Clinical outcomes of ascending aortic replacement for aneurysm and the impact of center volume: a nationwide population-based study

OBJECTIVES: To evaluate contemporary outcomes of elective ascending aortic replacement (AAR) and the impact of center volume using a nationwide database. METHODS: Adults undergoing elective AAR for aneurysms (2003-2021) were identified from the Korean National Health Insurance Service database. Acute dissections, ruptures, and arch involvements were excluded. Restricted cubic splines (RCS) and multivariable regression evaluated the impact of institutional volume and concomitant procedures. RESULTS: Among 5,209 patients, operative mortality and stroke rates were 2.9% and 2.2%. Over a 5.9-year median follow-up, RCS revealed a significant non-linear inverse relationship between annual institutional volume and mortality. Treatment at high-volume centers (≥10 cases/year) independently lowered operative mortality (odds ratio, 0.26; 95% confidence interval, 0.18-0.37) and long-term mortality (hazard ratio, 0.64; 95% confidence interval, 0.57-0.73). Distinct clinical phenotypes, including bicuspid aortic valves and concomitant aortic valve surgery, were associated with favorable survival. CONCLUSIONS: Elective AAR demonstrates low perioperative risk and stable long-term survival, significantly influenced by annual institutional volume and clinical phenotypes. These findings support dedicated aortic centers and individualized risk stratification.