Long-Term Outcomes Comparing Minimally Invasive Mitral Valve Repair versus Conventional Mitral Valve Surgery

Objectives: To compare the long term outcomes between minimally invasive mitral valve repair (MiMVR) and conventional surgery. Current retrospective comparisons between the techniques frequently report echocardiographical (echo) outcomes early after surgery and rarely report them later. Methods: Patients were selected for MiMVR by the surgical multi-disciplinary meeting from June 2008-March 2013. Patients included had at least two transthoracic post-operative echocardiograms. Echocardiographic parameters including left ventricular size and systolic function, degree of mitral regurgitation (MR) and mean mitral valve gradient were recorded. Clinical outcomes including all-cause mortality, re-operation, recurrence of at least moderate MR and elevated mean mitral valve gradients > 5 mmHg were recorded and compared using Kaplan-Meier survival analysis. Results: 223 patients were screened, 96 (43%) met the criteria and were included. Thirty-seven patients underwent conventional surgery and 59 underwent MiMVR. Mean clinical follow-up was 6.3 years and echo follow up was 3.2 years. There was a significantly higher recurrence of moderate MR in the conventional group (38% (n = 19) versus 17% (n = 10)). The mean LV end-diastolic diameter was 4.8 cm (conventional) versus 5.0 cm (MiMVR). The incidence of elevated PG was 26% (n = 13, conventional) and 23% (n = 14, MiMVR). There was no significant difference in incidence in re-operation (conventional 12% (n = 6), MiMVR 8.3% (n = 5)). Long-term mortality was higher in the conventional group (1.7% vs. 18% p = 0.004) although the logistic Euroscore was significantly higher 6.8% ± 5.4 vs. 3.6% ± 1.6. Conclusions: Minimally invasive mitral valve surgery is safe and feasible in selected patients with good medium and long-term echocardiographic follow-up.