Understanding risk assessment in cardiac surgery patients.

Understanding the risk of surgery in valvular disease is of interest because aging of the population renders decision making more difficult and the magnitude of risk will influence not only the decision to intervene but also the choice of intervention and its timing. To assist clinicians in assessing the risk of cardiac surgery, multivariate risk scores are increasingly used to estimate operative mortality. Overall, the currently available scores, mostly U.S. Society of Thoracic Surgeons score and European System for Cardiac operative Risk Evaluation, achieve acceptable discrimination but suboptimal calibration in estimating the operative mortality of heart valve surgery. The intrinsic limitations of scoring systems highlight the fact that risk scores should be integrated into clinical judgment but should not be a substitute for it. A multidisciplinary approach involving cardiologists, cardiac surgeons, and anesthesiologists is required for this purpose, especially in high-risk patients.