Introduction: Radiofrequency (RF) ablation of cavotricuspid isthmus (CTI) is an effective treatment for atrial flutter (AFL). This prospective, randomized study aimed to compare cryoablation (CRYO) with 10 mm tip RF catheter ablation (10RF) and 4.0 mm tip RF irrigated catheter ablation (IRRF) regarding the efficacy, safety, and long-term prognosis.
Materials and methods: Two hundred sixteen patients (51 CRYO, 84 10RF, and 81 IRRF) with CTI dependent AFL (median age 62 years) were randomized to CRYO, 10RF or IRRF catheters. The primary endpoint was the long-term efficacy defined as no symptomatic recurrences of AFL during the 12-month follow-up. The ablation endpoint was bidirectional CTI block.
Results: The acute success rates were 98% for CRYO, 96% for 10RF, and 96% for IRRF (p=0.99). The application duration was longer with CRYO (1346 ± 49 sec) than 10RF (334 ± 37) and IRRF (440 ± 53) (p<0.01). The application time was significantly shorter with CRYO (5.6 ± 1.6) than 10RF (9.7 ± 2.2) and IRRF (11.1 ± 3.1) (p<0.01). The success rates during 12-month followup were 9% for CRYO, 96% for 10RF, and 97% for IRRF (p=0.86). No major adverse events occurred. Pain perception was not recognized for CRYO different from the 10RF and IRRF.
Conclusion: CRYO of AFL was not inferior to 10RF or IRRF but had a significantly longer application duration and a smaller number of application time.
Catheter ablation, Atrial flutter, Radiofrequency current energy, Cryo-ablation, Large tip ablation catheter, Irrigation ablation catheter