Trends in Isolated and Combined Aortic Valve Replacement for Severe Aortic Stenosis in Patients Younger Than 65 Years.

Background: Recent data demonstrate near equalization in the use of transcatheter aortic valve replacement (TAVR) and isolated bioprosthetic surgical aortic valve replacement (SAVR) in patients aged <65 years for treatment of isolated aortic stenosis (AS). Whether these trends are also seen across the entire spectrum of aortic valve replacement (AVR) procedures (including mechanical SAVR and concomitant procedures) is unknown. Methods: This retrospective study included patients aged <65 years who underwent AVR for severe AS in the multicenter Northern New England Cardiovascular Disease Group registry between 2015 and 2023. Patients were stratified by approach: TAVR, isolated SAVR, and combined SAVR (SAVR with concomitant procedures). Results: Of 1254 patients younger than 65 years who underwent AVR, 21.9% underwent TAVR, 39.7% underwent isolated SAVR, and 38.4% underwent combined SAVR. TAVR utilization more than doubled during the study period, with near equalization of TAVR and isolated bioprosthetic SAVR (28.3% and 30.8% of all AVR in 2021-2023, respectively). However, when including mechanical AVR and combined SAVR, TAVR only comprised approximately one-fourth of all AVR procedures. TAVR patients had a significantly higher burden of comorbidities compared with patients receiving isolated or combined SAVR. Conclusions: In this multicenter study, there is a consistent increase in TAVR use in patients <65 years old with preferential TAVR utilization in patients with higher comorbidities and risk. While approximately 50% of younger patients with isolated AS are receiving TAVR in recent study years, the overall utilization of TAVR in the broader group of patients with both isolated and combined AS remains approximately 25% of the overall AVR cohort.