Relation of the Sequential Organ Failure Assessment score to morbidity and mortality after cardiac surgery

Organ dysfunction evaluation using Sequential Organ Failure Assessment (SOFA) has been shown to predict mortality and morbidity in adult cardiac surgical patients with prolonged recovery. The purpose of this study was to evaluate the utility of SOFA in prediction of mortality and morbidity in a cohort of heterogeneous consecutive adult cardiac surgical patients.

A prospective study of 857 consecutive patients entering in a single cardiac postoperative intensive care unit was assigned during the year 2004. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) of each patient was assessed preoperatively. SOFA was calculated daily until intensive care unit discharge or for a maximum of 7 days. SOFA change between the first and the third postoperative day, maximum SOFA during the first 3 days, and maximal SOFA were calculated. Length of intensive care unit stay and 30-day mortality were assessed.

Maximum SOFA during the first 3 days and maximal SOFA-predicted 30-day mortality (area under the curve, 0.763 and 0.779, respectively) also correlated with the length of intensive care unit stay (p < 0.001 and p < 0.001, respectively). The EuroSCORE predicted both mortality and intensive care unit stay (p < 0.0001 and p < 0.0001). The correlation coefficient between the EuroSCORE and maximum SOFA during the first 3 days or maximal SOFA was low (r = 0.34 and 0.33, respectively, p < 0.0001 and p = 0.0001).

The SOFA score is an independent predictor of mortality and length of stay in cardiac surgical patients. The SOFA score is associated with mortality and morbidity even when assessed in the early postoperative period after adult cardiac surgery.