ObjectiveReoperative aortic root replacement (ARR) is a technically challenging procedure. This study assesses the influence of reoperation on outcomes following ARR, particularly after prior acute type A aortic dissection (ATAAD) repair. MethodsOf the 1823 patients in this study, 1592 (87.3%) underwent primary ARR, and 231 (12.7%) underwent reoperative ARR. Within the reoperative ARR group, 69 patients (29.9%) had previous ATAAD repair, and 162 patients (70.1%) underwent reoperative ARR for other indications. ResultsReoperative ARR patients exhibited higher rates of ischemic heart disease (13.9% vs. 3%, p<0.001), diabetes (10% vs. 5.3%, p=0.009), chronic pulmonary disease (9.1% vs. 5%, p=0.018), renal impairment (17.7% vs. 5.3%, p<0.001), and had lower ejection fraction (45.5 ± 8.1 vs. 47.6 ± 7.9, p<0.001) compared to primary ARR.The overall operative mortality was 0.4%, with no significant difference between groups (0.9% vs. 0.3%, p=0.485). At multivariable analysis previous operation was the most powerful predictor for major adverse events [OR 3.20 (2.12-4.79), p<0.001]. Reoperative ARR had a lower 10-year survival compared to primary ARR (67.4% vs. 85.9%, log-rank p<0.001). Multivariable analysis further confirmed that reoperation was significantly associated with 10-year mortality [HR 1.76 (1.01-3.06), p=0.044]. Among the reoperative ARR group, operative mortality after previous ATAAD repair was similar to that for other etiologies (0% v 1.2%, p=0.880). ConclusionPatients undergoing reoperative ARR have more comorbidities and extensive aortic disease compared to those undergoing primary surgery. They face a 3.5-fold increased risk of major adverse events but no difference in operative mortality compared to primary ARR.