Predictors of bioprosthetic valve dysfunction after transcatheter aortic valve implantation

Background: Recently, the Valve Academic Research Consortium (VARC)-3 criteria redefined bioprosthetic valve dysfunction (BVD) after transcatheter aortic valve implantation (TAVI). However, the rate of BVD is scarcely reported in current practice. Aims: We aimed to evaluate the rate and predictors of BVD after TAVI based on the VARC-3 criteria. Methods: We retrospectively analysed patients who had undergone TAVI using single-centre data. BVD was reported as exposure-adjusted event rates with a patient-year unit (per 100 patient-years). Predictors of BVD after TAVI were analysed using Fine-Gray competing risk regression to account for the competing risk of death. Results: Among 514 patients, the rate of BVD was 7.5 events per 100 patient-years (n=74) at a median follow-up of 1.9 years. The main cause of BVD was moderate or severe prosthesis-patient mismatch (PPM; n=59). The Fine-Gray model demonstrated that predilatation was associated with a lower rate of BVD, mainly moderate or severe PPM (adjusted subdistribution hazard ratio [sub-HR] 0.42, 95% confidence interval [CI]: 0.21-0.88). In a subgroup analysis, the patients with a small aortic annulus (area <400 mm² or perimeter <72 mm) tended to benefit from predilatation (p for interaction=0.03). The same regression model also demonstrated that a small balloon-expandable valve (BEV; ≤23 mm) was associated with a higher rate of BVD (adjusted sub-HR 2.46, 95% CI: 1.38-4.38). Conclusions: Our study suggested that the rate of BVD in patients undergoing TAVI is relatively low at midterm follow-up. Predilatation, particularly in small annuli and small BEV might have an impact on BVD, mainly caused by moderate or severe PPM, after TAVI.