Cardiac Surgery in
Patients Age
80
Years or Older
WALTER H. MERRILL, M.D., JAMES R. STEWART, M.D., WILLIAM H. FRIST, M.D., JOHN W. HAMMON, JR., M.D., and HARVEY W. BENDER, JR., M.D.
Between February 1978 and August 1989, forty patients age 80 years or older underwent cardiac surgery at this institution. Patient age varied from 80 to 87 years (mean, 82.4 years). Operative indications were angina pectoris or congestive heart failure. Twenty-eight patients underwent coronary artery bypass (CAB) alone and 12 underwent valve -replacement(s) with or without CAB. The operative mortality rate was 10%. Postoperative hospitalization averaged 14 days. There were three late cardiac deaths at 13, 36, and 48 months after operation and one late noncardiac death. Thirty-two survivors have been followed from 1 to 86 months (mean, 20 months). All experienced sustained improvement in functional status and minimal late morbidity. All survivors remained in NYHA class 1 or 2. Cardiac surgical procedures in patients older than 80 years can be performed with increased but acceptable mortality and morbidity rates. Most patients achieve sustained symptomatic improvement and excellent long-term survival.
From the Department of Cardiac and Thoracic Surgery, Vanderbilt University School of Medicine, The Vanderbilt Clinic, Nashville, Tennessee
mortality rates, long-term survival, and functional capacity. Patients and Methods
I N RECENT YEARS it has become apparent that the number of persons 80 years of age or older is increasing in the United States. It has been reported that 43% of all Americans will reach the age of 80 years and will live, on average, almost 8 more years.' Symptomatic heart disease is present in approximately 40% of all persons age 80 years or older. Many patients with symptoms that are refractory to aggressive medical therapy may be potential candidates for cardiac surgery. During the past several years excellent results have been reported in older persons undergoing valve replacement or coronary artery bypass (CAB). These encouraging results have led to an increasing frequency of operation in patients older than 80 years. To determine the efficacy of cardiac surgery in the octogenarian population, we reviewed the course of our patients who were 80 years of age or older and analyzed their operative morbidity and Presented at the 101st Annual Meeting of the Southern Surgical Association, Hot Springs, Virginia, December 3-6, 1989. Address reprint requests to Walter H. Merrill, M.D., The Vanderbilt Clinic, Room 2973, Nashville, TN 37232.
Between February 1978 and August 1989, forty patients age 80 years or older underwent cardiac surgical procedures at the Vanderbilt University Medical Center. All patient records were reviewed to assess age, sex, diagnosis, risk factors, operative procedure, perioperative complications, and long-term follow-up. The Canadian Cardiovascular Society classification was used to grade angina pectoris. Each patient was assigned a New York Heart Association (NYHA) functional classification. Cardiac catheterization was performed in all patients. The degree of valve stenosis or insufficiency was quantitated using standard catheterization techniques. Narrowing of the left main coronary artery by more than 50% and narrowing of the other coronary arteries by more than 70% was considered sufficiently severe to warrant myocardial revascularization. The operative technique consisted of standard median sternotomy and nonpulsatile cardiopulmonary bypass. Moderate hypothermia to 25 to 28 C was used. The operative procedures were performed with standard aortic clamping and a single dose of hyperkalemic crystalloid cardioplegia (4 C) and either continuous or intermittent topical myocardial cooling. All CAB grafts were performed with autogenous reversed saphenous vein. All valve replacements were performed with bioprostheses. Perioperative data included time in intensive care unit, total time in hospital after operation, operative mortality (death during the initial hospitalization), and complica-
772
Vol. 211 - No. 6
CARDIAC SURGERY IN PATIENTS AGE 80 YEARS OR OLDER
tions. Early survival was defined by patient discharge from the hospital. All surviving patients were evaluated within the month of October 1989 through direct patient contact or by information obtained from the patients' personal physicians, or both. The level of physical activity was determined and graded by the NYHA functional classification.
773
perienced postinfarction angina. Hemodynamically significant coronary artery disease was documented as follows: left main and three-vessel coronary artery disease was present in 7 patients, left main and two-vessel coronary artery disease was present in 1 patient, three-vessel disease was present in 20 patients, two-vessel disease was present in 5 patients, and one-vessel disease was present in 2 patients. In the 35 patients undergoing CAB with or without associated procedures, the mean number of distal
slow ventricular response rate after operation. An additional patient with preoperative third degree atrioventricular block required insertion of an atrioventricular sequential pacemaker. Four patients developed the new onset of atrial fibrillation, but in all cases normal sinus rhythm was restored with appropriate medical therapy. Two patients experienced a superficial wound infection from their saphenous vein harvest sites, but no patient developed a sternal wound infection or dehiscence. Two patients developed a temporary neurologic deficit that cleared completely by the time of discharge. The 36 hospital survivors stayed a mean of 4.6 days in the intensive care unit (range, 2 to 21 days). Their postoperative convalescent time after leaving the intensive care unit was a mean of 10 days (range, 3 to 23 days). A total of three late cardiac-related deaths occurred after operation. One patient who had undergone a three-vessel CAB experienced mild angina and dyspnea on exertion late after operation, and this patient died 13 months after operation, probably due to an acute myocardial infarction. One patient who had undergone aortic valve replacement and a two-vessel CAB suffered severe late postoperative depression and died 3 years after operation of multisystem organ failure. One patient who had undergone a single vessel CAB did extremely well after operation but died at 48 months, probably due to an acute myocardial infarction. There was one additional late noncardiac death. This patient had undergone mitral valve replacement and had no cardiac symptoms, but she died of widespread metastatic breast carcinoma 10 months after operation. No patients were lost to follow-up. The 32 long-term survivors have been followed an average of 20 months (range, 1 to 86 months). All of the long-term survivors are reasonably active consistent with their overall general health. From a cardiovascular standpoint all are in NYHA functional class 1 or 2. All survivors are improved compared to their preoperative status.
anastomoses was 2.7. The operative mortality rate was 10% (4 of 40 patients). One patient who underwent aortic valve replacement and a two-vessel CAB experienced cardiogenic shock and died several hours after operation. Another patient who underwent CAB had postoperative bleeding and had to be returned to the operating room for control of bleeding. This patient developed low cardiac output and died of cardiogenic shock on postoperative day 1. Two additional patients, one of whom underwent aortic valve replacement and one of whom underwent CAB, died 2 weeks after operation from multiple neurologic insults and multiorgan system failure. The 36 patients who survived operation experienced several perioperative complications. Two patients required insertion of a permanent transvenous pacemaker. One patient in chronic atrial fibrillation had an unacceptably
Discussion The major cause of death and disability among elderly persons is cardiovascular disease. By the age of 80 years, 20% of all men and women have an established clinical diagnosis of coronary artery disease. It is responsible for more than two thirds of all cardiac deaths in the elderly. Coronary artery disease is usually more severe in elderly patients. Severe unstable angina and acute myocardial infarction are often the presenting symptoms. The incidence of multivessel disease is greater and there is an increased likelihood of complications. Atypical clinical presentations are more common in the elderly than in younger patients.2 In recent years there has been some diminution in the age-adjusted cardiac mortality rate. The exact factors that have led to this change are unknown but are probably
Results A total of 28 patients underwent CAB alone and 12 patients underwent valve replacement(s) with or without CAB. Of those patients undergoing valve operation, 6 had aortic valve replacement plus CAB, 2 had aortic valve replacement alone, 2 had mitral valve replacement, 1 had mitral valve replacement and CAB, and 1 patient underwent replacement of the mitral and aortic valves after a previous aortic and mitral valvuloplasty. Patient age varied from 80 to 87 years (mean, 82.4 years). There were 21 men and 19 women. All patients had severe symptoms before operation that were refractory to aggressive medical therapy. The indication for operation was angina pectoris in 28 patients, congestive heart failure in 7 patients, and angina plus congestive heart failure in 5 patients. All patients were in NYHA functional class 3 or 4 before operation. Two patients required insertion of the intraortic balloon before operation in an attempt to stabilize their conditions. Of those patients with angina pectoris, 17 were classified as unstable, and an additional eight patients ex-
774
MERRILL AND OTHERS
related to a decreasing risk for coronary artery disease and a decreasing incidence of rheumatic heart disease. However there is an increasing proportion of elderly patients in the general population. This demographic change far outweighs the decrease in the age-adjusted mortality rate.2 The prevalence of senile calcific aortic stenosis is increasing as the percentage of elderly persons in the general population increases. This has resulted in more elderly patients with symptomatic aortic stenosis, despite the reduction in the incidence of rheumatic fever.3 Therefore cardiac disease will probably continue to be the dominant cause of death in the elderly in the future. In recent years an increasing number of nonoperative treatment options for various heart conditions have been developed. These have included balloon valvuloplasty, coronary angioplasty, and thrombolysis. The increasing use of these modalities may result in a large number of severely ill, symptomatic elderly patients presenting for possible surgical intervention after having failed one or more of the alternative nonsurgical methods.4 Thus surgeons may be called on to consider performing complex cardiac surgical procedures in older, sicker patients. There are more operative risks in older patients for several reasons. These include limited cardiac reserve secondary to cardiovascular disease and to the effects of aging, an increased frequency of urgent or emergency procedures, and the postoperative failure of noncardiac organs. Additional risk factors include associated peripheral and cerebral vascular disease and left main coronary artery stenosis..4 Previous studies have documented that advanced age is an independent predictor of operative mortality.' Older patients have a greater incidence of multiple chronic noncardiac medical illnesses.6 Also there is a higher incidence of cardiovascular compromise due to hypertension, diabetes mellitus, and peripheral and cerebral vascular disease. The appropriate selection of elderly patients for cardiac operative procedures is very important. It is well known that chronologic and physiologic age may be disparate. Physiologic age is difficult if not impossible to assess. In the absence of definitive studies, patient selection must be based on available data and clinical judgment. The indications for operation are the same as they are in younger patients.7 In the current series, patients were operated on for angina pectoris refractory to medical treatment, significant left main coronary artery stenosis, or congestive heart failure due to valvular stenosis or insufficiency. Patients were excluded if they exhibited severe noncardiac illness, intractable heart failure that was thought not likely to be improved by operation, or substantial mental impairment that was not thought to be due to cardiac decompensation. Before operation patients are stabilized, if possible, with
Ann. Surg. * June 1990
aggressive medical management. This may include the use of intravenous nitroglycerin or heparin infusion, inotropic support as necessary, mechanical ventilation, and, in some instances, insertion of the intra-aortic balloon pump. The operative procedure must be carried out in a well-planned, expeditious but unhurried manner. All major coronary artery systems with significant stenoses should be revascularized if possible, but an excessive number of grafts should not be performed. The achievement of adequate hemostasis in the operating room is extremely important to help stabilize the postoperative condition of these patients who are often critically ill. Only one of our patients had to be returned to the operating room for postoperative bleeding. This is in contrast to other studies that have noted a much higher incidence of
postoperative bleeding.7 Postoperative management of elderly cardiac surgery patients presents many complex challenges to the surgical team. There is a relatively high incidence of arrhythmias.8 Prompt control of arrhythmias is necessary in an attempt to avoid low cardiac output and systemic embolization. Extubation must be performed cautiously only after assuring an adequate level of consciousness, sufficient strength to cough and ventilate spontaneously, and adequate hemodynamic performance. This can be accomplished with repeated patient evaluations during a period of progressive but cautious weaning of the ventilator. Renal reserve is generally limited in the elderly, so nephrotoxic agents must be avoided or used with great caution. A program of careful nutritional repletion and progressive exercise and ambulation should be undertaken. Early postoperative confusion and combativeness is ameliorated by frequent contact and discussion between the patient, health care team, and family members. The overall good long-term survival and excellent symptomatic status of our patients is extremely encouraging. These results are corroborated by the findings of Horneffer et al.,9 who studied a group of patients age 70 years and older who underwent CAB. In that study patients over 70 years who underwent successful coronary bypass grafting had a relative probability of survival that was greater than their age-, race-, and sex-matched counterparts in the general population. The level of postoperative rehabilitation was similar to that achieved by younger patients. Most patients reported substantial improvement in activity level after CAB grafting. In the present series all CAB grafts were performed with saphenous vein. A recent study by Gardner et al.'° indicates that grafting with the left internal mammary artery appears to be an independent predictor of improved early and late survival in patients age 70 years or older. These data deserve further study and verification. The choice of a valve substitute in elderly patients remains controversial. Structural deterioration of a bio-
Vol.211 * No.6
CARDIAC SURGERY IN PATIENTS AGE 80 YEARS OR OLDER
prosthetic valve is uncommon in patients age 70 years or older, even up to 10 to 12 years after operation." Borkon et al. 12 analyzed patients 70 years or older who underwent isolated aortic valve replacement. At an average followup of 4.3 years, no patient required reoperation or experienced structural valve failure. Recipients of bioprosthetic valves experienced fewer valve-related complications than patients receiving mechanical valves. In another study of patients older than 80 years who underwent aortic valve replacement there was excellent long-term function of the bioprosthetic valve with very little evidence of late structural deterioration.'3 In contrast, Antunes'4 has documented excellent function of mechanical prostheses in elderly patients. He noted a similar incidence of thromboembolic and hemorrhagic episodes in the elderly and in younger patients. These data did not confirm the supposition that thromboembolic and hemorrhagic complications are accompanied by higher morbidity and mortality rates in elderly patients. In this series overall satisfactory results have been achieved in patients undergoing single or combined procedures. There has been a low operative mortality rate and a low incidence of late postoperative deaths. Other reports3"13 have noted a considerably higher risk of perioperative mortality and morbidity in patients undergoing combined cardiac procedures. One report3 suggested a more conservative posture in patients who require a combined procedure. Patients age 80 years or older who present with severe cardiac symptoms refractory to medical therapy should be considered potential candidates for operative intervention. The advanced extent of their cardiovascular pathology and the high likelihood ofassociated disease states will inevitably result in a higher incidence of operative death and complications compared to younger patients.
DISCUSSION DR. FRED ALLEN CRAWFORD, JR. (Charleston, South Carolina): Our experience at the Medical University of South Carolina over a similar interval mirrors almost exactly the experience from Vanderbilt. In the period 1980 through November 1989, a little more than 3000 adult patients have undergone coronary bypass and/or valve replacement at our institution. Thirty-four, or about 1%, were older than 80 years. As you see, we were unable to demonstrate a significant difference in raw operative mortality for the group as a whole or for the subsets of valve replacement or coronary bypass, although there is a trend of higher risk in elderly patients. This slide is more complex, but the bars represent the number of patients operated on at our institution each year for valve replacement and/or coronary bypass, and the solid line represents the percentage of the overall group older than 65 years, 70 years, 75 years, and 80 years, and what this shows simply is that an increasing percentage of our population of patients who are having valve or coronary bypass surgery are in this elderly group. I have three questions for Dr. Merrill. First, is it true that the operative risk is not much higher in the elderly patient or are we just being more selective in the patients on whom we operate?
775 But despite these limitations, quite satisfactory patient survival and long-term rehabilitation can be achieved. References 1. Bureau of Census. Projections of the population of the United States by age, sex, and race: 1983-2080. Washington, DC: Government Printing Office, 1984. Current population reports. Series P-25, no. 952. 2. Killen DA. Cardiac surgery in the elderly. In Adkins RB Jr, Scott HW Jr, eds. Surgical care for the elderly. Baltimore: Williams and Wilkins, 1988. pp. 203-20. 3. Levinson JR, Akins CW, Buckley MJ, et al. Octogenarians with aortic stenosis: outcome after aortic valve replacement. Circulation 1989; 80(Suppl I):49-56. 4. Grondin CM, Thornton JC, Engle JC, et al. Cardiac surgery in septuagenarians: is there a difference in mortality and morbidity. J Thorac Cardiovasc Surg 1989; 98:908-14. 5. Fremes SE, Goldman BS, Ivanov J, et al. Valvular surgery in the elderly. Circulation 1989; 80 (Suppl I):77-90. 6. Naunheim KS, Kern MJ, McBride LR, et al. Coronary artery bypass surgery in patients aged 80 years or older. Am J Cardiol 1987;
59:804-807. 7. Rich MW, Sandza JG, Kleiger RE, Connors JP. Cardiac operations in patients over 80 years of age. J Thorac Cardiovasc Surg 1985;
90:56-60. 8. Edmunds LH Jr, Stephenson LW, Edie RN, Ratcliffe MB. Openheart surgery in octogenarians. N Engl J Med 1988; 319:131136. 9. Horneffer PJ, Gardner TJ, Manolio TA, et al. The effects of age on outcome after coronary bypass surgery. Circulation 1987; 76 (Suppl V):6-12. 10. Gardner TJ, Greene PS, Rykiel MF, et al. Routine use of the left internal mammary artery graft in the elderly. Ann Thorac Surg 1990; 49:188-194. 11. Jamieson WRE, Burr LH, Munro Al, et al. Cardiac valve replacement in the elderly: clinical performance of biological prostheses. Ann Thorac Surg 1989; 48:173-185. 12. Borkon AM, Soule LM, Baughman KL, et al. Aortic valve selection in the elderly patient. Ann Thorac Surg 1988; 46:270-277. 13. Fiore AC, Naunheim KS, Barner HB, et al. Valve replacement in the octogenarian. Ann Thorac Surg 1989; 48:104-108. 14. Antunes MJ. Valve replacement in the elderly: is the mechanical valve a good alternative. J Thorac Cardiovasc Surg 1989; 98: 485-491.
If the latter is true, how do your selection criteria differ in this group? Second, does this low risk hold up the patient who needs reoperation? And finally, in this population, do you routinely use the internal mammary artery for revascularization, and what is your valve ofchoice? DR. TIMOTHY J. GARDNER (Baltimore, Maryland): The increasingly older age of patients who are referred for cardiac surgery is a fact of the present day. Operating on elderly patients, even those in their 80s, does not represent misguided clinical enthusiasm. It is an appropriate response to the increasingly elderly portion of our population. In our own practice the mean age of patients having bypass grafting has risen from 54 years in 1978 to 63 years in 1989. Furthermore, the median age of our adult patients now is 68 years. Our clinical data also reflect the experience in Nashville and to some extent the Charleston experience. From 1982 to 1988, we operated on 91 patients who were 80 years and older. Forty-seven patients in this age range had bypass grafting only, with 4% mortality. Twenty-three patients had bypass grafting and valve replacement with a 21% mortality rate. For valve replacement only, there were 20 patients and a 10% mortality rate. We had one patient with an acute dissection and one acute VSD.
Patients Age
80
Years or Older
WALTER H. MERRILL, M.D., JAMES R. STEWART, M.D., WILLIAM H. FRIST, M.D., JOHN W. HAMMON, JR., M.D., and HARVEY W. BENDER, JR., M.D.
Between February 1978 and August 1989, forty patients age 80 years or older underwent cardiac surgery at this institution. Patient age varied from 80 to 87 years (mean, 82.4 years). Operative indications were angina pectoris or congestive heart failure. Twenty-eight patients underwent coronary artery bypass (CAB) alone and 12 underwent valve -replacement(s) with or without CAB. The operative mortality rate was 10%. Postoperative hospitalization averaged 14 days. There were three late cardiac deaths at 13, 36, and 48 months after operation and one late noncardiac death. Thirty-two survivors have been followed from 1 to 86 months (mean, 20 months). All experienced sustained improvement in functional status and minimal late morbidity. All survivors remained in NYHA class 1 or 2. Cardiac surgical procedures in patients older than 80 years can be performed with increased but acceptable mortality and morbidity rates. Most patients achieve sustained symptomatic improvement and excellent long-term survival.
From the Department of Cardiac and Thoracic Surgery, Vanderbilt University School of Medicine, The Vanderbilt Clinic, Nashville, Tennessee
mortality rates, long-term survival, and functional capacity. Patients and Methods
I N RECENT YEARS it has become apparent that the number of persons 80 years of age or older is increasing in the United States. It has been reported that 43% of all Americans will reach the age of 80 years and will live, on average, almost 8 more years.' Symptomatic heart disease is present in approximately 40% of all persons age 80 years or older. Many patients with symptoms that are refractory to aggressive medical therapy may be potential candidates for cardiac surgery. During the past several years excellent results have been reported in older persons undergoing valve replacement or coronary artery bypass (CAB). These encouraging results have led to an increasing frequency of operation in patients older than 80 years. To determine the efficacy of cardiac surgery in the octogenarian population, we reviewed the course of our patients who were 80 years of age or older and analyzed their operative morbidity and Presented at the 101st Annual Meeting of the Southern Surgical Association, Hot Springs, Virginia, December 3-6, 1989. Address reprint requests to Walter H. Merrill, M.D., The Vanderbilt Clinic, Room 2973, Nashville, TN 37232.
Between February 1978 and August 1989, forty patients age 80 years or older underwent cardiac surgical procedures at the Vanderbilt University Medical Center. All patient records were reviewed to assess age, sex, diagnosis, risk factors, operative procedure, perioperative complications, and long-term follow-up. The Canadian Cardiovascular Society classification was used to grade angina pectoris. Each patient was assigned a New York Heart Association (NYHA) functional classification. Cardiac catheterization was performed in all patients. The degree of valve stenosis or insufficiency was quantitated using standard catheterization techniques. Narrowing of the left main coronary artery by more than 50% and narrowing of the other coronary arteries by more than 70% was considered sufficiently severe to warrant myocardial revascularization. The operative technique consisted of standard median sternotomy and nonpulsatile cardiopulmonary bypass. Moderate hypothermia to 25 to 28 C was used. The operative procedures were performed with standard aortic clamping and a single dose of hyperkalemic crystalloid cardioplegia (4 C) and either continuous or intermittent topical myocardial cooling. All CAB grafts were performed with autogenous reversed saphenous vein. All valve replacements were performed with bioprostheses. Perioperative data included time in intensive care unit, total time in hospital after operation, operative mortality (death during the initial hospitalization), and complica-
772
Vol. 211 - No. 6
CARDIAC SURGERY IN PATIENTS AGE 80 YEARS OR OLDER
tions. Early survival was defined by patient discharge from the hospital. All surviving patients were evaluated within the month of October 1989 through direct patient contact or by information obtained from the patients' personal physicians, or both. The level of physical activity was determined and graded by the NYHA functional classification.
773
perienced postinfarction angina. Hemodynamically significant coronary artery disease was documented as follows: left main and three-vessel coronary artery disease was present in 7 patients, left main and two-vessel coronary artery disease was present in 1 patient, three-vessel disease was present in 20 patients, two-vessel disease was present in 5 patients, and one-vessel disease was present in 2 patients. In the 35 patients undergoing CAB with or without associated procedures, the mean number of distal
slow ventricular response rate after operation. An additional patient with preoperative third degree atrioventricular block required insertion of an atrioventricular sequential pacemaker. Four patients developed the new onset of atrial fibrillation, but in all cases normal sinus rhythm was restored with appropriate medical therapy. Two patients experienced a superficial wound infection from their saphenous vein harvest sites, but no patient developed a sternal wound infection or dehiscence. Two patients developed a temporary neurologic deficit that cleared completely by the time of discharge. The 36 hospital survivors stayed a mean of 4.6 days in the intensive care unit (range, 2 to 21 days). Their postoperative convalescent time after leaving the intensive care unit was a mean of 10 days (range, 3 to 23 days). A total of three late cardiac-related deaths occurred after operation. One patient who had undergone a three-vessel CAB experienced mild angina and dyspnea on exertion late after operation, and this patient died 13 months after operation, probably due to an acute myocardial infarction. One patient who had undergone aortic valve replacement and a two-vessel CAB suffered severe late postoperative depression and died 3 years after operation of multisystem organ failure. One patient who had undergone a single vessel CAB did extremely well after operation but died at 48 months, probably due to an acute myocardial infarction. There was one additional late noncardiac death. This patient had undergone mitral valve replacement and had no cardiac symptoms, but she died of widespread metastatic breast carcinoma 10 months after operation. No patients were lost to follow-up. The 32 long-term survivors have been followed an average of 20 months (range, 1 to 86 months). All of the long-term survivors are reasonably active consistent with their overall general health. From a cardiovascular standpoint all are in NYHA functional class 1 or 2. All survivors are improved compared to their preoperative status.
anastomoses was 2.7. The operative mortality rate was 10% (4 of 40 patients). One patient who underwent aortic valve replacement and a two-vessel CAB experienced cardiogenic shock and died several hours after operation. Another patient who underwent CAB had postoperative bleeding and had to be returned to the operating room for control of bleeding. This patient developed low cardiac output and died of cardiogenic shock on postoperative day 1. Two additional patients, one of whom underwent aortic valve replacement and one of whom underwent CAB, died 2 weeks after operation from multiple neurologic insults and multiorgan system failure. The 36 patients who survived operation experienced several perioperative complications. Two patients required insertion of a permanent transvenous pacemaker. One patient in chronic atrial fibrillation had an unacceptably
Discussion The major cause of death and disability among elderly persons is cardiovascular disease. By the age of 80 years, 20% of all men and women have an established clinical diagnosis of coronary artery disease. It is responsible for more than two thirds of all cardiac deaths in the elderly. Coronary artery disease is usually more severe in elderly patients. Severe unstable angina and acute myocardial infarction are often the presenting symptoms. The incidence of multivessel disease is greater and there is an increased likelihood of complications. Atypical clinical presentations are more common in the elderly than in younger patients.2 In recent years there has been some diminution in the age-adjusted cardiac mortality rate. The exact factors that have led to this change are unknown but are probably
Results A total of 28 patients underwent CAB alone and 12 patients underwent valve replacement(s) with or without CAB. Of those patients undergoing valve operation, 6 had aortic valve replacement plus CAB, 2 had aortic valve replacement alone, 2 had mitral valve replacement, 1 had mitral valve replacement and CAB, and 1 patient underwent replacement of the mitral and aortic valves after a previous aortic and mitral valvuloplasty. Patient age varied from 80 to 87 years (mean, 82.4 years). There were 21 men and 19 women. All patients had severe symptoms before operation that were refractory to aggressive medical therapy. The indication for operation was angina pectoris in 28 patients, congestive heart failure in 7 patients, and angina plus congestive heart failure in 5 patients. All patients were in NYHA functional class 3 or 4 before operation. Two patients required insertion of the intraortic balloon before operation in an attempt to stabilize their conditions. Of those patients with angina pectoris, 17 were classified as unstable, and an additional eight patients ex-
774
MERRILL AND OTHERS
related to a decreasing risk for coronary artery disease and a decreasing incidence of rheumatic heart disease. However there is an increasing proportion of elderly patients in the general population. This demographic change far outweighs the decrease in the age-adjusted mortality rate.2 The prevalence of senile calcific aortic stenosis is increasing as the percentage of elderly persons in the general population increases. This has resulted in more elderly patients with symptomatic aortic stenosis, despite the reduction in the incidence of rheumatic fever.3 Therefore cardiac disease will probably continue to be the dominant cause of death in the elderly in the future. In recent years an increasing number of nonoperative treatment options for various heart conditions have been developed. These have included balloon valvuloplasty, coronary angioplasty, and thrombolysis. The increasing use of these modalities may result in a large number of severely ill, symptomatic elderly patients presenting for possible surgical intervention after having failed one or more of the alternative nonsurgical methods.4 Thus surgeons may be called on to consider performing complex cardiac surgical procedures in older, sicker patients. There are more operative risks in older patients for several reasons. These include limited cardiac reserve secondary to cardiovascular disease and to the effects of aging, an increased frequency of urgent or emergency procedures, and the postoperative failure of noncardiac organs. Additional risk factors include associated peripheral and cerebral vascular disease and left main coronary artery stenosis..4 Previous studies have documented that advanced age is an independent predictor of operative mortality.' Older patients have a greater incidence of multiple chronic noncardiac medical illnesses.6 Also there is a higher incidence of cardiovascular compromise due to hypertension, diabetes mellitus, and peripheral and cerebral vascular disease. The appropriate selection of elderly patients for cardiac operative procedures is very important. It is well known that chronologic and physiologic age may be disparate. Physiologic age is difficult if not impossible to assess. In the absence of definitive studies, patient selection must be based on available data and clinical judgment. The indications for operation are the same as they are in younger patients.7 In the current series, patients were operated on for angina pectoris refractory to medical treatment, significant left main coronary artery stenosis, or congestive heart failure due to valvular stenosis or insufficiency. Patients were excluded if they exhibited severe noncardiac illness, intractable heart failure that was thought not likely to be improved by operation, or substantial mental impairment that was not thought to be due to cardiac decompensation. Before operation patients are stabilized, if possible, with
Ann. Surg. * June 1990
aggressive medical management. This may include the use of intravenous nitroglycerin or heparin infusion, inotropic support as necessary, mechanical ventilation, and, in some instances, insertion of the intra-aortic balloon pump. The operative procedure must be carried out in a well-planned, expeditious but unhurried manner. All major coronary artery systems with significant stenoses should be revascularized if possible, but an excessive number of grafts should not be performed. The achievement of adequate hemostasis in the operating room is extremely important to help stabilize the postoperative condition of these patients who are often critically ill. Only one of our patients had to be returned to the operating room for postoperative bleeding. This is in contrast to other studies that have noted a much higher incidence of
postoperative bleeding.7 Postoperative management of elderly cardiac surgery patients presents many complex challenges to the surgical team. There is a relatively high incidence of arrhythmias.8 Prompt control of arrhythmias is necessary in an attempt to avoid low cardiac output and systemic embolization. Extubation must be performed cautiously only after assuring an adequate level of consciousness, sufficient strength to cough and ventilate spontaneously, and adequate hemodynamic performance. This can be accomplished with repeated patient evaluations during a period of progressive but cautious weaning of the ventilator. Renal reserve is generally limited in the elderly, so nephrotoxic agents must be avoided or used with great caution. A program of careful nutritional repletion and progressive exercise and ambulation should be undertaken. Early postoperative confusion and combativeness is ameliorated by frequent contact and discussion between the patient, health care team, and family members. The overall good long-term survival and excellent symptomatic status of our patients is extremely encouraging. These results are corroborated by the findings of Horneffer et al.,9 who studied a group of patients age 70 years and older who underwent CAB. In that study patients over 70 years who underwent successful coronary bypass grafting had a relative probability of survival that was greater than their age-, race-, and sex-matched counterparts in the general population. The level of postoperative rehabilitation was similar to that achieved by younger patients. Most patients reported substantial improvement in activity level after CAB grafting. In the present series all CAB grafts were performed with saphenous vein. A recent study by Gardner et al.'° indicates that grafting with the left internal mammary artery appears to be an independent predictor of improved early and late survival in patients age 70 years or older. These data deserve further study and verification. The choice of a valve substitute in elderly patients remains controversial. Structural deterioration of a bio-
Vol.211 * No.6
CARDIAC SURGERY IN PATIENTS AGE 80 YEARS OR OLDER
prosthetic valve is uncommon in patients age 70 years or older, even up to 10 to 12 years after operation." Borkon et al. 12 analyzed patients 70 years or older who underwent isolated aortic valve replacement. At an average followup of 4.3 years, no patient required reoperation or experienced structural valve failure. Recipients of bioprosthetic valves experienced fewer valve-related complications than patients receiving mechanical valves. In another study of patients older than 80 years who underwent aortic valve replacement there was excellent long-term function of the bioprosthetic valve with very little evidence of late structural deterioration.'3 In contrast, Antunes'4 has documented excellent function of mechanical prostheses in elderly patients. He noted a similar incidence of thromboembolic and hemorrhagic episodes in the elderly and in younger patients. These data did not confirm the supposition that thromboembolic and hemorrhagic complications are accompanied by higher morbidity and mortality rates in elderly patients. In this series overall satisfactory results have been achieved in patients undergoing single or combined procedures. There has been a low operative mortality rate and a low incidence of late postoperative deaths. Other reports3"13 have noted a considerably higher risk of perioperative mortality and morbidity in patients undergoing combined cardiac procedures. One report3 suggested a more conservative posture in patients who require a combined procedure. Patients age 80 years or older who present with severe cardiac symptoms refractory to medical therapy should be considered potential candidates for operative intervention. The advanced extent of their cardiovascular pathology and the high likelihood ofassociated disease states will inevitably result in a higher incidence of operative death and complications compared to younger patients.
DISCUSSION DR. FRED ALLEN CRAWFORD, JR. (Charleston, South Carolina): Our experience at the Medical University of South Carolina over a similar interval mirrors almost exactly the experience from Vanderbilt. In the period 1980 through November 1989, a little more than 3000 adult patients have undergone coronary bypass and/or valve replacement at our institution. Thirty-four, or about 1%, were older than 80 years. As you see, we were unable to demonstrate a significant difference in raw operative mortality for the group as a whole or for the subsets of valve replacement or coronary bypass, although there is a trend of higher risk in elderly patients. This slide is more complex, but the bars represent the number of patients operated on at our institution each year for valve replacement and/or coronary bypass, and the solid line represents the percentage of the overall group older than 65 years, 70 years, 75 years, and 80 years, and what this shows simply is that an increasing percentage of our population of patients who are having valve or coronary bypass surgery are in this elderly group. I have three questions for Dr. Merrill. First, is it true that the operative risk is not much higher in the elderly patient or are we just being more selective in the patients on whom we operate?
775 But despite these limitations, quite satisfactory patient survival and long-term rehabilitation can be achieved. References 1. Bureau of Census. Projections of the population of the United States by age, sex, and race: 1983-2080. Washington, DC: Government Printing Office, 1984. Current population reports. Series P-25, no. 952. 2. Killen DA. Cardiac surgery in the elderly. In Adkins RB Jr, Scott HW Jr, eds. Surgical care for the elderly. Baltimore: Williams and Wilkins, 1988. pp. 203-20. 3. Levinson JR, Akins CW, Buckley MJ, et al. Octogenarians with aortic stenosis: outcome after aortic valve replacement. Circulation 1989; 80(Suppl I):49-56. 4. Grondin CM, Thornton JC, Engle JC, et al. Cardiac surgery in septuagenarians: is there a difference in mortality and morbidity. J Thorac Cardiovasc Surg 1989; 98:908-14. 5. Fremes SE, Goldman BS, Ivanov J, et al. Valvular surgery in the elderly. Circulation 1989; 80 (Suppl I):77-90. 6. Naunheim KS, Kern MJ, McBride LR, et al. Coronary artery bypass surgery in patients aged 80 years or older. Am J Cardiol 1987;
59:804-807. 7. Rich MW, Sandza JG, Kleiger RE, Connors JP. Cardiac operations in patients over 80 years of age. J Thorac Cardiovasc Surg 1985;
90:56-60. 8. Edmunds LH Jr, Stephenson LW, Edie RN, Ratcliffe MB. Openheart surgery in octogenarians. N Engl J Med 1988; 319:131136. 9. Horneffer PJ, Gardner TJ, Manolio TA, et al. The effects of age on outcome after coronary bypass surgery. Circulation 1987; 76 (Suppl V):6-12. 10. Gardner TJ, Greene PS, Rykiel MF, et al. Routine use of the left internal mammary artery graft in the elderly. Ann Thorac Surg 1990; 49:188-194. 11. Jamieson WRE, Burr LH, Munro Al, et al. Cardiac valve replacement in the elderly: clinical performance of biological prostheses. Ann Thorac Surg 1989; 48:173-185. 12. Borkon AM, Soule LM, Baughman KL, et al. Aortic valve selection in the elderly patient. Ann Thorac Surg 1988; 46:270-277. 13. Fiore AC, Naunheim KS, Barner HB, et al. Valve replacement in the octogenarian. Ann Thorac Surg 1989; 48:104-108. 14. Antunes MJ. Valve replacement in the elderly: is the mechanical valve a good alternative. J Thorac Cardiovasc Surg 1989; 98: 485-491.
If the latter is true, how do your selection criteria differ in this group? Second, does this low risk hold up the patient who needs reoperation? And finally, in this population, do you routinely use the internal mammary artery for revascularization, and what is your valve ofchoice? DR. TIMOTHY J. GARDNER (Baltimore, Maryland): The increasingly older age of patients who are referred for cardiac surgery is a fact of the present day. Operating on elderly patients, even those in their 80s, does not represent misguided clinical enthusiasm. It is an appropriate response to the increasingly elderly portion of our population. In our own practice the mean age of patients having bypass grafting has risen from 54 years in 1978 to 63 years in 1989. Furthermore, the median age of our adult patients now is 68 years. Our clinical data also reflect the experience in Nashville and to some extent the Charleston experience. From 1982 to 1988, we operated on 91 patients who were 80 years and older. Forty-seven patients in this age range had bypass grafting only, with 4% mortality. Twenty-three patients had bypass grafting and valve replacement with a 21% mortality rate. For valve replacement only, there were 20 patients and a 10% mortality rate. We had one patient with an acute dissection and one acute VSD.
