Outcomes of transcatheter edge-to-edge repair for atrial functional mitral regurgitation: A meta-analysis of observational studies

Background: Transcatheter edge-to-edge repair (TEER) may have potential benefits in the treatment of atrial functional mitral regurgitation (AFMR), but robust evidence is currently lacking. We conducted a systematic review and meta-analysis to investigate the clinical outcomes of TEER for AFMR, including comparisons to ventricular functional MR (VFMR). Methods: MEDLINE and EMBASE were searched through January 2023 to identify studies eligible for analysis. The primary outcome was postprocedural MR severity. Postprocedural New York Heart Association (NYHA) functional class classification and all-cause mortality were also evaluated. Outcomes were stratified into short term (postprocedure to 6 months) and long term (6 months to 2 years). Results: A total of eight observational studies met the inclusion criteria, enrolling 539 AFMR and 3486 VFMR patients. Postprocedural MR grade ≤2 in the AFMR group was observed in 93.7% (454/491 patients; 95% confidence interval (CI), 91.1%–96.2%, I² = 24.3%) and 97.1% (89/93 patients; 95% CI, 92.9%–100%, I² = 26.4%) in short- and long-term follow-up, respectively. There was no difference in the rates of postprocedural MR grade ≤2 between AFMR and VFMR either in short-term (risk ratio [RR], 1.00 [95% CI, 0.95–1.06]; p = 0.90; I² = 53%) or long-term follow-up (RR, 1.08 [95% CI, 0.89–1.32]; p = 0.44; I² = 22%). Similarly, no difference was observed between AFMR and VFMR in the rates of postprocedural NYHA class ≤2 or all-cause mortality. Conclusion: TEER provides similar clinical outcomes for AFMR and VFMR. A high rate of MR grade ≤2 was observed in patients at both short- and long-term follow-ups. Further prospective studies with TEER versus medical therapy and/or rhythm control for AFMR are warranted.