Efficacy and Safety of Left Atrial Substrate Modification by Cryoballoon Ablation in Persistent Atrial Fibrillation: Study Protocol for a Randomized Controlled Trial (LACA Trial)

Background: For patients with persistent atrial fibrillation (AF), pulmonary vein isolation (PVI) constitutes one of the main ablative procedure, but whether further left atrial (LA) substrate modification can optimize prognosis remains unclear. The purpose of the study efficacy and safety of Left Atrial substrate modification by Cryoballoon Ablation in persistent AF (LACA trial) is to clarify the efficacy and safety of PVI versus PVI plus LA substrate modification in persistent AF. Methods and design: This is a prospective, randomized controlled trial (RCT). Two hundred and fifty-six patients with persistent AF undergoing initial cryoballoon ablation will be randomly assigned in a 1:1 ratio to PVI alone or PVI plus LA substrate modification. The primary endpoint is the occurrence rate of atrial tachyarrhythmias (ATs) at 1 year after procedure. Secondary endpoints included safety of procedure, arrhythmia events during the blank period, quality of life assessment, thromboembolism, severe bleeding, cardiovascular death, and all-cause death. This is a prospective RCT designed to clarify the outcomes of PVI versus PVI plus LA substrate modification by cryoballoon ablation in persistent AF. Expected Outcomes: We hypothesize that, compared with PVI, the addition of LA substrate modification to PVI will lead to a lower rate of AF recurrence. Conclusion: This study evaluates if adding LA substrate modification to PVI improves outcomes in persistent AF versus PVI alone. Results will guide therapy by assessing superiority in sustaining sinus rhythm.