ASSESSMENT OF THE IMPACT OF CORONARY ARTERY SURGERY ON MORTALITY AFTER RECOVERY FROM MYOCARDIAL INFARCTION

Abstract
Death rates over a nine year period were studied in 1,232 survivors of myocardial infarction. From 1973 to 1981, the 29 to 365 day case fatality rate in 28 day survivors dropped from 13.3% to 3.2%. This down‐trend in case fatality was highly significant, averaging 14.3% in each year. After adjustment for changes in age and severity of infarction, using a prognostic score derived from the Perth Coronary Register (the PCR score), the estimated decline was still 12.2% in each year. During the nine years, the rate of coronary surgery in the post‐infarction year rose from 1.5% to 12.0%. Overall, the surgically treated cases had a lower case fatality rate (1.6%) than the medically treated cases (7.7%). However, the surgical cases had a better prognosis at the time of infarction than the medical cases. When the severity of infarction (PCR score) and year of admission were considered, coronary surgery in the post‐infarction year had no independent effect on outcome.