Angina pectoris and coronary bypass surgery: Patterns of prevalence and recurrence in 3105 consecutive patients followed up to 11 years

Many studies document the effectiveness of bypass surgery in relieving angina pectoris. Few, however, have described patterns of prevalence preoperatively and recurrence postoperatively. After excluding those known to be dead and those residing outside the continental United States, we attempted to contact all patients who had undergone first bypass surgery by us. Follow-up was 94.4% complete. Women had a higher prevalence of preoperative angina and lesser relief after surgery (p < 0.01). Because of this difference, only men presenting with angina preoperatively were analyzed in detail. In this subgroup, the cumulative percentage of patients with total relief of angina was 87% after the first year; thereafter, the percentage decreased 6%/year. The cumulative percentage of patients improved (those with no angina plus those with less angina than before surgery) was 97% after the first year; thereafter the percentage decreased 0.9%/year. Duration of angina preoperatively had no effect on recurrence unless preoperative duration was less than 6 months. Preoperative left ventricular function had little effect on relief of angina postoperatively. In a short follow-up, 1.5 to 2 years after the original study, we found that patients with postoperative angina had twice the mortality rate of those totally free of angina (p = 0.000004). Furthermore, those with angina at rest had twice the mortality rate of those who had angina but never at rest (p = 0.009).