Although survival after coronary artery bypass grafting (CABG) is themost serious outcome information, the quality of life in living patients islargely determined by the freedom from ischemic events. The return ofangina, acute myocardial infarct and sudden death were studied in a large(n = 5880) population of patients undergoing CABG between 1971 and 1987.The freedom from angina pectoris was 95%, 83% and 63% at 1, 5 and 10 years,respectively, after surgery. Early return of angina was related to bothprocedure incremental risk factors (incomplete revascularization andnon-use of the internal mammary (thoracic) artery (IMA) as a conduit) andpatient incremental risk factors (aggressiveness of the atheroscleroticprocess and severity of preCABG symptoms). Late angina return was relatedto patient risk factors including coexisting factors (hyperlipidemia andhypertension), preCABG symptom severity and gender (female). The freedomfrom an acute fatal or non-fatal postCABG myocardial infarct was 99%, 96%and 85% at 1, 5 and 10 years after surgery. The incremental risk factorsfor early infarction were related to incomplete revascularization, but lateinfarction was related to lipid levels, coexisting diseases (diabetes,positive family history) and non-use of IMA to LAD. The freedom from suddendeath was 99.8%, 99% and 97% at 1, 5 and 10 years, respectively, aftersurgery. The incremental risk factors were dominated by the severity of theleft ventricular dysfunction. The freedom from any ischemic event (any ofthe previous three) was 93%, 79% and 54% at 1, 5 and 10 years,respectively, after surgery. The incremental risk factors included allthose cited above for the specific components. Patient- specificpredictions validate the influences of these risk factors. They demonstratethat unlike the profound influence of the use of the IMA on survival, thereis little benefit of the use of the IMA on return of ischemic events overand above the effect of revascularization per se. The study demonstratesthat most patients will experience return of ischemic symptoms within aperiod of 15-20 years after surgery, but that this is most likely to bereturn of angina and rarely sudden death.