Clinical Trial: Early Percutaneous Mitral Intervention in Asymptomatic Moderate Mitral Stenosis

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: Early Percutaneous Mitral Intervention Versus Conventional Management in Asymptomatic Moderate Mitral Stenosis

Brief Summary: 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.

Detailed Summary:

We enroll consecutive asymptomatic patients with moderate mitral stenosis who are candidates for both early percutaneous mitral commissurotomy (PMC) and conventional treatment at 3 centers in Seoul, Korea.

Echocardiographic evaluation is performed before enrollment, immediately after PMC and annually during follow-up. All patients undergo two-dimensional echocardiography and/or transesophageal echocardiography to detect left atrial thrombi. Morphologic features of the mitral valve (MV) are categorized as described previously (14), and total echocardiographic score is obtained by adding the scores for leaflet mobility, thickness, calcification, and subvalvular lesions. The MVA is measured by direct planimetry of the mitral orifice, and MS severity is graded as mild, moderate, or severe when MVA was > 1.5, 1.0 to 1.5, or < 1.0 cm2, respectively. The severity of mitral and tricuspid regurgitation is assessed semiquantitatively or using quantitative methods and classified as mild, moderate, or severe. Pulmonary artery systolic pressure (PAP) is estimated by continuous wave Doppler with the simplified Bernoulli equation.

All study patients regularly visit their attending physicians at 3 monthly interval for maintenance of anticoagulation therapy or every year for annual re-evaluation. Patients in the conventional treatment group who become symptomatic during follow-up are referred for PMC or mitral valve surgery. An embolic event is defined as a systemic embolism fulfilling both prespecified criteria: acute onset of clinical symptoms or signs of embolism and occurrence of new lesions confirmed by imaging studies. A specific diagnosis of cerebral infarction is confirmed by an experienced neurologist and additional brain magnetic resonance imaging is performed if indicated.


Sponsor: Asan Medical Center

Current Primary Outcome: Composite of cardiovascular event [ Time Frame: Participants will be followed for the duration of the trial, a minimum follow-up of 3 years ]

Composite of cardiovascular mortality, cerebral infarction, systemic embolic events that occurred during follow-up, and PMC-related complications; procedural mortality and urgent MV surgery.


Original Primary Outcome: Composite of cardiovascular event [ Time Frame: Participants will be followed for the duration of the trial, an expected average of 3 years ]

Composite of cardiovascular mortality, cerebral infarction, systemic embolic events that occurred during follow-up, and PMC-related complications; procedural mortality and urgent MV surgery.


Current Secondary Outcome:

  • all-cause death and each component of cardiovascular event [ Time Frame: Participants will be followed for the duration of the trial, a minimum follow-up of 3 years ]
    all-cause death and any component of composite primary end point.
  • Mitral valve replacement [ Time Frame: Participants will be followed for the duration of the trial, a minimum follow-up of 3 years ]


Original Secondary Outcome: all-cause death and each component of cardiovascular event [ Time Frame: Participants will be followed for the duration of the trial, an expected average of 3 years ]

all-cause death and any component of composite primary end point.


Information By: Asan Medical Center

Dates:
Date Received: July 28, 2011
Date Started: July 2011
Date Completion: December 2023
Last Updated: July 20, 2016
Last Verified: July 2016