MULTIVARIATE RISK FACTOR-ANALYSIS OF CLINICAL OUTCOME 15 YEARS AFTER VENOUS CORONARY-ARTERY BYPASS GRAFT-SURGERY

Background: Knowledge is still lacking about pre-operative and postope rative factors which predict the long-term prognosis of patients who u ndergo venous coronary artery bypass graft surgery. Methods and Result s; Four hundred and twenty-eight consecutive patients who underwent is olated venous coronary artery bypass graft surgery with or without lef t ventricular aneurysm surgery between 1 April 1976 and 1 April 1977, were followed prospectively. Follow-up was 99.8% complete and averaged 15.4 years for the survivors. Two prognostic models were set up to il lustrate the influence of 21 variables, present at and, 5 years after, surgery, on the occurrence of six different clinical events. Multivar iate analysis was performed using the Cox regression model. Age, left ventricular function, pre-operative severity of angina and diabetes me llitus are continuous incremental risk factors for one or more events. Revascularization with sequential grafts only, and obesity at operati on are incremented risk factors for acute myocardial infarction. From the 'classical' risk factors present 5 years after surgery hypertensio n is an incremental risk factor for both overall and cardiac mortality , diabetes mellitus for cardiac mortality, myocardial infarction, ball oon angioplasty and smoking for all clinical events except mortality. Conclusions: Well-known pre-operative factors including 'classical' ri sk factors, present late after surgery, influence the occurrence of cl inical events. Treatment of these factors may result in better long-te rm prognosis after venous bypass graft surgery.