Safety and Efficacy of Novel Morphology Classification-Guided Mitral Valve Transcatheter Edge-to-Edge Repair for Patients With Commissural Degenerative Mitral Regurgitation: Design and Rationale of the TEER-CD Trial

Background: Mitral commissural prolapse or flail, characterized by intricate and diverse anatomical features, poses a significant challenge in mitral transcatheter edge-to-edge repair (M-TEER). Previous studies have largely focused on central mitral regurgitation with favorable valve anatomy or a general broad spectrum of complex mitral regurgitation. However, no established approach is currently available for M-TEER in commissural degenerative mitral regurgitation (DMR). Methods: Therefore, this study aimed to evaluate the efficacy and safety of a novel morphology classification-guided M-TEER strategy for treating commissural DMR using the MitraClip system. This prospective, multicenter, single-arm, objective performance criteria study involved 12 experienced centers in Asia, primarily located in China. Patients with symptomatic moderate-to-severe (3+) and severe (4+) native DMR and commissural involvement were stratified into three morphological categories based on an echocardiographic core laboratory analysis, and tailored M-TEER strategies were proposed. The primary endpoint is the proportion of patients achieving a mitral regurgitation (MR) grade of ≤1+ without repeat mitral intervention at one-year follow-up. Clinical, echocardiographic, functional, and quality-of-life outcomes were assessed over one year. Results: Based on statistical power calculations, a total of 148 patients are required to achieve adequate power to test the primary efficacy hypothesis, accounting for an estimated 10% attrition rate at 12 months. Conclusions: The morphology classification system enhances M-TEER for commissural DMR by addressing the unique challenges of this approach, enabling tailored interventions that optimize procedural success and patient outcomes. Clinical Trial Registration: ChiCTR2400090258, https://www.chictr.org.cn/showproj.html?proj=239191.