Long-Term Outcomes of Early Surgery for Asymptomatic Severe Chronic Mitral Regurgitation

Background and aim of the study: The long-term outcomes of early surgery in patients with asymptomatic severe chronic mitral regurgitation (MR) and the impact of preoperative left ventricular dysfunction, atrial fibrillation (AF) and/or pulmonary hypertension (PH) on outcomes in this patient group, were evaluated. Methods: Between 1992 and 2007, a total of 212 patients (mean age 50 +/- 15 years) with asymptomatic severe chronic degenerative MR underwent early mitral valve surgery within 12 months after echocardiographic diagnosis at the authors' institution. Mitral valve repair was attempted in all cases. The mean follow up period was 82 +/- 36 months. The patients were allocated to two groups; 111 with preoperative left ventricular dysfunction, AF and/or PH (group A), and 101 patients without those findings (group B). The outcomes were compared using univariate and multivariate analyses. Results: Mitral valve repair was performed successfully in 211 patients (99.5%). The operative mortality was 0.5% (1/212). The 10-year actuarial survivals were 97.3% in all patients, 95.1% in group A, and 100% in group B. The 10-year cardiac adverse event-free rates (cardiac death, mitral valve reoperation or readmission with congestive heart failure) were 94.7% in all patients, 92.7% in group A, and 96.2% in group B. The seven-year freedom rates from recurrent MR were 93.1% in all patients, 90.0% in group A, and 97.0% in group B. In comparative analyses, group A had poorer late outcomes than group B, although the differences were not statistically significant. The multivariate analysis failed to show that preoperative left ventricular dysfunction, AF and/or PH were significantly associated with late cardiac adverse event (HR: 2.1, 95% CI: 0.4 to 10.8; p = 0.392). Conclusion: Early surgery for asymptomatic chronic MR demonstrated excellent early and late outcomes. The study results failed to confirm that preoperative left ventricular dysfunction, AF and/or PH were significantly associated with adverse outcomes of early mitral valve surgery in this patient group.