Minimally invasive mitral valve repair revisited: Respect or Resect? Amidst competing risks

BACKGROUND: Mitral valve repair (MVr) remains the preferred surgical treatment for degenerative mitral regurgitation (DMR), offering superior long-term outcomes compared with mitral valve replacement (MVR). However, the optimal surgical strategy-leaflet preservation with or without neochordal implantation ('Respect') versus leaflet resection ('Resect'), or a combination thereof ('Both')-remains a matter of debate. Our aim was to compare the longer-term outcomes of these techniques in minimally invasive mitral valve surgery, in a real-world cohort encompassing anatomically complex valve pathology. METHODS: In this single-center, retrospective cohort study, 447 consecutive patients who underwent isolated MVr via right lateral mini-thoracotomy between 2006 and 2014 were included and analyzed. Patients were stratified according to the surgical repair technique ('Respect', 'Resect', or 'Both'). Primary endpoints were valve performance measures: freedom from mitral valve-related reoperation and mitral regurgitation severity during follow-up. Secondary endpoints were all-cause mortality and major adverse cardiac and cerebrovascular events (MACCE). Competing risk regression (Fine-Gray) was applied to account for death as a competing event. RESULTS: Of the total cohort, 293 patients (65.5%) underwent MVr using the 'Respect' technique, 109 (24.4%) underwent leaflet resection ('Resect'), and 45 (10.1%) received a combined approach ('Both'). In-hospital mortality was 0.7%, and cerebrovascular events occurred in 0.9% of patients. At a mean follow-up of 5 years, durable mitral valve competence was present in 88.4% of patients (MR grade ≤ I). Five-year freedom from mitral valve-related reoperation was 93.3%, with no significant differences between techniques (P = 0.647). Five-year survival was 94.0%, and 5-year freedom from MACCE was 96.8%, with no statistically significant differences between techniques. Competing risk analysis (death as competing event) confirmed the absence of significant intergroup differences. CONCLUSION: This study demonstrates that all three techniques yield equally favorable longer-term outcomes in a minimally invasive setting, extending even to anatomically complex degenerative pathologies such as Barlow's disease, bileaflet involvement, and anterior leaflet prolapse. A morphology-guided, individualized surgical approach emerges as a reliable and durable standard for the management of DMR.