Risk for Increased Mean Diastolic Gradient after Transcatheter Edge-to-Edge Mitral Valve Repair: A Quantitative Three-Dimensional Transesophageal Echocardiographic Analysis

Abstract

Background: Iatrogenic mitral stenosis is a known limitation of transcatheter edge-to-edge mitral valve repair (TMVr), but determinants of increased postprocedural mean diastolic gradient (MG) are not well defined. The aim of this study was to determine correlates of increased post-TMVr MG or aborted clip implantation due to increased MG.

Methods: Procedural three-dimensional transesophageal echocardiographic (TEE) data sets of 112 patients who underwent TMVr were retrospectively analyzed. Three-dimensional TEE mitral valve area (MVA) planimetry and mitral annular calcification (MAC) were quantified using multiplanar reconstruction. When MAC extension into the mitral leaflets was present, MAC with leaflet calcification (MAC-LC) length was recorded as the maximum distance from the mitral annulus to the most distal leaflet calcification. Increased MG after TMVr, measured on intraprocedural TEE imaging, was defined as ≥5 mm Hg or aborted clip implantation due to increased MG.

Results: Baseline MVA was 5.9 ± 1.7 cm², baseline MG was 2.1 ± 1.2 mm Hg, and MAC-LC length was 4.0 ± 4.5 mm. Thirty-two patients (29%) had increased post-TMVr MG. Risk for increased post-TMVr MG was 86%, 28%, and 14% in patients with baseline MVA < 4.0, 4.0 to 6.0, and >6.0 cm², respectively (P < .001). In patients with baseline MVA 4.0 to 6.0 cm², concurrent baseline MG ≥ 4 mm Hg or MAC-LC ≥ 6 mm was associated with higher risk for increased post-TMVr MG (53% vs 12%, P = .002). In patients with baseline MVA < 4.0 and >6.0 cm², the risk for increased post-TMVr MG was similar in the presence or absence of baseline MG ≥ 4 mm Hg or MAC-LC ≥ 6 mm (P > .05 for both).

Conclusions: Patients with baseline three-dimensional TEE MVA < 4.0 cm² are at high risk for increased post-TMVr MG. Additionally, patients with borderline MVA (4.0-6.0 cm²) and concurrent MAC-LC length ≥ 6 mm or baseline MG ≥ 4 mm Hg are at moderate risk for increased MG after TMVr.

Keywords: 3D echocardiography; Mitral regurgitation; Mitral stenosis; Transcatheter mitral valve repair.