CORONARY ANTENY DISEASE SEPTEMBER 1, 1992, VOL. 70, NO. 6

Performance Status and Outcome After Coronary Artery Bypass Grafting in Persons

Aged 80 to 93 Years Donald D. Glower, MD, Thomas D. Christopher, MD, Carmelo A. Milano, MD,

William D. White, MPH, L. Richard Smith, PhD, Robert H. Jones, MD, and David C. Sabiston, Jr., MD

Although coronary artery bypass grafthrg (CABG) effectivety eliminates or diminishes symptoms of myocardial ischsmia, the overall performance sta- tus and functional outcome in elderly patients un- dergdng CAB0 is poorly documented. Theretore, 86 consecutive patients aged 60 to 93 years un- dergobtg isetated CABG were reviewed. Preepera- tive, Intraoperative, and postoperative characterts- ttcs and pre- and postoperative performance sta- tus (Kamofsky score) were examined. Forty patients (47%) were women, and most patients had highly symptomatic coronary artery disease with cfass III or IV anghta in 94% and unstable anghta in 90%. Significant co-morbid disease was present in 49% of patients, and cardiac catheter- lxatlon revealed feft main or 3-vessef disease in 74% of patients. The rate of significant in-hospital complkatlons was 29%, with btfectfon in 14% stroke in 9%, and respbatory failure fn 8% befng most frequent. Median performance status (Kar- nofsky score) improved from 30 to 70% (p = 0.0001) with 89% of hospital survtvors being dis- charged home. Factors assocfated with faikre to a&eve a successful functional outcome at dis- charge were presence of 1 or more preoperative co-morbfd condiUon8 (p = O&46), preoperative myocardial infarctton within 7 days of operation (p <O.Ol), and postoperattve low cardiac output (p <O.Ol). 6uwfval at 30 days, 6 months, and 3 years were 90,78, and 64%, resp&ivety. lhese data demonstrate that CABG can be offered to se- lected elderly patients with acmble morbfdity and mortality, marked improvement in perfor- mance status, and an acceptable quality of life.

(Am J Cardiol1992;70:667-571)

From the Departments of Surgery, and Community and Family Medi- cine, Duke University Medical Center, Durham, North Carolina. Man- uscript received April 2,1992; revised manuscript received and accepted May 20,1992.

Address for reprints: Donald D. Glower, MD, Box 3851, Duke University Medical Center, Durham, North Carolina 277 10.

M any reports have established that, relative to younger patients, elderly patients aged >65 to 75 years are at increased risk for mortality

and perioperative complications after coronary artery bypass grafting (CABG).‘** As the patient population with coronary artery disease grows older, and as mor- bidity and mortality with CABG continue to decrease, CABG in patients aged 280 years is now becoming quite common. Recent reports document increased but acceptable operative and long-term mortality rates after coronary bypass grafting in carefully selected patients over the age of 80, despite a significantly increased complication rate.2-5 What remains to be documented is the overall performance status and functional outcome of these patients, many of whom have significant dis- ability before operation. This latter issue is of increasing importance given recent concerns about the cost effec- tiveness of health care and about increasing liitations on the availability of health care resources, A study was therefore undertaken to examine in detail the perfor- mance status and outcome of CABG in patients aged 180 years at a single institution.

METHOD8 A retrospective analysis was undertaken in all 86 pa-

tients aged 80 to 93 years undergoing isolated CABG at a single institution through February 1991. Data were collected regarding preoperative cardiac and surgical history, preoperative co-morbid conditions, preoperative performance status, cardiac catheterization data, intra- operative data, postoperative in-hospital course, perfor- mance status at discharge, and long-term survival. Sig- nificant coronary artery disease was defined as >70% stenosis of 1 or more coronary arteries. Performance status was assessed using the Kamofsky scoring system6 (Table I), and symptomatic status both for angina and congestive heart failure was rated using the classitica- tion of the Canadian Cardiovascular Society.7 All oper- ations were performed with moderate systemic hype thermia (28 to 32OC) and either bubble or membrane oxygenators. Crystalloid cardioplegia was used in all pa- tients except 2 in whom the aorta was not occluded be- cause of extensive aortic disease. Follow-up was com-

CORONARY BYPASS IN THE ELDERLY 567

TABLE I Kamofsky Performance Status Scale6

Normal activity; able to work; no special care

100% normal activity; 90% minor symptoms; 80% moderate symptoms

At home; unable to work; can care 70% self-care, less than normal for most personal needs activity; 60% needs some help;

50% needs much help Needs institutional care 40% disabled; 30% severely dis-

abled requiring special care; 20% needs active support; 10% moribund; 0% dead

TABLE II Preoperative Co-Morbid Disorders

Disorders

Systemic hypertension f > 140/90 mm Hg) Cerebrovascular disease Cigarette smoking in last 10 years Peripheral vascular disease Diabetes mellitus Chronic lung disease Pulmonary edema Chronic atrial fibrillation Renal insufficiency (Cr 22) Malignancy Aortic aneurysm

Cr = creatinine.

No. (% total)

58 (67) 23 (27) 23 (27) 20 (23) 12 (14) ll(13)

8 (9) 4 (5) 4 (5) 3 (3) 2 (2)

plete to 1990 in 76 of 86 patients (88%), and mean fol- low-up duration was 17 f 17 months.

The &i-square test and Fisher’s exact test were used where appropriate to make univariate comparisons, and survival was computed by the method of Kaplan and Meier. All data are presented as mean f standard devi- ation unless otherwise stated.

RESULTS

Using standard definitions of coronary atherosclero- sis,* cardiac catheterization demonstrated left main cor- onary disease in 21 patients (24%), 3-vessel coronary disease in 60 (70%), 2-vessel disease in 17 (20%), and l- vessel disease in 5 (6%). On a scale of l+ to 4+, thir- teen patients had L2+ mitral regurgitation, 1 patient had 2+ aortic regurgitation, and 4 patients had mild aortic stenosis. Preoperative ejection fraction was <50% in 37 patients (43%) (mean ejection fraction 52 f ll%, range 24 to 74).

The fast patient aged >80 years to undergo CABG Each patient underwent a mean of 3.0 f 0.9 bypass at this institution did so in 1983. Since that time, grafts. Forty-live patients (52%) underwent internal CABG in patients aged >80 years has become increas- mammary artery grafting, including 37 with isolated ingly frequent (Figure l), and at this institution in left internal mammary, 1 with isolated right internal 1990,2.2% (20 of 893) of all patients undergoing isolat- mammary, and 7 (8%) with bilateral internal mammary

0 1983 1984 1985198619871988 1989 1990 1991

Year of Operation (2Mo)

ed CABG were aged 280 years. Thirty-nine patients (45%) were women (mean age 81 f 2 years, range 80 to 93). Seventy-two patients (84%) had class IV angina, and 17 (20%) had class III or IV congestive heart fail- ure. The angina1 pattern was classified as unstable in 45 patients, postinfarction in 19, progressive in 13, and sta- ble in 9. Twenty-three patients (27%) had had a myo- cardial infarction within the previous 30 days, and 46 patients (53%) were underwent operation directly from the coronary care unit or the cardiac catheterization laboratory because of unstable or postinfarction angina. Eight patients required a preoperative intraaortic bal- loon pump, 4 patients required preoperative intubation, and 4 patients were in cardiogenic shock preoperatively. only 4 patients had undergone preoperative thromboly- sis, 2 patients had undergone previous CABG, and only 6 patients had undergone previous coronary angioplasty.

Significant co-morbid disease (renal, pulmonary, ce- rebrovascular, peripheral vascular, hematologic or gas- trointestinal) was present in 42 of 86 patients (49%) in- cluding 31 patients (36%) with other significant vascu- lar disease (Table II). only 23 patients (27%) had smoked cigarettes in the last 10 years, and only 12 pa- tients (14%) had diabetes mellitus, making diabetes and smoking less prevalent than in the overall population undergoing CABG at this institution.

0 1 2 3 4 5 6 7 >7

Number of ICU Days

MuI THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 70 SEPTEMBER 1. 1992

artery grafting. Mean aortic clamp time was 45 f 19 minutes with a cardiopulmonary bypass time of 111 f 40 minutes.

Postoperatively, median stay in the intensive care unit was 2 days (25th and 75th percentiles were 1 and 4 days, respectively) (Figure 2). Significant postoperative complications occurred in 25 patients (29%), with stroke (8 patients), pneumonia (6 patients), other infec- tion (11 patients), respiratory insufficiency (7 patients), bleeding (6 patients), and renal failure (4 patients) be- ing most frequent. No patient developed mediastinitis. Twenty-eight patients (33%) required some form of postoperative organ support, including L2 inotropic agents in 18 patients (21%), nutritional support in 15 (17%), intraaortic balloon pumping in 13 (15%), venti- lation >48 hours in 13 (15%), and dialysis in 3 (3%). Thirty-day mortality was 10.5% (9 of 86), with in-hos- pital mortality being 13.9% (12 of 86). The most fre- quent cause of in-hospital death was respiratory failure, occurring in 5 patients. Median hospital stay was 16 days (25th and 75th percentiles were 12 and 22 days,

40 , I

n Postoperative

12 3 4 5 6 7 a 9 10

Stay Duration (Weeks)

40

30

2 20

: 'jfj 10 a

6 0

ta

fi 3o

3 20

10

n ”

0 10 20 30 40 50 60 70 60 90 100

Karnofsky Score

respectively) (Figure 3) and median postoperative stay was 10 days.

Mean Karnofsky score was 27 f 15% preoperatively (median 20%) and was significantly increased to 60 f 27% (median 70%) at discharge (p = 0.0001) (Figure 4). The median change in Kamofsky score was +40% (Figure 5), and 89% of hospital survivors achieved 220% increase in Karnofsky performance score at dis- charge. Eighty-nine percent (66 of 74) hospital survi- vors were discharged home, and of the remajning 11% (8 of 74), 5 were discharged to nursing facilities because of inadequate functional recovery, and 3 went to a nurs- ing facility only because of inadequate family support. Late survival f 95% confidence limits was 78 f 7% at 6

-

-60 -40 -20 0 +20 40 l 60 +eo

Change in Karnofsky Score

66 58 52 35 34 29 26 18 14 N at Risk

t 01

0 12 3 4 5

Postoperative Time (Years)

CORONARY BYPASS IN THE ELDERLY 569

months, 74 f 9% at 1 year, 64 f 11% at 3 years, and 50 f 15% at 5 years (Figure 6). Cardiac causes were responsible for 56% (10 of 18) of late deaths.

Several preoperative, intraoperative and postopera- tive factors were associated with in-hospital mortality. The presence of Ll significant preoperative co-morbid disorder increased in-hospital mortality from 3 of 43 (7%) to 9 of 40 (23%) (p = 0.04). Preoperative myocar- dial infarction within 1 week of operation significantly increased in-hospital mortality from 7 of 74 (9%) to 6 of 12 (5O%) (p <O.Ol). Preoperative gender, congestive heart failure, ejection fraction, cardiogenic shock, year of operation, and internal mammary artery grafting were not significantly related to in-hospital mortality. Postoperative respiratory failure increased mortality from 4 of 64 (6%) to 8 of 18 (44%) (p <O.Ol), postoper- ative low cardiac output (cardiac index <2.0 for 4 hours) increased mortality from 4 of 66 (6%) to 8 of 20 (4O%) (p <O.Ol), and postoperative stroke tended to in- crease in-hospital mortality from 7 of 78 (9%) to 3 of 8 (38%) (p >0.2).

To examine the effects of perioperative factors on Kamofsky performance status at discharge, a successful functional outcome was defined as a discharge Kar- nofsky score of at least 60 and 2O% greater than the preoperative score. By this definition, 60 of 86 (70%) patients achieved a successful functional outcome from coronary bypass grafting. One or more preoperative co morbid conditions decreased the likelihood of a success- ful functional outcome from 29 of 36 (81%) to 29 of 48 (6O%) (p = 0.048). Women tended to be more likely to have a successful functional outcome (32 of 40 or 8O%) than men (28 of 46 or 61%) (p = 0.054) and women tended to have a lower hospital mortality rate (3 of 40 [8%] vs 9 of 46 [2O%], p = 0.10). Preoperative myocar- dial infarction within 7 days of operation decreased the likelihood of successful functional outcome from 55 of 73 (75%) to 5 of 13 (38%) (p <O.Ol). Postoperative low cardiac output decreased successful functional outcome from 52 of 66 (79%) to 8 of 20 (4O%) (p <O.Ol).

DISCUSSION Few data are available regarding overall perfor-

mance status and functional outcome after CABG in elderly patients. Data do exist regarding the New York Heart Association classification of cardiac symptoms after CABG, with the consensus indicating that CABG effectively relieves angina in most elderly patients.3-5 In fact, Carey et al9 found that at 5 to 10 years after CABG, symptomatic health status index for patients >65 years old was actually better than for younger pa- tients. The major limitation of the New York Heart As- sociation functional classification and other schemes such as health status index9 is that they do not consider functional limitations not due to cardiac disease. In the extremely elderly, noncardiac disorders are common. Thus, an elderly patient who achieved an excellent car- diac functional outcome after coronary bypass grafting could still be very debilitated with poor quality of life and need for long-term nursing care.

The Kamofsky score was originally designed to as- sess overall performance status in cancer patients,‘j and

Kamofsky performance status of patients after CABG has received little attention, perhaps because many pa- tients have been quite functional both before and after surgery. On the other hand, elderly patients tend to have significant preoperative disability from noncardiac disease and thus might be expected to have impaired functional status both before and after CABG. As to our knowledge, this study is the first to document the overall performance status at the time of discharge after CABG in patients aged >80 years old. The percentage of patients discharged to a nursing home has not been previously documented in this population and is espe- cially important in planning the future need for health care resources. This importance is heightened by the in- creasing numbers of elderly patients undergoing CABG, since operation may increase survival but also may in- crease the net number of patients requiring nursing care.

Elderly patients with coronary artery disease are a distinct population from younger patients in many ways. The lack of gender differences in the elderly, with 45% of patients in the present study being women as opposed to 23% of the general CABG population at this institu- tion being women is noteworthy. Several studies report- ed that, as with younger patients, older women had a higher in-hospital mortality rate than their male coun- terparts2y4 Yet, other investigators found that female gender was an operative risk factor for young patients, but not for the elderly.lO The present study demon- strated a trend for elderly women to have a decreased in-hospital mortality rate and improved functional out- come, but the trend did not achieve significance. In gen- eral, female gender appears to be a less significant risk factor in the elderly than in younger patients, and whether any effects of female gender in the elderly is in fact due to body weight or size remains unclear.

In addition to the lack of gender differences, elderly patients are more likely to have preoperative co-morbid conditions and perioperative complications than youn- ger patients, as confirmed in this study and others.2-5 The association between unfavorable outcome and such preoperative factors as recent myocardial infarction and 1 or more co-morbid disorders suggests that outcome in the elderly may be improved by careful patient selec- tion. Unfortunately, older patients with highly sympto- matic and severe coronary disease may actually have greater risk from nonoperative therapy than from oper- ation, and selecting patients to improve operative mor- tality rate may not benefit the mortality rate in the pop ulation as a whole.” Moreover, the increased risk of patients undergoing operation early after myocardial in- farction may reflect unstable myocardial perfusion re quiring urgent intervention, and delay of operation may increase rather than decrease risk in these patients. Thus, preoperative risk factors such as cc-morbid dis- ease and recent infarction are useful in assessing prog- nosis, but the optimal role of risk factors in patient se- lection remains to be demonstrated.

The present study has several limitations. Although the small sample size decreases the ability to interrelate or detect factors influencing outcome, the present series is among the largest from any single institution to date.

570 THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 70 SEPTEMBER 1, 1992

Second, the fact that the 86 patients in this series are highly selected from the entire population of octogenari- ans does limit interpretation of this study. Third, the present study is a relatively short-term study since few patients 180 years old underwent CABG >5 to 7 years ago. Finally, the present study only begins to address optimal selection of elderly patients for CABG. Clearly, elderly patients with relatively few co-morbid conditions but with severely debilitating coronary artery disease may obtain excellent functional benefit from operation. Yet, further data are needed to address whether operat- ing on elderly patients with even greater risk or less sig- nificant symptoms could also provide functional benefit at an acceptable cost. The role of alternative therapies such as angioplasty in the elderly similarly remains to be documented.

Despite the severe disability and frequent comorbid- ity that characterized the preoperative octogenarians in the current study, the discharge performance status and the functional outcome were remarkably good. Seventy percent of patients experienced significant increase in overall performance status and were relatively self-suffi- cient at discharge. Only 18 patients (20%) either died before discharge or required nursing home placement for physical disability. Median stay in the intensive care unit (2 days) and postoperative in-hospital stay (10 days) were only slightly higher than those reported for the overall CABG population, and the cost of providing care to these patients would therefore be only modestly higher than average. Careful follow-up of these patients

is required to continually reevaluate the benefit ob- tained given the increased cost of delivering health care in this high-risk group of patients.

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