Outcomes of mitral TEER in non-responders to cardiac resynchronization therapy: A systematic review and Meta-analysis

Background Secondary mitral regurgitation (MR) worsens in 10–15 % of heart failure (HF) patients receiving cardiac resynchronization therapy (CRT). Transcatheter edge-to-edge repair (TEER) with Mitra-Clip (Abbot Vascular, Santa Clara, CA, USA) therapy is associated with improved survival and decreased rates of hospitalization for HF in selected patients with secondary MR. Data on TEER outcomes in CRT-non-responders are limited. The purpose of this meta-analysis was to evaluate outcomes of mitral TEER with Mitra-Clip in CRT-non-responders. Methods Cochrane, Scopus, MEDLINE, and EMBASE were searched for studies discussing outcomes of Mitra-Clip in CRT non-responders. Two reviewers were independently involved in screening studies and extracting relevant data. Individual study incidence rate estimates underwent logit transformation to calculate the weighted summary proportion under the random effect model. Results A total of eight reports met the inclusion criteria (439 patients). Mitra-Clip improved MR grade to ≤2+ in 83.8 % and 86.8 % of CRT non-responders at six months and one year, respectively. Symptomatic improvement (New York Heart Association class ≤II) was also found in 71 % and 78.1 % of CRT non-responders at six months and one year, respectively. The pooled overall incidence estimates of mortality at 30 days, 6 months, 1 year, and 2 years were 3.6 %, 9.2 %, 17.8 %, and 25.9 %, respectively. Conclusion TEER with Mitra-Clip in patients with significant secondary MR who do not respond to CRT was associated with MR improvement, alleviation of symptoms, and mortality rates similar to those in the COAPT trial.