Indian experience with cryoablation for paroxysmal and persistent atrial fibrillation

While the safety and efficacy of cryoablation procedures have been well-established in Western populations, data regarding these outcomes in the subcontinent remain limited.

This retrospective observational study included patients with paroxysmal atrial fibrillation (PAF) or persistent atrial fibrillation (PsAF) treated with cryoballoon catheter ablation according to standard clinical practice. The primary efficacy endpoints (mean follow-up of 15.3 months) were freedom from AF/atrial flutter (AFL)/atrial tachycardia (AT) lasting ≥30 s. The primary safety endpoint was the occurrence of serious procedure-related adverse events within 30 days of the procedure.

The study population included 66 consecutive patients with recurrent symptomatic atrial fibrillation despite medications and underwent the cryoablation procedure for rhythm control. The cohort had a mean age of 55 ± 14 years, was 77 % male, had a CHA2DS2-VASc score of 1.63 ± 1.53, and had been diagnosed with AF for a mean of 2.93 ± 3.25 years before cryoablation. Patients with PAF comprised 75.8 % of the total cohort. The PsAF subgroup had a significantly larger mean left atrial (LA) diameter (42 mm vs. 36 mm; p < 0.01), lower LVEF (57 % vs 63 %; p = 0.016), fewer presyncope episodes (6 % vs. 30 %; p = 0.048), and higher amiodarone use within last one year (69 % vs. 22 %; p < 0.01). Two serious procedure-related events (3.03 %) occurred (phrenic nerve injury), both of which resolved within 3 months' follow-up. Freedom from recurrence of atrial arrhythmia at 12 months was 71 % (95 % CI 55-81 %), with a significant difference between PAF 84 % (95 % CI 68-92 %) and PsAF 34 % (95 % CI 10-60 %) groups. Presence of atrial arrhythmia at the beginning of the study (87 % vs 51 %) and failure to terminate it after completion of ablative procedure, requiring electrical cardioversion, impose a higher risk (83 % vs 28 %) of recurrence. No difference was found between the PVI and PVI + groups.

Cryoballoon ablation demonstrated efficiency, safety, and effectiveness in treating patients with paroxysmal and persistent AF. 12-month atrial arrhythmia-free survival rates were significantly higher in patients with PAF compared to those with PsAF. Pre-procedural atrial arrhythmias and post-procedural atrial arrhythmias requiring cardioversion are associated with a higher risk of recurrence. Major procedural adverse effects were comparable to those reported in global standards.