Effect of Percutaneous Edge-to-Edge Repair on Mitral Valve Area and Its Association With Pulmonary Hypertension and Outcomes

Abstract

Percutaneous edge-to-edge repair using the MitraClip system causes reduction in mitral valve area (MVA). However, its clinical impact is not fully elucidated. This study assessed the impact of postprocedural MVA reduction on pulmonary hypertension and outcomes. A total of 92 patients with grades 3 to 4+ mitral regurgitation (MR) who underwent MitraClip therapy were retrospectively reviewed. Using intraprocedural, 3-dimensional transesophageal echocardiography, postprocedural MVA was obtained by 2 optimized planes through the medial and lateral orifices of the repaired valve. MVA was reduced by 60.1% immediately after MitraClip procedure (p <0.001). Postprocedural MVA correlated moderately with mean transmitral pressure gradient (TMPG) in the majority of patients (r=-0.56, p <0.001), but discordance of MVA and TMPG was observed in 40% of patients. In multivariable linear regression analysis, postprocedural MVA ≤1.94cm2 was independently associated with a blunted decrease in systolic pulmonary artery pressure at 1-month follow-up (β-estimate-4.63, 95% confidence interval-9.71 to-0.15, p=0.042). Postprocedural MVA ≤1.94cm2 was an independent predictor of all-cause mortality and heart failure hospitalization after MitraClip (hazard ratio 4.28, 95% confidence interval 1.56 to 11.7, p= 0.005) even after adjustment for age, gender, atrial fibrillation, cause of MR, left ventricular systolic function, pre-existing pulmonary hypertension, and residual MR. After further adjustment for TMPG ≥5mm Hg, postprocedural MVA ≤1.94cm2 remained predictive for adverse outcomes (p= 0.048). In conclusion, the intraprocedural assessment of MVA by 3-dimensional transesophageal echocardiography can predict hemodynamic response and postprocedural prognosis after MitraClip therapy.