Rangasamy V, Xu X, Susheela AT, et al. - As the risk of adverse outcomes increases with fluctuations in blood glucose (glycemic variability), researchers here investigated predictive value of 2 measures of glycemic variability—(1) coefficient of variation (CV) and (2) the Blood Glucose Risk Index (BGRI)—for adverse outcomes after cardiac surgery. They conducted prospective, observational study of 1,963 adult patients undergoing cardiac surgery. They hourly measured postoperative blood glucose levels for the first 24 hours and averaged these every 4 hours (4, 8, 12, 16, 20, and 24 hours). One hundred seventy (8.7%) patients had major adverse events. While only the fourth quartile of CV displayed association, BGRI was correlated significantly to MAE. Addition of the standard Society of Thoracic Surgeons risk index led to an increase in the predictive ability of CV and BGRI. Findings here indicate good predictive ability of both CV and the BGRI. As the BGRI is a continuous variable, it is suggested a preferred measure of glycemic variability in predicting adverse outcomes (cutoff value 2.24) after cardiac surgery.