In this international registry study, the authors validated and refitted EuroSCORE II to predict 120-day mortality after elective or urgent isolated coronary artery bypass grafting (CABG) using nationwide data from the Netherlands and Sweden. The derivation cohort included 45,016 Dutch procedures, and external validation used 16,374 Swedish procedures, for a total of 61,390 CABG cases from 24 centers. The refitted model recalibrated the original EuroSCORE II and, with an added age–by–sex interaction, achieved a C statistic of 0.80. Compared with the original model, it showed similar discrimination but better calibration, with the original EuroSCORE II tending to underpredict risk in high-risk patients. The authors conclude that this refitted model improves risk stratification for contemporary isolated CABG.
