Reduction of AF Burden After Cryoballoon Ablation in Patients With Early Persistent AF: The COOL-PER Trial.

Background: Limited data exist on reducing the atrial fibrillation (AF) burden, the regression from persistent to paroxysmal AF, and symptom improvement after cryoablation in patients with persistent AF.

Objectives: This study sought to evaluate the efficacy of cryoablation in reducing the AF burden, regression to paroxysmal AF, and symptom improvement in patients with early persistent AF.

Methods: This investigator-initiated, multicenter, and prospective cohort study enrolled the patients with early persistent AF (≤3 years). All patients were inserted an implantable loop recorder at the time of trial entry. AF burden (percentage of time in AF) and actual AF type were evaluated during pre-cryoablation and 12-month follow-up after cryoablation. AF-related symptoms and quality of life were assessed.

Results: A total of 130 patients were enrolled (median age 61 years [Q1-Q3: 54-67 years]; median duration of persistent AF 6 months [Q1-Q3: 4-10 months]). The mean AF burden before cryoablation was 77 ± 34% (25.4% of high-burden paroxysmal AF; 74.6% of implantable loop recorder-confirmed persistent AF), which was reduced to 9 ± 21% after 12-month follow-up (mean 68 ± 37% of AF burden reduction; P < 0.001). Of the total, 38.5% had no recurrence of AF, 43.1% had a recurrence of paroxysmal AF, and 18.5% had a recurrence of persistent AF. Among those with confirmed persistent AF at baseline, 76% of patients showed regression to paroxysmal AF or no recurrence. After cryoablation, 77% of patients improved AF-related symptoms and quality of life as assessed by 36-Item Short Form Survey questionnaires.

Conclusions: In patients with early persistent AF, cryoablation significantly reduced AF burden and achieved regression of AF type followed by symptom improvement. (Cryoablation for Pulmonary Vein Isolation Alone in Patients with Early Persistent AF Assessed by Continuous Monitoring [COOL-PER]; NCT05507749).