BOSTON—A single-center randomized trial found that pulmonary vein isolation with the cryoballoon ablation technique was as effective as open irrigated radiofrequency in patients with paroxysmal atrial fibrillation (PAF).
Further, the mean total procedure time was 167.4 minutes in the cryoballoon group and 189.1 minutes in the radiofrequency group. The 22-minute difference was statistically significant.
Lead researcher Armin Luik, MD, of Staedtisches Klinkum Karlsruhe in Karlsruhe, Germany, presented the results on May 14 during a late-breaking clinical trials session at Heart Rhythm 2015.
Luik said the researchers received 20,000 euros from Medtronic at the beginning of the study to buy Holter monitoring devices. However, they received no additional funding.
After six months, 63 percent of patients in the cryoballoon group and 62 percent of patients in the radiofrequency group were free of AF without persistent complications. During the first six months, redo procedures could not be given.
After a year, 68 percent of patients in the cryoballoon group and 65 percent of patients in the radiofrequency group were free of AF. Redo procedures were performed in 19.9 percent of patients in the cryoballoon group and 19.5 percent of patients in the radiofrequency group.
The study randomized 315 adults between 18 and 75 years old who had two episodes of PAF within the last three months, including one documented case. They also were required to have failed treatment with at least one antiarrythmic drug (AAD).
The study’s protocol mentioned AADs should not be given after the ablation procedure, while the redo procedure was required to use the same energy source as the index procedure.
At baseline, the mean age was approximately 60, and 60 percent of patients were males. The groups were well balanced. At 12 months, 24 patients had dropped out of the study, including one who committed suicide, one who died from a motorcycle accident and 22 who refused to come to follow-up visits.
Complications were found in 12.2 percent of patients in the cryoballoon group and 5 percent of patients in the radiofrequency group. The difference was due to the higher rate of phrenic nerve palsy: 0 percent in the radiofrequency group and 5.8 percent in the cryoballoon group.