The Clinical Impact of Mitral Gradient Post Transcatheter Edge-To-Edge Repair: A Systematic Review and Meta-Analysis

Background: Mitral transcatheter edge-to-edge repair (TEER) is a minimally invasive therapy for severe mitral regurgitation (MR) in patients with high surgical risk. TEER results in a tissue bridge that decreases mitral valve area, potentially leading to elevated mean gradient. The clinical impact of elevated gradient on outcomes is unclear.

Methods: This systematic review and meta-analysis was based on a comprehensive search of five databases. We included studies that evaluated post mitral TEER gradient on one of the following outcomes: all-cause mortality, combined endpoints, symptoms, hospitalizations, and mitral valve re-intervention. Meta-analysis was conducted using the random-effects model.

Results: Out of 6458 citations, 17 studies were included (2017-2024) reporting on 7748 patients. There was significant heterogeneity between studies related to the cutoff used to define elevated gradient, etiology of MR, and outcomes. Elevated mitral gradient post TEER (4, 4.5, 5 mmHg) was associated with worse combined endpoint (HR = 1.35, 95% CI 1.07-1.71; I² 64%), but not all-cause mortality (HR = 1.25, 95% CI 0.97-1.59; I² 45%) or risk of hospitalization. For the combined endpoint, this association was mainly significant in patients who had mitral gradient assessed using discharge echocardiogram (HR = 1.39, 95% CI 1.07-1.81; I² 62%) for all patients and for those with degenerative MR.

Conclusion: Despite the heterogeneity between studies, the current analysis suggests that patients with elevated mitral gradient post TEER are at risk of worse clinical outcomes, particularly in patients who had mitral gradient assessed using discharge transthoracic echocardiogram.