Reduction of myocardial necrosis using "CLOSE" protocol during pulmonary vein isolation-Preliminary results from ACTIVE-AF trial.

Background: New protocols of pulmonary veins isolation (PVI) result in easier and more efficient procedure performance. Ablation index (AI) is the novel tool which helps to achieve transmural lesions during catheter ablation. However, benefit of this protocol in the reduction of myocardial injury is still not known.
Purpose: The aim of the study was to compare myocardial injury during catheter ablation using standard and AI protocol.
Methods: To the analysis we included 24 patients with paroxysmal atrial fibrillation, who underwent radiofrequency catheter PVI using CARTO system (Biosense Webster, Inc). In all patients cardiac troponin I (cTnI) levels were assessed before and 24 hours after the procedure. In 12 patients PVI was performed using continuous applications (dragging technique) and in 12 patients during PVI ablation AI protocol was implemented. To unify analyzed groups, we excluded patients with additional ablation lines (including line separating ipsilateral pulmonary veins).
Results: In analyzed group mean age was 59.3 ± 7.7 years and 18 (75%) patients were male. There were no differences in the clinical characteristic between both subgroups. Trend in shorter total x-ray time was observed in AI group compared with dragging group (8.6 ± 5.4 vs. 5.3 ± 3.2 min.; P  = .093) with no differences in total procedure time (146.3 ± 28.9 vs. 153.2 ± 37.1 min.; P  = .616). Twenty-four hours after the PVI procedure cTnI levels were significantly lower in AI group than in dragging group (1.984 ± 0.644 vs. 3.369 ± 1.818 ng/mL; P  = .026), with no difference in mean baseline cTnI levels (0.004 ± 0.006 vs. 0.015 ± 0.032 ng/mL; P  = .304).
Conclusion: Presented study revealed that compared with standard, continuous applications, AI protocol implementation results in reduction of myocardial injury during catheter PVI in patients with paroxysmal atrial fibrillation.
Competing Interests: The local institutional review board of Medical University of Warsaw approved trial on October 6, 2016 (number KB/143/2016), and the trial was registered at the ClinicalTrials.gov on July 26, 2016 (identifier: NCT02844959). All the other authors report that they have no relationships to disclose that are relevant to the contents of this paper.
(© 2020 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.)