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 study that suggest that AF may have to be treated more aggressively before patients undergo this type of transcatheter procedure in order to improve outcomes. Mitral regurgitation develops when the mitral valve, which controls the flow of blood from the left atrium into the left ventricle, becomes distorted from the enlarged left ventricle so...