Valve-in-Valve TAVR for Degenerated Surgical Valves in Patients With Small Aortic Annuli: A Report From a Japanese Nationwide Registry.

Valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) provides an alternative treatment for high-risk patients with failed surgical bioprosthetic aortic valves. However, limited data exist on ViV-TAVR outcomes in patients with small aortic annuli, particularly among the relatively small-statured Japanese population. We analyzed data from the J-TVT (Japan Transcatheter Valve Therapy) registry, which included all TAVR institutions across Japan, with data collected from July 2018, when ViV-TAVR was approved, through December 2022. A small aortic annulus was defined as an aortic annulus area of ≤314 mm², measured using preoperative computed tomography for ViV-TAVR. Prosthesis-patient mismatch (PPM) was defined as an indexed effective orifice area <0.85 cm²/m², assessed using echocardiography within 30 days after ViV-TAVR. The composite endpoint was evaluated at 30 days and 1 year. Among 47 800 individuals, 1029 underwent ViV-TAVR, resulting in a final sample of 405 patients. The mean indexed effective orifice area was 0.83 cm²/m² in the small annulus group (n=225) and 0.94 cm²/m² in the nonsmall group (n=180), with PPM rates of 59.2% and 44.4%, respectively. Small annuli were independently associated with PPM (hazard ratio, 1.9 [95% CI, 1.26-2.87]; P=0.002). No differences in 30-day and 1-year outcomes were observed between groups. Among the 225 patients with small annuli, the mean indexed effective orifice area was 0.76 cm2/m2 in the balloon-expandable valve group (n=61) and 0.86 cm2/m2 in the supraannular self-expanding valve group (n=164), with PPM rates of 67.2% and 56.1%, respectively. No differences in outcomes were noted based on the type of valve implanted. ViV-TAVR for small aortic annuli in Japanese patients was associated with an increased risk of PPM; however, no differences in clinical outcomes were observed according to aortic annulus size or valve type. Due to the small size of our sample, further research is required to validate these findings.