Durable Burden Suppression and Recurrence Patterns After Cryoablation in Early Persistent AF: 3-Year Results of COOL-PER Trial

BACKGROUND: Long-term rhythm outcomes following cryoballoon ablation (CBA) in early persistent atrial fibrillation (AF) remain incompletely characterized. OBJECTIVE: To evaluate 3-year AF burden trajectories, subsequent recurrence patterns detected by implantable loop recorder (ILR), and association with healthcare resource utilization (HCRU). METHODS: The COOL-PER trial was a prospective, multicenter, single-arm study enrolling patients with early persistent AF (duration ≤3 years). An ILR was implanted 7-90 days before CBA for continuous rhythm monitoring. RESULTS: Among 130 enrolled patients, 123 completed 3-year follow-up (mean age 60.5±8.4 years; 25.2% female). Median AF burden decreased from 99.9% [IQR 53.1-100.0] at baseline to 0.1% [0.0-4.2], 0.5% [0.0-9.1], and 0.7% [0.0-9.5] at 1, 2, and 3 years (all P<0.001). Of 47 patients recurrence-free at 1 year, 25 (53.2%) developed subsequent recurrence, and 20 (80.0%) detected by ILR alone. Compared with first-year recurrence, subsequent recurrence was less often persistent (4.0% vs 28.9%; P=0.001) with lower AF burden (0.1% [0.0-1.6] vs 2.8% [0.4-18.7]; P=0.010). Persistent-type recurrence and AF burden ≥10% were both associated with more additional rhythm control interventions (78.3% vs. 30.8% vs. 0%; 78.6% vs. 39.1% vs. 0%; both P<0.001) and cardiovascular hospitalization (17.4% vs. 3.8% vs. 0%, P=0.045; 14.3% vs. 4.3% vs. 0%, P=0.029). CONCLUSIONS: CBA achieved durable AF burden suppression over 3-years in early persistent AF. Subsequent recurrence after the first year was common, predominantly detectable by ILR only. Subsequent recurrences were often paroxysmal with lower AF burden and associated with lower HCRU, supporting the value of continuous long-term rhythm monitoring for characterizing rhythm status beyond the first post-ablation year.