1. Department of Cardiovascular Surgery, The Mount Sinai Hospital, New York, NY, USA; 2. Department of Adult Cardiac Surgery, CHU Lyon, Inserm 1407, Lyon, France; 3. University of Rennes, CHU Rennes, Inserm, LTSI – UMR 1099, Rennes, France
The first two randomised controlled trials on secondary MR (MITRA-FR and COAPT) have recently been published1,2. These two studies had an excellent quality of follow-up modality with few lost patients, confirming the poor prognosis of this disease. The safety of MitraClip implantation (equivalent in both studies if we use the same definition of complications) and its efficacy to decrease mitral regurgitation (MR) (around 95% procedural success defined as residual MR ≤2+) are confirmed but we have to understand why two studies with apparently similar designs led to such different clinical results.
Several reasons could explain why MITRA-FR is negative: