Atrial Fibrillation and Transcatheter Repair of Functional Mitral Regurgitation: Evidence From a Meta-Regression

Objectives: The aim of this study was to assess the impact of atrial fibrillation (AF) on mortality and efficacy in patients with functional mitral regurgitation (FMR) undergoing MitraClip implantation.

Background: AF is a common arrhythmia in patients with severe FMR undergoing transcatheter mitral valve repair with the MitraClip device. Although AF has been consistently shown to be associated with poor outcomes after mitral valve surgery, the impact of AF on outcomes of MitraClip placement in patients with FMR has not been well studied.

Methods: Prospective, retrospective registries, observational studies, and randomized controlled trials on MitraClip reporting AF and FMR as one of the variables from inception until January 2019 were included.

Results: Of the initial 1,694 studies, 15 studies met the inclusion criteria. From a total of 5,184 patients, 2,105 patients were identified to have FMR and AF. All-cause 30-day mortality in patients with FMR was 3.7% (95% confidence interval: 2.87 to 4.66) and 1-year mortality was 17.9% (95% confidence interval: 16.01 to 19.71). The meta-regression analysis studying the impact of AF among patients with FMR treated with the MitraClip demonstrated no difference in mortality at 30 days but demonstrated significantly increased mortality at 1 year (95% confidence interval: 0.0006 to 0.0027) (p = 0.004). AF did not influence procedural success.

Conclusions: This meta-regression identifies AF as an independent negative predictor of long-term mortality after MitraClip implantation in patients with FMR. The mechanism of worse outcomes in patients with AF requires further study.