Serial evaluation of the Sequential Organ failure assessment (SOFA) score in patients undergoing cardiac surgery

Aims: The purpose of this study was to evaluate the usefulness of repeated measurements of the SOFA score in terms of survival in cardiac surgery patients.

Methods: This prospective study consisted of all consecutive adult patients undergoing cardiac surgery with cardiopulmonary bypass between January 2003 and October 2005. The SOFA score was calculated daily until discharge. Initial SOFA score, maximum SOFA score, and delta-SOFA scores (differences between subsequent scores) were calculated and their correlations with mortality were assessed.

Results: A total of 2372 patients with a mean age of 66.2±11.2 years were admitted to the ICU after cardiac surgery. The operations performed were 1518 (64%) isolated CABG, 332 (14%) isolated valve surgery, 237 (10%) combined CABG with valve surgery, 95 (4%) surgery of the thoracic aorta, and 190 (8%) other procedures. The overall mortality rate was n=85 (3.6%). The mean stay on the ICU was 3.0±6.1 days. The receiver operating characteristic (ROC) curve of the maximum SOFA score was excellent with a value of 0.97. When analyzing trends in the SOFA Score during the first 96 hours (1038 patients), regardless of the initial score, the mortality rate was 30.6% when the score increased, 17.2% when it remained unchanged, and 2.0% when it decreased.

Conclusion: The highest SOFA Score during the ICU stay showed an excellent discrimination. Serial evaluation of the SOFA Score during the first 96 hours is a good indicator of prognosis in cardiac surgical patients.