Introduction:
Catheter ablation of cavo-tricuspid isthmus (CTI) is considered to be the most effective therapy for eliminating target arrhythmia in lone atrial flutter (AFL). However, many patients subsequently develop AF after CTI ablation. Therefore, prophylactic pulmonary vein antrum isolation (PVAI) along with CTI ablation could be considered as an alternate option in these patients. We aimed to compare long-term incidence of post-ablation atrial fibrillation following CTI alone or CTI plus PVAI in patients presenting with isolated AFL and no history of atrial fibrillation.
Methods:
This multi-center prospective randomized study enrolled 216 patients undergoing catheter ablation for isolated typical atrial flutter. Patients were randomized to CTI alone (group 1, n=108, 61.2±9.7 year, 75% male, LVEF 59±10%) or combined ablation CTI+PVAI (group 2, n=108, 62.4±9.3 year, 73% male, LVEF 57±11%). Insertible Loop Recorder (ILR) was implanted in 21 and 19 patients from group 1 and 2 respectively, on the day of the ablation procedure. Remaining patients were monitored for recurrence with event recorders, ECG, 7-day Holter and cardiology evaluation. All patients were followed up for 18±6 months for recurrence.
Results:
Compared to group 1, group 2 had significantly longer average procedural duration (75.9±33 min vs. 161±48 min [p <0.001]) and fluoroscopy time (15.9±12.3 min vs 56.4+21 min [p<0.001]). At the end of 18±6 months follow-up, 65 (60.2%) in group 1 and 77 (71.3%) in group 2 were arrhythmia free off-AAD (log-rank p=0.044). A subgroup analysis was performed with a 55 year age cut-off. In the <55 age group the CTI only population had similar success as in CTI+PVI without undergoing the additional PVI (21 of 24 [83.3%] vs. 19 of 22 [86.4%] respectively, log-rank p=0.74). In the ≥55 group, having CTI+PVI showed significantly higher success compared to CTI only; 45 of 84 (53.6%) were AF/AT free in CTI only group compared to 58 of 86 (67.4%) with CTI+PVI (log-rank p= 0.029). Distribution of AF incidence was not different between patients with and without ILR.
Conclusion:
Prophylactic PVAI in lone atrial flutter caused marked reduction in new-onset AF in patients ≥ 55 years whereas younger patients (<55 years) did not incur any benefit from the additional procedure.
Crucial role of pulmonary vein firing as an initiator of typical atrial flutter: Evidence of a close relationship between atrial fibrillation and typical atrial flutter
