Mitral regurgitation of degenerative etiology: should the timing of surgery be changed in the mitral valve repair era?

The timing of surgery in patients with chronic mitral regurgitation is a controversial issue. Left ventricular dysfunction progresses silently and is partly predictable; depressed left ventricular contractility sometimes accompanies a normal ejection fraction. Severe symptoms remain a clear recommendation for surgery. However several factors suggest that surgery should not be delayed until severe symptoms appear: impact on survival of ejection fraction < 60%, preoperative symptoms, and atrial fibrillation. Early surgery is justified in patients with degenerative mitral regurgitation independently of the type of lesion (prolapse of posterior, anterior or both the leaflets), because the addition of new techniques to the surgical armamentarium has neutralized prolapse of the anterior leaflet as an incremental risk factor for reoperation. In conclusion, early surgery is a reasonable treatment for low-risk patients with repairable valves and should be considered in asymptomatic patients with ejection fraction approaching the lower limit of normal, history of paroxysmal atrial fibrillation or pulmonary hypertension during exercise.