Is mitral annuloplasty an effective treatment for severe atrial functional mitral regurgitation?

Introduction: Unlike secondary mitral regurgitation (MR) in the setting of left ventricular disease, results of surgical treatment of severe atrial functional MR has remained largely unspoken. The aim of this study is to analyze short to midterm results of isolated ring annuloplasty in patients with severe atrial functional MR, in comparison with a matched cohort of patients with secondary MR. Methods: A retrospective review of our Institutional database was carried out to find all patients fulfilling strict echocardiographic criteria to define atrial functional MR. A control group of patients with MR secondary to ventricular disease was selected. All patients underwent mitral repair by means of isolated ring annuloplasty. Mortality, reoperation for severe MR, and recurrence of MR were assessed by clinical and echocardiographic follow-up. Cumulative incidence function (CIF) of recurrence of MR using death and reoperation as the competitive risk was used. Results: Twenty patients were selected for the study group and 25 for the control group. There were no differences between the two groups in terms of mortality and reoperation rate. At 2 years, the CIF of recurrence of MR ≥ 3+ and ≥ 2+ was significantly higher in patients with secondary MR compared to patients with atrial functional MR (20.8 ± 8.29% vs 5.9 ± 5.71% and 45.8 ± 10.17% vs 5.9 ± 5.71%). Conclusion: In patients with severe atrial functional MR, mitral valve repair by means of isolated ring annuloplasty seems a more effective and durable treatment as compared to patients with MR secondary to ventricular disease. Larger cohorts with longer follow up are needed to confirm these results.