Early Mitral ValvE Repair Versus Watchful Waiting for Asymptomatic SEvere Degenerative Mitral Regurgitation

Experimental group: In patients randomized to early mitral valve repair, surgery will be performed within 3 months after randomization. Clinical interview will be performed at discharge, at 6 months and afterwards yearly until the end of follow-up. Echocardiography will be performed at discharge, at 6 months and at the end of follow-up.

Control group: Patients randomized to initial conservative management will be followed up by clinical interview and echocardiography every 6 months. Patients will be instructed to report any change in functional status in a prompt manner. Surgery will be indicated at the onset of symptoms or if one or more of the following occur during follow-up: LV end-systolic diameter >40mm, LV ejection fraction <60%, recurrent atrial fibrillation, or resting systolic pulmonary artery pressure >50mmHg.

Inclusion criteria

• Asymptomatic patients according history or an exercise test in those able to perform it if there is a doubt about the absence of symptoms
• Severe (grade IV) degenerative MR due to leaflet prolapse assessed by echocardiography
• LV ejection fraction by Simpson biplane method ≥60% and LV end-systolic diameter by TM echocardiography ≤40mm
• Sinus rhythm on the inclusion ECG
• Pulmonary artery pressure ≤50 mmHg by Doppler echocardiography.
• High probability of mitral valve repair
• EuroSCORE II ≤ 3%

Exclusion criteria

• Mitral stenosis or > mild aortic valve disease (stenosis or regurgitation)
• Congenital heart disease (except patent foramen ovale or atrial septal defect)
• Patients with cardiac prostheses
• Previous myocardial infarction
• Previous cardiac surgery
• Extra cardiac comorbidity with life expectancy < 5 years
• Recent history of psychiatric disease (including drug or alcohol abuse)
• Therapy with an investigational intervention at the time of screening or plan to enrol patient in additional intervention study during participation in this trial