Herbert N. Hultgren

The Veterans Administration Cooperative Study of stable angina: current status.

The current status of the Veterans Administration Cooperative Study of the effect of surgery on survival in patients with stable angina is presented. The outcome in 686 adult miles randomly allocated to medical or surgical treatment groups in 1972-1974 was studied in subgroups of patients classified by invasive (arteriographic) and noninvasive risk factors. In 91 patients with left main lesions reducing the luminal diameter 50% or more, surgery signiflcantly improved survival in the two-thirds characterized as middle or high risk by four simple noninvasive predictors of prognosis (New York Heart Association functional classification III or IV, history of myocardial infarction, history of hypertension, and ST-segment depression on the resting baseline ECG as assessed on a centralized reading). Patients with three-vessel disease and no significant disease of the left main coronary artery also had better survival rates when treated surgically. However, this was statistically significant at 6 years only in the 10 hospitals in which the aggregate operative mortality was 3.3%. Patients without left main lesions were also categorized by four noninvasive predictors of risk. Categorizing such patients into roughly equal groups of high, middle, and low risk identifieid a high-risk group, in which surgery was associated with statistically improved survival, and low- and middle-risk groups in which it was not. The use of both invasive and noninvasive factors to assess risk in patients with chronic stable angina pectoris provided greater predictive power than either angiography or noninvasive factors alone.

Ischemic myocardial injury during cardiopulmonary bypass surgery

Abstract ECGs and serum levels of SGOT, LDH, and CPK were examined during the immediate postoperative period in 126 patients who had cardiac surgery during cardiopulmonary bypass. None had coronary disease and valve replacement was performed in 97 patients. Miscellaneous procedures not involving the coronary arteries were performed in 29. In surviving patients, ECG signs of acute myocardial infarction appeared in 8 (7 per cent) and changes compatible with acute ischemic injury were seen in 38 (30 per cent). Elevation of SGOT exceeding 90 units occurred in 32 per cent of patients and LDH levels over 900 units occurred in 37 per cent. In patients with ECG evidence of postoperative infarction or ischemia, 70 per cent had abnormal SGOT levels and 70 per cent had abnormal LDH levels. In 40 patients with SGOT levels exceeding 90 units, 80 per cent had ECG evidence of acute infarction or ischemia. In 80 patients without ECG changes, only 10 per cent had SGOT levels exceeding 90 units. CPK levels correlated poorly with ECG evidence of ischemia or infarction. Patients who demonstrated ECG and serum enzyme evidence of ischemic injury or myocardial infarction had longer total perfusion times during surgery (P

Ten-year incidence of myocardial infarction and prognosis after infarction : department of veterans affairs cooperative study of coronary artery bypass surgery

BackgroundThe 10-year incidence of myocardial infarction (fatal and nonfatal) and the prognosis after infarction were evaluated in 686 patients with stable angina who were randomly assigned to medical or surgical treatment in the Veterans Administration Cooperative Study of Coronary Artery Bypass Surgery. Methods and ResultsMyocardial infarction was defined by either new Q wave findings or clinical symptoms compatible with myocardial infarction accompanied by serum enzyme elevations with or without electrocardiographic findings. Treatment comparisons were made according to original treatment assignment; 35% of the medical cohort had bypass surgery during the 10-year follow-up period. The overall cumulative infarction rate was somewhat higher in patients assigned to surgery (36%) than in medical patients (31%) (p = 0.13) due to perioperative infarctions (13%) and an accelerated infarction rate after the fifth year of follow-up (average, 2.4%Y/yr in the surgical group versus 1.4%/yr in the medical group). The 10-year cumulative incidence of death or myocardial infarction was also higher in surgical (54%) than in medical (49o) patients (p = 0.20). According to the Cox model, the estimated risk of death after infarction was 59% lower in surgical than in medical patients (p<0.0001). The reduction in postinfarction mortality with surgery was most striking in the first month after the event: 99% in the first month (p<0.0001) and 49% subsequently (p<0.0001). The estimated risk of death in the absence of infarction was nearly identical regardless of treatment (p = 0.75). Exclusion of perioperative infarctions did not alter the findings. ConclusionsAlthough surgery does not reduce the incidence of myocardial infarction overall, it does reduce the risk of mortality after infarction, particularly in the first 30 days after the event (fatal infarctions). (Circulation 1991;83:747–755

Ten-Year effect of medical and surgical therapy on quality of life: Veterans administration cooperative study of coronary artery surgery☆

The long-term effect of medical vs surgical therapy on quality of life was evaluated by New York Heart Association functional classification, severity of angina and exercise performance in 427 surviving patients with stable angina at 10 years. Surgically assigned patients had significantly more improvement in functional classification, relief of angina and exercise performance at 1 and 5 years than medically assigned patients. Relative to entry, functional classification was improved in 65% of surgically treated patients at 1 year and in 51% at 5 years, compared with 45% and 40%, respectively, of medically treated patients. Marked improvement in angina was observed in 49% of surgical patients at 1 year and in 41% at 5 years, vs 12% and 17%, respectively, in medical patients. At 10 years, quality of life was not significantly different in the 2 treatment groups: 52% of surgical patients had an improved functional classification, compared with 46% of medical patients, while 33% of surgical and 37% of medical patients had a marked improvement in angina. Exclusion of medical and surgical nonadherers had little effect on the 1- and 5-year comparisons. The 10-year treatment differences, however, were accentuated when 123 medically assigned patients who later underwent operation and who benefited from it were excluded from the analysis. In surgical patients, a strong association was observed between graft patency and functional class at 1 year, but not at 5 and 10 years. In general, patients with some or all grafts open had more improvement in functional classification than patients with all grafts closed.(ABSTRACT TRUNCATED AT 250 WORDS)

Unstable angina: Comparison of medical and surgical management

Medical versus surgical treatment of unstable angina was compared in a prospective nonrandomized study of 118 patients. Acute transient ST-T wave changes were present during chest pain in all patients. Acute infarction was excluded by serial electrocardiograms and enzyme studies. All patients admitted to the coronary care unit from 1970 to 1975 who fulfilled the entry criteria were included in the study. The starting point for data evaluation was 5 days after hospital admission. Characteristics at entry were similar in 66 medically treated patients and 52 patients who had coronary bypass vein graft surgery. During a mean follow-up period of 23 months in 66 medically treated patients with unstable angina the incidence rate of nonfatal myocardial infarction was 17% and the total mortality rate 21 percent compared with respective rates of 19% and 5.8% in 52 surgically treated patients. In the surgical group 8 patients (15%) had a perioperative infarction and only 2 (4%) had a late infarction; one patient (2%) died at operation. Symptomatic improvement was observed more frequently in the surgically treated group. Sixty percent of surgically treated patients were free of angina compared with 21% of medically treated patients. Eight medically treated patients (12%) required late surgical treatment for persistent severe angina despite optimal medical management.

Effect of lithium on cardiovascular performance: Report on extended ambulatory monitoring and exercise testing before and during lithium therapy☆

To assess the effect of long-term lithium therapy on cardiac arrhythmias and cardiovascular performance, extended ambulatory electrocardiographic monitoring was performed in 12 patients, and rest and exercise electrocardiograms in 10 of 12, before and during lithium therapy. Lithium increased the frequency of premature ventricular contractions in three patients, decreased it in one, and produced no change in eight. Three of four patients with atrial arrhythmias showed improvement during lithium therapy. Exercise performance was unchanged. Although 7 of the 12 patients manifested T wave flattening in the resting electrocardiogram, none had S-T segment displacement at rest or on treadmill exercise. Before lithium therapy, arrhythmias on exercise included premature atrial contractions in four patients, ventricular arrhythmias in four (premature ventricular contractions in four, with couplets in two and with ventricular tachycardia in one). During lithium therapy, exercise did not provoke premature atrial contractions or ventricular tachycardia in any of the patients, but three patients had premature ventricular contractions (with couplets in one case). We conclude that lithium at therapeutic levels may precipitate or aggravate ventricular arrhythmias. When administered to patients with heart disease, factors that interfere with renal clearance of lithium (heart failure, salt restriction, long-term diuretic therapy) must be recognized and doses must be adjusted accordingly. Careful follow-up and electrocardiographic monitoring are advisable if lithium is to be used in the presence of ventricular arrhythmias. Cardiovascular performance as assessed by treadmill exercise testing was not affected by long-term lithium therapy.

Effect of coronary bypass surgery on longevity in high and low risk patients. Report from the V.A. Cooperative Coronary Surgery Study.

There is considerable uncertainty about the effects of bypass surgery on the longevity of patients with coronary-artery disease and angina. The Cleveland Clinic has reported improved survival after surgical treatment; the Duke University study indicated improvement in a high-risk subgroup only. The Veterans Administration (V.A.) randomised study initially reported improved survival only for patients with significant left main artery (L.M.) disease. Further analysis of the V.A. study shows that survival in the high-risk subgroup was 87% for the surgically treated patients and 74% for those treated medically--a highly significant difference after four years of follow-up. However, exclusion of the L.M. group reduced the difference to a non-significant one of 84% versus 79%. For patients not in the high-risk subgroup, survival at four years (with L.M. excluded) was 93% for those treated surgically and 96% for those treated medically. For all patients the rates were 85% and 86%, respectively. These findings indicate that in the evaluation of the effects of bypass surgery on longevity the characteristics of the coronary-artery disease are critical.

Effect of coronary arterial bypass surgery on exercise-induced ventricular arrhythmias: Long-term follow-up of a prospective randomized study

The effect of coronary arterial bypass surgery on exercise-induced ventricular arrhythmias and their relation to sudden death was examined in 102 patients with stable angina pectoris randomly assigned to medical and surgical therapy (54 and 48 patients, respectively). Symptom-limited treadmill tests were performed at entry and at 1 and 5 years. The surgical group demonstrated significant improvement in exercise performance at 1 year compared with the medical group, and at 5 years exercise-induced ischemia as evidenced by S-T depression and exertional angina remained substantially decreased in the surgical group with little change in the medical group. However, the frequency and severity of exercise-induced ventricular arrhythmias in each group remained unchanged at 1 and 5 years from those at entry. Similar results were obtained from an evaluation of ventricular arrhythmias in the electrocardiogram at rest. With the exception of exercise-induced ventricular tachycardia and fibrillation, no relation was found between ventricular arrhythmias and sudden death. Coronary bypass grafting does not decrease the frequency or severity of exercise-induced or resting ventricular arrhythmias. In patients with stable angina pectoris, with the exception of ventricular tachycardia and fibrillation, exercise-induced ventricular arrhythmias are poor predictors of sudden death. The data suggest that exercise-induced ventricular arrhythmias may not be related to ischemia but to other effects of exercise such as cardiac stimulation by catecholamines or other factors.

Five-year effect of medical and surgical therapy on resting left ventricular function in stable angina: Veterans administration cooperative study

The effect of coronary artery bypass grafting (CABG) and medical therapy on 5-year resting left ventricular (LV) function was studied in 194 randomized patients with stable angina in the Veterans Administration Study of Coronary Artery Bypass Surgery. LV ejection fraction (EF) was determined in a central laboratory. The 92 medical and 102 surgical patients were comparable at entry with respect to historic, angiographic and electrocardiographic prognostic indicators. Twenty-eight percent of the medical and 30% of the surgical patients had a baseline EF of less than 50%. There was no significant change in mean EF between baseline and 5-year values in either treatment group. The baseline and 5-year values were 56 and 58% in each treatment group. Intervening myocardial infarction (MI) had an adverse effect in medically treated patients (59 to 46%, p less than 0.01) and in surgically treated patients with late MI (58 to 47%, difference not significant). Perioperative MI was not associated with a decrease in EF (56 to 58%, difference not significant). These findings extend the similar results of previous short-term studies of the effect of coronary bypass surgery on resting LV function to 5 years, and provide data in a comparable medical control group.

Left bundle branch block and mechanical events of the cardiac cycle.

Left bundle branch block (LBBB) is associated with a prolongation of the interval from the QRS onset to the onset of left ventricular (LV) ejection. The locus and prevalence of specific sites of delay were examined in 56 patients with complete LBBB using echocardiography, phonocardiography and external pulse recordings. The results were compared with those in 52 control subjects without LBBB. The onset of the QRS complex was used as the initial reference point of measurement of time intervals. The following abnormalities were found in patients with LBBB: (1) delayed mitral valve closure (Q-MC greater than 0.08 second) was the major site of delay in 23% of patients; (2) prolongation of the LV isovolumetric contraction time (greater than 0.06 second) was the major site of delay in 41%; (3) both Q-MC and LV isovolumetric contraction time were prolonged in 18%; and (4) in 26% of patients the onset of ventricular contraction determined by the onset of the increase of the apex impulse was delayed (Q-VC greater than 0.07 second). The most common cause of delayed ejection was a prolonged LV isovolumetric contraction time, which occurred in 59% of patients. A control group of 20 patients with abnormal LV function but without LBBB had a low incidence of the 3 types of delay in LV ejection (0 to 15%). Thus, the major abnormalities in the cardiac cycle in LBBB are due to the conduction defect and not to LV dysfunction. The results of this study suggest the presence of variable abnormalities of conduction in complete LBBB.