Validation of the Novel ARCH Score for Mortality Prediction in Acute Type A Aortic Dissection

All articles of this category (opens in new window) Background: To evaluate the predictive performance of the recently described ARCH score for in-hospital mortality in patients undergoing urgent surgery for acute type A aortic dissection (ATAAD). Methods: A retrospective analysis was conducted on 192 consecutive patients who underwent surgical treatment for ATAAD at a single tertiary center from January 2019 to June 2024. The ARCH score was retrospectively calculated using published regression formulas. Key endpoints included in-hospital mortality, as well as secondary outcomes such as perioperative stroke and organ dysfunction. Model performance was assessed through its discrimination (area under the receiver operating characteristic curve, AUC), calibration (Hosmer–Lemeshow test, calibration plots), and accuracy (Brier score, mean absolute error). Results: Median patient age was 69 years (IQR: 59–77); 50.5% were male. The median ARCH score was 0.18 (IQR: 0.13–0.23), with the actual in-hospital mortality at 14.8%. The ARCH score demonstrated moderate discrimination (AUC 0.748, 95% CI: 0.641–0.856), acceptable calibration (Hosmer–Lemeshow p = 0.17), and a Brier score of 0.114. Calibration plots revealed the ARCH score aligned best in intermediate risk ranges but underestimated mortality for patients with higher risk profiles. Perioperative stroke occurred in 15.3% and renal failure requiring dialysis in 7.9% of patients. Conclusion: This is the first validation of the ARCH score specifically in patients undergoing surgery for ATAAD. In this cohort, the ARCH score provided a clinically meaningful prediction of in-hospital mortality after urgent ATAAD surgery, with moderate discrimination and satisfactory calibration. It offers a practical tool for perioperative risk assessment, though continued external validation is warranted to optimize its applicability. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany