Mount Sinai Health System Jul 18 2025 Patients with heart failure and atrial fibrillation (AF) at the time of mitral transcatheter edge-to-edge repair (M-TEER) for severe mitral regurgitation are more than twice as likely to die or be rehospitalized for heart failure, compared to patients without AF. These are the findings from a Mount Sinai Fuster Heart Hospital study that links the presence of AF at the time of the procedure to worse outcomes following the procedure. The results, published