Cryoballoon Ablation of RooF line combined with pulmonary vein Isolation for persistent atrial fibrillation (The CARFI-PerAF Randomized Clinical Trial)

Background The limited effectiveness of pulmonary vein isolation (PVI) alone using cryoballoon ablation (CBA) led to addictive ablation in procedures of persistent atrial fibrillation (AF) ablation. Roof line (RL) ablation in addition to PVI hold great promise for reduction of AF recurrence after CBA. The randomized controlled CARFI-PerAF trial aimed to prospectively investigate the efficacy of a novel CBA strategy for block of RL and reduction of AF recurrence. Methods One hundred and ten patients who were diagnosed with persistent AF were randomized into PVI group and PVI+RL group. ‘Quarter balloon ablation technique’ and ‘roof distortion technique’ were used to improve quality of RL ablation. Conduction block of RL was confirmed by both voltage mapping and upper right atrial septum pacing. Primary effectiveness was freedom from AF or atrial tachycardia absent class I/III antiarrhythmic drugs through 12-month follow-up according to ECGs collected by portable device and 24-hour Holter. Results There was no significant difference in AF recurrence between PVI group and PVI+RL group (63.5% vs 76.2%, P = 0.296) after 532.7 ± 171.0 days of follow-up. However, blocked RL was associated with a significant reduction in risk of AF recurrence in the PVI+RL group (84.0% vs 45.5%, P = 0.025). The shape of RL was the only factor affecting the success rate of RL block. Patients with ‘Regular’ shape of RL predicted a higher rate of RL block than other types (89.7% vs 56.3%, P = 0.014). Conclusions Blocked roof line ablation was associated with a significant reduction in risk of atrial fibrillation recurrence after cryoballoon ablation. Patients with ‘Regular’ shape of roof line may benefit more from roof line ablation. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial ChiCTR2000039746 ### Funding Statement This study was supported by a grant from the National Natural Science Foundation of China (No. 82000283), the Shanghai Municipal Health Commission (No. 202140497) and the Natural Science Foundation of Shanghai (No.20ZR1456700). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was conducted in accordance with the Declaration of Helsinki and was approved by the institutional review board of Shanghai Changhai Hospital (CHEC2020-116). Informed consent was obtained from all participants. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available.