Impact of mitral valve complexity on outcomes following transcatheter mitral valve edge-to-edge repair

Mitral valve edge-to-edge repair (M-TEER) is increasingly being used for the treatment of severe mitral regurgitation; however, outcomes in inoperable patients with very complex or even unfavourable mitral valve (MV) disease as ‘ultima ratio’ are unknown. The study aimed to evaluate patient outcomes according to mitral valve anatomical complexity, as suggested in a recent review article.

In this single-centre, retrospective analysis, consecutive patients who underwent M-TEER were categorized as ‘Non-Complex’ (NC), ‘Complex’ (C), ‘Very Complex’ (VC), and ‘Ultimately Complex’ (UC). Study endpoints were MR reduction, symptomatic improvement as expressed by changes in New York Heart Association (NYHA) functional class and two-year survival. The study included 789 consecutive patients at a mean age of 74.9 ± 11.1 years (42.7% female; 49% with secondary and 51% with primary or mixed MV disease). 203 patients (25.7%), 409 patients (51.8%), 138 patients (17.5%), and 39 patients (4.9%) were classified as NC, C, VC, UC, respectively. Improvement to NYHA functional class ≤ II and 2-year survival rates were comparable across anatomical complexity groups (NYHA ≤ II: 68.4%, 61.8%, 63.5%, and 75.0%, P = 0.454; survival: 64.6%, 71.2%, 68.0%, and 71.0%; P = 0.454; for NC, C, VC, and UC, respectively). MR reduction was observed in all categories and it was comparable in secondary MV disease, while increasing MV complexity was associated with an increasing prevalence of residual MR ≥3 + in primary MR (7.9%, 8.3%, 10.9%, and 23.0% for NC, C, VC, and UC, respectively; P = 0.002).

This study provides the first large-scale validation of a recently proposed mitral valve complexity framework. Anatomical complexity showed an etiology-specific impact, with no relevant effect on MR reduction or clinical outcomes in SMR, but increasing residual MR in primary disease. Given an acceptable rate of MR reduction, M-TEER can even be considered in selected patients with unfavourable MV anatomy as ‘ultima ratio’.