Mortality, recurrent angina pectoris and late myocardial infarction in patients surgically treated for coronary heart disease

This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. The independent risk factor for these two end-points was hypertension. The study suggests that stratification of independent risk factors facilitates comparison of mortality in different centres and permits improved quality control.