Kazunori Omote, Masanori Yamamoto, Atsushi Sugiura, Tetsuro Shimura, Shunsuke Kubo, Yuki Izumi, Mike Saji, Masahiko Asami, Yusuke Enta, Shinichi Shirai, Masaki Izumo, Shingo Mizuno, Yusuke Watanabe, Makoto Amaki, Kazuhisa Kodama, Hisao Otsuki, Toru Naganuma, Hiroki Bota, Yohei Ohno, Masahiro Yamawaki, Daisuke Hachinohe, Hiroshi Ueno, Gaku Nakazawa, Toshiaki Otsuka, Kentaro Hayashida, OCEAN-Mitral Investigators
In patients with ventricular functional MR and LVEF <20%, M-TEER was feasible and associated with meaningful symptomatic improvement without excess risk of death or HF hospitalization, although CV mortality remained higher, likely reflecting advanced myocardial disease.
BACKGROUND: Patients with functional mitral regurgitation (MR) and very severe left ventricular (LV) dysfunction (LV ejection fraction [LVEF] <20%) have been largely excluded from randomized trials of mitral transcatheter edge-to-edge repair (M-TEER), leaving a substantial knowledge gap regarding the role of M-TEER in this high-risk population.
OBJECTIVES: This study aimed to evaluate the safety, feasibility, and 1-year outcomes of M-TEER in patients with functional MR and LVEF <20%.
METHODS: The OCEAN (Optimized Catheter Valvular Intervention)-Mitral registry prospectively enrolled patients undergoing M-TEER. Among patients with functional MR and LVEF ≤40% (n = 1,538), outcomes were compared between those with LVEF <20% (n = 103) and 20%≤ LVEF ≤40% (n = 1,435). The primary endpoint was the composite of all-cause death and heart failure (HF) hospitalization at 1 year. Secondary endpoints included cardiovascular (CV) death and procedural outcomes.
RESULTS: Acute procedural success was similar between groups (n = 103 [100%, LVEF <20%] vs n = 1,390 [97%, 20%≤ LVEF ≤40%]), with comparable residual MR and postprocedural transmitral pressure gradients. In-hospital mortality did not differ by LVEF category (n = 5 [5%] vs n = 58 [4%]). Both groups showed significant improvement in NYHA functional class at 1 year, although functional status remained worse in patients with LVEF <20%. After adjustment, the primary endpoint did not differ significantly between groups (LVEF <20% vs 20%≤ LVEF ≤40%; HR: 1.24; 95% CI: 0.82-1.88). However, LVEF <20% was independently associated with higher CV mortality (HR: 2.00; 95% CI: 1.08-3.68).
CONCLUSIONS: In patients with ventricular functional MR and LVEF <20%, M-TEER was feasible and associated with meaningful symptomatic improvement without excess risk of death or HF hospitalization, although CV mortality remained higher, likely reflecting advanced myocardial disease.