Preoperative risk indicators of death at an early and late stage after coronary artery bypass grafting.

The aim of the study was to describe mortality during a period of two years after coronary artery bypass surgery (CABG) in relation to preoperative risk factors. Included were all the patients in western Sweden in whom CABG was performed between June 1988 and June 1991, without concomitant procedures or re-operations. The study was prospective in design. In all, 2000 patients with a median age of 64 years were operated upon. Early (within 30 days) mortality was 3.0% and late (30-day-2-year) mortality was 4.2%. Total two-year mortality was 7.1%. For patients undergoing coronary artery bypass grafting, the factors found to be independently predictive of early mortality were female sex, renal dysfunction (creatine clearance < 60ml/min), left main stenosis, number of diseased vessels, previous myocardial infarction, and functional class. We found that a history of congestive heart failure, a history of cerebrovascular disease, diabetes mellitus, renal dysfunction and intermittent claudication were independent risk factors for late mortality. In conclusion, with the exception of renal dysfunction, preoperative risk factors for death within 30 days after CABG differ from risk factors for death between 30 days and two years after CABG.