- Email: [email protected]
Cost, Outcome, and Functional Status in Octogenarians and Septuagenarians after Cardiac Surgery
Cost, Outcome, and Functional Status in Octogenarians and Septuagenarians After Cardiac Surgery* Milo Engoren, MD, FCCP; Cynthia Arslanian-Engoren, PhD, RN, CNS; Donna Steckel, BSN, RN; Julie Neihardt, BSN, RN; and Nancy Fenn-Buderer, MS
Study objectives: To evaluate cost, outcome, and functional status of octogenarians and septuagenarians after cardiac surgery. Design: Observational case control study. Retrospective analysis of hospital cost and outcome. Prospective analysis of functional status at 1 to 2 years. Patients: One hundred three consecutive octogenarians and 103 randomly selected septuagenarians who underwent cardiac surgery. Setting: A university-affiliated tertiary care center. Measurements and results: Compared to septuagenarians, octogenarians were more likely to be widowed (p < 0.001) and to have had preoperative strokes (p < 0.05) but were less likely to have diabetes mellitus (p < 0.001). They were less likely to have undergone mitral valve surgery (p < 0.01) but were more likely to have undergone coronary artery bypass graft surgery without cardiopulmonary bypass (p < 0.001). The hospital mortality rate was 6% in the younger group and 9% in the older group (odds ratio, 1.5; 95% confidence interval [CI], 0.5 to 4.5; p > 0.05). In patients undergoing isolated CABG, the mortality rate was 1.4% in the septuagenarians and 8.2% in the octogenarians (odds ratio, 6.2; 95% CI, 0.7 to 52.7; p ⴝ 0.12). Despite similar ICU, postoperative, and total lengths of stay, the median hospital direct variable cost was 35% higher for the octogenarians. At late follow-up, octogenarians had lower levels of physical functioning and general health but otherwise had levels of function that were similar to those of septuagenarians. Conclusion: Cardiac surgery can be performed in the elderly with good hospital and late functional results, but at a higher hospital cost than that for younger patients. (CHEST 2002; 122:1309 –1315) Key words: cardiac surgery; coronary artery bypass grafting; direct variable cost; functional outcome; octogenarians; septuagenarians; survival Abbreviations: CABG ⫽ coronary artery bypass graft; CI ⫽ confidence interval; CVA ⫽ cerebrovascular accident; CVICU ⫽ cardiovascular ICU; ECF ⫽ extended care facility; RR ⫽ relative risk; SF-36 ⫽ 36-item short form; TCU ⫽ transitional care unit
population is the fastest growing part T heof elderly the US population, with an estimated 10
million persons aged ⱖ 80 years. Other westernized countries, including Japan, also have large and increasing elderly segments of their populations. Forty percent of these elderly persons have symptomatic
*From the Departments of Anesthesiology (Dr. Engoren), Cardiovascular Nursing (Ms. Steckel and Ms. Neihardt), and Research (Ms. Fenn-Buderer), St. Vincent Mercy Medical Center, Toledo, OH; and the Division of Acute, Critical, and Long-Term Care (Dr. Arslanian-Engoren), School of Nursing, University of Michigan, Ann Arbor, MI. Received September 28, 2001; revision accepted April 23, 2002. Correspondence to: Milo Engoren, MD, FCCP, Department of Anesthesiology, St. Vincent Mercy Medical Center, 2213 Cherry St, Toledo, OH 43608; e-mail: [email protected] www.chestjournal.org
cardiac disease.1,2 Surgery, a well-accepted means of increasing survival and improving quality of life in patients ⬍ 70 years of age, is becoming more common in septuagenarians and even octogenarians. However, perceptions by elderly patients, their families, and their physicians that they may have lower functional reserve and more comorbidities than younger patients, which are more likely to lead to complications or death, may make cardiologists and cardiac surgeons hesitant to offer elderly patients life-saving or symptom-resolving cardiac surgery. Yet, few studies exist to show the benefits, risks, and costs of cardiac surgery in octogenarians. Previous studies3– 6 have had small populations, are from the 1980s (improvements in perioperative techniques CHEST / 122 / 4 / OCTOBER, 2002
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and care may make these results obsolete), or have not evaluated functional outcomes and costs in the same population. Therefore, the purpose of this study was twofold, as follows: (1) to determine hospital outcomes and costs; and (2) to measure functional outcomes at 1 to 2 years in octogenarians compared to septuagenarians following cardiac surgery.
Materials and Methods This study was approved by the institutional review board of a university-affiliated, tertiary care medical center. The hospital’s computerized medical information system was queried for all patients 70 to 89 years of age who had undergone cardiac surgery between January 1, 1998, and December 31, 1999. All patients who were 80 to 89 years old (cases) and an equal number of randomly selected patients who were 70 to 79 years old (control subjects) from the same time period had their charts reviewed by a single examiner. Because we wanted to see whether premorbid conditions varied between the two groups, we used randomly selected control subjects rather than matching control subjects for any particular characteristic. Charts were reviewed for the following: patient sex; marital status (ie, married, widowed, divorced, or single); comorbidities (ie, hypertension, stroke, cerebrovascular accident [CVA], myocardial infarction, diabetes mellitus, and COPD); use of antidepressant, antipsychotic, or anxiolytic medications (ie, CNS drug use); year of surgery (1998 or 1999); whether cardiac catheterization was performed during the same hospital admission as was the cardiac surgery; type of cardiac surgery (ie, coronary artery bypass grafts [CABGs], aortic valve repair or replacement, mitral valve repair or replacement, carotid artery endarterectomy performed simultaneously with the cardiac surgery, or other surgery, such as ascending aortic aneurysmectomy, left ventricular aneurysmectomy, tricuspid valve repair, and femoral artery aneurysmectomy, performed simultaneously with the primary cardiac surgery; use of cardiopulmonary bypass; transfusion; re-exploration for bleeding; the development of a new focal central neurologic event (ie, CVA); the development of a new global neurologic deficit not related to anesthesia or medicines that lasted ⬎ 24 h (encephalopathy); preoperative and peak postoperative serum creatinine levels; the development of renal dysfunction (defined as a creatinine level of ⱖ 2.0 mg/dL if the preoperative creatinine level was normal, or a rise in the creatinine level of ⱖ 1.0 mg/dL if the preoperative creatinine level was ⱖ 1.5 mg/dL); hemodialysis; prolonged mechanical ventilation (defined as a requirement for mechanical ventilation beyond 7 am the day after surgery; atrial fibrillation; hospital outcome; and discharge to home, extended care facility (ECF), transitional care unit (TCU), rehabilitation hospital, or other location. Direct variable cost was obtained from the hospital’s accounting department. All billed items and their associated costs were assigned to 1 of the following 14 cost categories: preop (all costs incurred before the morning of surgery); anesthesia (costs of anesthetics, equipment, and disposables used by the anesthesiologist); perfusion (costs of cardiopulmonary bypass equipment, cardioplegia, and disposables used by the perfusionist); surgery (all other costs related to the use of the operating room, surgical equipment, and disposables used by the surgeon); cardiovascular ICU (CVICU) [costs related to nursing, equipment, and room in the cardiovascular ICU]; postop room (costs related to nursing, equipment, and room on the stepdown unit); respiratory (costs related to respiratory equipment, treatments, and therapist time); laboratory, blood bank (blood typing and transfusions); Ekg & 1310
vasc lab (electrocardiograms and noninvasive vascular studies); radiology, pharmacy, therapies (physical, occupational, and speech therapy); and supplies. Death was determined from the Social Security Death Index, obituaries in The Toledo Blade, and hospital records. Three trained registered nurses attempted to contact all survivors. If the survivor gave oral informed consent, the 36-item short form (SF-36) questionnaire7 was administered during the same telephone conversation. Statistical Analysis In addition to analyzing all patients who had undergone cardiac surgery, patients who had undergone only CABG surgery (ie, CABG-only group) were compared. Univariate comparisons between groups were made using 2 tests for categoric characteristics or Mann-Whitney-Wilcoxon tests for continuous characteristics. Linear regression analysis using forward, backward, and stepwise selection was used to explain the variability in direct variable cost.
Results One hundred three patients in each group underwent cardiac surgery and were studied (Table 1). Octogenarians were more likely to be widowed (p ⱕ 0.001), while septuagenarians were more likely to be married (p ⬍ 0.01). Octogenarians were more likely to have had preoperative strokes (p ⫽ 0.05) but were less likely to have diabetes mellitus (p ⬍ 0.001). Other comorbidities were distributed similarly. Octogenarians were less likely to have undergone mitral valve surgery (p ⫽ 0.01) but were more likely to have their CABGs performed without cardiopulmonary bypass (p ⬍ 0.001). Postoperative complications were similar between the two groups (Table 2). The hospital mortality rate was 5.8% in the younger group and 8.7% in the older group (relative risk [RR], 1.5; 95% confidence interval [CI], 0.5 to 4.5; p ⬎ 0.05). Of the nine octogenarians who died, two died of cardiac failure on the day of surgery. Four of the remaining seven octogenarians required re-exploration surgery for bleeding, one had a CVA, two had encephalopathy, and six had sufficient renal dysfunction to undergo dialysis. Of the six septuagenarians who died, one died of heart failure on the first postoperative day. Two of the remaining five septuagenarians required re-exploration surgery for bleeding, three had encephalopathy, and four required hemodialysis. In patients undergoing isolated CABGs, the mortality rate was 1.4% among septuagenarians and 8.2% among octogenarians (RR, 6.2; 95% CI, 0.7 to 52.7; p ⫽ 0.12). Older patients were less likely to be discharged from the hospital directly to home (RR, 0.3; 95% CI, 0.17 to 0.6; p ⱕ 0.01) and were more likely to be discharged to a TCU or ECF (RR, 3.0; 95% CI, 1.7 to 5.6; p ⱕ 0.01). Despite similar ICU, postoperative, and total lengths of stays, Clinical Investigations
Table 1—Preoperative and Intraoperative Characteristics* Septuagenarians Characteristics Male sex Marital status Married Widowed Divorced Single Hypertension Preoperative CVA Preoperative MI Diabetes mellitus COPD CNS drug use Renal dysfunction Year of surgery, 1998 Cardiac catheter Reoperation CABG AVR MVR CEA Other# Off-pump Creatinine,** mg/dL Hemoglobin,** g/dL
Octogenarians
No. (n ⫽ 103)
% (n ⫽ 100)
64
62
71†‡ 20§㛳 5 7 84 11¶ 55 39§ 15 19 13 64 70 5 93 9 15† 10 4 3§ 1.1 13.4
69†‡ 19§㛳 5 7 82 11¶ 53 38§ 15 18 13 62 68 5 90 9 15† 10 4 3§ (0.9–1.3) (11.7–14.4)
No. (n ⫽ 103)
% (n ⫽ 100)
53 49†‡ 43§㛳 3 8 79 21¶ 45 17§ 14 18 10 51 70 5 95 16 4† 7 6 18§ 1.1 13.3
51 48†‡ 42§㛳 3 8 77 20¶ 44 17§ 14 17 10 50 68 5 92 16 4† 7 6 18§ (0.9–1.3) (11.6–14.0)
*MI ⫽ myocardial infarction; CNS drug use ⫽ use of antidepressants, antipsychotics, or anxiolytics preoperatively; AVR ⫽ aortic valve replacement or repair; MVR ⫽ mitral valve replacement or repair; CEA ⫽ carotid artery endarterectomy. †p ⱕ 0.01. ‡Married vs all other marital statuses. §p ⱕ 0.001. 㛳Widowed vs all other marital statuses. ¶p ⱕ 0.05. #Septuagenarians: three ascending aortic aneursymectomies and one left ventricular aneursymectomy; octogenarians: four ascending aortic aneursymectomies, one tricuspid valve repair, and one femoral artery aneursymectomy. **Values given as median (interquartile range).
the median hospital cost was 35% higher for the octogenarians (Table 3). By linear regression, higher cost was associated with being an octogenarian, having re-exploration surgery for bleeding, and longer hospital length of stay. Having the surgery performed without cardiopulmonary bypass was associated with a lower cost (Table 4). Survival was similar both in the all-patient groups and the CABG-only groups. The 1-year survival rate among the all-patient septuagenarians was 83% (95% CI, 76 to 91%) compared to 85% (95% CI, 79 to 92%) among octogenarians. The 2-year survival rates were 82% (95% CI, 75 to 90%) and 84% (95% CI, 77 to 91%), respectively (Fig 1, top) No patient in the CABG-only groups died between 1 and 2 years after surgery, giving 1-year and 2-year survival rates of 90% (95% CI, 83 to 97%) in septuagenarians and 88% (95% CI, 80 to 95%) in octogenarians (Fig 1, bottom). At the follow-up of the 97 septuagenarians who www.chestjournal.org
survived hospitalization, 66 completed the interview, 13 were dead, 9 refused the interview, 5 were lost to follow-up, 3 were in ECFs, and 1 was hospitalized. The octogenarians had similar outcomes and participation. Of the 94 who survived hospitalization, 59 completed the interview, 7 were dead, 9 refused the interview, 18 were lost to follow-up, and 1 was in an ECF. The 45 living patients who did not participate in the interview or were lost to follow-up were slightly older (median, 81 years of age [interquartile range, 76 to 83 years] vs 79 years of age [interquartile range, 74 to 81 years], respectively; p ⫽ 0.02), had higher preoperative creatinine levels (median, 1.2 mg/dL [interquartile range, 1.0 to 1.3 mg/dL] vs 1.0 mg/dL [interquartile range, 0.9 to 1.2 mg/dL], respectively; p ⫽ 0.01), were more likely to have undergone aortic valve surgery (median, 21% vs 7%, respectively; p ⫽ 0.01), were more likely to develop atrial fibrillation (median, 49% vs 32%; CHEST / 122 / 4 / OCTOBER, 2002
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Table 2—Complications and Discharge Location* Septuagenarians Variables Transfusion Reexploration New CVA Encephalopathy Renal dysfunction Prolonged ventilation Dialysis Atrial fibrillation Died Discharged to Home ECF TCU Rehabilitation hospital Other Died Peak creatinine, mg/dL
No. 64 5 5 17 25 18 10 36 6 48† 10 30 5 4 6 1.3
% 62 5 5 17 25 18 10 36 6 47† 10 29 5 4 6 (1.0–2.0)
Table 4 —Predictors of Cost*
Octogenarians No. 75 8 4 19 18 19 7 41 9 22† 24 40 7 1 9 1.2
Predictors Constant Hospital LOS Re-exploration Octogenarian Off-pump
% 73 8 4 19 18 19 7 41 9
Coefficient $⫺5,403 $896 $21,865 $7,282 $⫺9,585
95% CI
p Value
$⫺13,356–$2,549 $744–$1,048 $11,682–$32,049 $2,340–$12,224 $⫺17,715–$1,455
⬍ 0.001 ⬍ 0.001 0.004 0.021
*Coefficient ⫽ the amount that the occurrence of each categoric variable (ie, re-exploration, octogenarian, off-pump) increases direct variable cost.
21† 23 39 7 1 9 (0.9–1.6)
*New CVA ⫽ intraoperative or postoperative stroke. †p ⱕ 0.01 (discharge to home vs all other locations).
p ⫽ 0.04), had spent a longer time in the hospital (median, 10 days [interquartile range, 7 to 18 days] vs 7 days [interquartile range, 6 to 11 days], respectively; p ⬍ 0.01), and had higher hospital costs (median, $12,853 [interquartile range, $7,954 to $22,262] vs $9,412 [interquartile range, $6,404 to 14,638]; p ⫽ 0.02) than the 125 who were interviewed. The interviews showed that both groups had excellent social functioning and role-emotional outcomes (Table 5). The values for the other SF-36
scales were similar between the two groups except that the octogenarians had lower levels of physical functioning and general health. Discussion Despite a higher prevalence of preoperative stroke, which is a risk factor for hospital mortality after cardiac surgery, we found that octogenarians underwent cardiac surgery with hospital survival rates and complication rates that were similar to those of septuagenarians but at a higher hospital cost. Our hospital mortality rate (8.2% in octogenarians) is similar to or lower (5.6 to 24.3%) than those found in other studies evaluating CABG.6,8 Using Medicare data, Peterson et al9 found a hospital mortality rate of 11.5% in 24,461 patients aged ⱖ 80 years and had undergone isolated CABG surgery between 1987 and 1990. The 1-year mortality rate for those patients was 19%, compared to 12% in this study. Our lower rate may be due to differences in patient
Table 3—Lengths of Stay and Direct Variable Costs* Variables
Septuagenarians
Octogenarians
CVICU LOS, d Postoperative LOS, d Total LOS, d Total costs, $ Pre-operative Anesthesia Perfusion Surgery CVICU Postoperative room Respiratory Laboratory Blood bank ECG & vascular laboratory Radiology Pharmacy Therapies Supplies
1 (1–3) 6 (5–10) 8 (6–13) 9,383 (6,321–16,992)† 641 (410–1,284) 279 (217–532) 1,772 (1,216–2,540) 2,299 (1,773–3,780) 816 (433–1,867) 655 (1,094–2,212) 67 (30–196) 217 (111–442) 102 (34–254) 29 (67–120) 37 (11–134) 592 (343–1,226) 236 (106–439) 70 (39–149)
1 (1–3) 6 (5–9) 9 (6–13) 12,624 (7,836–22,124)† 743 (511–1,710) 356 (250–542) 2,224 (1,461–2,710) 3,041 (1,984–3,787) 1,154 (481–2,858) 761 (1,492–2,676) 146 (32–263) 258 (107–633) 91 (32–457) 31 (77–138) 90 (26–426) 702 (450–1,723) 221 (139–523) 95 (36–231)
*Values given as median (interquartile range). All p values are ⬎ 0.05 unless indicated. LOS ⫽ length of stay. †p ⱕ 0.01. 1312
Clinical Investigations
Figure 1. Top: Kaplan-Meier plots of 2-year survival rates from the time of surgery for septuagenarians (– – –) and octogenarians (——) after all cardiac surgeries. Bottom: Kaplan-Meier plots of 2-year survival rates from the time of surgery for septuagenarians (– – –) and octogenarians (——) after CABG-only surgery.
selection or to improvements in operative techniques and perioperative care over the last decade. Many factors have been found to be associated with increased mortality among the octogenarians,
particularly emergency surgery, complexity of the surgery, and the presence of comorbidities.5,10,11 Whether due to different criteria for patient selection or to improvements in stabilization in the catheterization laboratory, we, unlike Avery et al,5 had few emergency patients with severe hemodynamic instability. Where Glower et al11 noted an in-hospital mortality rate of 23% in octogenarian patients with any comorbidities, compared to 7% in patients without any comorbidities, we found that almost all of our octogenarian patients (92.2%) had at least one comorbidity. However, this high rate of comorbidities is similar to those cited in other studies.3,5 We found that the older group was more likely to have had their CABG surgery performed without cardiopulmonary bypass (ie, off-pump surgery). While firm data are lacking, off-pump surgery is felt to cause less postoperative neurologic and renal dysfunction.12 This may have contributed to the similar rates of cerebral and renal dysfunction in our two groups. The occurrence of complications predicted a worse outcome, with dialysis being a prominent marker of hospital death. The survival rate among patients initiating dialysis was 30% among octogenarians and 57% among septuagenarians (p ⬎ 0.05). This finding is similar to patients in a general ICU. Octogenarians initiating hemodialysis in the ICU had a survival rate (33.3%) that was similar to that of nonoctogenarians (36.4%).13 Peterson et al9 attributed the 20% higher cost for octogenarian patients to their longer average length of hospital stay (3.9 days). Avery et al5 noted an average 26.8% higher cost for their octogenarian patients, which was explained on the basis of a 37% longer average hospital length of stay and a higher intensity of illness. In contrast, our study found identical median ICU and postoperative lengths of stays and similar total lengths of stays between the younger and older groups. Despite this, the median
Table 5—Functional Outcome* Septuagenarians
Octogenarians
Variables
No.
Median (IQ Range)
Mean ⫾ SD
No.
Median (IQ Range)
Mean ⫾ SD
Physical functioning Role-physical Bodily pain General health Vitality Social functioning Role-emotional Mental health
66 66 66 66 66 66 65 66
75 (35–90)† 75 (25–100) 72 (61–100) 72 (50–84)‡ 50 (35–75) 100 (75–100) 100 (67–100) 72 (60–80)
67 ⫾ 31 64 ⫾ 38 72 ⫾ 25 67 ⫾ 25 54 ⫾ 25 83 ⫾ 23 86 ⫾ 27 68 ⫾ 12
59 58 58 58 58 58 58 58
55 (28–80)† 50 (25–75) 73 (51–100) 64 (40–77)‡ 50 (25–70) 100 (75–100) 100 (67–100) 72 (64–80)
54 ⫾ 30 53 ⫾ 36 69 ⫾ 29 58 ⫾ 24 47 ⫾ 29 82 ⫾ 26 79 ⫾ 36 69 ⫾ 17
*The No. of patients varies slightly because not all patients answered every question. †p ⱕ 0.01. ‡p ⱕ 0.05. www.chestjournal.org
CHEST / 122 / 4 / OCTOBER, 2002
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costs were 35% higher in the older group. While costs were hundreds of dollars higher in the octogenarian group for the high-cost categories of surgery, perfusion, and CVICU stay, these did not reach statistical significance, probably because of inadequate power to detect subgroup differences. Previous studies have found mean postoperative lengths of stays of 10 to 16 days5,9,11,14 and mean total hospital lengths of stays of 22 days3 for elderly patients, which are considerably longer than the median postoperative length of stay of 6 days and the total hospital length of stay of 9 days in this study. This probably relates to our fast-track cardiac program,15 the availability of a TCU contiguous to the hospital, and nearby ECFs. Only 21% of our octogenarians were discharged to home, which is significantly less than the rate for the septuagenarians (47%). The higher rate of octogenarians being discharged to places other than home was partially due to octogenarians being less likely to be married. But, even comparing married octogenarians to married septuagenarians, married octogenarians were still less likely to be discharged to home (33% vs 51%, respectively; p ⬍ 0.05). Further evaluation is needed to determine whether this is related to spousal disability or other reasons. It was also significantly less than the 64% reported elsewhere.3 A higher rate of admission to the TCU or ECFs may be the tradeoff for a short hospital length of stay. We found that other than octogenarians having lower levels of physical functioning and general health, octogenarians and septuagenarians had similar functional outcomes. The octogenarians in our study had similar scores or trends to better scores than the general population that was ⱖ 75 years old,7 but they had lower scores than Canadian octogenarians after cardiac surgery.3 Fruitman et al3 administered the SF-36 to 99 of 103 octogenarian survivors at 15.7 ⫾ 6.9 months after their cardiac surgery in Halifax, NS, Canada. They found consistently higher scores for five of the eight scales than we found (p ⬍ 0.01 for Role-Physical, Bodily Pain, General Health Perceptions, and Mental Health; p ⬍ 0.05 for Vitality; and p ⬎ 0.05 for Physical Functioning, Social Functioning, and Role-Emotional). Whether this is due to different patient characteristics, different versions of the SF-36, or differences in the social services, medical care, and prescription drug benefits between Canada and the United States cannot be determined. A limitation of this study is that it was conducted at only one institution. Other hospitals may have different experiences. A multicenter study might also provide sufficient statistical power to detect a difference in mortality. However, the population is similar in size to those in most other studies evaluating cardiac surgery in the elderly.3,14,16 –19 Given the 1314
hospital mortality rates that we found (septuagenarians, 5.8%; octogenarians, 8.7%), it would take approximately 1,250 patients in each group to find a statistically significant difference, with a type I error of 0.05% and 80% power. The moderate number of patients studied also precludes us from developing a risk model for predicting death, complications, cost, or functional outcome. Another limitation is that one fourth of the survivors did not consent to be interviewed or could not be located. Given that these 46 patients were slightly older, were more likely to have renal dysfunction, were more likely to have undergone aortic valve surgery, were more likely to develop atrial fibrillation, and were more likely to cost more, they may not have as good functional outcomes as those who participated in the interview.
Conclusion We found that cardiac surgery can be performed in the elderly with good hospital and late functional results, but at higher hospital costs than those for younger patients.
References 1 National Center for Health Statistics. National Health Survey 1983–1985. Atlanta, GA: Centers for Disease Control and Prevention, 1986 2 Preˆtre R, Turina MI. Cardiac valve surgery in the octogenarian. Heart 2000; 83:116 –121 3 Fruitman DS, MacDougall CE, Ross DB. Cardiac surgery in octogenarians: can elderly patients benefit? Quality of life after cardiac surgery. Ann Thorac Surg 1999; 68:2129 –2135 4 Schmitz C, Welz A, Reichart B. Is cardiac surgery justified in patients in the ninth decade of life? J Card Surg 1998; 13:113–119 5 Avery GJ, Ley SJ, Hill JD, et al. Cardiac surgery in the octogenarian: evaluation of risk, cost, and outcome. Ann Thorac Surg 2001; 79:591–596 6 Mick MJ, Simpfendorfer C, Arnold AZ, et al. Early and late results of coronary angioplasty and bypass in octogenarians. Am J Cardiol 1991; 68:1316 –1320 7 Ware JE Jr, Snow KK, Kosinski M, et al. SF-36 health survey manual, and interpretation guide. Lincoln, RI: Quality Metric, 1997 8 Edmunds LH, Stephenson LW, Edie RN, et al. Open heart surgery in octogenarians. N Engl J Med. 1988; 319:131–136 9 Peterson ED, Cowper PA, Jollis JG, et al. Outcomes of coronary artery bypass graft surgery in 24,461 patients aged 80 years or older. Circulation 1995; 92(suppl):II85–II91 10 Craver JM, Puskas JD, Weintraub WW, et al. 601 octogenarians undergoing cardiac surgery: outcome and comparison with younger age groups. Ann Thorac Surg 1999; 67:1104–1110 11 Glower DD, Christopher TD, Milano CA, et al. Performance status and outcome after coronary artery bypass grafting in persons aged 80 –93 years. Am J Cardiol 1992; 70:567–571 12 Plomondon ME, Cleveland JC Jr, Ludwig ST, et al. Off-pump coronary artery bypass is associated with improved riskClinical Investigations
adjusted outcomes. Ann Thorac Surg 2001; 72:114 –119 13 Baldyga AP, Paganini EP, Chaff C, et al. Acute dialytic support of the octogenarian: is it worth it? ASAIO J 1993; 39:M805–M808 14 Freeman WK, Schaff HV, O’Brien PC, et al. Cardiac surgery in the octogenarian: perioperative outcome and clinical follow-up. J Am Coll Cardiol 1991; 18:29 –35 15 Engoren M, Kraras C, Garzia F. Propofol based v fentanylisoflurane based anesthesia for cardiac surgery. J Cardiothorac Vasc Anesth 1998; 12:177–181 16 Utley JR, Leyland SA. Coronary artery bypass grafting in the
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octogenarian. Thorac Cardiovasc Surg 1991; 101:866 – 870 17 Ko W, Gold JP, Lazzaro R, et al. Survival analysis of octogenarian patients with coronary artery disease managed by elective coronary artery bypass surgery vs conventional medical treatment. Circulation 1992; 86(suppl): II191–II197 18 Sollano JA, Rose EA, Williams DL, et al. Cost-effectiveness of coronary artery bypass surgery in octogenarians. Ann Surg 1998; 228:297–306 19 Kumar P, Zehr KJ, Chang A, et al. Quality of life in octogenarians after open heart surgery. Chest 1995; 108:919–926
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Study objectives: To evaluate cost, outcome, and functional status of octogenarians and septuagenarians after cardiac surgery. Design: Observational case control study. Retrospective analysis of hospital cost and outcome. Prospective analysis of functional status at 1 to 2 years. Patients: One hundred three consecutive octogenarians and 103 randomly selected septuagenarians who underwent cardiac surgery. Setting: A university-affiliated tertiary care center. Measurements and results: Compared to septuagenarians, octogenarians were more likely to be widowed (p < 0.001) and to have had preoperative strokes (p < 0.05) but were less likely to have diabetes mellitus (p < 0.001). They were less likely to have undergone mitral valve surgery (p < 0.01) but were more likely to have undergone coronary artery bypass graft surgery without cardiopulmonary bypass (p < 0.001). The hospital mortality rate was 6% in the younger group and 9% in the older group (odds ratio, 1.5; 95% confidence interval [CI], 0.5 to 4.5; p > 0.05). In patients undergoing isolated CABG, the mortality rate was 1.4% in the septuagenarians and 8.2% in the octogenarians (odds ratio, 6.2; 95% CI, 0.7 to 52.7; p ⴝ 0.12). Despite similar ICU, postoperative, and total lengths of stay, the median hospital direct variable cost was 35% higher for the octogenarians. At late follow-up, octogenarians had lower levels of physical functioning and general health but otherwise had levels of function that were similar to those of septuagenarians. Conclusion: Cardiac surgery can be performed in the elderly with good hospital and late functional results, but at a higher hospital cost than that for younger patients. (CHEST 2002; 122:1309 –1315) Key words: cardiac surgery; coronary artery bypass grafting; direct variable cost; functional outcome; octogenarians; septuagenarians; survival Abbreviations: CABG ⫽ coronary artery bypass graft; CI ⫽ confidence interval; CVA ⫽ cerebrovascular accident; CVICU ⫽ cardiovascular ICU; ECF ⫽ extended care facility; RR ⫽ relative risk; SF-36 ⫽ 36-item short form; TCU ⫽ transitional care unit
population is the fastest growing part T heof elderly the US population, with an estimated 10
million persons aged ⱖ 80 years. Other westernized countries, including Japan, also have large and increasing elderly segments of their populations. Forty percent of these elderly persons have symptomatic
*From the Departments of Anesthesiology (Dr. Engoren), Cardiovascular Nursing (Ms. Steckel and Ms. Neihardt), and Research (Ms. Fenn-Buderer), St. Vincent Mercy Medical Center, Toledo, OH; and the Division of Acute, Critical, and Long-Term Care (Dr. Arslanian-Engoren), School of Nursing, University of Michigan, Ann Arbor, MI. Received September 28, 2001; revision accepted April 23, 2002. Correspondence to: Milo Engoren, MD, FCCP, Department of Anesthesiology, St. Vincent Mercy Medical Center, 2213 Cherry St, Toledo, OH 43608; e-mail: [email protected] www.chestjournal.org
cardiac disease.1,2 Surgery, a well-accepted means of increasing survival and improving quality of life in patients ⬍ 70 years of age, is becoming more common in septuagenarians and even octogenarians. However, perceptions by elderly patients, their families, and their physicians that they may have lower functional reserve and more comorbidities than younger patients, which are more likely to lead to complications or death, may make cardiologists and cardiac surgeons hesitant to offer elderly patients life-saving or symptom-resolving cardiac surgery. Yet, few studies exist to show the benefits, risks, and costs of cardiac surgery in octogenarians. Previous studies3– 6 have had small populations, are from the 1980s (improvements in perioperative techniques CHEST / 122 / 4 / OCTOBER, 2002
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and care may make these results obsolete), or have not evaluated functional outcomes and costs in the same population. Therefore, the purpose of this study was twofold, as follows: (1) to determine hospital outcomes and costs; and (2) to measure functional outcomes at 1 to 2 years in octogenarians compared to septuagenarians following cardiac surgery.
Materials and Methods This study was approved by the institutional review board of a university-affiliated, tertiary care medical center. The hospital’s computerized medical information system was queried for all patients 70 to 89 years of age who had undergone cardiac surgery between January 1, 1998, and December 31, 1999. All patients who were 80 to 89 years old (cases) and an equal number of randomly selected patients who were 70 to 79 years old (control subjects) from the same time period had their charts reviewed by a single examiner. Because we wanted to see whether premorbid conditions varied between the two groups, we used randomly selected control subjects rather than matching control subjects for any particular characteristic. Charts were reviewed for the following: patient sex; marital status (ie, married, widowed, divorced, or single); comorbidities (ie, hypertension, stroke, cerebrovascular accident [CVA], myocardial infarction, diabetes mellitus, and COPD); use of antidepressant, antipsychotic, or anxiolytic medications (ie, CNS drug use); year of surgery (1998 or 1999); whether cardiac catheterization was performed during the same hospital admission as was the cardiac surgery; type of cardiac surgery (ie, coronary artery bypass grafts [CABGs], aortic valve repair or replacement, mitral valve repair or replacement, carotid artery endarterectomy performed simultaneously with the cardiac surgery, or other surgery, such as ascending aortic aneurysmectomy, left ventricular aneurysmectomy, tricuspid valve repair, and femoral artery aneurysmectomy, performed simultaneously with the primary cardiac surgery; use of cardiopulmonary bypass; transfusion; re-exploration for bleeding; the development of a new focal central neurologic event (ie, CVA); the development of a new global neurologic deficit not related to anesthesia or medicines that lasted ⬎ 24 h (encephalopathy); preoperative and peak postoperative serum creatinine levels; the development of renal dysfunction (defined as a creatinine level of ⱖ 2.0 mg/dL if the preoperative creatinine level was normal, or a rise in the creatinine level of ⱖ 1.0 mg/dL if the preoperative creatinine level was ⱖ 1.5 mg/dL); hemodialysis; prolonged mechanical ventilation (defined as a requirement for mechanical ventilation beyond 7 am the day after surgery; atrial fibrillation; hospital outcome; and discharge to home, extended care facility (ECF), transitional care unit (TCU), rehabilitation hospital, or other location. Direct variable cost was obtained from the hospital’s accounting department. All billed items and their associated costs were assigned to 1 of the following 14 cost categories: preop (all costs incurred before the morning of surgery); anesthesia (costs of anesthetics, equipment, and disposables used by the anesthesiologist); perfusion (costs of cardiopulmonary bypass equipment, cardioplegia, and disposables used by the perfusionist); surgery (all other costs related to the use of the operating room, surgical equipment, and disposables used by the surgeon); cardiovascular ICU (CVICU) [costs related to nursing, equipment, and room in the cardiovascular ICU]; postop room (costs related to nursing, equipment, and room on the stepdown unit); respiratory (costs related to respiratory equipment, treatments, and therapist time); laboratory, blood bank (blood typing and transfusions); Ekg & 1310
vasc lab (electrocardiograms and noninvasive vascular studies); radiology, pharmacy, therapies (physical, occupational, and speech therapy); and supplies. Death was determined from the Social Security Death Index, obituaries in The Toledo Blade, and hospital records. Three trained registered nurses attempted to contact all survivors. If the survivor gave oral informed consent, the 36-item short form (SF-36) questionnaire7 was administered during the same telephone conversation. Statistical Analysis In addition to analyzing all patients who had undergone cardiac surgery, patients who had undergone only CABG surgery (ie, CABG-only group) were compared. Univariate comparisons between groups were made using 2 tests for categoric characteristics or Mann-Whitney-Wilcoxon tests for continuous characteristics. Linear regression analysis using forward, backward, and stepwise selection was used to explain the variability in direct variable cost.
Results One hundred three patients in each group underwent cardiac surgery and were studied (Table 1). Octogenarians were more likely to be widowed (p ⱕ 0.001), while septuagenarians were more likely to be married (p ⬍ 0.01). Octogenarians were more likely to have had preoperative strokes (p ⫽ 0.05) but were less likely to have diabetes mellitus (p ⬍ 0.001). Other comorbidities were distributed similarly. Octogenarians were less likely to have undergone mitral valve surgery (p ⫽ 0.01) but were more likely to have their CABGs performed without cardiopulmonary bypass (p ⬍ 0.001). Postoperative complications were similar between the two groups (Table 2). The hospital mortality rate was 5.8% in the younger group and 8.7% in the older group (relative risk [RR], 1.5; 95% confidence interval [CI], 0.5 to 4.5; p ⬎ 0.05). Of the nine octogenarians who died, two died of cardiac failure on the day of surgery. Four of the remaining seven octogenarians required re-exploration surgery for bleeding, one had a CVA, two had encephalopathy, and six had sufficient renal dysfunction to undergo dialysis. Of the six septuagenarians who died, one died of heart failure on the first postoperative day. Two of the remaining five septuagenarians required re-exploration surgery for bleeding, three had encephalopathy, and four required hemodialysis. In patients undergoing isolated CABGs, the mortality rate was 1.4% among septuagenarians and 8.2% among octogenarians (RR, 6.2; 95% CI, 0.7 to 52.7; p ⫽ 0.12). Older patients were less likely to be discharged from the hospital directly to home (RR, 0.3; 95% CI, 0.17 to 0.6; p ⱕ 0.01) and were more likely to be discharged to a TCU or ECF (RR, 3.0; 95% CI, 1.7 to 5.6; p ⱕ 0.01). Despite similar ICU, postoperative, and total lengths of stays, Clinical Investigations
Table 1—Preoperative and Intraoperative Characteristics* Septuagenarians Characteristics Male sex Marital status Married Widowed Divorced Single Hypertension Preoperative CVA Preoperative MI Diabetes mellitus COPD CNS drug use Renal dysfunction Year of surgery, 1998 Cardiac catheter Reoperation CABG AVR MVR CEA Other# Off-pump Creatinine,** mg/dL Hemoglobin,** g/dL
Octogenarians
No. (n ⫽ 103)
% (n ⫽ 100)
64
62
71†‡ 20§㛳 5 7 84 11¶ 55 39§ 15 19 13 64 70 5 93 9 15† 10 4 3§ 1.1 13.4
69†‡ 19§㛳 5 7 82 11¶ 53 38§ 15 18 13 62 68 5 90 9 15† 10 4 3§ (0.9–1.3) (11.7–14.4)
No. (n ⫽ 103)
% (n ⫽ 100)
53 49†‡ 43§㛳 3 8 79 21¶ 45 17§ 14 18 10 51 70 5 95 16 4† 7 6 18§ 1.1 13.3
51 48†‡ 42§㛳 3 8 77 20¶ 44 17§ 14 17 10 50 68 5 92 16 4† 7 6 18§ (0.9–1.3) (11.6–14.0)
*MI ⫽ myocardial infarction; CNS drug use ⫽ use of antidepressants, antipsychotics, or anxiolytics preoperatively; AVR ⫽ aortic valve replacement or repair; MVR ⫽ mitral valve replacement or repair; CEA ⫽ carotid artery endarterectomy. †p ⱕ 0.01. ‡Married vs all other marital statuses. §p ⱕ 0.001. 㛳Widowed vs all other marital statuses. ¶p ⱕ 0.05. #Septuagenarians: three ascending aortic aneursymectomies and one left ventricular aneursymectomy; octogenarians: four ascending aortic aneursymectomies, one tricuspid valve repair, and one femoral artery aneursymectomy. **Values given as median (interquartile range).
the median hospital cost was 35% higher for the octogenarians (Table 3). By linear regression, higher cost was associated with being an octogenarian, having re-exploration surgery for bleeding, and longer hospital length of stay. Having the surgery performed without cardiopulmonary bypass was associated with a lower cost (Table 4). Survival was similar both in the all-patient groups and the CABG-only groups. The 1-year survival rate among the all-patient septuagenarians was 83% (95% CI, 76 to 91%) compared to 85% (95% CI, 79 to 92%) among octogenarians. The 2-year survival rates were 82% (95% CI, 75 to 90%) and 84% (95% CI, 77 to 91%), respectively (Fig 1, top) No patient in the CABG-only groups died between 1 and 2 years after surgery, giving 1-year and 2-year survival rates of 90% (95% CI, 83 to 97%) in septuagenarians and 88% (95% CI, 80 to 95%) in octogenarians (Fig 1, bottom). At the follow-up of the 97 septuagenarians who www.chestjournal.org
survived hospitalization, 66 completed the interview, 13 were dead, 9 refused the interview, 5 were lost to follow-up, 3 were in ECFs, and 1 was hospitalized. The octogenarians had similar outcomes and participation. Of the 94 who survived hospitalization, 59 completed the interview, 7 were dead, 9 refused the interview, 18 were lost to follow-up, and 1 was in an ECF. The 45 living patients who did not participate in the interview or were lost to follow-up were slightly older (median, 81 years of age [interquartile range, 76 to 83 years] vs 79 years of age [interquartile range, 74 to 81 years], respectively; p ⫽ 0.02), had higher preoperative creatinine levels (median, 1.2 mg/dL [interquartile range, 1.0 to 1.3 mg/dL] vs 1.0 mg/dL [interquartile range, 0.9 to 1.2 mg/dL], respectively; p ⫽ 0.01), were more likely to have undergone aortic valve surgery (median, 21% vs 7%, respectively; p ⫽ 0.01), were more likely to develop atrial fibrillation (median, 49% vs 32%; CHEST / 122 / 4 / OCTOBER, 2002
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Table 2—Complications and Discharge Location* Septuagenarians Variables Transfusion Reexploration New CVA Encephalopathy Renal dysfunction Prolonged ventilation Dialysis Atrial fibrillation Died Discharged to Home ECF TCU Rehabilitation hospital Other Died Peak creatinine, mg/dL
No. 64 5 5 17 25 18 10 36 6 48† 10 30 5 4 6 1.3
% 62 5 5 17 25 18 10 36 6 47† 10 29 5 4 6 (1.0–2.0)
Table 4 —Predictors of Cost*
Octogenarians No. 75 8 4 19 18 19 7 41 9 22† 24 40 7 1 9 1.2
Predictors Constant Hospital LOS Re-exploration Octogenarian Off-pump
% 73 8 4 19 18 19 7 41 9
Coefficient $⫺5,403 $896 $21,865 $7,282 $⫺9,585
95% CI
p Value
$⫺13,356–$2,549 $744–$1,048 $11,682–$32,049 $2,340–$12,224 $⫺17,715–$1,455
⬍ 0.001 ⬍ 0.001 0.004 0.021
*Coefficient ⫽ the amount that the occurrence of each categoric variable (ie, re-exploration, octogenarian, off-pump) increases direct variable cost.
21† 23 39 7 1 9 (0.9–1.6)
*New CVA ⫽ intraoperative or postoperative stroke. †p ⱕ 0.01 (discharge to home vs all other locations).
p ⫽ 0.04), had spent a longer time in the hospital (median, 10 days [interquartile range, 7 to 18 days] vs 7 days [interquartile range, 6 to 11 days], respectively; p ⬍ 0.01), and had higher hospital costs (median, $12,853 [interquartile range, $7,954 to $22,262] vs $9,412 [interquartile range, $6,404 to 14,638]; p ⫽ 0.02) than the 125 who were interviewed. The interviews showed that both groups had excellent social functioning and role-emotional outcomes (Table 5). The values for the other SF-36
scales were similar between the two groups except that the octogenarians had lower levels of physical functioning and general health. Discussion Despite a higher prevalence of preoperative stroke, which is a risk factor for hospital mortality after cardiac surgery, we found that octogenarians underwent cardiac surgery with hospital survival rates and complication rates that were similar to those of septuagenarians but at a higher hospital cost. Our hospital mortality rate (8.2% in octogenarians) is similar to or lower (5.6 to 24.3%) than those found in other studies evaluating CABG.6,8 Using Medicare data, Peterson et al9 found a hospital mortality rate of 11.5% in 24,461 patients aged ⱖ 80 years and had undergone isolated CABG surgery between 1987 and 1990. The 1-year mortality rate for those patients was 19%, compared to 12% in this study. Our lower rate may be due to differences in patient
Table 3—Lengths of Stay and Direct Variable Costs* Variables
Septuagenarians
Octogenarians
CVICU LOS, d Postoperative LOS, d Total LOS, d Total costs, $ Pre-operative Anesthesia Perfusion Surgery CVICU Postoperative room Respiratory Laboratory Blood bank ECG & vascular laboratory Radiology Pharmacy Therapies Supplies
1 (1–3) 6 (5–10) 8 (6–13) 9,383 (6,321–16,992)† 641 (410–1,284) 279 (217–532) 1,772 (1,216–2,540) 2,299 (1,773–3,780) 816 (433–1,867) 655 (1,094–2,212) 67 (30–196) 217 (111–442) 102 (34–254) 29 (67–120) 37 (11–134) 592 (343–1,226) 236 (106–439) 70 (39–149)
1 (1–3) 6 (5–9) 9 (6–13) 12,624 (7,836–22,124)† 743 (511–1,710) 356 (250–542) 2,224 (1,461–2,710) 3,041 (1,984–3,787) 1,154 (481–2,858) 761 (1,492–2,676) 146 (32–263) 258 (107–633) 91 (32–457) 31 (77–138) 90 (26–426) 702 (450–1,723) 221 (139–523) 95 (36–231)
*Values given as median (interquartile range). All p values are ⬎ 0.05 unless indicated. LOS ⫽ length of stay. †p ⱕ 0.01. 1312
Clinical Investigations
Figure 1. Top: Kaplan-Meier plots of 2-year survival rates from the time of surgery for septuagenarians (– – –) and octogenarians (——) after all cardiac surgeries. Bottom: Kaplan-Meier plots of 2-year survival rates from the time of surgery for septuagenarians (– – –) and octogenarians (——) after CABG-only surgery.
selection or to improvements in operative techniques and perioperative care over the last decade. Many factors have been found to be associated with increased mortality among the octogenarians,
particularly emergency surgery, complexity of the surgery, and the presence of comorbidities.5,10,11 Whether due to different criteria for patient selection or to improvements in stabilization in the catheterization laboratory, we, unlike Avery et al,5 had few emergency patients with severe hemodynamic instability. Where Glower et al11 noted an in-hospital mortality rate of 23% in octogenarian patients with any comorbidities, compared to 7% in patients without any comorbidities, we found that almost all of our octogenarian patients (92.2%) had at least one comorbidity. However, this high rate of comorbidities is similar to those cited in other studies.3,5 We found that the older group was more likely to have had their CABG surgery performed without cardiopulmonary bypass (ie, off-pump surgery). While firm data are lacking, off-pump surgery is felt to cause less postoperative neurologic and renal dysfunction.12 This may have contributed to the similar rates of cerebral and renal dysfunction in our two groups. The occurrence of complications predicted a worse outcome, with dialysis being a prominent marker of hospital death. The survival rate among patients initiating dialysis was 30% among octogenarians and 57% among septuagenarians (p ⬎ 0.05). This finding is similar to patients in a general ICU. Octogenarians initiating hemodialysis in the ICU had a survival rate (33.3%) that was similar to that of nonoctogenarians (36.4%).13 Peterson et al9 attributed the 20% higher cost for octogenarian patients to their longer average length of hospital stay (3.9 days). Avery et al5 noted an average 26.8% higher cost for their octogenarian patients, which was explained on the basis of a 37% longer average hospital length of stay and a higher intensity of illness. In contrast, our study found identical median ICU and postoperative lengths of stays and similar total lengths of stays between the younger and older groups. Despite this, the median
Table 5—Functional Outcome* Septuagenarians
Octogenarians
Variables
No.
Median (IQ Range)
Mean ⫾ SD
No.
Median (IQ Range)
Mean ⫾ SD
Physical functioning Role-physical Bodily pain General health Vitality Social functioning Role-emotional Mental health
66 66 66 66 66 66 65 66
75 (35–90)† 75 (25–100) 72 (61–100) 72 (50–84)‡ 50 (35–75) 100 (75–100) 100 (67–100) 72 (60–80)
67 ⫾ 31 64 ⫾ 38 72 ⫾ 25 67 ⫾ 25 54 ⫾ 25 83 ⫾ 23 86 ⫾ 27 68 ⫾ 12
59 58 58 58 58 58 58 58
55 (28–80)† 50 (25–75) 73 (51–100) 64 (40–77)‡ 50 (25–70) 100 (75–100) 100 (67–100) 72 (64–80)
54 ⫾ 30 53 ⫾ 36 69 ⫾ 29 58 ⫾ 24 47 ⫾ 29 82 ⫾ 26 79 ⫾ 36 69 ⫾ 17
*The No. of patients varies slightly because not all patients answered every question. †p ⱕ 0.01. ‡p ⱕ 0.05. www.chestjournal.org
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costs were 35% higher in the older group. While costs were hundreds of dollars higher in the octogenarian group for the high-cost categories of surgery, perfusion, and CVICU stay, these did not reach statistical significance, probably because of inadequate power to detect subgroup differences. Previous studies have found mean postoperative lengths of stays of 10 to 16 days5,9,11,14 and mean total hospital lengths of stays of 22 days3 for elderly patients, which are considerably longer than the median postoperative length of stay of 6 days and the total hospital length of stay of 9 days in this study. This probably relates to our fast-track cardiac program,15 the availability of a TCU contiguous to the hospital, and nearby ECFs. Only 21% of our octogenarians were discharged to home, which is significantly less than the rate for the septuagenarians (47%). The higher rate of octogenarians being discharged to places other than home was partially due to octogenarians being less likely to be married. But, even comparing married octogenarians to married septuagenarians, married octogenarians were still less likely to be discharged to home (33% vs 51%, respectively; p ⬍ 0.05). Further evaluation is needed to determine whether this is related to spousal disability or other reasons. It was also significantly less than the 64% reported elsewhere.3 A higher rate of admission to the TCU or ECFs may be the tradeoff for a short hospital length of stay. We found that other than octogenarians having lower levels of physical functioning and general health, octogenarians and septuagenarians had similar functional outcomes. The octogenarians in our study had similar scores or trends to better scores than the general population that was ⱖ 75 years old,7 but they had lower scores than Canadian octogenarians after cardiac surgery.3 Fruitman et al3 administered the SF-36 to 99 of 103 octogenarian survivors at 15.7 ⫾ 6.9 months after their cardiac surgery in Halifax, NS, Canada. They found consistently higher scores for five of the eight scales than we found (p ⬍ 0.01 for Role-Physical, Bodily Pain, General Health Perceptions, and Mental Health; p ⬍ 0.05 for Vitality; and p ⬎ 0.05 for Physical Functioning, Social Functioning, and Role-Emotional). Whether this is due to different patient characteristics, different versions of the SF-36, or differences in the social services, medical care, and prescription drug benefits between Canada and the United States cannot be determined. A limitation of this study is that it was conducted at only one institution. Other hospitals may have different experiences. A multicenter study might also provide sufficient statistical power to detect a difference in mortality. However, the population is similar in size to those in most other studies evaluating cardiac surgery in the elderly.3,14,16 –19 Given the 1314
hospital mortality rates that we found (septuagenarians, 5.8%; octogenarians, 8.7%), it would take approximately 1,250 patients in each group to find a statistically significant difference, with a type I error of 0.05% and 80% power. The moderate number of patients studied also precludes us from developing a risk model for predicting death, complications, cost, or functional outcome. Another limitation is that one fourth of the survivors did not consent to be interviewed or could not be located. Given that these 46 patients were slightly older, were more likely to have renal dysfunction, were more likely to have undergone aortic valve surgery, were more likely to develop atrial fibrillation, and were more likely to cost more, they may not have as good functional outcomes as those who participated in the interview.
Conclusion We found that cardiac surgery can be performed in the elderly with good hospital and late functional results, but at higher hospital costs than those for younger patients.
References 1 National Center for Health Statistics. National Health Survey 1983–1985. Atlanta, GA: Centers for Disease Control and Prevention, 1986 2 Preˆtre R, Turina MI. Cardiac valve surgery in the octogenarian. Heart 2000; 83:116 –121 3 Fruitman DS, MacDougall CE, Ross DB. Cardiac surgery in octogenarians: can elderly patients benefit? Quality of life after cardiac surgery. Ann Thorac Surg 1999; 68:2129 –2135 4 Schmitz C, Welz A, Reichart B. Is cardiac surgery justified in patients in the ninth decade of life? J Card Surg 1998; 13:113–119 5 Avery GJ, Ley SJ, Hill JD, et al. Cardiac surgery in the octogenarian: evaluation of risk, cost, and outcome. Ann Thorac Surg 2001; 79:591–596 6 Mick MJ, Simpfendorfer C, Arnold AZ, et al. Early and late results of coronary angioplasty and bypass in octogenarians. Am J Cardiol 1991; 68:1316 –1320 7 Ware JE Jr, Snow KK, Kosinski M, et al. SF-36 health survey manual, and interpretation guide. Lincoln, RI: Quality Metric, 1997 8 Edmunds LH, Stephenson LW, Edie RN, et al. Open heart surgery in octogenarians. N Engl J Med. 1988; 319:131–136 9 Peterson ED, Cowper PA, Jollis JG, et al. Outcomes of coronary artery bypass graft surgery in 24,461 patients aged 80 years or older. Circulation 1995; 92(suppl):II85–II91 10 Craver JM, Puskas JD, Weintraub WW, et al. 601 octogenarians undergoing cardiac surgery: outcome and comparison with younger age groups. Ann Thorac Surg 1999; 67:1104–1110 11 Glower DD, Christopher TD, Milano CA, et al. Performance status and outcome after coronary artery bypass grafting in persons aged 80 –93 years. Am J Cardiol 1992; 70:567–571 12 Plomondon ME, Cleveland JC Jr, Ludwig ST, et al. Off-pump coronary artery bypass is associated with improved riskClinical Investigations
adjusted outcomes. Ann Thorac Surg 2001; 72:114 –119 13 Baldyga AP, Paganini EP, Chaff C, et al. Acute dialytic support of the octogenarian: is it worth it? ASAIO J 1993; 39:M805–M808 14 Freeman WK, Schaff HV, O’Brien PC, et al. Cardiac surgery in the octogenarian: perioperative outcome and clinical follow-up. J Am Coll Cardiol 1991; 18:29 –35 15 Engoren M, Kraras C, Garzia F. Propofol based v fentanylisoflurane based anesthesia for cardiac surgery. J Cardiothorac Vasc Anesth 1998; 12:177–181 16 Utley JR, Leyland SA. Coronary artery bypass grafting in the
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