Transcatheter Therapy in Secondary Mitral Regurgitation: Recent Clinical Evidence and Emerging Frontiers

Secondary mitral regurgitation (SMR) is a common valvular disorder in patients with heart failure and is associated with poor prognosis. Transcatheter edge-to-edge repair (TEER), particularly with the MitraClip device, has emerged as a less invasive alternative to surgery, with growing evidence supporting its clinical role. However, trial results have been heterogeneous, and optimal patient selection remains under debate. A narrative literature review was conducted using a targeted manual search of PubMed (2018-2026), with the terms ("secondary mitral regurgitation" OR "functional mitral regurgitation") AND (transcatheter OR MitraClip) AND (randomized OR trial OR meta-analysis). A total of 13 key studies were included, comprising randomized clinical trials, meta-analyses, and relevant prospective series, complemented by 30 selected supporting studies used for contextualization. Recent trials such as COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) and RESHAPE-HF2 (Randomized Study of the MitraClip Device in Heart Failure Patients with Clinically Significant Functional Mitral Regurgitation) suggest that TEER reduces heart failure hospitalizations in selected patients, while MATTERHORN (Multicenter Mitral Valve Reconstruction for Advanced Insufficiency of Functional or Ischemic Origin) supports transcatheter repair as a safer short-term alternative to surgery in appropriate cases. The concept of disproportionate mitral regurgitation has become central to identifying candidates most likely to benefit. Alternative devices such as PASCAL (Edwards Lifesciences, Irvine, California) and emerging technologies, including transcatheter mitral valve replacement (TMVR), are expanding therapeutic options. TEER is a valuable and safe therapeutic option for patients with SMR who remain symptomatic despite optimal medical therapy, particularly when careful clinical and anatomical selection is applied. Although this review has methodological limitations inherent to its narrative design, it provides an updated and clinically relevant overview of current evidence and future directions in SMR management.