The goal of the trial was to evaluate pulmonary vein isolation with cryoballoon ablation versus radiofrequency current ablation among patients with paroxysmal atrial fibrillation.

Contribution to the Literature: The FIRE AND ICE trial showed that cryoballoon ablation was noninferior to radiofrequency current ablation.

Study Design

  • Randomized
  • Parallel

Patients with symptomatic paroxysmal atrial fibrillation were randomized to pulmonary vein isolation by cryoballoon ablation (n = 378) versus radiofrequency current ablation (n = 384).

  • Total number of enrollees: 762
  • Duration of follow-up: mean 1.5 years
  • Mean patient age: 60 years
  • Percentage female: 27%

Other salient features/characteristics:

CHA2DS2-VASc score:

  • 0: 16%
  • 1: 29%
  • 2: 25%
  • 3: 16%
  • 4: 11%
  • 5: 3%
  • 6: <1%

Inclusion criteria:

  • Patients with symptomatic paroxysmal atrial fibrillation
  • Antiarrhythmic drug failure
  • 18-75 years of age

Exclusion criteria:

  • Previous left atrial ablation or surgery
  • Percutaneous coronary intervention or myocardial infarction in the last 3 months
  • Transient ischemic attack or stroke in the last 6 months
  • Left ventricular ejection fraction <35%
  • Left atrial diameter >50 mm

Principal Findings:

The primary outcome, recurrent atrial fibrillation, occurred in 34.6% of the cryoballoon ablation group versus 35.9% of the radiofrequency current ablation group (p for noninferiority = 0.0004, p for superiority = 0.74). The primary outcome was the same in all tested subgroups and among different types of ablation catheters.

Secondary outcomes:

  • Primary safety event: 10.2% with cryoablation vs. 12.8% with radiofrequency ablation (p = 0.24)
  • Procedure time: 124 minutes with cryoablation vs. 142 minutes with radiofrequency ablation (p < 0.0001)
  • Fluoroscopy time: 22 minutes with cryoablation vs. 17 minutes with radiofrequency ablation (p < 0.0001)
  • Phrenic nerve injury: 2.7% with cryoablation vs. 0% with radiofrequency ablation (p = 0.001)
  • Repeat ablations: 11.8% with cryoablation vs. 17.6% with radiofrequency ablation (p = 0.03)
  • Direct-current cardioversions: 3.2% with cryoablation vs. 6.4% with radiofrequency ablation (p = 0.04)
  • All-cause rehospitalizations: 32.6% with cryoablation vs. 41.5% with radiofrequency ablation (p = 0.01)


Among patients with drug-refractory paroxysmal atrial fibrillation, pulmonary vein isolation by cryoballoon ablation was noninferior to radiofrequency current ablation. Safety outcomes were also similar between treatment groups. While efficacy and safety outcomes were similar, procedure times were shortest with cryoablation and fluoroscopy times were shortest with radiofrequency balloon ablation. Patients treated with cryoablation also had fewer repeat ablations, cardioversions, or rehospitalizations.


Kuck KH, Fürnkranz A, Chun KR, et al., on behalf of the FIRE AND ICE Investigators. Cryoballoon or radiofrequency ablation for symptomatic paroxysmal atrial fibrillation: reintervention, rehospitalization, and quality-of-life outcomes in the FIRE AND ICE trial. Eur Heart J 2016;Jul 5:[Epub ahead of print].

Kuck KH, Brugada J, Furnkranz A, et al., on behalf of the FIRE AND ICE Investigators. Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation. N Engl J Med 2016;374:2235-45.

Presented by Dr. Karl-Heinz Kuck at the American College of Cardiology Annual Scientific Session, Chicago, IL, April 4, 2016.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Noninvasive Imaging, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Cardiac Surgery and Arrhythmias, Nuclear Imaging

Keywords: Ablation Techniques, ACC Annual Scientific Session, Anti-Arrhythmia Agents, Arrhythmias, Cardiac, Atrial Fibrillation, Catheter Ablation, Cryosurgery, Fluoroscopy, Phrenic Nerve, Pulmonary Veins

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