[Peroperative myocardial infarction and myocardial ischemia in non cardiac surgery: prevalence and predictive factors].

BACKGROUND: The decrease in the prevalence of infarction in the population has not been accompanied by a reduction in postinfarct mortality, particularly in the population segment which does not present major symptoms of coronary disease. The aim of the present study was to determine the incidence and predictive factors of cardiac complications in patients undergoing non cardiac surgery. METHODS: Eight hundred seventy-five patients undergoing elective surgery from May 1990-1991 had some of the following criteria: history of heart disease, major surgery, and medical risk other than cardiac. A sample of 328 patients was selected to whom an ECG an CK-MB isoenzyme test were performed on admission, every 8 h, and at the second and third days. Infarction or ischemia were diagnosed by electrocardiographic and enzymatic criteria. Minimum follow up was 72 hours. RESULTS: IAM was diagnosed in 10 cases (3%, confidence interval 95%, 2 to 4%) and ischemia in 47 cases (14%, CI 95%, 11 to 18%). Operative mortality of cardiac origin was 4% (CI 95%, 2 to 6%). Arrhythmia not preoperatively present was detected in 11%, hemodynamic instability in 25%, and sinusal tachycardia in 21%. Other complications were: abdominal 12%, respiratory 14%, neurologic 6% and renal 4%. The appearance of cardiac complications was related with: ASA classification (p < 0.05), previous history of heart disease (p < 0.01), cardiovascular drug administration (p < 0.01) and changes in preoperative electrocardiogram (p < 0.001). CONCLUSIONS: The present study suggests that patients with changes of the ST-T segment in the preoperative ECG should undergo examination to determine the degree of cardiac involvement. A strict peroperative hemodynamic control may reduce the prevalence of cardiac complications in those patients at high risk.