Performance of EuroSCORE II in Octogenarians Undergoing Coronary Artery Surgery (from the KROK Registry).

Background: Octogenarians constitute the fastest-growing segment within contemporary cardiac surgery, yet precise risk assessment in this age group remains challenging. Aims: This study aimed to evaluate EuroSCORE II reliability in octogenarians undergoing isolated coronary surgery and to create an adjustment formula if necessary. Patients and Methods: All octogenarians who had isolated coronary surgery in Poland from January 2012 to December 2023, recorded in the Polish National Registry of Cardiac Surgical Procedures (KROK registry), were retrospectively assessed. EuroSCORE II's reliability was measured using the ROC curve area and observed-to-predicted mortality ratio, differentiating on-pump and off-pump cases. A nomogram was developed to enhance predictive accuracy. Results: Among 5771 octogenarians, 2729 (47.3%) underwent on-pump and 3042 (52.7%) underwent off-pump surgery. EuroSCORE II demonstrated reliability in off-pump patients (AUC:0.72, O/E ratio:0.98) but underestimated mortality for on-pump cases (AUC:0.73, O/E ratio:1.62). The lowest predicted mortality group (0.50-1.82%) showed the greatest discrepancies. Calibration was improved by adding a coefficient and creating a nomogram. Conclusions: EuroSCORE II was dependable in predicting outcomes for Polish octogenarians undergoing isolated coronary surgery. Observed mortality following on-pump surgeries was higher than expected, which was corrected by adding a coefficient to the initial EuroSCORE II calculation.