Transcatheter edge-to-edge mitral valve repair using G4 clips in the treatment of patients with central and noncentral severe primary mitral regurgitation

Objective. To evaluate in-hospital outcomes in patients with central and noncentral severe primary mitral regurgitation (PMR) after transcatheter edge-to-edge mitral valve repair (TMVR). Material and methods. The study included 62 high risk patients with severe symptomatic PMR: group 1 — 45 (72.6%) patients with central mitral regurgitation (MR), group 2 — 17 (27.4%) patients with noncentral MR. Mean age was 75 [68; 83] years, and 58.1% of patients were men. MitraClip G4 devices were implanted. Left ventricular (LV) volumetric dimensions, ejection fraction, and central hemodynamic parameters were assessed using echocardiography at baseline and 4-5 days after intervention. A detailed quantitative analysis of MR was performed, and mean mitral valve pressure gradient was calculated. Results. In early postoperative period, MR significantly reduced in both groups (p<0.001). Technical success rate was comparable in both cohorts (95.6% in central MR and 82.4% in noncentral MR, p=0.12). Hemodynamic efficacy of TMVR was more obvious in the 1st group as evidenced left ventricular end-diastolic volume (LVEDV) and LV central hemodynamic parameters. LVEDV decreased in the first group from 140 [103; 161] to 113 [87; 140] ml (p<0.001), in the second group — from 118 [94; 170] to 110 [83; 166] ml (p=0.015). Chordae tendineae rupture did not affect technical success of TMVR, but was associated with implantation of two clips (p=0.03). The number of clips did not differ between patients with central (1.56) and noncentral (1.53) MR (p=0.88). TMVR increased mean mitral valve pressure gradient in both cohorts of patients. However, this parameter was similar in postoperative period in both groups with increased number of clips. Conclusion. Transcatheter edge-to-edge mitral valve repair using G4 clips is an effective correction of central and noncentral severe primary mitral regurgitation.