Changes in survival and symptom relief in a longitudinal study of patients after bypass surgery

The first 350 patients having coronary surgery at Stanford Medical Center (excluding patients with aneurysmectomy or valve replacement) have been followed sequentially utilizing a computer-based information system. Our experience spans 72 months (900 patient-years), with an average follow-up of 30 months. Hospital mortality was 4.9%. Actuarial analysis revealed survival of 91% at 1 year and 80% at 6 years. Forty patients (11.5%) had 43 late myocardial infarctions, of which 5 were fatal. Analyses of selected patient subgroups revealed significantly poorer survival in patients with prior myocardial infarction (P less than 0.05), significant congestive heart failure, or mitral regurgitation (P less than 0.01). Survival in multigrafted (and multivessel) patients was not significantly different from survival in single-grafted (predominantly single-vessel) patients. Actuarial studies suggest improved survival in patients with multivessel disease after coronary artery surgery. Between an initial evaluation at 9 months postoperatively (range: 2 to 40 months) and the most recent evaluation after 30 months (range: 6 to 72 months), 13% of patients showed further clinical improvement, 47% were unchanged, while 40% deteriorated with respect to chest pain. We conclude that initial symptomatic benefits may not be maintained in late follow-up studies owing to progression of underlying vascular disease.