Mitral regurgitation in atrial fibrillation: Is a simple repair enough to tackle a complex problem?

Background: Clinical and echocardiographic results of valve repair for mitral regurgitation in the setting of atrial fibrillation are poorly studied.

Methods: Between January 2008 and December 2020, 89 patients underwent valve repair for mitral regurgitation in the setting of atrial fibrillation. Clinical and echocardiographic follow-up data were collected and studied. The primary composite endpoint consisted of all-cause mortality or hospitalization for heart failure.

Results: Valve repair with true-sized annuloplasty was performed in 83 (93 %) and restrictive annuloplasty in 6 (7 %) patients. Early mortality occurred in 3 (3 %) and residual mitral regurgitation in 1 (1 %) patient. During a median follow-up of 5.4 years (interquartile range 3.4-9.5), 25 patients died, 6 due to end-stage heart failure. Ten patients were hospitalized for heart failure. The estimated event-free survival rate at 10 years was 48.2 % (95 % CI 33.5 %-62.9 %). Recurrent mitral regurgitation was observed in 14 patients and most often caused by leaflet tethering. When analyzed as a time-dependent variable, recurrent regurgitation was related to the occurrence of the primary endpoint (hazard ratio 3.192, 95 % CI 1.219-8.359, p = 0.018). On exploratory sub-analyses, no recurrent regurgitation was observed after restrictive annuloplasty or in patients with paroxysmal atrial fibrillation. Moreover, recurrent regurgitation was observed more often when signs of left ventricular impairment were present preoperatively.

Conclusions: Despite good initial results, recurrent regurgitation was a frequent observation after valve repair for mitral regurgitation in atrial fibrillation and had an effect on heart failure related morbidity and mortality. Refinements in the timing of surgery and surgical technique might help improve outcomes.