Objectives:This study was carried out to analyze the effects of residual mitral regurgitation (MR) and mean mitral valve pressure gradient (MVPG) after percutaneous edge-to-edge mitral valve repair (PMVR) using the MitraClip system.

Background:The clinical value of an increase in MVPG after successful PMVR is not clear. 

Methods: Two hundred fifty-five patients with MR not eligible for conventional surgery who underwent PMVR were analyzed. MVPG and MR were determined by transesophageal echocardiography (TEE) immediately at the end of the procedure. Kaplan-Meier and Cox regression analyses were performed to evaluate the impact of residual MR and MVPG on the outcome. A combined clinical endpoint (all-cause mortality, MV surgery, redo procedure, implantation of a left ventricular assist device) was used.

Results: After PMVR, MVPG increased from 1.6 ± 0.9 mmHg to 3.1 ± 1.6 mmHg (p < 0.001), while MR was successfully reduced from 3.5 ± 0.5 to 1.2 ± 0.6 (p < 0.001). After PMVR, 49 patients had a mean gradient of 4.4 mmHg or higher (mean MVPG in this group,5.5 ±1.0 mmHg). In Kaplan-Meier and Cox regression analyses, residual MR was predictive for the combined endpoint. In contrast, elevated MVPG was not associated with an increase in primary endpoint events in the overall PMVR cohort. We observed, however, that patients with degenerative MR showed increased occurrence of the primary endpoint in the group with an elevated pressure gradient, whereas this was not observed in the subgroup with functional MR. 

Conclusions: Reduction of MR, but not elevated MVPG, was predictive for clinical outcome in this cohort of PMVR patients.