Clinical impact of initial surgical aortic bioprosthetic valve size on mid-term outcomes of transcatheter valve-in-valve in Japanese patients

Clinical outcomes of transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) procedures have been reported to be poor in patients initially implanted with small bioprosthetic valves. The aim of this study was to evaluate mid-term outcomes of TAV-in-SAV for small SAVs using data from a Japanese multicenter registry. A total of 185 TAV-in-SAV procedures performed between January 2013 and March 2024 at 10 centers in Japan were analyzed. The primary endpoint was overall 4-year Kaplan–Meier survival. Clinical outcomes were also compared between initial ≤ 21 mm SAV (small group) vs. > 21 mm SAV (non-small group). The mean age was 82.4 years; 46.5% were female. One hundred sixteen (62.7%) patients were in the small group (≤ 21 mm SAV in 40 patients; > 21 mm SAV in 76 patients). The Evolut platform was used in 150 patients (81.1%), especially in the small group (103 patients, 88.8%). The 4-year survival in the small group (69.1%) was comparable to that in the non-small group (79.6%) (p = 0.79). Similarly, freedom from cardiovascular mortality at 4 years in the small group (91.3%) was comparable to that in the non-small group (90.1%) (p = 0.096). This multicenter retrospective study shows that TAV-in-SAV in Japanese patients yields satisfactory mid-term outcomes. Despite advanced age, overall and freedom from cardiovascular mortality at 4 years were comparable to previous international reports, with no significant difference by valve size. (ClinicalTrials.gov number, NCT06826027.)