Influence of preoperative variables upon the results of coronary artery bypass surgery.
One thousand ninety-six consecutive patients who received aorta-to-coronary artery bypass vein grafts were followed up to 4 years postoperatively. The early mortality was 1.7%; the 4-year survival rate, computed by actuarial methods, was 93.1%; the incidence of peri-operative myocardial infarction was 1.9%. After 4 years, 94.4% of the patients were free of peri- and postoperative infarcts. Angina pectoris was relieved in 85.7% and eliminated in 62.8% of the survivors. An analysis of the effects of ten preoperative variables on operative results showed that operative risk (early mortality, perioperative myocardial infarction) was not influenced by any of the variables. Late results (4-year mortality, 4-year infarction rate), however, were negatively affected by impaired ventricular function. Symptomatic improvement was more pronounced in men than in women.