title: CoolLoop® First: A First In Man Study To Test A Novel Circular Cryoablation System In Paroxysmal Atrial Fibrillation.
abstract: BACKGROUND
  Pulmonary vein (PV) isolation is the mainstay of catheter treatment of paroxysmal atrial fibrillation (AF). The CoolLoop® cryoablation catheter (AFreeze® GmbH; Innsbruck, Austria) was developed to create wide and complete circular lesions around the PVs. In this study we evaluated feasibility and safety of this novel ablation system in humans.
  
  
  METHODS
  10 patients (6M/4F; 57.6±7.6y) with paroxysmal AF were included in 2 referral centers. The CoolLoop® catheter was positioned at each PV antrum using a steerable transseptal sheath. Subsequently, 2-6 double-freezes over 5min were performed at each vein and PV-isolation was assessed thereafter using a circular mapping catheter. During cryoablation of the right PVs, pacing was used to monitor phrenic nerve function.
  
  
  RESULTS
  The CoolLoop® catheter could be successfully positioned at each PV. A mean of 5.6±1.8 cryoablations were performed in the LSPV, 5.2±1.6 in the LIPV, 6.3±2.5 in the RSPV and 5.4±1.6 in the RIPV, respectively. Mean procedure time was 251±60min and mean fluoroscopy time was 44.0±13.2min. 6 / 10 LSPV, 6 / 10 LIPV, 5 / 10 RSPV and 6 / 10 RIPV could be isolated exclusively using the novel cryoablation system. One patient developed groin hematoma and a brief episode of ST-elevation due to air embolism was observed in another subject. No other clinical complications occurred during 3 months of follow up.
  
  
  CONCLUSIONS
  PV-isolation for paroxysmal atrial fibrillation using the CoolLoop® catheter is feasible and appears safe. Clinical long term efficacy still needs to be evaluated and will be compared with established catheters used for AF ablation.
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Stuehlinger
authors.affiliation: Department of Internal Medicine 1, Linz General Hospital (AKh Linz), Linz, Austria.
authors.forename: Simon
authors.initials: S
authors.lastname: Hoenig
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Karin
authors.initials: K
authors.lastname: Spuller
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Koman
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Stoeger
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Poelzl
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Hanno
authors.initials: H
authors.lastname: Ulmer
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Otmar
authors.initials: O
authors.lastname: Pachinger
authors.affiliation: University Clinic of Internal Medicine III / Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Steinwender
keywords: Ablation; Antrum; Cryothermia; Left Atrial Ablation; Pulmonary Vein Isolation