Comparative Evaluation of ARCH and GERAADA Scores for Mortality Prediction in Acute Type A Aortic Dissection.

OBJECTIVES

To compare the predictive performance of the German Registry for Acute Aortic Dissection Type A (GERAADA) and new ARCH (Arch Reconstruction under Circulatory Arrest with Hypothermia) scores for in-hospital mortality in patients undergoing urgent surgery for acute type A aortic dissection (ATAAD).

METHODS

Between January 2019 and June 2024, 192 patients were surgically treated for ATAAD at a single centre. Scores were calculated and compared. Model performance was assessed by discrimination (area under the receiver operating characteristic curve, AUC), calibration (Hosmer-Lemeshow test, calibration plots), and accuracy (Brier score, mean absolute error).

RESULTS

Median age was 69 years (interquartile range [IQR] 59-77), and 50.5% were male. Median GERAADA risk score was 19.3% (IQR 11.7-29.6), and actual in-hospital mortality was 14.8%. GERAADA score: AUC 0.791 (95% confidence interval [CI], 0.694-0.887), Brier score 0.118, Hosmer-Lemeshow P = .11. ARCH score: AUC 0.748 (95% CI, 0.641-0.856), Brier score 0.114, Hosmer-Lemeshow P = .17. The GERAADA score demonstrated more consistent calibration and slightly higher, not statistically significant, discrimination, while the ARCH score showed marginally better overall accuracy but underestimated mortality in higher-risk patients.

CONCLUSIONS

This is the first validation of the ARCH score specifically in patients undergoing surgery for ATAAD. Both GERAADA and ARCH scores provide an acceptable prediction of early in-hospital mortality after ATAAD surgery. The GERAADA score achieved marginally higher, but statistically non-significant, discrimination, particularly in identifying high-risk patients, whereas the ARCH score provides slightly more accurate individual risk estimates but less effective separation of survivors from non-survivors.