Transcatheter Edge-to-Edge Repair for Severe Mitral Regurgitation in a Patient with a Massive Left Atrium: A Case Report

Abstract Background Transcatheter edge-to-edge repair (TEER) poses significant technical challenges in patients with a massive left atrium (LA), where conventional anatomical criteria often deem the procedure unsuitable. Case Summary A 77-year-old man at prohibitive surgical risk presented with a giant LA (113 × 129 × 133 mm) and severe mitral regurgitation (MR). After pacemaker implantation, TEER was performed. Despite suboptimal echocardiographic windows and challenging leaflet capture, a tailored posteroinferior transseptal puncture 4.67 cm above the mitral annular plane provided a stable trajectory, enabling successful navigation and deployment of three MitraClip devices (Abbott, Santa Clara, CA, USA). The procedure achieved an excellent outcome with a mean gradient of 5 mmHg and only mild residual MR. Marked left atrial reverse remodeling and symptomatic improvement were observed at 1-month follow-up. Discussion This case demonstrates that TEER is a viable and effective intervention for patients with extreme LA enlargement, challenging conventional anatomical selection criteria. Success hinges on technical precision—particularly an optimized transseptal puncture—and prioritizing favorable hemodynamic outcomes over rigid anatomic thresholds.