Catheter ablation of atrial fibrillation and atrial tachycardia in patients with pulmonary hypertension: a randomised study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The study was supported by the Ministry of Health of the Czech Republic. BACKGROUND: Atrial fibrillation (AF) and other atrial tachycardias (ATs), including typical atrial flutter (AFL), are common in patients with pulmonary hypertension. Frequently, several supraventricular arrhythmias are successively observed in individual patients. PURPOSE: We investigated the hypothesis of whether more extensive radiofrequency catheter ablation of the bi-atrial arrhythmogenic substrate instead of clinical arrhythmia ablation 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 catheter ablation were enrolled in 3 centers and randomized 1:1 into two parallel treatments arms: (A) Clinical arrhythmia ablation and (B) Clinical arrhythmia plus substrate-based ablation. The primary endpoint was arrhythmia recurrence >30 s without antiarrhythmic drugs after the 3-month blanking period. RESULTS: A total of 77 patients (mean age 67 ± 10 years; 41 males) were enrolled. The presumable clinical arrhythmia was AF in 38 and AT in 36 patients, including typical AFL in 23 patients. During the median follow-up period of 13 (IQR: 12; 19) months, the primary endpoint occurred in 15 patients (42 %) vs. 17 patients (45 %) in the group B vs. A (hazard ratio: 0.97, 95% confidence interval: 0.49-2.0). There was no excess of procedural complications and clinical follow-up events including an all-cause death in group B. CONCLUSION: Extensive ablation, compared with a limited approach, was not beneficial in terms of arrhythmia recurrence in patients with AF / AT and pulmonary hypertension.