Angina pectoris, one to 10 years after aorto-coronary bypass surgery

The incidence of angina pectoris (AP) after bypass surgery was assessed in 1041 patients operated on consecutively between 1971 and 1980. Of the 977 survivors, 920 (94%) participated in the study with a followup time varying from 1 to 10 years (mean 3.5 years). Post-operative angina pectoris was present at 1 year in 277 patients (30%), at 3 years in 46%, at 8 years in 50%. The pain limited usual physical activities in 17.5%, 30% and 25%, respectively at these times. Nonetheless, 89% of the respondents felt improved by surgery. Factors without predictive value for late outcome were sex, number of pre-operative diseased vessels, and pre-operative ejection fraction. A correlation was found between post-operative AP and younger age at surgery in the males only (P< 0.001); between AP and patency rate of the bypass graft (P<0.005) and with the status of the coronary arterial tree at three years post-operatively (P<0.001) in both sexes. The percentage of patients with recurrent AP increased with time after surgery up to 3 years, but remained stable thereafter. In conclusion, post-operative AP seems initially related to decreased functioning of the bypass graft, later to progression of coronary sclerosis in the native circulation.