Three-year follow-up of atrial fibrillation burden reduction after cryoballoon pulmonary vein isolation in early persistent atrial fibrillation: results from the COOL-PER trial

Background Limited data are available regarding the long-term efficacy of cryoballoon ablation (CBA), a single-shot pulmonary vein isolation (PVI) technique, in patients with persistent atrial fibrillation (AF). Long-term efficacy, particularly regarding changes in AF burden assessed through continuous rhythm monitoring, has been rarely reported. Objectives To evaluate the long-term efficacy of PVI using CBA in patients with early persistent AF, diagnosed within a 3-year, and its impact on disease-specific healthcare resource utilization (HCRU). Methods This multicenter prospective cohort study enrolled 130 patients with early persistent AF. Implantable loop recorders (ILRs) were inserted pre-CBA to monitor AF burden. During a 3-year follow-up, we assessed AF burden and disease-specific healthcare resource utilization (HCRU) for additional rhythm control interventions, including direct current cardioversion (DCC) and repeat catheter or surgical ablation. Results Of the 130 participants, 113 completed the 3-year follow-up. AF free survival at 36 months were 62.3% assessed by 12-lead ECG and 17.0% by ILR (Figure 1, Panel A). The mean AF burden decreased from 77.3±34.0% pre-procedure to 10.8±25.2% at 1 year, with no significant difference at 3 years (11.1±27.7%, Figure1, Panel B). During follow-up, 47 patients (41.6%) underwent additional rhythm control interventions: repeat ablations 21, DCCs 16, and both 10. Recurrence patterns after the 3-month blanking period, as assessed by ILR, revealed that 80 patients recurred as paroxysmal AF, while 25 recurred as persistent AF. Among those with paroxysmal AF recurrence, 40.0% experienced a HCRU event. In contrast, 84% of patients with persistent AF recurrence required additional interventions, while only 3.3% of patients without recurrence experienced HCRU events (Persistent AF vs paroxysmal AF p<0.001, paroxysmal AF vs no recurrence: p<0.001, Figure 2). Conclusions CBA effectively reduced AF burden in early persistent AF patients, with durable outcome over three years, however there was significant difference of AF recurrence rate according to assessment methods. Also, patients with paroxysmal AF recurrence exhibited lower HCRU, compared to those with persistent AF recurrence.