Choice of Balloon-Expandable Versus Self-Expanding Transcatheter Aortic Valve Impacts Hemodynamics Differently According to Aortic Annular Size

Abstract

We sought to determine whether balloon-expandable valve (BEV) and self-expanding valve (SEV) affect valve hemodynamics differently according to native aortic annulus size. Transcatheter aortic valve replacement can achieve superior prosthetic valve hemodynamics compared with surgical aortic valve replacement, particularly in patients with small aortic annulus. One hundred ninety-three consecutive transcatheter aortic valve replacement patients were grouped into tertiles defined by computed tomography derived aortic annulus systolic perimeter. The predischarge echocardiogram was analyzed for prosthetic valve hemodynamics. Tertile perimeter cutoffs were 73 and 80mm. STS score decreased as annulus size increased (7.8% vs 7.6% vs 6.0%, p ≤0.05 for small, medium, and large annulus, respectively). In patients with small aortic annulus, SEV was associated with significantly higher dimensionless index (0.64 vs 0.53, p= 0.02) and lower peak velocity (1.8 vs 2.4m/sec, p <0.001) and a trend toward lower mean gradient (7.5 vs 10.0mm Hg, p= 0.07) compared with BEV. These differences were attenuated and absent in patients with medium and large annulus, respectively. Few patients had moderate/severe paravalvular leak, with no association with valve type or annulus size. There was no difference in mortality between tertiles or valve type at 30days or 1year. There was no association between aortic annulus perimeter and 1-year mortality by univariate analysis (hazard ratio 1.00, 95% CI 0.95 to 1.05, p= 0.86) or multivariate analysis (hazard ratio 1.02, 95% CI 0.95 to 1.09, p= 0.60). In conclusion, SEV hemodynamics was superior to BEV in patients with small aortic annulus. This difference was diminished in patients with larger aortic annulus. This study highlights the importance of valve selection in patients with small aortic annulus.