BOSTON – An ultra-low-temperature ablation catheter was safe and effective in the first 48 atrial fibrillation (AF) patients to undergo treatment with the device.
Mitchel L. Zoler/MDedge News
Dr. Tom De Potter
The ultra-low-temperature catheter, cooled by liquid nitrogen to –196° C, showed excellent safety and a high success rate, in the modest number of patients who have been followed for 6 or 12 months, Tom De Potter, MD, said at the annual International AF Symposium. The catheter is capable of delivering both focal and linear lesions, said Dr. De Potter, a cardiac electrophysiologist at the Cardiovascular Center of OLV Hospital in Aalst, Belgium.
He reported results on the first 48 AF patients treated with the catheter at either his center or at St. Antonius Hospital in Nieuwegein, the Netherlands, in the CryoCure2 (Investigation of the Adagio Cryoablation System in Patients With Atrial Fibrillation) study. The investigators included safety findings only from the first 13 patients treated, but they assessed both safety and efficacy for the following 35 patients.
The safety review showed one patient with a groin-puncture injury, and two patients with phrenic nerve palsy, but no cases of phrenic nerve palsy in the most recent 41 patients who were treated with an updated version of the catheter that included a cryomapping feature. None of the 48 patients had a stroke, transient ischemic attack, esophageal injury, tamponade, or MI.
The 35 patients reviewed for efficacy included 10 patients with paroxysmal AF and 25 with persistent AF. All five of the paroxysmal AF patients followed for at least 6 months, and all four of those patients followed for 12 months, showed no AF recurrences. One of the persistent AF patients never achieved cardioversion at the time of the ablation procedure. All 17 other persistent AF patients followed for at least 6 months remained in sinus rhythm at 6 months. Among the eight of these patients followed for at least 12 months after treatment, one patient had AF recurrence, so the current 12-month rate of freedom from recurrence is seven of nine patients (including the one who never achieved cardioversion), or 78%.
The average procedure time to perform pulmonary vein isolation (PVI) only was 106 minutes, and procedure time was 116 minutes in the patients who underwent PVI plus additional ablation procedures. Average ablation time was 12 minutes among those just having PVI, and 14 minutes in those who underwent PVI plus other ablations. The cryoablation catheter comes with 20 electrodes that allow it to also record electrograms.
The attraction of the ultra-low-temperature cryoablation catheter used in the study is it “can achieve complete PVI considerably faster” than other ablation methods while also achieving “unsurpassed efficacy,” Dr. De Potter said in a written statement. In addition, “the new, adjustable diagnostic capacity simplifies the procedure and makes it much less operator dependent,” he added.