Mortality Associated With Proportionality of Secondary Mitral Regurgitation After Transcatheter Mitral Valve Repair: North American Mitraclip for Functional Mitral Regurgitation Registry.

Overview

abstract

The association, if any, between the effective regurgitant orifice (EROA) to left ventricular end-diastolic volume (LVEDV) ratio and 1-year mortality is controversial in patients undergoing mitral transcatheter edge-to-edge repair (m-TEER) with the MitraClip™ system. This study's objective was to determine the association between EROA/LVEDV and 1-year mortality among patients undergoing m-TEER with MitraClip™.In patients with severe secondary (functional) mitral regurgitation, we analyzed registry data from 11 centers using generalized linear models with the generalized estimating equations approach. We studied 525 patients with secondary MR who underwent m-TEER. Most patients were male (63%) and were NYHA class III (61%) or IV (21%). Mitral regurgitation was caused by ischemic cardiomyopathy in 51% of patients. EROA/LVEDV values varied widely with median=0.19 mm²/mL, interquartile range [0.12,0.28] mm²/mL, and 187 (36%) patients had values <0.15 mm²/mL. Post-procedural mitral regurgitation severity improved substantially, being 1+ or less in 74%, 2+ in 20%, 3+ in 4%, and 4+ in 2%. 1-year mortality was 22%. After adjustment for confounders, the logarithmic transformation(Ln) of EROA/LVEDV was associated with 1-year mortality (odds ratio=0.600, 95% confidence interval [0.386,0.933], p=0.023). A higher Society of Thoracic Surgeons risk score was also associated with increased mortality. In conclusion, lower values of Ln(EROA/LVEDV) were associated with increased 1-year mortality in this multi-center registry. The slope of the association is steep at low values, but gradually becomes flatter as Ln(EROA/LVEDV) increases.