Outcome prediction following coronary surgery and reoperation for bleeding (from the KROK Registry)

Objectives To assess the reliability of EuroSCORE II in an entire population after isolated coronary artery surgery and separately among patients who underwent redo surgery due to bleeding, and to create a model predicting hospital death among patients who underwent redo surgery owing to bleeding. Design Retrospective study based on data from the Polish National Registry of Cardiac Surgical Procedures. Setting Multi-institutional study. Participants The study comprised 41,353 patients who underwent isolated coronary artery surgery in Poland between January 2012 and December 2014. Interventions None. Measurements and Main Results EuroSCORE II reliability was estimated using the area under the receiver operating characteristics curve (AUC), the observed-to-expected surgical mortality ratio (O/E), and the Hosmer-Lemeshow test. Parameters of the function correcting the original EuroSCORE II were determined using the least squares method. The original score was adjusted using a created formula. Among the 41,353 patients, 1,406 (3.4%) underwent reexploration. Even though EuroSCORE II was reliable in predicting hospital mortality in the entire population (AUC 0.76, O/E ratio 1.08), it greatly underestimated mortality for patients who required reexploration (AUC 0.74, O/E ratio 4.33). In this subpopulation, the worst performance of the EuroSCORE II was noted among patients with the lowest predicted mortality (0.50%-0.82%) Accurate calibration was obtained by adding a coefficient and creating a nomogram. Conclusions EuroSCORE II was reliable in a Polish population undergoing isolated coronary surgery. After redo surgery for bleeding, the observed mortality was much higher than in the overall coronary population, but the rate was made more accurate by adding a coefficient to the initially calculated EuroSCORE II.