Proximal vs Extensive Repair in Acute Type A Aortic Dissection Surgery.

BACKGROUND: This purpose of this study was to evaluate the impact of proximal vs extensive repair on mortality and how this impact is influenced by patient characteristics. METHODS: Of 5510 patients with acute type A aortic dissection from 13 Chinese hospitals (2016-2021) categorized by proximal vs extensive repair, 4038 patients were used for for model derivation using eXtreme gradient boosting and 1472 patients for model validation. RESULTS: Operative mortality of extensive repair was higher than proximal repair (10.4% vs 2.9%; odd ratio [OR], 3.833; 95% CI, 2.810-5.229; P < .001) with a number needed to harm of 15 (95% CI, 13-19). Seven top features of importance were selected to develop an alphabet risk model (age, body mass index, platelet-to-leucocyte ratio, albumin, hemoglobin, serum creatinine, and preoperative malperfusion), with an area under the curve of 0.767 (95% CI, 0.733-0.800) and 0.727 (95% CI, 0.689-0.764) in the derivation and validation cohorts, respectively. The absolute rate differences in mortality between the 2 repair strategies increased progressively as predicted risk rose; however it did not become statistically significant until the predicted risk exceeded 4.5%. Extensive repair was associated with similar risk of mortality (OR, 2.540; 95% CI, 0.944-6.831) for patients with a risk probability < 4.5% but higher risk (OR, 2.164; 95% CI, 1.679-2.788) for patients with a risk probability > 4.5% compared with proximal repair. CONCLUSIONS: Extensive repair is associated with higher mortality than proximal repair; however it did not carry a significantly higher risk of mortality until the predicted probability exceeded a certain threshold. Choosing the right surgery should be based on individualized risk prediction and treatment effect. (ClinicalTrials.gov no. NCT04918108.).