INFLUENCE OF LEFT-VENTRICULAR FUNCTION ON SURVIVAL AFTER CORONARY-ARTERY BYPASS-GRAFTING

Background. Preoperative left ventricular function is a most important predictor for survival in patients with ischemic heart disease. To el ucidate the optimal timing of recommended coronary artery bypass graft ing, we investigated the influence of different aspects of preoperativ e left ventricular function on relative survival. Methods. To calculat e the relative survival and estimate the disease-specific survival, we compared 6,514 patients who survived the first month after primary co ronary artery bypass grafting with the general Swedish population stra tified by age, sex, and 5-year calendar period. In particular we studi ed the relation between relative survival and different aspects of lef t ventricular performance, namely left ventricular function at rest, N ew York Heart Association functional class, and number of previous myo cardial infarctions. Results. The three variables (left ventricular fu nction at rest, New York Heart Association functional class, and numbe r of previous myocardial infarctions) as well as age and follow-up yea r gave independent information concerning relative survival. The resul ts from this multivariate analysis were used to define a risk score fo r each patient. Patients were categorized into different risk groups. Patients in the low-risk group (30% of the total) showed a survival be tter than that of the population at large for 9 years after operation. The medium-risk group had no or low excess mortality for about 7 year s, and the high-risk group (25%) showed increased excess mortality imm ediately after operation. Conclusions. If primary coronary artery bypa ss grafting is performed before the left ventricular function and phys ical performance deteriorate, survival is excellent. (C) 1997 by The S ociety of Thoracic Surgeons.