Ethnic Variation in Aortic Root Anatomy and Prosthesis Sizing in TAVI: A UK Matched study

Background Ethnic variation in aortic root anatomy may influence transcatheter aortic valve implantation (TAVI) planning and outcomes. While Asian patients are reported to have smaller aortic dimensions than Western counterparts, data for Southeast Asians in the UK are scarce. Methods We retrospectively analysed all Southeast Asian patients undergoing TAVI at a large UK centre (January 2018-October 2023), matched 2:1 by age and sex to Caucasian patients. Baseline demographics, CT-derived aortic measurements, procedural details, and post-procedural outcomes were compared. Results Of 1,230 patients undergoing TAVI, 44 Southeast Asians were matched to 84 Caucasians. Compared with Caucasians, Southeast Asians had lower BMI (25.8 ± 4.6 vs 29.4 ± 6.5 kg/m², p = 0.001) and smaller annular areas (390.3±89.5 vs 469.4±89.3 mm², p < 0.001), perimeters (71±7.8 vs 78±7.6 mm, p <0.001), and sinus heights (20.1±3.2 vs 22.6 ± 3.3 mm, p <0.001). Indexed annular area did not differ significantly (229±42.7 vs 242±41.6 mm²/m², p =0.10). Median valve size was smaller in Southeast Asians (23 mm vs 26 mm, p <0.001). Residual aortic regurgitation (AR) post-implant was more frequent in Southeast Asians, with fewer having no AR (47.7% vs 78.6%) and a higher proportion with mild (50.0% vs 19.0%) or moderate AR (2.3% vs 1.2%). Post-TAVI gradients were similar between groups. Conclusion Southeast Asian patients in the UK undergoing TAVI have smaller annular dimensions and receive smaller prostheses compared with Caucasians, partly reflecting differences in body habitus. These findings have implications for prosthesis selection, procedural planning, and lifetime valve management.