title: 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.
abstract: BACKGROUND
  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).
  
  
  OBJECTIVE
  The purpose of this study was to determine the persistence of BCB in a prospective randomized multicenter trial of the two ablation techniques.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors: Department of Cardiology, Kerckhoff-Klinik, Bad Nauheim, Germany. m.kuniss@kerckhoff-klinik.de
authors: Malte
authors: M
authors: Kuniss
authors: Thomas
authors: T
authors: Vogtmann
authors: Rodolfo
authors: R
authors: Ventura
authors: Stephan
authors: S
authors: Willems
authors: Jürgen
authors: J
authors: Vogt
authors: Gerian
authors: G
authors: Grönefeld
authors: Stefan
authors: S
authors: Hohnloser
authors: Bernhard
authors: B
authors: Zrenner
authors: Ali
authors: A
authors: Erdogan
authors: Gunnar
authors: G
authors: Klein
authors: Bernd
authors: B
authors: Lemke
authors: Jörg
authors: J
authors: Neuzner
authors: Thomas
authors: T
authors: Neumann
authors: Christian W
authors: CW
authors: Hamm
authors: Heinz-Friedrich
authors: HF
authors: Pitschner
mesh_terms: D000368:Aged; D001282:Atrial Flutter / Q000601:surgery*; D054849:Cardiac Electrophysiology; D017115:Catheter Ablation; D003452:Cryosurgery; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome; D014261:Tricuspid Valve / Q000601:surgery*; D014682:Vena Cava, Inferior / Q000601:surgery*