Mesh ablator vs. cryoballoon pulmonary vein ablation of symptomatic paroxysmal atrial fibrillation: results of the MACPAF study

Aims Catheter ablation of the pulmonary veins (PVs) is a promising therapeutic approach for symptomatic atrial fibrillation (AF). The prospective randomized single-centre study 'Mesh Ablator versus Cryoballoon Pulmonary Vein Ablation of Symptomatic Paroxysmal Atrial Fibrillation' (MACPAF; clinicaltrials.gov NCT01061931) compared the efficacy and safety of two balloon-based PV ablation systems. Methods and results Thirty-two patients underwent PV ablation for symptomatic paroxysmal AF using the Arctic Front (R) or the HD Mesh Ablator (R) catheter according to study protocol. The primary endpoint was complete PV isolation (PVI) at the end of the ablation procedure, determined by exit block after achieving entrance block Long-term follow-up data are not included in this publication. Patients' mean age was 61.7 +/- 8.9 years, 43.2% were female, and median CHA(2)DS(2)-VASc score was 2.0. In the intention-to-treat analysis, the rate of the primary endpoint was 56.5% in patients randomized to the Arctic Front (R) and 9.5% in patients randomized to the HD Mesh Ablator (R) catheter (P = 0.001). In the perprotocol analysis, complete PVI was achieved in 13(76.5%) of 17 Arctic Front (R) patients but in none of the 15 HD Mesh Ablator (R) patients (P < 0.0001). There were one major and two minor complications in each study arm but no clinically evident stroke. Post-procedural AF recurrence was detected within hospital stay in two (11.8%) Arctic Front (R) patients and in seven (46.7%) HD Mesh Ablator (R) patients (P = 0.049). Conclusion The MACPAF study revealed a superiority of the Arctic Front (R) catheter concerning complete PVI. Owing to the insufficient efficacy of the HD Mesh Ablator (R) catheter, the safety board decided to stop MACPAF prematurely.