Catheter Ablation for AF in Patients With Severe Mitral Regurgitation After Successful Transcatheter Mitral-Valve Repair

CABA-MiTRA-AFNET12 is a non-commercial, parallel-group, prospective, randomised, open, blinded endpoint assessment (PROBE), multi-centre, therapy strategy trial. The trial investigates patients with severe mitral valve regurgitation who have undergone transcatheter edge-to-edge mitral valve repair (M-TEER) and have concomitant atrial fibrillation (AF). The objective is to assess whether catheter ablation of AF is superior to standard-of-care treatment in patients after TEER in reduction of major adverse cardiovascular and cerebrovascular events (MACCE).

The occurrence of atrial fibrillation (AF) as the most frequent arrhythmia is associated with an increased risk of stroke, acute coronary syndrome, heart failure, and cardiovascular death. AF is often associated with mitral valve regurgitation (MR) which represents the most frequent valvular heart disease in an elderly population. Both entities are not only linked by a complex pathophysiologic interplay but also the incidence of both is expected to increase due to the demographic factors, aging and obesity. AF is also a frequent comorbidity in patients with mitral valve regurgitation (MR) undergoing transcatheter edge-to-edge repair (TEER) with an incidence between 33-53% in randomized controlled trials. This is of particular clinical relevance due the complex and deleterious interaction between AF, MR, and left ventricular dysfunction. AF may pronounce left ventricular systolic dysfunction and enhance functional MR by mitral annulus dilatation (3). Current data has shown that AF contributes markedly to the course of functional MR and determines an unfavourable outcome. Catheter ablation (CA) for AF in the setting of congestive heart failure (CHF) has recently been demonstrated to be associated with a prognostic benefit in all stages of systolic left ventricular heart failure (heart failure with reduced ejection fraction, HFrEF). Although, the benefit of rhythm control in general, but also after surgical mitral valve repair (MVR) has been shown data in the setting of AF in TEER is sparse. In a recent multi-center observational cohort, the outcome of patients undergoing CA before or after TEER was investigated. As a proof of concept, it was shown that CA was associated with a prognostic benefit outweighing the negative influence of AF. Thus, the present study aims at investigating the prognostic relevance of CA following TEER in a randomized, prospective design.