Computed Tomography-Based Oversizing Degrees and Incidence of Paravalvular Regurgitation of a New Generation Transcatheter Heart Valve.

Objectives: The aim of the study was to investigate the influence of the extent of computed tomography (CT)-based area and perimeter oversizing on the incidence and severity of paravalvular aortic regurgitation (PAR) for the Edwards SAPIEN 3 (Edwards Lifesciences, Irvine, California) device, using CT data and echocardiographic outcome data of the PARTNER II (Placement of AoRTic TraNscathetER Valves Trial II) SAPIEN 3 intermediate-risk cohort.

Background: Transcatheter heart valve (THV) sizing algorithms are device specific, requiring refinements for new valve designs.

Methods: A total of 835 intermediate-risk patients with severe, symptomatic aortic stenosis enrolled in a multicenter, nonrandomized registry at 57 sites in the United States and Canada with available systolic CT data and echocardiographic follow-up were included in this analysis. THV size selection was primarily CT guided based on annular area. Area-based and perimeter-based oversizing was calculated using systolic annular CT dimensions and nominal dimensions of the implanted THV size. PAR was assessed at 30 days according to a 5-class scheme.

Results: Mean oversizing by area was 7.7 ± 9.4% and mean oversizing by perimeter was 1.7 ± 4.4%. An inverse proportional relationship between degree of oversizing and frequency and severity of PAR was observed for both area and perimeter oversizing. Perimeter and area oversizing confer similar predictive capacity in regard to the occurrence of PAR after THV implantation (area under the curve: 0.78 [95% confidence interval: 0.70 to 0.85] vs. area under the curve: 0.78 [95% confidence interval: 0.72 to 0.85]; p < 0.0001). No aortic root ruptures were observed.

Conclusions: For the SAPIEN 3 THV, the frequency and extent of PAR is inversely related to the degree of oversizing with acceptable rates of PAR being achieved at lower degrees of oversizing. Perimeter and area oversizing confer similar predictive capacity in regard to the occurrence of PAR after implantation of the SAPIEN 3 THV. Therefore, the SAPIEN 3 THV may offer the opportunity to reduce the risk of annular rupture associated with more significant degrees of oversizing in borderline annular anatomy. (The PARTNER II Trial: Placement of AoRTic TraNscathetER Valves [PARTNER II]; NCT01314313).