CATHETER ABLATION OF ATRIAL FIBRILLATION/TACHYCARDIA IN PATIENTS WITH PULMONARY HYPERTENSION: A MULTICENTRE RANDOMIZED TRIAL

Background: Atrial fibrillation (AF) and related atrial tachycardias (ATs) are common arrhythmias in patients with pulmonary hypertension (PH). The long-term efficacy and safety of radiofrequency catheter ablation (RFCA) for AF / AT in the PH population have not yet been prospectively studied. We investigated the hypothesis of whether extensive RFCA of the arrhythmogenic substrate on top of selective ablation of clinical arrhythmia alone results in superior clinical outcomes in patients with PH and AF / AT.
Methods: Patients with combined post- and pre-capillary or isolated pre-capillary PH and AF /AT indicated to RFCA were enrolled in 3 centers and randomized 1:1 into two parallel treatments arms: (A) “Clinical” ablation and (B) “Clinical” plus substrate-based ablation. The primary endpoint of the study was documented arrhythmia recurrence >30 s without antiarrhythmic drugs during the post-blanking period after the index ablation.
Results: A total of 77 patients (71 [61; 75] years; 41 males) were enrolled in the study. 43 (56%) patients had AF and 34 (44%) had AT. The median duration of the follow-up period was 14 (12; 21) months. The primary endpoint occurred in a comparable number of patients in group A and B (17 patients [45 %] vs. 15 patients [42 %]; HR: 1.03; 95% CI 0.51 to 2.06; p=NS). When compared to AF patients (irrespective to randomisation schema), the primary endpoint occurred significantly less frequently in AT group (9 [25%] vs. 23 [61%]; HR 0.3 (95% CI 0.14 to 0.66); p = 0.003). The occurrence of the primary endpoint in AF and AT patients according to the randomization group is visualized in Figure.
Conclusion: The trial in patients with PH and AF / AT prospectively demonstrated that more extensive ablation is not associated with improved clinical outcomes. However, better results were achieved in patients with AT. NCT04053361.