External validation of the German Registry for Acute Aortic Dissection Type A score in patients undergoing surgery for acute type A aortic dissection

Objective: Surgery for acute type A aortic dissection carries a high risk of morbidity and mortality compared with routine cardiac surgical procedures. The German Registry for Acute Aortic Dissection Type A score has been recommended for use as a mortality risk-stratification tool in recent guidelines. We sought to externally validate this score in our local population. Methods: All consecutive patients undergoing surgery for acute type A aortic dissection from 2007 to 2021 were included. Logistic regression analyses were performed. Model discrimination was assessed by C-statistic with 95% CIs as part of the receiver operating characteristic analysis. Model performance was visualized by calibration plot and quantified by the Brier score. Results: A total of 587 patients were included. The mean age was 61 years (+/- 13.5), with 42.08% of patients aged more than 65 years; 40.37% were female. The mean circulatory arrest time was 30.9 minutes (+/- 16.5). Hemiarch replacement was performed in 62% of patients, and total arch replacement was performed in 35.3% of patients. Thirty-day mortality was observed in 66 patients (11.24%), and stroke was present in 7.16% of patients. The C-statistic revealed good discriminatory ability for predicting 30-day mortality (area under the receiver operating characteristic curve, 0.73; 95% CI, 0.67-0.79; P < .0001). Model calibration was good (Brier score = 0.094). Conclusions: The German Registry for Acute Aortic Dissection Type A score for 30-day mortality showed good discriminatory ability in our local population along with good ability for prediction of mortality, indicating its potential clinical utility in the population with acute type A aortic dissection.