Prognosis of elevated mitral valve pressure gradient after transcatheter edge-to-edge repair: systematic review and meta-analysis

Elevation in mitral valve pressure gradient (MVPG) after mitral valve transcatheter edge-to-edge repair (M-TEER) is common, however, evidence on its prognosis is scarce and debatable. Thus, this study aims to investigate the impact of increased MVPG after M-TEER on outcomes. Studies reporting the associations between the elevated MVPG after M-TEER and outcomes were identified in a systematic search of published literatures. Associations were pooled by meta-analysis using a random-effects model. The primary outcome was the composite of all-cause mortality and heart failure (HF) hospitalization. Seven observational studies with 2,730 patients (mean age, 77.7 ± 9.3 yrs; male, 64.4%; functional mitral regurgitation [MR], 65.2%) were eligible for the present analysis. M-TEER was performed entirely using the MitraClip system (Abbott), followed by 29.7% of patients having increased MVPG. Elevated post-procedural MVPG was not associated with a higher risk of the primary outcome, compared to low MVPG [hazard ratio (HR) = 1.22; 95% confidence interval (CI) 0.95-1.58; p=0.12; I2 = 53.5%). However, the prognosis of elevated MVPG was observed in degenerative MR patients (HR = 1.37; 95% CI 1.03-1.84; p = 0.03; I2 = 0%), whereas not in functional MR patients. Patients with low MVPG + high residual MR had a higher risk of the primary outcome than those with high MVPG + low residual MR after M-TEER (HR = 1.50; 95% CI 1.10-2.03; p = 0.01; I2 = 13%). In conclusion, elevated MVPG seems to predict adverse outcomes mainly in patients with degenerative MR. Future studies are needed to prove these findings.