Enhanced assessment of perioperative mortality risk in adults with congenital heart disease

Background In-hospital mortality is a rare, yet feared complication following cardiac surgery in adult congenital heart disease (ACHD). A risk score, developed and validated in ACHD, can be helpful to optimize risk assessment. Objectives To assess the performance of EuroSCORE II components and procedure-related Adult Congenital Heart Surgery (ACHS) score, identify additional risk factors, and develop a novel risk score for predicting in-hospital mortality after ACHD surgery. Methods We assessed perioperative survival in patients >16 years undergoing congenital heart surgery in a large tertiary center between 2003 and 2019. A risk variable derived PErioperative ACHd (PEACH) score was calculated for each patient. Internal and external validation of the model was undertaken, including testing in a validation cohort of patients operated in a second European ACHD center. Results The development cohort comprised 1782 procedures performed during the study period. Re-sternotomy was undertaken in 897(50.3%). There were 31(1.7%) in-hospital deaths. The PErioperative ACHd (PEACH) score showed excellent discrimination ability (AUC 0.88, 95%CI:0.83-0.94), and performed better than the ACHS score in our population (ACHS AUC 0.69, 95%CI:0.6-0.78, p=0.0003). A simple 3-tiered risk stratification was formed: PEACH score 0 (in-hospital mortality 0.2%), 1-2 (3.6%), ≥3 (17.2%). In a validation cohort of 975 procedures, the PEACH score retained its discriminative ability (AUC 0.75, 95%CI:0.72-0.77) and was well calibrated (Hosmer Lemishow 2 goodness-of-fit p=0.55). There was agreement in expected and observed perioperative mortality between cohorts. Conclusions The PEACH score is a simple, novel peri-operative risk score developed and validated specifically for ACHD patients undergoing cardiac surgery. Condensed abstract: The PEACH score is a simple, novel peri-operative risk score developed and validated specifically for ACHD patients undergoing cardiac surgery. In this study, we assessed the performance of components of the existing EuroSCORE II and ACHS score in predicting in-hospital mortality after ACHD surgery and combined them with other predictors of peri-operative mortality into a single PErioperative ACHd (PEACH) score. This novel score showed good discrimination ability in both development (AUC 0.88, 95%CI:0.82-0.94) and external validation (ACHS score AUC 0.69, 95%CI:0.6-0.78, p=0.0003) cohorts, with good agreement between expected and observed perioperative mortality