Impact of Annular Oversizing on Paravalvular Regurgitation and Valve Hemodynamics: New Insights From PARTNER 3

Objectives: This study sought to investigate the impact of computed tomography (CT)-based area and perimeter oversizing on the incidence of paravalvular regurgitation (PVR) and valve hemodynamics in patients treated with the SAPIEN 3 transcatheter heart valve (THV).

Background: The incremental value of considering annular perimeter or left ventricular outflow tract measurements and the impact of THV oversizing on valve hemodynamics are not well defined.

Methods: The PARTNER 3 (Placement of Aortic Transcatheter Valves 3) trial included 495 low-surgical-risk patients with severe aortic stenosis who underwent THV implantation. THV sizing was based on annular area assessed by CT. Area- and perimeter-based oversizing was determined using systolic annular CT dimensions and nominal dimensions of the implanted THV. PVR, effective orifice area, and mean gradient were assessed on 30-day transthoracic echocardiography.

Results: Of 485 patients with available CT and echocardiography data, mean oversizing was 7.9 ± 8.7% for the annulus area and 2.1 ± 4.1% for the perimeter. A very low incidence of ≥moderate PVR (0.6%) was observed, including patients with minimal annular oversizing. Incidence of ≥mild PVR and need for procedural post-dilatation were inversely related to the degree of oversizing. For patients with annular dimensions suitable for 2 THV sizes, the larger THV with both area and perimeter oversizing was associated with the lowest incidence of ≥mild PVR (12.0% vs 43.4%; P < 0.0001). Left ventricular outflow tract area oversizing was not associated with PVR. THV prosthesis size, rather than degree of oversizing, had greatest impact on effective orifice area and mean gradient.

Conclusions: In low-surgical-risk patients, a low incidence of ≥moderate PVR was observed, including patients with minimal THV oversizing. The degree of prosthesis oversizing had the greatest impact on reducing mild PVR and incidence of post-dilatation, without impacting valve hemodynamics. In selected patients with annular dimensions in between 2 valve sizes, the larger THV device oversized to both the annular area and perimeter reduced PVR and optimized THV hemodynamics.