Cryoballoon ablation was found to be noninferior for efficacy and safety compared with radiofrequency (RF) ablation in patients with drug-refractory paroxysmal atrial fibrillation (AF).

Dr Karl-Heinz Kuck, MD of the Department of Cardiology, Asklepios Klinik St. Georg in Hamburg, Germany presented the study findings at the 2016 American College of Cardiology Annual Scientific Sessions & Expo (ACC) in Chicago.

“FIRE and ICE is the largest catheter ablation trial in AF until now. It didn’t show any significant difference with respect to either efficacy or safety,” Dr Kuck noted in an ACC press conference.


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“It really shows for the very first time that such a simplified approach is as good as a rather complex ablation approach,” he continued.

In a simultaneously published paper in the New England Journal of Medicine,  the authors noted that RF ablation and cryoablation with pulmonary vein isolation are the standard treatments for drug-refractory paroxysmal AF. Although RF ablation is the most common method, the technique requires higher levels of training and is typically only available at specialized centers. 

Sandeep Jain, MD, co-director of the Center for Atrial Fibrillation at the University of Pittsburgh Medical Center Heart and Vascular Institute echoed that sentiment. “However, the learning curve [for RF ablation] is steep and involves a point-by-point technique in which significant catheter manipulation is required,” he told Cardiology Advisor. “Cryoballoon has become available more recently and applies treatment to a larger area with each application and the learning curve appears to be more straightforward.” 

Dr Kuck and colleagues conducted a randomized, multicenter, noninferiority trial to assess RF ablation compared to cryoballoon ablation, a potentially simpler approach. 

Patients with beta-blocker or class I or class III antiarrhythmic refractory AF were randomized 1:1 to RF or cryoballoon ablation. 

The cohort included 352 patients in the RF group and 341 patients in cryoballoon group without major deviation from the study protocol. Most patients scheduled follow up visits (85% vs 87%, respectively) and more than half transmitted echocardiograms (60% vs 58%, respectively).

The primary efficacy end point of first documented clinical failure (eg, AF recurrence, atrial tachycardia or flutter, repeat ablation, or need for antiarrhythmics) within 90-days occurred in 143 patients in the RF group and 138 patients in the cryoballoon group (1-year Kaplan-Meier event rate estimates: 34.6% vs 35.9%, hazard ratio [HR]: 0.96; 95% confidence interval [CI]: 0.76-1.22; P<.001 for noninferiority).

Further, the primary safety end point of death, cerebrovascular events, or treatment related adverse events occurred in 51 patients in the RF group and 40 patients in the cryoballoon group (1-year Kaplan-Meier event rate estimates: 10.2% vs 12.8%; HR: 0.78; 95% CI: 0.52-1.18; P=0.24).

Finally, the procedure duration and left atrial dwell time for cryoballoon ablation vs RF ablation was shorter (124 vs 141 minutes; P<.001). However, the mean total fluoroscopy time for RF ablation was shorter than for cryoballoon ablation (17 vs 22 minutes; P<.001). 

”In summary, in the FIRE AND ICE trial, we found that in the treatment of patients with drug refractory paroxysmal atrial fibrillation, pulmonary- vein isolation by means of cryoballoon ablation was noninferior to pulmonary-vein isolation by RF ablation in terms of efficacy and safety,” the authors concluded.

Disclosures: The study was supported by Medtronic. Drs Arentz, Furnkranz, Chun, Metzner, Kunk, and Pocock reported financial disclosures related Medtronic.

References

  1. Kuck KH, Brugada J, Furnkranz A, et al. Presentation 410-10. Cryoballoon or radiofrequency ablation for paroxysmal atrial fibrillation. Presented at the 65th Annual Scientific Sessions and Expo of the American College of Cardiology. April 2-4, 2016; Chicago, IL.  
  2. Kuck KH, Brugada J, Furnkranz A, et al. Cryoballoon or radiofrequency ablation for paroxysmal atrial fibrillation. N Engl J Med. April 4, 2016; DOI: 10.1056/NEJMoa1602014.