title: Cryothermal vs. radiofrequency ablation as atrial flutter therapy: a randomized comparison.
abstract: OBJECTIVE
  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.
  
  
  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 and 97% (73 of 75) for RF (P = 0.86). No major adverse events occurred in any group.
  
  
  CONCLUSIONS
  Cryoablation of isthmus-dependent AFL is not inferior to RF but with significantly less procedure-related pain.
authors.affiliation: Department of Cardiology, Karolinska Institute, University Hospital, S-141 86 Stockholm, Sweden. hamid.bastani@karolinska.se
authors.forename: Hamid
authors.initials: H
authors.lastname: Bastani
authors.forename: Nikola
authors.initials: N
authors.lastname: Drca
authors.forename: Per
authors.initials: P
authors.lastname: Insulander
authors.forename: Jonas
authors.initials: J
authors.lastname: Schwieler
authors.forename: Frieder
authors.initials: F
authors.lastname: Braunschweig
authors.forename: Göran
authors.initials: G
authors.lastname: Kennebäck
authors.forename: Bita
authors.initials: B
authors.lastname: Sadigh
authors.forename: Jari
authors.initials: J
authors.lastname: Tapanainen
authors.forename: Mats
authors.initials: M
authors.lastname: Jensen-Urstad
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001282:Atrial Flutter / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D062906:Cardiac Catheters; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation; D016009:Chi-Square Distribution; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation; D018572:Disease-Free Survival; D004562:Electrocardiography; D004867:Equipment Design; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D010147:Pain Measurement; D058748:Pain Perception; D011446:Prospective Studies; D012008:Recurrence; D016037:Single-Blind Method; D013548:Sweden; D013997:Time Factors; D016896:Treatment Outcome