Valve-sparing aortic root replacement: Defining high-volume centres using prospective data

OBJECTIVES: Valve-sparing aortic root replacement is technically demanding and may vary in institutional procedural volumes, rendering the establishment of thresholds for centres of expertise challenging. This study aims to identify an annual case volume that could define a high-volume centre for valve-sparing aortic root replacement using data from the Heart Valve Society Aortic Valve database. METHODS: All consecutive elective patients undergoing valve-sparing aortic root replacement within the Heart Valve Society Aortic Valve database were included. The primary early outcome was a composite of mortality, thromboembolic events, reinterventions, intraoperative conversions, and recurrent aortic regurgitation grade ≥2 within 30 days. The primary long-term outcome was freedom from aortic valve reintervention. Volume-outcome associations were modelled using restricted cubic splines; the high-volume threshold was derived using the elbow method. Analyses were adjusted for EuroSCORE II. RESULTS: In total, 2,668 patients from 37 centres were included. Annual volume was not significantly associated with the early composite outcome (p = 0.8003). However, a significant non-linear volume-outcome association was found for long-term aortic valve reintervention-free survival (p = 0.0023), with improved outcomes at centres performing ≥12 cases per year (95% CI: 10-12). These results were consistent in sensitivity analyses (p < 0.0001). CONCLUSIONS: An annual institutional volume of ≥ 12 valve-sparing aortic root replacements is associated with improved long-term valve durability and survival, while early postoperative outcomes appear less sensitive to annual case load given their low event rates. This high-volume threshold may serve as a benchmark for centres already experienced in aortic valve and/or root surgery and guide quality improvement efforts.