Abstract 13915: Cryoballoon Catheter Ablation versus Antiarrhythmic Drug as a First-Line Therapy for Patients With Paroxysmal Atrial Fibrillation: Results of the Cryo-FIRST Study

Abstract

Introduction: Early catheter ablation (CA) may increase procedure efficacy and reduce the risk of atrial fibrillation (AF) disease progression. Cryo-FIRST (NCT01803438) evaluated whether pulmonary vein isolation (PVI) with cryoballoon CA is superior to antiarrhythmic drug (AAD) therapy as a first-line treatment for the prevention of atrial arrhythmia recurrence (AAR) in patients with paroxysmal AF (PAF). Methods: Patients with symptomatic PAF, free of heart disease and not administered an AAD for >48 hours were enrolled at 18 sites in 9 countries, randomized (1:1) to cryoballoon CA (Arctic Front Advance, Medtronic) or AAD therapy (Class IC or III). Using a 90-day blanking period, subjects were followed at 1, 3, 6, 9, and 12 months by 7-day Holter monitoring. Primary endpoint failure was defined as AAR lasting >30 s. Safety was evaluated by comparing the incidence of serious adverse events (SAEs). Palpitations were monitored by a patient diary. Results: Of the 218 randomized subjects (age 52±13 years, 68% male), 187 (86%) completed the 12-month follow-up. Crossovers occurred in 20 subjects (9%; 1 subject from CA-to-AAD and 19 from AAD-to-CA). By intention-to-treat analysis, freedom from AAR after blanking was achieved in 82.2% of subjects in the cryoballoon CA arm and 67.6% of subjects in the AAD arm (HR=0.48, 95% CI: 0.26-0.86; P =0.013). There were no group differences in the time-to-first SAEs (HR=0.76, 95% CI: 0.46-1.26; P =0.28), and there was no death, atrio-esophageal fistula, pericardial tamponade, or stroke reported during the study. Also, there was no phrenic nerve injury present at the time of hospital discharge. The incidence rate of symptomatic palpitations after the 3 month follow-up was lower in the cryoballoon CA (4.61 days/year) compared to the AAD arm (15.18 days/year; IRR=0.30, 95% CI: 0.16-0.58; P<0.001) with a mean duration [min]of 54.4 (131.1) for CA and 102.7 (162.8) for AAD. Conclusions: Cryoballoon CA was superior to AAD for the prevention of AAR in treatment naïve patients with PAF, and CA was associated with less frequent symptom recurrence. Moreover, CA had a safety profile comparable to AAD therapy. These results suggest cryoballoon CA is an effective first-line treatment for patients with symptomatic PAF.