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

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).

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.

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.

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.

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.