RESUMEN
The purpose of this study was to present data concerning morbidity and mortality after cardiac surgery and to establish a method to make the presentation comparable to other reports. The main difficulty in comparing results of surgery of one institution with those of another is the lack of a simple and widely acceptable quantification of risk. A preoperative risk classification of patients requires readily available and objective data. The shortage of standardized criteria for comparing outcome was obvious as only a few comprehensive reports regarding preoperative predictors were found in the literature. The method of Tuman et al is based on 12 preoperative risk factors that are reasonably free of observer bias and practically obtainable. This method was used to report the results of 628 consecutive patients undergoing coronary revascularization or valvular surgery. Total in-hospital morbidity was 3.5% and mortality 1.0%. The most important predictors for postoperative morbidity were valvular surgery, advanced age, renal dysfunction, recent myocardial infarction and pulmonary hypertension. The system is most useful in predicting good outcome in low-risk patients. The identification of high-risk patients is valuable in spite of the limited predictive ability, by allowing special attention to be directed to the patient at risk.