Prospective randomized comparison of durability of bidirectional conduction block in the cavotricuspid isthmus in patients after ablation of common atrial flutter using cryothermy and radiofrequency energy: the CRYOTIP study

• Published in: Heart rhythm Vol. 6; no. 12; p. 1699
• Main Authors: Kuniss, Malte, Vogtmann, Thomas, Ventura, Rodolfo, Willems, Stephan, Vogt, Jürgen, Grönefeld, Gerian, Hohnloser, Stefan, Zrenner, Bernhard, Erdogan, Ali, Klein, Gunnar, Lemke, Bernd, Neuzner, Jörg, Neumann, Thomas, Hamm, Christian W, Pitschner, Heinz-Friedrich
• Format: Journal Article
• Language: English
• Published: United States 01.12.2009
• Subjects: Aged; Atrial Flutter - surgery; Cardiac Electrophysiology; Catheter Ablation; Cryosurgery; Female; Heart Conduction System - physiopathology; Heart Conduction System - surgery; Humans; Male; Middle Aged; Time Factors; Treatment Outcome; Tricuspid Valve - surgery; Vena Cava, Inferior - surgery
• ISSN: 1556-3871
• DOI: 10.1016/j.hrthm.2009.09.012

Recent studies have shown that cryoablation and radiofrequency (RF) ablation are comparable with regard to success rates and safety in the treatment of common atrial flutter (AFL). Long-term success requires persistence of bidirectional conduction block (BCB) in the inferior cavotricuspid isthmus (CTI). The purpose of this study was to determine the persistence of BCB in a prospective randomized multicenter trial of the two ablation techniques. A total of 191 patients were randomized to RF ablation or cryoablation of the CTI using an 8-mm-tip catheter. In all patients, BCB was defined as the ablation end-point. Primary end-point of the study was nonpersistence of achieved BCB and/or ECG-documented relapse of common AFL within 3-month follow-up. Acute success rates were 91% (83/91) in the RF group and 89% (80/90) in the cryoablation group (P = NS). Invasive follow-up after 3 months with repeated electrophysiologic study was available for 60 patients in the RF group and 64 patients in the cryoablation group. Persistent BCB could be confirmed in 85% of the RF group versus 65.6% of the cryoablation group. The primary end-point was achieved in 15% of the RF group and 34.4% of the cryoablation group (P = .014). As a secondary end-point, pain perception during ablation was significant lower in the cryoablation group (P <.001). Persistence of BCB in patients treated with cryoablation reinvestigated after 3 months is inferior to that patients treated with RF ablation, as evidenced by the higher recurrence rate of common AFL seen in this study.