Risk factors of recurrent angina pectoris and of non-fatal myocardial infarction after coronary artery bypass surgery.

The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass grafting (CABG) at the Cardiovascular Unit of Rikshospitalet, Oslo, between 1982 and 1986, were analyzed on factors associated with the return of angina pectoris and of non-fatal post CABG myocardial infarction. The closing date was 1st January 1993, with a mean follow-up time of 7.4 years. Recurrent angina pectoris was experienced by 118 (11.6%) patients and 102 (10%) patients experienced non-fatal post CABG myocardial infarction during the observation period. Altogether 30 possible risk factors were analyzed. The cumulative incidence of recurrent angina was initially low after operation, followed by a rise after 4 years. One, 5 and 10 years after the operation, survival free from angina rates were 97.8%, 91.8% and 80.6%, respectively. The cumulative incidence of post CABG myocardial infarction was also low initially, followed by a rise after 4 years. The survival free of non-fatal post CABG myocardial infarction rate was 98.9%, 96% and 83.5%, at 1, 5 and 10 years after surgery, respectively. The incremental risk factor of recurrent angina pectoris was hypertension. The independent risk factors of non-fatal post CABG myocardial infarction were hypertension and preoperative stenosis of the left-sided, versus right-sided, coronary arteries. The study emphasizes the favorable effect of coronary bypass surgery on the functional outcome in patients with symptomatic coronary artery disease.