Cryothermal vs. radiofrequency ablation as atrial flutter therapy: a randomized comparison

Aims Radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI) is an effective treatment for atrial flutter (AFL). However, RF may injure cardiac structures such as the atrio-ventricular node or the right coronary artery and is usually painful. This prospective, randomized study compares cryoablation (Cryo) with RF ablation regarding efficacy, safety, and perceived pain. Methods and results One-hundred and fifty-three patients (78 Cryo; 75 RF) with CTI-dependent AFL—median age 65 years (range 34– 82), 140 men (91%)—were randomized to Cryo or RF. Primary endpoint was demonstration of long-term efficacy defined as no symptomatic recurrence of AFL at the 6-month follow-up. Radiofrequency ablation was performed with a 3.5 mm open-irrigated-tip catheter and Cryo with a 9 F, 8 mm tip catheter. Ablation endpoint was bidirectional CTI block. Pain was evaluated with a visual analogue scale (VAS; 0–10). The acute success rate was 92 % for Cryo and 95 % for RF (P 0.58). Procedural time was longer in the Cryo group (152+ 54 min) than the RF group (116+41 min) (P, 0.001). Cryoablation was considerably less painful compared with RF (mean VAS-Cryo 0.7+1.2 vs. VAS-RF 4.6+2.0; P, 0.001). Success rate at 6-month follow-up was 93 % (73 of 78) for Cryo an