Early Percutaneous Mitral Intervention in Asymptomatic Moderate Mitral Stenosis

Although percutaneous mitral commissurotomy (PMC) has been accepted as an effective treatment for symptomatic patients with moderate or severe mitral stenosis (MS), most asymptomatic patients are not candidates for PMC owing to the small but inherent procedure-related risks. Asymptomatic patients with MS show good survival rates up to 10 years, but there was a sudden deterioration precipitated by atrial fibrillation or embolism in half of the patients. Because the success rates of PMC were improved to more than 95% in ideal patients from highly selected centers and early PMC may decrease the occurrence of adverse events, such as atrial fibrillation or embolism, experienced centers tend to perform PMC at an early stage of disease. However, the potential benefits of early preemptive PMC in asymptomatic patients should be balanced against the real risks related to the procedure, and further studies of the efficacy of PMC in the prevention of embolism are necessary to extend its indications to asymptomatic patients. To the best of our knowledge, No randomized trials have been performed to ascertain the optimal timing of intervention in asymptomatic patients with significant MS. The early percutaneous MITral Intervention versus conventional manaGement in Asymptomatic moderate miTral stEnosis (MITIGATE) trial was designed to compare clinical outcomes of early intervention with those of a conventional management based on current guidelines in asymptomatic moderate mitral stenosis.