Results of Reoperation

Results of Reoperation for Recurrent Angina Pectoris William I. Norwood, M.D., Lawrence H. Cohn, M.D., and John J. Collins, Jr., M.D. ABSTRACT Although a coronary bypass operation improves the quality of life and possibly prolongs it, a small percentage of patients do not have satisfactory results and require reoperation. From July, 1970, to March, 1975,358 patients underwent coronary bypass for chronic disabling or preinfarction angina. Angina requiring operation recurred in 24 men and 2 women. Hyperlipoproteinemia was present in 19 of the 26 (73'/0), and 3 patients had early-onset diabetes mellitus. Only 2 of 14 patients with progression of arteriosclerosis were helped by a second operation. Of 7 patients with occluded grafts, local disease, and no progression, 5 were helped by reoperation. Patients with occluded coronary bypass grafts without progression of arteriosclerosis benefit substantially from a second revascularization procedure. A guarded prognosis must be held, however, for those with progression of arteriosclerosis with hyperlipopmteinemia or juvenile-onset diabetes who undergo reoperation. Patients with initially diffuse disease and graft occlusion also seem to benefit less from a second operation. The operative management of ischemic heart disease by bypass of proximal obstructions of the coronary vascular bed has been characterized in recent years by low operative mortality and significant improvement in the quality of the patient's life [7, 9, 10, 151. In addition, there is suggestive evidence that surgical revascularization may increase survival of patients with advanced coronary artery disease [71. Such an appealing combination of real and possible benefits has contributed to the rapid accumulation of a substantial and increasing number of From the Department of Surgery, Harvard Medical School, and the Division of Thoracic and Cardiac Surgery, Peter Bent Brigham Hospital, Boston, MA. Accepted for publication Apr 15, 1976. Address reprint requests to Dr. Collins, Chief, Division of Thoracic and Cardiac Surgery, Peter Bent Brigham Hospital, 721 Huntington Ave, Boston, MA 02115. patients managed by coronary artery bypass operations. Despite generally satisfactory results, significant angina may recur within a few years in 12 to 20% of patients so treated [4, 7, 11,121. Furthermore, since operative manipulation of the coronary arteries per se is not expected to arrest or attenuate the primary atherosclerotic process, the incidence of angina recurrence due to disease progression will almost certainly increase with time. The experience at the Peter Bent Brigham Hospital with operative treatment of patients experiencing recurrent angina following coronary artery bypass has been reviewed. The focus of this review has been on the relationships between the presenting characteristics of the recurrent angina, the etiology of the recurrence, and the results of operative management. Clinical Material From July 1,1970, to March 1,1975,519 patients underwent operative treatment for coronary artery disease at the Peter Bent Brigham Hospital; 358 of these had chronic disabling angina with satisfactory ventricular function. During this interval, 26 patients with recurrent angina pectoris following coronary artery revascularization were operated on at this hospital. Of these, 6 had had their first operation at other institutions. All 26 patients had initially been seen with chronic disabling angina pectoris that was refractory to medical management. There were 24 men and only 2 women (7%), whereas of the 358 patients primarily treated for chronic disabling angina, 44 (14%) were women. The average age in the primary and recurrent angina groups was similar (49.6 and 48.5 years, respectively). Several factors have been associated with increased risk for coronary artery disease [4,11]. In this series, 7 patients (27%) had hypertension, 2 (8%) had hyperuricemia, 8 (31%) had clinically significant diabetes mellitus (of which 3 had 9

10 The Annals of Thoracic Surgery Vol 23 No 1 January 1977 early-onset diabetes), and 19 (73%) had hyperlipoproteinemia (10 with type I1 and 9 with type Iv). The initial revascularization procedures for these patients had included 12 single bypass grafts, 11 double grafts, 2 triple grafts, and 1 quadruple graft. Twenty-one patients had had grafts to the left anterior descending coronary artery (6 using the internal mammary artery), 11 had had right coronary artery grafts (3 with concomitant distal endarterectomy), and 11 had had grafts to the left circumflex coronary artery (Table 1). Angina pectoris recurred within one week to 30 months (mean, 6 months) after the original procedure, and all patients were sufficiently disabled by the recurrent pain to require intensive therapy with analgesics, nitrates, propran- 0101, or combinations of these agents. Based on repeat cardiac catheterization, recurrent angina was attributed to total occlusion of at least 1 graft in 17 patients, other technical problems (stenosis of an anastomosis or tenting of a graft) in 4, and significant progression of coronary obstructive disease ( > 70% obstruction) in 5. Of the patients with occluded grafts, only 3 had more than 1 nonfunctioning graft. Eleven left anterior descending grafts (4 using the internal mammary artery), 5 circumflex marginal grafts, and 6 right coronary artery grafts (2 combined with endarterectomy) were found to be occluded. Twelve patients (46%) had no progression of arteriosclerotic disease as interpreted from coronary angiography, and the average time between preoperative and postoperative catheterizations in this group with graft lailures was 10 months. The interval between caiheterizations for the 5 patients thought to have recurrent angina on the basis of progression of disease only was 29 months. In the 14 patients with progression of disease, there was no apparent predilection for advancing obstruction in grafted versus iingrafted vessels. The treatment at reoperation consisted of a single bypass graft in 16 patients, double grafts in 8 patients, internal mammary artery implants only in 2 patients, and a saphenous vein graft from aorta to posterior cardiac vein with proximal ligation of the cardiac vein in 1 patient. Of the secondary grafts, 16 were to the left anterior descending corcinary artery (7 using the internal mammary artery), 5 were to the left circumflex system, and 9 were to the right coronary artery (4 with concomitant endarterectomy). In addition, 2 patients had saphenous vein interposed in a previous vein graft where a stenotic lesion was excised, and 1 patient had a saphenous vein graft from the aorta to a previously grafted internal mammary artery. All operations were performed with cardiopulmonary bypass using a bubble oxygenator, heniodilution, and moderate systemic hypothermia (30 C). Table 1. Operation for Recurrent Angina No. of Bypassed No. of Vessels No. of Operation Vessels Patients Bypassed Patients Primary operation 1 12 LAD 21 2 11 RCA 11 >2 3 LCF 11 IMI 3...... Secondary operation 1 16 LAD 16 2 8 RCA 9 >2 0 LCF 5 IMI 2..... LAD = left anterior descending coronary artery; RCA = right coronary artery; LCF =: left circumflex coronary artery, IMI = internal mammary artery implant.

~ 11 Norwood, Cohn, and Collins: Reoperation for Recurrent Angina Pectoris All patients have been personally followed by one or more of the authors. The follow-up period was 6 to 48 months, with a mean of 20 months. ]Results There were 2 (8%) in-hospital deaths among the 26 patients who underwent reoperation for recurrent angina (Table 2). There was 1 late death from acute myocardial ischemia at 1 year follow- :ing an internal mammary artery graft to the left anterior descending coronary artery (4%), for a total mortality of 12%. Four months prior to the!late death, repeat catheterization had revealed a patent graft but poor distal runoff. Of the 3 patients who died, 2 were insulin-dependent juvenile-onset diabetics who were less than 35 years of age. Three patients suffered a perioperative myocardial infarction diagnosed by electrocardiographic and serum enzyme alterations at reoperation, and 4 additional patients sustained a myocardial infarction during the follow-up period, 1 of whom died. Significant angina recurred in 12 (52%) of the 23 patients followed 6 to 48 months after operation for recurrent angina. Mild angina, occurring only occasionally on extreme exertion and not requiring medication, has been reported by 4 patients. Chronic congestive heart failure requiring maintenance on digitalis and diuretics is a continuing problem for 1 patient. Seven of 23 (30%) are asymptomatic. Comment Probably the most striking feature of operation for recurrent angina pectoris is that symptoms Table 2. Results of Coronary Vascular Operation for Recurrent Angina in 26 Patients Result No. of Patients Asymptomatic 7 30 Mild angina 4 17 Significant angina 12 52 Perioperative infarction 4 17 Pulmonary embolus 0.. Cerebrovascular accident 0.. Died 3 12 Percent were not abated for a significant interval in more than one-half of these patients. The prognosis for patients undergoing secondary operation for coronary obstructive disease is dependent on the cause of the recurrent symptoms and whether significant myocardial ischemia is associated with it. Although some persons may experience persistent or recurrent angina with angiographically satisfactory revascularization, most will be found to have at least one major vessel inadequately perfused. Our previously reported experience indicates that inadequate perfusion was demonstrated in 26% of asymptomatic patients and in 100 /~ of those with recurrent angina at postoperative angiography [12]. Many institutions report abatement of angina pectoris by initial direct coronary revascularization in about 75% of patients [l, 51. One might anticipate that patients with recurrent angina having occluded grafts without evidence of progression of disease would probably be benefited by a second procedure. Of the 7 patients in this series who became asymptomatic, 5 fit these criteria. Although 10 patients in this series were judged to have occluded grafts without progression of disease, 4 had diffuse obstructions in multiple vessels initially, making it difficult to recognize any extending disease. Similarly, patients judged in retrospect to have had significant obstruction in a major coronary artery that was not bypassed would be expected to benefit from a second procedure. Four patients met this criterion. Two of them had 70% obstruction in the left circumflex and left anterior descending coronary arteries, respectively, and both are symptomatic following secondary grafting. Two patients had highgrade lesions in the right coronary artery (one in a left dominant coronary artery system). One patient died, and the other has severe angina 2 years after a second procedure. The majority of patients (68%) with recurrent angina had 1 or more occluded grafts. Various reports indicate that the 1-year patency of saphenous vein grafts is about 75% [l, 21. Although the etiology of graft occlusion is not altogether clear, several studies (including a report of 38 patients who underwent reoperation

12 The Annals of Thoracic Surgery Vol 23 No 1 January 1977 for coronary disease) have correlated low graft flow with graft occlusion [3]. In addition, the etiology of occlusion was not elucidated in most patients by exploration of the grafts, although 2 patients were thought to have inordinately dense adhesions and the graft in a third patient was found to be kinked. Histological examination of the occluded veins universally revealed medial hypertrophy and fibrosis of the intima and media. No atheromas have been observed in the veins. Progression of arteriosclerotic disease in ungrafted arteries was considered the sole cause of recurrent angina in only 5 (19O/0) of the patients. The average interval between initial preoperative angiography and the study following recurrence of symptoms was 29 months for these 5 patients, compared with 10.2 months for those who had no progression of disease but had occluded grafts. Recent interest has focused on the rate of progression of obstructive disease in grafted versus ungrafted vessels [8, 131. Some reports suggest that partially obstructing lesions proximal to graft anastomoses are at greater risk to occlude than lesions of ungrafted vessels, raising some concern about the total dependence on a vein graft that may itself ultimately occlude D31. Although the numbers are small in this series, 14 patients demonstrated progression of arteriosclerotic disease in the interval between preoperative and repeat angiography. Five of these patients had advancing disease in previously grafted coronary arteries, 3 patients had progression of obstruction in ungrafted vessels, and 6 had advancing disease in both (Table 3). Three vessels that were merely stenotic before operation were occluded proximal to the bypass graft at the time of the second study. One of these patients with an obstructed left anterior descending coronary artery had an occluded graft to that artery, but myocardial infarction did not occur. Of the 14 patients who demonstrated progression of disease by angiography, only 2 were benefited by a second operative procedure. Only 3 of these 14 did not have some form of hyperlipoproteinemia, and 2 of the 3 were improved by the second operation. Although any Table 3. Etiology of Recurrent Angina Etiology Occluded graft Tented or stenosed graft Progression of disease Without occluded graft With occluded graft In grafted vessel only In ungrafted vessel only In both No. of Patients 17 4 14 5 9 5 3 6 conclusion should be guarded in the light of an overall high incidence of hyperlipidemid in this series, it is noteworthy that only 1 of the 14 patients with pi-ogression of disease and hyperlipidemia was benefited by a second operative procedure. Juvenile-onset diabetes mellitus also correlates with a poor prognosis. Two of the 3 patients who died had diabetes mellitus. This disease has been shown to be associated with increased coronary vascular resistance in the face of angiographically patent vascular anatomy 161, and one would expect that a loss of correlation between the angiographic appearance of vessels and myocardial ischemia or altered coronary hemodynamics would render a successful operative outcome less likely. The incidence of serious postoperative complications (excluding death) was the same following reoperation as it was following the primary operation (see Table 2). However, technical problems attendant on the dissection of adhesions and loss of surface anatomy affected the outcome in 4 of the 26 patients. Two patients underwent internal mammary artery implantations instead of direct revascularization. One of the 2 is currently asymptomatic. A third patient received only 1 bypass graft when 2 had been planned; he is currently asymptomatic. The rationale and technique of providing arterial blood flow to a clistally ligated coronary vein for treatment of myocardial ischemia has recently been reported [141. One patient in this series was so managed but without abatement of symptoms. Finally, preserving previously established functioning bypass grafts while exposing the

13 Norwood, Cohn, and Collins: Reoperation for Recurrent Angina Pectoris heart has not always been easy. On 1 occasion, a patent internal mammary artery graft was anastomosed to the transected mammary artery. With this repair and a new vein bypass graft to a second artery, the patient is without symptoms 112 months postoperatively. In conclusion, the outcome in patients who underwent operation for recurrent angina pectoris was different from the outcome in those :selected for initial revascularization because of ischemic coronary artery disease. Although the (complication rate attendant on a second procedure was low, substantial relief of symptoms was experienced by only 48% of the patients. 'The patients with the best outlook were those having occluded grafts without progression of disease. The majority of them became symptomatic within a year of their initial operation, and usually within the first 6 months. Symptomatic relief in this group was similar to that observed in the patients treated initially. A guarded prognosis must be held for those with evidence of progression of disease, particularly when it occurs in conjunction with some form of hyperlipoproteinemia. These patients usually became symptomatic later than 1 year after their initial operation. The few young, symptomatic, juvenile-onset diabetics in this series had very poor outcomes. References Alderman EL, Matlof HJ, Wexler L, et al: Results of direct coronary artery surgery for treatment of angina pectoris. N Engl J Med 288:535, 1973 Anderson RP, Rahimtoola SH, Bonchek LI, et al: Prognosis of patients with coronary artery disease after coronary bypass operations: time related progress of 532 patients with disabling angina pectoris. Circulation 50:272, 1974 Benedict JS, Buhl TL, Henney RP: Revasculariza- 4. 5. 6. 7. 8. 9. 12. 13. 14. 15. tion of the ischemic myocardium. Arch Surg 108:40, 1974 Burggraft GW, Parker JO: Prognosis in coronary artery disease: angiographic, hemodynamic and clinical factors. Circulation 51:146, 1975 Cheanvechai C, Effler DB, Groves LK, et al: Triple bypass graft for treatment of severe triple coronary vessel disease. Ann Thorac Surg 17:545,1974 Chychola N, Gau GT, Pluth JR, et al: Myocardial revascularization: comparison of operability and surgical results in diabetic and nondiabetic patients. J Thorac Cardiovasc Surg 65:856, 1973 Cohn LH, Boyden CM, Collins JJ Jr: Improved long-term survival after aorto-coronary bypass for advanced coronary artery disease. Am J Surg 129:380, 1975 Glassman E, Spencer FC, Krauss KR, et al: Changes in underlying coronary circulation secondary to bypass grafting. Circulation 49,5O:Suppl2:80, 1974 Hall RJ, Garcia E, Al-Bassam MS, et al: Aortocoronary bypass surgery 1969-1973: review of 2566 patients. Bull Tex Heart Inst 1:74, 1974 10. Hutchinson JE, Green GE, Mekhjian HA, et al: Coronary bypass grafting in 376 consecutive patients with three operative deaths. J Thorac Cardiovasc Surg 67:7, 1974 11, Kannel WB, Feinleib M: Natural history of angina pectoris in the Framingham study. Am J Cardiol 29:154, 1972 Levine JA, Bechtel DJ, Gorlin R, et al: Coronary artery anatomy before and after direct revascularization surgery: clinical and cinearteriographic studies in67 selectedpatients. Am Heart J 89:561, 1975 Maurer BJ, Oberman A, Holt JH Jr, et al: Changes in grafted and nongrafted coronary arteries following saphenous vein bypass grafting. Circulation 50:293, 1974 Park SB, Magovern GJ, Liebler GA, et al: Direct selective myocardial revascularization by internal mammary artery-coronary vein anastomosis. J Thorac Cardiovasc Surg 69:63, 1975 Sheldon WC, Rincon G, Effler DB, et al: Vein graft surgery for coronary artery disease: survival and angiographical results in 1000 patients. Circulation 48:184, 1973