0.001

23.02% 28.07% 48.91% 8.9% 78.35%

<0.001 0.007

46.4% 1.71%

<0.001 <0.001

22.88%

<0.001

26.38% 6.92%

<0.001 0.808

23.35%

<0.001

1.98%

0.301

4.32% 2.96%

<0.001 0.618

12.21%

15.55%

0.3%

0.44% 1.70%

<0.001 <.0001

Median household income category for patient’s zip code (percentile) 1. 0-25th 33.91% 2. 26-50th 24.97% 3. 51-75th 22.02% 4. 76-100th 16.89% Primary Payer Medicare / 78.44% Medicaid Private including 16.15% HMO Self pay/no charge/ 5.14% other Hospital characteristics Hospital bed size Small 11.39% Medium 24.46% Large 64.14% Location/Teaching status of Hospital Rural 6.34% Urban nonteaching 35.92% Urban teaching 57.73% Hospital Region Northeast 19.02% Midwest or North 20.07% Central South 35.02% West 11.82% Admission types Non elective 49.41% Elective admission 50% Admission day Weekdays 91.53% Weekend 8.47% Disposition Home 77.54% Facility 22.1% Death 1.4% Amputation 13.42% Above-knee 1.74% amputation Below-knee 3.05% amputation Minor amputation 9.58% Cost 23408185

Overall

p-value

YES 0.026

33.9% 24.54% 21.87% 17.76%

33.91% 24.87% 21.98% 17.09%

82.53%

79.39%

13.66%

15.57%

3.72%

4.81%

10.95% 31.68% 57.37%

11.29% 26.14% 22.57%

<0.001

<0.001

<0.001 5.52% 39.8% 54.99%

6.08% 36.82% 57.1%

15.48% 27.54%

18.2% 21.81%

34.68% 11.11%

34.94% 11.65%

43.81% 54.14%

48.11% 50.96%

93.42% 6.58%

91.97% 8.03%

80.78% 18.92% 0.78% 11.51% 1.24%

78.3% 21.36% 1.26% 12.98% 1.62%

<0.001 <0.001 <0.001

2.61%

2.95%

0.005

<0.001

<0.001 <0.001 <0.001

8.31% 9.28% <0.001 25196 359 23817165 <0.001

HMO ¼ Health Maintenance Organization. * Defined as a body mass index of 30 or greater.

<0.001

0.002 <0.001

propensity scoring method to establish matched cohorts. A propensity score, which was assigned to each hospitalization, was based on multivariate logistic regression model that examined the impact of 10 variables (patient demographics, co-morbidities, and hospital characteristics) on

Miscellaneous/In-Hospital Outcomes of Peripheral Atherectomy Table 2 Complication table Variable

Overall (weighted) Overall (unweighted) Any complications Any Vascular complication Compartment syndrome Rupture of artery Arteriovenous fistula Atheroembolism of lower extremity Injury to blood vessels of lower extremity Vascular complications requiring surgery Post-op hemorrhage requiring transfusion Vascular device, implant, and graft complications Other nonspecific peripheral vascular complications Accidental puncture Iatrogenic cardiac complications Respiratory complications (Post-op respiratory failure) Postoperative-Stroke/ TIA Renal and metabolic complications Postoperative PE Postoperative DVT Postoperative infectious complications

679

Table 3 Propensity score match (1:2 match) Atherectomy

Overall

P-value

NO

YES

10138(76.77) 50690(76.77) 16.31% 11.33%

3068(23.23) 15340(23.23) 13.2% 9.45%

13206 66030 15.59% 10.9%

<.001 <.001

0.64%

0.39%

0.58%

0.001

0.04% 0.15%

0.03% 0.2%

0.04% 0.16%

0.701 0.194

0.31%

0.13%

0.27%

<0.001

0.04%

0.13%

0.06%

<.001

3.45%

2.28%

3.18%

<.001

1.51%

1.83%

1.58%

0.006

4.91%

4.14%

4.73%

<.001

1.42%

1.27%

1.39%

0.166

0.75% 0.77% 2.97%

0.62% 0.49% 2.38%

0.72% 0.7% 2.83%

0.094 <0.001 <.001

0.15%

0.2%

0.16%

0.194

0.39%

0.36%

0.39%

0.528

0.24% 1.12% 2.15%

0.1% 0.65% 1.63%

0.2% 1.01% 2.03%

0.001 <.001 <.001

DVT ¼ deep vein thrombosis; PE ¼ pulmonary embolism; TIA ¼ transient ischemic attack.

the likelihood of treatment assignment. Patients with similar propensity score in 2 treatment groups were matched using a 1 to 2 scheme without replacement using greedy methods.12 Furthermore, we investigated the institutional variation in atherectomy utilization by creating 3 separate hierarchical logistic regression models: model 1: unconditional model with only hospital ID intercept; model 2: model 1 þ patient level variables including age, gender, Charlson score, admission day, admission type, primary payer; model 3: model 2 þ hospital level variables such as hospital region,

Variable

Age (years) Female Charlson/Deyo comorbidity index 0 1 >¼2 Primary Payer Medicare / Medicaid Private including HMO Self pay/no charge/other Admission types Elective admission Non-elective admission Admission day Weekdays Weekend Median household income category for patient’s zip code (percentile) 1. 0-25th 2. 26-50th 3. 51-75th 4. 76-100th Hospital Region Northeast Midwest or North Central South West Hospital Teaching status Rural Urban non teaching Urban teaching Hospital bed size Small Medium Large c-index Outcomes Death Above-knee amputation Below-knee amputation Minor amputation Overall amputation Any complication Any vascular complication Any complication/in hospital mortality Cost of care

Atherectomy NO 5046

YES 2523

700.16 44.0%

700.23 44.3%

21.2% 28.3% 50.5%

21.0% 28.5% 50.5%

82.3% 13.9% 3.8%

82.2% 13.9% 3.9%

44.8% 55.2%

44.8% 55.2%

93.7% 6.3%

93.8% 6.2%

P-value

0.991 0.806 0.957

0.985

0.960

0.946

0.968

36.1% 25.3% 21.0% 17.5%

35.8% 25.1% 21.4% 17.7%

18.5% 27.0% 41.3% 13.1%

18.2% 28.5% 40.5% 12.8%

4.8% 36.8% 58.4%

5.1% 36.2% 58.8%

10.4% 29.8% 59.8% 0.59%

10.7% 29.7% 59.7%

0.631

0.737

0.941

1.53% 1.74%

0.71% 1.39%

0.003 0.247

2.93%

2.46%

0.235

9.16% 12.92% 16.09% 10.98% 16.45%

8.01% 11.18% 13.24% 9.51% 13.36%

0.095 0.029 0.001 0.049 <0.001

22635251

24790397

<0.001

HMO ¼ Health Maintenance Organization.

location/teaching status, and bed size. For each model, between-hospital variance was calculated along with C statistic to account for model discrimination. Interclass correlation coefficient was calculated to determine the

680

The American Journal of Cardiology (www.ajconline.org)

Table 4 Multivariate analyses of in-hospital mortality and amputation In-hospital mortality

Age (per 10 increase) Female Intervention type Atherectomy Charlson/Deyo comorbidity index 0 1 >¼2 Primary Payer Medicare / Medicaid Private including HMO Self pay/no charge/other Admission types Elective admission Non-elective admission Admission day Weekdays Weekend Hospital Region Northeast Midwest or North Central South West Hospital Teaching status Rural Urban non teaching Urban teaching Hospital bed size Small Medium Large c- index

Amputation

Odds ratio

LL

HL

Pvalue

Odds ratio

LL

HL

Pvalue

1.42 1.10

1.21 0.78

1.66 1.57

<0.001 0.58

0.94 0.72

0.89 0.64

1.00 0.81

0.04 <0.001

0.46

0.28

0.75

0.002

0.83

0.71

0.97

0.020

Referent 1.43 4.60

Referent 0.65 2.48

Referent 3.13 8.52

0.37 <0.001

Referent 1.73 4.78

Referent 1.38 3.89

Referent 2.17 5.87

<0.001 <0.001

Referent 0.80 0.69

Referent 0.42 0.21

Referent 1.52 2.23

0.51 0.53

Referent 0.89 1.12

Referent 0.73 0.87

Referent 1.07 1.45

0.22 0.38

Referent 1.90

Referent 1.32

Referent 2.75

0.001

Referent 3.04

Referent 2.61

Referent 3.53

<0.001

Referent 1.17

Referent 0.68

Referent 2.01

0.58

Referent 0.98

Referent 0.81

Referent 1.19

0.86

Referent 1.03 1.20 0.97

Referent 0.62 0.77 0.51

Referent 1.71 1.88 1.85

0.90 0.42 0.93

Referent 0.88 1.38 1.15

Referent 0.69 1.12 0.90

Referent 1.12 1.68 1.45

0.31 0.002 0.26

Referent 0.96 0.85

Referent 0.46 0.41

Referent 2.01 1.76

0.92 0.66

Referent 1.14 1.14

Referent 0.83 0.84

Referent 1.56 1.55

0.42 0.41

Referent 0.87 0.96 0.75

Referent 0.49 0.57

Referent 1.56 1.61

0.64 0.87

Referent 1.14 1.17 0.74

Referent 0.84 0.88

Referent 1.55 1.56

0.39 0.28

HMO ¼ Health Maintenance Organization; LL ¼ lower limit; UL ¼ upper limit.

proportion of variance attributable to between-hospital variance.13 The median odds ratio was also calculated to quantify the extent to which the variation in utilization of atherectomy was secondary to clustering of patients within hospitals. All supplementary material will be available online only. Results Table 1 lists the baseline characteristics of the 2 study cohorts (atherectomy vs no atherectomy group). Atherectomy group had 56.03% men, 60.95% were whites, and 50.81% of the patients had a CCI score of 2 compared with no atherectomy group with 56.23% men (p ¼ 0.656), 66.82% whites (p <0.001), and CCI score of 2 in 48.33% (p <0.001). Medicare/Medicaid was the primary payer (82.53% vs 78.44%, p <0.001). A majority of procedures were done in large (57.37% vs 64.14%, p <0.001) and urban teaching (54.99% vs 57.73%, p <0.001) hospitals. The overall rate of periprocedural complications (Table 2) was 15.59%. Atherectomy use was associated with a lower rate of complications (13.2%) compared with the cohort without

atherectomy use (16.31%; p <0.001). The overall rate of vascular complications was 10.9% (9.45% in atherectomy group vs 11.33% in no atherectomy group, p <0.001). The rate of amputation was lower in the atherectomy group (11.51%) compared with the group without atherectomy (13.42%; p <0.001). Table 3 lists the baseline characteristics in a propensitymatched cohort. Patient demographics, coemorbidities (CCI score), and hospital characteristics were similar among 2 groups. Atherectomy utilization was associated with a lower rate of amputation (11.18% vs 12.92%, p ¼ 0.029), in-hospital mortality (0.71% vs 1.53%, p 0.001), any complication (13.24% vs 16.09%, p 0.001), and any vascular complication (9.51% vs 10.98%, p 0.049). Atherectomy use was however associated with higher costs ($24,790  397 vs $22635  251, p <0.001). Multivariate analysis (Table 4) revealed age (odds ratio [OR], 95% CI, p value; 1.42, 1.21 to 1.66, <0.001) to predict in-hospital mortality and a baseline co-morbidity status as depicted by a higher CCI score (CCI  2) to be significant predictor of in-hospital mortality (4.60, 2.48 to 8.52, <0.001) and amputation (4.78, 3.89 to 5.87, <0.001).

Miscellaneous/In-Hospital Outcomes of Peripheral Atherectomy

681

Figure 2. Outcomes in different angioplasty-based interventions. (A) In hospital Mortality in different angioplasty based interventions. (B) Amputation rate in different angioplasty based interventions. (C) Any complications in different angioplasty based interventions. (D) In hospital mortality/ any complications in different angioplasty based interventions.

Figure 3. Outcomes in different stent-based interventions. (A) In hospital mortality in different stent based interventions. (B) Amputation rate in different stent based interventions. (C) Any complications in different stent based interventions. (D) In hospital mortality/ any complications in different stent based interventions.

682

The American Journal of Cardiology (www.ajconline.org)

Table 5 Subgroup analyses of amputation and in-hospital mortality/complications Subgroup analysis amputation

Odds ratio

LL

UL

Pvalue

Chronic limb ischemia Acute limb ischemia Critical limb ischemia Stents Angioplasty Age80 years Non elective admission Charlson score 2

0.74 1.00 0.83 0.76 0.72 0.82 0.86 0.82

0.59 0.52 0.66 0.58 0.60 0.61 0.72 0.69

0.93 1.93 1.03 1.02 0.87 1.09 1.04 0.99

Subgroup analysis of in hospital mortality/any complications

Odds ratio

LL

UL

Pvalue

cindex

Chronic limb ischemia Acute limb ischemia Critical limb ischemia Stents Angioplasty Age 80 years Non elective admission Charlson score 2

0.84 0.85 0.77 0.95 0.61 0.73 0.76 0.74

0.70 0.55 0.62 0.77 0.51 0.56 0.63 0.62

1.01 1.32 0.96 1.17 0.74 0.95 0.90 0.87

0.06 0.48 0.02 0.63 <0.001 0.02 0.002 0.002

0.60 0.62 0.57 0.58 0.61 0.60 0.58 0.57

0.01 0.99 0.09 0.06 0.001 0.17 0.12 0.03

cindex 0.83 0.69 0.67 0.76 0.73 0.7 0.66 0.66

LL ¼ lower limit; UL ¼ upper limit. All models were adjusted for age, gender, Charlson/Deyo co-morbidity index, primary payer, admission type, admission day, hospital region, hospital teaching status, and hospital bed size.

Table 6 Variation in utilization of atherectomy

c-index Variance ICC MOR

Model 1 0.838

Model 2 0.84

Model 3 0.83

1.07(0.93-1.22) 0.24(0.22-0.27) 2.67

1.05(0.90-1.19) 0.24(0.21-0.27) 2.65

0.96(0.82-1.12) 0.22(0.20-0.25) 2.55

Model 1- empty model. Model 2- age, gender, Charlson score, payment, admission type, and weekend admission. Model 3-Model 2 þ hospital region, hospital location/teaching, and hospital bedsize. ICC ¼ intraclass correlation coefficient; MOR ¼ means odds ratio.

Nonelective procedures (OR, 95% CI, p value; 1.90, 1.32 to 2.75, p 0.001 for mortality, 3.04, 2.61 to 3.53, <0.001 for amputation) also predicted worse primary outcomes. Atherectomy utilization (OR, 95% CI, p value) was independently predictive of lower in-hospital mortality (0.46, 0.28 to 0.75, 0.002), lower amputation rates (0.83, 0.71 to 0.97, 0.020), and lower secondary composite outcome of inhospital mortality and complications (OR 0.79, 95% CI 0.69 to 0.90, p 0.001). The best outcomes were seen when atherectomy was used as an adjunct to either angioplasty or stenting. Atherectomy when used alone was associated with worse outcomes (Figures 2 and 3) than either angioplasty or stenting alone. Atherectomy (OR, 95% CI, p value) use was also predictive of lower rates of amputation in various subgroups

(Table 5) including chronic limb ischemia (0.74, 0.59 to 0.93, 0.010), angioplasty (0.72, 0.60 to 0.87, 0.001), and those with a higher burden of baseline co-morbidities (0.82, 0.69 to 0.99, 0.035). There was a significant increase in hospitalization costs with the use of atherectomy (þ$1875, 95% CI þ 811 to þ2940, p 0.001). The significant predictors (OR, 95% CI, p value) of atherectomy utilization (Supplementary Table 4) included age (1.13, 1.08 to 1.18, <0.001) and higher CCI score 2 (1.22, 1.07 to 1.39, 0.004). Emergent/nonelective procedures had significantly lower utilization of atherectomy (OR 0.83, 95% CI 0.72 to 0.96, p 0.010). We observed approximately 24% between-hospital variation in the rates of atherectomy as depicted by the interclass correlation coefficient s across different models presented in Table 6. This variation was not affected by the patient or hospital characteristics. The median odds ratio (2.67 for the unadjusted model and 2.55 for the fully adjusted model) indicated that a randomly selected patient at any given hospital had nearly 2.5efold higher odds of undergoing atherectomy compared with another identical patient at a different random hospital in the sample. Discussion The lower extremity vessels secondary to a unique combination of pathophysiological stresses, physical vascular strain (torsion, lengthening, and rotation) along with metabolic risk factors are associated with a significant burden of calcified atherosclerotic disease. Diffuse disease with poor distal runoff, and the presence of chronic total occlusions further contribute to the complexity of infrainguinal disease. Heavily calcified lesions can be recalcitrant to angioplasty and/or stenting. Angioplasty alone runs the potential risk of arterial dissection or perforation in bulky calcified lesions especially when using high-pressure balloon inflations. Atherectomy offers plausible benefits by reducing the plaque volume14 before angioplasty and lesion preparation for stent placement. In a study by Aboufakher et al,15 the use of atherectomy was associated with 24% reduction in plaque volume and subsequent 64% luminal increase confirmed with atherectomy. Despite supportive data for the use of atherectomy devices, most of these studies have been limited because of their small sample sizes,16e18 lack of comparative arms16,19 or clinical end points, and restricted patient populations or lesion complexities.7,20 The lack of substantial study and/or definitive guidelines for the use of atherectomy was also suggested by a wide hospital-level variation noted in our study. This variation was random/independent of patient and hospital characteristics; thus, reflecting institutional preferences and perhaps calls for further study to clarify benefits of atherectomy in peripheral revascularization. Our study included a large sample size with a real-world, unrestricted patient population from the largest publicly available national database. Atherectomy was associated with lower rates of amputation, in-hospital mortality, and complications including vascular complications compared with propensity-matched subjects who did not receive atherectomy during peripheral revascularization. On multivariate analysis, we also noted atherectomy to be predictive

Miscellaneous/In-Hospital Outcomes of Peripheral Atherectomy

of superior primary and secondary outcomes when used as an adjunct to angioplasty (with or without stenting). Atherectomy alone was used in a very small minority of patients (2.3%) and was associated with worse primary and secondary outcomes in our study. Previous study in coronary vasculature has also indicated poor outcomes when atherectomy was used alone. The benefit of atherectomy is in improving acute procedural success (less dissection and bail out stenting by improving vessel compliance). This is primarily obtained by performing atherectomy with adjunctive balloon angioplasty or stenting as noted in our study. Importantly, the vascular complications requiring surgery were also lower in the atherectomy group both on propensity matching and multivariate analysis. The overall rate of vascular complications in our study was comparable to previous study on the use of atherectomy devices. In the recent DEFINITVE LE trial (Determination of Effectiveness of SilverHawk Peripheral Plaque Excision [SilverHawk Device] for the Treatment of Infrainguinal Vessels/Lower Extremities)21 evaluating directional atherectomy in infrainguinal lesions, vascular complications occurred in 11.3% of the patients comparable to 9.45% seen in the atherectomy group in our study. In an additional subgroup analysis, atherectomy was associated with significantly lower amputation and in-hospital mortality/complications in patients with higher CCI score and chronic limb ischemia with a nonsignificant trend toward better outcomes in other subgroups. Indeed, we also noted atherectomy to be used more often in patients more likely to have diffuse disease such as elderly and those with a higher burden of baseline coemorbidities. Atherectomy utilization was also associated with higher hospitalization costs. However, these initial costs must be weighed against potential benefits in terms of clinical outcomes. Long-term follow-up studies with riskadjusted cost analysis accounting for repeat hospitalizations, mortality, and revascularizations would shed more light on the costebenefit ratio of atherectomy. The limitations of analyzing a large administrative database include possibility of coding errors as well as undercoding of secondary and co-morbid diagnosis. We lacked detailed angiographic data (lesion complexity, the use of embolic protection devices, and so forth), long-term follow-up data and differentiation between the types of atherectomy device used, and so forth. The atherectomy devices have undergone technological advancements with newer devices like orbital atherectomy devices showing promise in recent trials.22 Our study primarily included atherectomy devices approved in or before 2012 (directional, rotational, and laser atherectomy devices). Moreover, the advent of newer drug eluting stents23 and DEB6 (both not evaluated in our study) has also provided excellent patency outcomes. Thus, newer atherectomy devices as well as their additive advantage beyond the use of newer stents and DEBs need to be evaluated in recent datasets and randomized studies. Nonetheless, our study included a realworld and large sample size with all lesion types and comprehensive analysis of various in-hospital outcomes for atherectomy in peripheral revascularization. The NIS data have been widely used before for such outcome analysis with a sound sampling design.24,25

683

Disclosures The authors have no conflicts of interest to disclose. Supplementary Data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j. amjcard.2015.11.025. 1. Adam DJ, Beard JD, Cleveland T, Bell J, Bradbury AW, Forbes JF, Fowkes FG, Gillepsie I, Ruckley CV, Raab G, Storkey H. Bypass versus angioplasty in severe ischaemia of the leg (BASIL): multicentre, randomised controlled trial. Lancet 2005;366:1925e1934. 2. Hirsch AT, Criqui MH, Treat-Jacobson D, Regensteiner JG, Creager MA, Olin JW, Krook SH, Hunninghake DB, Comerota AJ, Walsh ME, McDermott MM, Hiatt WR. Peripheral arterial disease detection, awareness, and treatment in primary care. JAMA 2001;286:1317e1324. 3. Hirsch AT, Hartman L, Town RJ, Virnig BA. National health care costs of peripheral arterial disease in the Medicare population. Vasc Med 2008;13:209e215. 4. Sussman M, Mallick R, Friedman M, Federico V, Josephs L, Vaitkus P, Menzin J. Failure of surgical and endovascular infrainguinal and iliac procedures in the management of peripheral arterial disease using data from electronic medical records. J Vasc Interv Radiol 2013;24: 378e391; 391 e1e3. 5. Abdulhannan P, Russell DA, Homer-Vanniasinkam S. Peripheral arterial disease: a literature review. Br Med Bull 2012;104:21e39. 6. Scheinert D, Duda S, Zeller T, Krankenberg H, Ricke J, Bosiers M, Tepe G, Naisbitt S, Rosenfield K. The LEVANT I (Lutonix paclitaxelcoated balloon for the prevention of femoropopliteal restenosis) trial for femoropopliteal revascularization: first-in-human randomized trial of low-dose drug-coated balloon versus uncoated balloon angioplasty. JACC Cardiovasc Interv 2014;7:10e19. 7. Quevedo HC, Arain SA, Ali G, Abi Rafeh N. A critical view of the peripheral atherectomy data in the treatment of infrainguinal arterial disease. J Invasive Cardiol 2014;26:22e29. 8. Singh T, Koul D, Szpunar S, Torey J, Dhabuwala J, Saigh L, Pires LA, Davis T. Tissue removal by ultrasound evaluation (the TRUE study): the Jetstream G2 system post-market peripheral vascular IVUS study. J Invasive Cardiol 2011;23:269e273. 9. Steiner C, Elixhauser A, Schnaier J. The healthcare cost and utilization project: an overview. Eff Clin Pract 2002;5:143e151. 10. McDonald KM, Romano PS, Geppert J, Davies SM, Duncan BW, Shojania KG, Hansen A. Measures of Patient Safety Based on Hospital Administrative Data - the Patient Safety Indicators. Rockville (MD): Agency for Healthcare Research and Quality (US); 2002. (Technical Reviews, No. 5.), Avalilable at: http://www.ncbi.nlm.nih.gov/books/NBK43854/. 11. Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol 1992;45:613e619. 12. Brunt ME, Egorova NN, Moskowitz AJ. Propensity score-matched analysis of open surgical and endovascular repair for type B aortic dissection. Int J Vasc Med 2011;2011:364046. 13. Safavi KC, Li SX, Dharmarajan K, Venkatesh AK, Strait KM, Lin H, Lowe TJ, Fazel R, Nallamothu BK, Krumholz HM. Hospital variation in the use of noninvasive cardiac imaging and its association with downstream testing, interventions, and outcomes. JAMA Intern Med 2014;176:546e553. 14. Franzone A, Ferrone M, Carotenuto G, Carbone A, Scudiero L, Serino F, Scudiero F, Izzo R, Piccolo R, Saviano S, Amato B, Perrino C, Trimarco B, Esposito G. The role of atherectomy in the treatment of lower extremity peripheral artery disease. BMC Surg 2012;12(Suppl 1):S13. 15. Aboufakher R, Torey J, Szpunar S, Davis T. Peripheral plaque volume changes pre- and post-rotational atherectomy followed by directional plaque excision: assessment by intravascular ultrasound and virtual histology. J Invasive Cardiol 2009;21:501e505. 16. Zeller T, Krankenberg H, Steinkamp H, Rastan A, Sixt S, Schmidt A, Sievert H, Minar E, Bosiers M, Peeters P, Balzer JO, Gray W, Tubler T, Wissgott C, Schwarzwalder U, Scheinert D. One-year outcome of percutaneous rotational atherectomy with aspiration in infrainguinal peripheral arterial occlusive disease: the multicenter pathway PVD trial. J Endovasc Ther 2009;16:653e662.

684

The American Journal of Cardiology (www.ajconline.org)

17. Zeller T, Rastan A, Sixt S, Schwarzwalder U, Schwarz T, Frank U, Burgelin K, Muller C, Rothenpieler U, Flugel PC, Tepe G, Neumann FJ. Long-term results after directional atherectomy of femoro-popliteal lesions. J Am Coll Cardiol 2006;48:1573e1578. 18. Laird JR, Zeller T, Gray BH, Scheinert D, Vranic M, Reiser C, Biamino G; Investigators L. Limb salvage following laser-assisted angioplasty for critical limb ischemia: results of the LACI multicenter trial. J Endovasc Ther 2006;13:1e11. 19. Dave RM, Patlola R, Kollmeyer K, Bunch F, Weinstock BS, Dippel E, Jaff MR, Popma J, Weissman N; CELLO Investigators. Excimer laser recanalization of femoropopliteal lesions and 1-year patency: results of the CELLO registry. J Endovasc Ther 2009;16:665e675. 20. Zeller T, Sixt S, Schwarzwalder U, Schwarz T, Frank U, Burgelin K, Pochert V, Muller C, Noory E, Krankenberg H, Hauswald K, Neumann FJ, Rastan A. Two-year results after directional atherectomy of infrapopliteal arteries with the SilverHawk device. J Endovasc Ther 2007;14:232e240. 21. McKinsey JF, Zeller T, Rocha-Singh KJ, Jaff MR, Garcia LA; DEFINITIVE LE Investigators. Lower extremity revascularization using directional atherectomy: 12-month prospective results of the DEFINITIVE LE study. JACC Cardiovasc Interv 2014;7:923e933. 22. Safian RD, Niazi K, Runyon JP, Dulas D, Weinstock B, Ramaiah V, Heuser R; OASIS Investigators. Orbital atherectomy for infrapopliteal

disease: device concept and outcome data for the OASIS trial. Catheter Cardiovasc Interv 2009;73:406e412. 23. Dake MD, Ansel GM, Jaff MR, Ohki T, Saxon RR, Smouse HB, Snyder SA, O’Leary EE, Tepe G, Scheinert D, Zeller T. Sustained safety and effectiveness of paclitaxel-eluting stents for femoropopliteal lesions: 2-year follow-up from the Zilver PTX randomized and single-arm clinical studies. J Am Coll Cardiol 2013;61: 2417e2427. 24. Panaich SS, Badheka AO, Chothani A, Mehta K, Patel NJ, Deshmukh A, Singh V, Savani GT, Arora S, Patel N, Bhalara V, Grover P, Shah N, Elder M, Mohamad T, Kaki A, Kondur A, Brown M, Grines C, Schreiber T. Results of ventricular septal myectomy and hypertrophic cardiomyopathy (from Nationwide Inpatient Sample [1998-2010]). Am J Cardiol 2014;114: 1390e1395. 25. Badheka AO, Patel NJ, Grover P, Singh V, Patel N, Arora S, Chothani A, Mehta K, Deshmukh A, Savani GT, Patel A, Panaich SS, Shah N, Rathod A, Brown M, Mohamad T, Tamburrino FV, Kar S, Makkar R, O’Neill WW, De Marchena E, Schreiber T, Grines CL, Rihal CS, Cohen MG. Impact of annual operator and institutional volume on percutaneous coronary intervention outcomes: a 5-year United States experience (2005-2009). Circulation 2014;130:1392e1406.