Should we operate on asymptomatic patients with severe mitral regurgitation?

The timing of surgery for chronic severe mitral regurgitation (MR) in asymptomatic patients with normal left ventricular (LV) function remains controversial. On the one hand, the natural history of chronic severe MR indicates a high likelihood of eventual progression to symptoms or LV dysfunction (1–3). In addition, hemodynamic compensation may allow LV size and ejection fraction to remain normal, even when myocardial dysfunction is already present (4,5). These factors, along with the physician’s ability to perform mitral valve repair with an operative mortality 1%, have led some to consider prophylactic mitral valve surgery to prevent the inevitable development of LV dysfunction before it becomes irreversible. On the other hand, it is