Transcatheter Versus Mechanical and Bioprosthetic Surgical Aortic Valve Replacement in Retrospective Patient Cohorts with Aortic Stenosis <75 Years.

Background: Comparisons between transcatheter and surgical aortic valve replacement (TAVR or SAVR) in younger aortic stenosis (AS) patients are scarce. The aim of the study was to evaluate the 5-year outcomes of AS patients <75 years undergoing TAVR or SAVR. Methods: This was a single-center study that retrospectively included AS patients <75 years who underwent transfemoral TAVR or SAVR from a Chinese real-world database (2014-2023). The primary outcome was defined as the composite of all-cause death, stroke, and cardiovascular rehospitalization at 5 years post-procedure. Robust risk adjustment was performed using inverse probability weighting (IPTW), multilevel regression models, and competing-risk analysis. Sensitivity analyses included comparison between TAVR and mechanical or bioprosthetic SAVR separately in the overall cohort and patients with bicuspid aortic valve (BAV). Results: A total of 1646 patients undergoing TAVR (n = 808) or SAVR (n = 838) were finally included. At baseline, TAVR patients had an older age [(67.9 ± 5.2) vs. (56.5 ± 9.6) years, p < 0.001] and a higher surgical risk score [(3.1 ± 1.5) vs. (2.1 ± 1.0) %, p < 0.001] than SAVR patients, which was well balanced after IPTW. The 5-year adjusted risk of the primary outcome was similar (TAVR 45.9% vs. SAVR 43.4%, weighted hazard ratio, 1.00, 95% confidence interval, 0.64-1.54, p = 0.986), which stayed comparable between TAVR and mechanical or bioprosthetic SAVR separately. In BAV patients (n = 516), the risk of death was 8.3% in the TAVR group and 3.4% in the SAVR group (p = 0.349). The risk of bioprosthetic structural valve deterioration at 5 years was comparable between groups in the overall cohort (5.7% vs. 8.4%, p = 0.478) and BAV patients (7.8% vs. 13.2%, p = 0.345). Conclusions: In this retrospective study of patients aged <75 years, the risk-adjusted 5-year major clinical outcomes were statistically similar between TAVR and SAVR. However, given the inherent historical imbalances, these exploratory findings should be interpreted with caution, and dedicated prospective studies are still needed in younger and BAV populations.