経カテーテル大動脈弁留置術（TAVI）から10年以上経過したバルーン拡張型弁の成績

Data on very long-term bioprosthesis durability after transcatheter aortic valve implantation (TAVI) are lacking. We sought to assess bioprosthetic valve durability beyond 10 years following TAVI with balloon-expandable valves.

We analyzed the data of a prospective single-center registry including consecutive patients undergoing TAVI with first-, second-, and third-generation balloon-expandable valves between 2007 and 2015 alive at one-year. The primary outcome was the valve-related long-term clinical efficacy according to VARC-3 consensus. Death was treated as a competing risk.

Among the 431 patients included, the median follow-up was 5 years (interquartile range 3-8 years) for the overall population, and 10 years (interquartile range 8-12 years) for the survived patients, with the longest follow-up reaching 15 years. The overall 10-year mortality rate was 87%. At 10 years, the cumulative incidence of the composite endpoint of valve-related long-term clinical efficacy (bioprosthetic valve failure, stroke and bleeding secondary to antithrombotic used for valve-related concerns) was 29%. Conversely, 71% remained free from the composite outcome after accounting for death as a competing risk. The cumulative incidence of moderate or severe HVD was 17%. The independent factors associated with moderate or severe HVD were age (subdistribution hazard ratio (sHR) 0.96, confidence interval (CI) 95% 0.94-0.99, p=0.009), severe patient-prosthesis mismatch (sHR 5.26, 95% CI 1.44-19.2, p = 0.012), and the absence of anticoagulant therapy at discharge (sHR 1.96, CI 95% 1.12-3.45, p=0.018). Bioprosthetic valve failure occurred in 9.1% of the population, and aortic valve reintervention in 4.4%. Echocardiographic parameters of bioprosthesis hemodynamic performance showed a slight progressive deterioration over time, with an increase in mean transaortic gradient (+0.54 mmHg/year, 95% CI 0.44-0.65) and a corresponding decrease in effective orifice area (-0.016 cm²/year, 95% CI -0.023 - -0.009).

These findings provide reassuring evidence supporting the very long-term durability of balloon-expandable valves after TAVI, although some signs of HVD were observed in about one fifth of patients. The protective effects of anticoagulation therapy on valve durability need further evaluation.