David K. Bone

Percutaneous transluminal coronary angioplasty in patients with prior coronary bypass surgery

To improve symptomatic status and avoid reoperation, 122 initial and 7 repeat percutaneous transluminal coronary angioplasty procedures were performed in 116 patients with disabling angina pectoris at a mean of 26.8 months (range 2 to 132) after coronary bypass surgery. Marked angiographic improvement (greater than 30% reduction in diameter stenosis) was obtained in 107 (88%) of the 122 initial procedures and in all 7 repetitions. Mean stenosis was reduced from 78 +/- 13% (mean +/- standard deviation) to 25 +/- 13% (p less than 0.0001) and mean pressure gradient from 49 +/- 15 to 11 +/- 8 mm Hg (p less than 0.0001). Complications were: emergency surgery (three patients), Q wave infarction (one patient), myocardial infarction by enzyme criteria only (four patients) and non-occluding coronary dissection (one patient). There were no neurologic or peripheral vascular complications and no early deaths. One late death occurred 14 months after an unsuccessful but uncomplicated angioplasty procedure. At a mean follow-up of 8.3 months, 88 patients (76%) were free of angina or in improved condition. In patients followed up for at least 6 months, evidence of restenosis occurred in 9 (53%) of 17 saphenous veins, 1 (50%) of 2 proximal graft anastomoses, 4 (18%) of 22 distal graft anastomoses and 5 (14%) of 37 native coronary arteries. When coronary anatomy is suitable, percutaneous transluminal angioplasty is an attractive alternative to reoperation in symptomatic patients with prior coronary bypass surgery.

Importance of complete revascularization in performance of the coronary bypass operation

Cardiac Data Bank records of 1,238 patients with triple-vessel disease (greater than or equal to 50% diameter reduction) who had undergone coronary bypass surgery were reviewed and divided into 2 groups depending on whether complete (n = 773) or incomplete (n = 465) revascularization had been accomplished. Patients with complete revascularization had a higher incidence of a normal preoperative electrocardiogram than did patients with incomplete revascularization (23 versus 14%, respectively, p less than 0.0001). The ejection fraction for both completely and incompletely revascularized patients was good (m = 0.60 and 0.57, respectively). The mean number of grafts per patient for the 2 groups was 3.8 and 2.6 (p less than 0.0001). There was no significant difference between the 2 groups with regard to postoperative inotropic requirements (8 and 7%), ventricular arrhythmias (1.8 and less than 1%), necessity for intraaortic balloon pumping (1.6 and 1.5%, hospital mortality (1.2 and 2.8%), or myocardial infarction (4.3 and 4.8%). Survival at 5 years was significantly greater (p less than 0.001) in patients with complete (88.5%) than in those with incomplete revascularization (83.5%). Reemployment occurred more often in patients with complete (52%) than in those with incomplete revascularization (40%) (p less than 0.001), and more patients were free of angina after complete (70%) than after incomplete revascularization (58%) (p less than 0.0005). Long-term survival appeared to be mediated primarily through improved revascularization rather than through differences in left ventricular function.

Efficacy of coronary artery bypass grafting in elderly patients with coronary artery disease

Abstract A consecutive series of 121 patients 70 years of age and older who underwent aortocoronary artery saphenous vein bypass grafting without other cardiac procedures during a 5 year period was analyzed and follow-up status ascertained. This group was compared with a consecutive series of 2,850 patients under the age of 70 who underwent aortocoronary bypass during the same period. The patients aged 70 years or greater had a higher incidence of unstable angina pectoris, congestive heart fallure and cardlomegaly on roentgenography. They had more severe coronary obstruction with a 29 percent incidence rate of left main coronary disease versus a 15 percent incidence rate in the patients aged less than 70 years (P

Concomitant carotid and coronary artery reconstruction.

Data are presented on 68 patients who underwent concomitant carotid endarterectomy (CE) and coronary artery bypass surgery (CAB) at Emory University Hospital from January 1974 to February 1981. This group is then compared with a randomly selected, matched population without known carotid disease who underwent CAB alone. Asymptomatic bruit was the reason for investigation in 40 patients (59%); another 23 patients (34%) experienced transient cerebral ischemic attacks (TIAs); and five patients (7%) had TIA and prior stroke. Carotid stenoses (>75% luminal narrowing) were demonstrated as follows: isolated left, 24 patients; isolated right, 27 patients; and bilateral lesions, 16 patients. One patient had innominate artery stenosis. Associated total occlusion of one or both vertebral arteries was demonstrated in six patients. Ninety-seven per cent of patients had disabling angina pectoris prior to operation; the angina was unstable in 57%, 15% had congestive heart failure, and 54% had had at least one prior myocardial infarction (MI). Single-vessel coronary disease was present in 12.5% of patients, double in 37.5%, triple in 41.1%, and left main stenosis in 9%; 43% of patients had abnormal ventricular contractility. CE was performed on 67 patients (36 left and 31 right); aortocarotid bypass was performed on one. The CE procedures were performed immediately prior to the sternotomy for CAB under the same anesthesia. CAB consisted of single bypass in eight patients (11.8%); double in 16 patients (23.5%); triple in 22 patients (32.4%); and quadruple or more in 22 patients (32.4%) (mean = 2.9 grafts per patient). There was no hospital mortality. Perioperative MI occurred in 2.0% and stroke with residual deficit in 1.3%. Cumulative survival is 98.5% at two years. Sixty-three patients (92%) reported improvement or elimination of anginal symptoms after operation. Kehospitalization for stroke was necessary in 3.7% patients. Postoperative activity levels are: self-care only, 3.9%; normal daily activity only, 17.6%; moderate exercise capability, 45%; and vigorous exercise capability, 33%. Comparison was made with a group of 84 randomly selected patients who underwent CAB alone during the same time interval. Data revealed no significant difference between the groups regarding sex, angina subset, ventricular function, coronary anatomy, vessels grafted, perioperative stroke or MI, mortality, or postoperative activity capability. Older age (59.8 vs. 55.6, p < 0.01) and less complete coronary revascularization possible (66 vs. 84%, p < 0.05) in the CE-CAB group were the only significant differences. Carotid stenosis co-existing in patients requiring CAB should be concomitantly corrected with the same risk and results expected from, CAB alone.

Clinical, anatomic and functional descriptors influencing morbidity, survival and adequacy of revascularization following coronary bypass.

Clinical data on 3,479 consecutive patients having coronary bypass surgery were retrospectively analyzed. Perioperative complications, incomplete revascularization, and reduced long-term survival could frequently be correlated with manifestations of myocardial damage. Patients with triple vessel and left main coronary disease had a greater frequency of inotropic requirements than did patients with single or double vessel disease (7.9% and 8.6% vs. 3.8% and 4.2%). Inotropic requirements in the perioperative period were significantly increased for patients with preoperative left ventricular dysfunction; a history of heart failure or multiple infarctions did not significantly increase the incidence of inotropic requirements. Presence of previous myocardial infarction, heart failure, or left ventricular contraction abnormalities significantly decreased the ability to achieve complete revascularization with bypass grafting. Hospital mortality since 1976 has been 0.8% (25/3,040). Hospital mortality was significantly increased by history of myocardial infarction, hypertension, heart failure, extent of anatomic disease, presence of preoperative ST-T wave changes, and severe abnormalities of left ventricular function. Hospital mortality in patients with ejection fraction <0.35 was 3.4% vs. 1.3% for those >0.35. Anginal pattern, history of hypertension, previous myocardial infarction, preoperative heart failure all significantly affected long-term survival. Occurrence of perioperative myocardial infarction did not adversely influence long-term survival. Patients with normal left ventricular function had excellent 42 month survival regardless of vessel disease (95%, 96%, and 94% for single, double, and triple vessel disease, respectively). Survival was significantly less for such patients with abnormal left ventricular function. Inability to achieve complete revascularization did not adversely affect hospital mortality, but did significantly reduce late survival. The important effect which complete revascularization had on long-term survival appeared to increase with increasing severity of coronary disease. Although bypass grafting improves survival in patients with multivessel disease and left ventricular dysfunction, the benefits appear to be significantly reduced once manifestations of left ventricular damage have occurred.

Coronary Bypass for Relief of Persistent Pain Following Acute Myocardial Infarction

Between January, 1976, and April, 1980, 116 patients had urgent myocardial revascularization for clinical instability within 30 days of acute myocardial infarction (MI). Group 1 (8 patients) had coronary bypass grafting within 24 hours of acute MI; Group 2 (20 patients) had coronary bypass grafting 2 to 7 days after acute MI; and Group 3 (88 patients) had coronary bypass grafting 8 to 30 days after infarction. Indications for operation were persistent or recurrent pain (81%), pain plus ventricular arrhythmias (12%), and pain plus compelling anatomy. The incidence of single-vessel, triple-vessel, and left main coronary artery disease was 28%, 31%, and 12%, respectively. There were no hospital deaths in the series. The incidence of inotropic requirements, postoperative intraaortic balloon pumping, ventricular arrhythmias, and perioperative infarction was higher in patients operated on within 7 days of acute MI than for patients having coronary bypass grafting after this time. There have been 5 late deaths during a mean follow-up of 14 months. Actuarial survival was 97% at 18 months. Seventy-one percent of patients are presently pain free. Graft patency was 84% in 17 patients recatheterized after coronary bypass grafting and in 14 patients, grafts placed into the area of infarction were patent. This study suggests that the frequency of perioperative complications will be increased in patients operated on within one week of MI, but after this period, coronary bypass grafting can be accomplished with the same morbidity as the of elective operation.

Porcine Cardiac Xenograft Valves: Analysis of Survival, Valve Failure, and Explantation

Porcine cardiac xenografts were used for cardiac valve replacement in 1,093 patients. Hospital mortality for aortic valve replacement (AVR) was 3.7%; for mitral valve replacement (MVR), 7.8%; and for AVR + MVR, 4.7%. Total follow-up was 2,036 patient-years; maximum, 7.3 years; and mean, 1.89 years. Actuarial survival (+/- standard error of the mean) for AVR was 84% +/- 2% at 56 months; for MVR, 84% +/- 3% at 56 months; and for AVR + MVR, 86% +/- 4% at 30 months. Nonfatal thromboembolism occurred in 8 of 1,030 patients (0.78%). Anticoagulation was not routinely employed. Fifty hospital survivors (4.8%) experienced valve dysfunction; 18 of the survivors (1.7%) died; and 32 of the survivors (3.1%) underwent reoperation. The rate of dysfunction increased slowly until the sixth year when an increased rate was observed (p less than 0.0001). Patients less than 34 years old had a higher incidence of dysfunction (p less than 0.01). Thirty-two hospital survivors (3.1%) underwent explantation of the porcine valve for late dysfunction. Valve dysfunction secondary to endocarditis and paravalvular leak occurred early, while leaflet deterioration or thrombosis was more gradual in onset and was noted later. The porcine valve has functioned well for 1 to 7 years with a low incidence of valve related morbidity and mortality without routine anticoagulation in patients older than 34 years of age.

Percutaneous transluminal coronary angioplasty: role of the surgeon.

Over a recent one-year period, 339 patients underwent percutaneous transluminal coronary angioplasty (PTCA) and were compared with 338 patients having isolated coronary artery bypass surgery. Patients undergoing PTCA had a shorter duration of angina, a lower number of prior myocardial infarctions, and better left ventricular function (p less than 0.01); PTCA was considered initially successful in 87% (295/339) of patients. Repeat angioplasty was performed in 18% of patients (34/339), with a successful outcome in all but 1. The most common finding at operation in those with failed angioplasty and urgent or emergency revascularization was dissection of an atheromatous plaque. There were 28 early failures (operation performed within 24 hours) and 24 late failures (operation at more than 24 hours), for early and late failure rates of 8.3% and 7.1%, respectively. Although the cumulative frequency of new Q-waves in the entire angioplasty series was low (2.7%), the incidence was high in those with angioplasty failure and subsequent operation (18%), and was significantly greater than in patients having elective coronary bypass (3.6%). Use of inotropic agents and lidocaine treatment for ventricular arrhythmias was also significantly higher in patients with unsuccessful PTCA who required operation than in those undergoing elective bypass (10% versus 3% and 10% versus 1.5%, respectively; p less than 0.01). Eleven of the 28 patients who were early failures were totally revascularized within 2 hours of angioplasty failure. Facilities and staff available for expedient revascularization accounted for the low morbidity and lack of mortality in PTCA failures.

Influence of left ventricular aneurysm on survival following the coronary bypass operation.

Patients having coronary bypass and aneurysm resection (N = 40) or aneurysm plication (N = 32) were compared with patients having coronary bypass without aneurysm (N = 2782). Unlike other series, the primary indication for surgery in the aneurysm patients was angina pectoris, with heart failure playing a secondary role. Multivessel disease was present in 83% of the patients with aneurysm. Total occlusion of the anterior descending coronary artery was more prevalent in the group of patients who had aneurysmectomy (75%) than in the group of patients who had plication (38%), and more grafts/ patient could be performed in the plication group (2.6 vs 2.0). Location of the aneurysm was most often antcroapical (N = 55) and infrequently inferior (N = 6). Septal wall motion was akinetic or aneurysmal in 47% of the aneurysmectomy group, and 10% of the plication group. Postoperative requirements for inotropcs or intra-aortic balloon assist was much higher in the aneurysm group (aneurysmectomy or plication) than in patients without aneurysm having bypass. Hospital mortality for aneurysm patients was 2.7% versus 1.4% in patients without aneurysms having coronary bypass. The actuarial survival rate at 42 months for all aneurysm patients was 90%. Improvement in anginal symptoms after plication and coronary bypass (96%) was more frequent than with aneurysmectomy and coronary bypass (76%) and this was attributed to larger viable muscle mass and greater revascularization. Although two-thirds of patients having surgery for aneurysms had improvement in heart failure symptoms after operation, 30% of those having aneurysmcctomies and 35% of those having plications said they were unimproved after surgery. However, this could be explained by the finding that a significant number (35% of the aneurysmectomy and 45% of the plication group) were in heart failure Class I prior to operation. Hospital mortality has been progressively reduced and late survival increased by the surgical treatment of left ventricular aneurysm, primarily through early operation at a time when coronary bypass can be used as an adjunct to aneurysm resection or plication.

Unstable Angina Pectoris: Comparison with the National Cooperative Study

Seventy-eight patients having prolonged pain (greater than 20 minutes) with transient S-T segment and T-wave changes and coronary artery bypass were compared to 288 patients previously reported in the National Cooperative Study on the treatment of unstable angina pectoris. Clinical characteristics observed in the present study that differed from those of the National Cooperative Study included a more chronic anginal pattern, slightly older age, greater number of women, and higher incidence of prior myocardial infarction. The severity of vessel disease was the same for both groups. Left ventricular function was slightly better in the present series. The incidence of perioperative infarction in the present series (3.8%) was significantly less than that for surgical patients reported in the National Cooperative Study (17%). Hospital mortality was also less: 1.2% versus 2.0 and 3.0% for the medical and surgical patients, respectively, in the National Cooperative Study. Late myocardial infarction was 11% and 13% at 30 months for medical and surgical patients in the National Cooperative Study, and only 3% at 43 months in the present surgical series. Actuarial survival for the entire patient population was 95% at 42 months. The reduced hospital mortality and perioperative infarction rates were attributed to immediate operation once acute myocardial infarction has been ruled out, advances in surgical and anesthetic technique, selection of patients with preserved left ventricular function, and a trend toward complete revascularization.