Medical Device Daily Washington Editor
CryoCath Technologies (Montreal) yesterday reported that it has received approval from the FDA to initiate a new investigational device exemption (IDE) study for the treatment of atrial fibrillation (AF).
CryoCath's upcoming study will use its developmental Arctic Front balloon catheter to treat AF and its Freezor MAX to treat atrial flutter when related to AF.
Steven Arless, president and CEO of CryoCath, told Medical Device Daily that the Arctic Front is positioned as the company's second-generation AF catheter, building on the success of its Arctic Circler device.
That device has been employed in its study using a "toolbox" approach with three of the company's catheters – the Arctic Circler Linear, Freezor Xtra and Freezor MAX – launched in 2003 (Medical Device Daily, Nov. 18, 2003).
"We have had very good results with Arctic Circler, but felt there was still room to improve," Arless said. "We want to get our efficacy rates up a little higher, reduce procedure times and make the procedures simpler so that every ablation center in the world would be interested in using it."
AF is a rapid vibration in the top two chambers of the heart. With more than 2 million Americans affected by this problem annually, it is the most prevalent arrhythmia. Up to 160,000 new cases are diagnosed each year in the U.S. It is a leading cause of stroke and hospitalizations, and it has become the most common complication of cardiovascular surgery.
Cryotherapy, or the use of "cold energy," is thought to be able to preserve the structural integrity of tissue by selectively destroying the cellular components through intra- and inter-cellular ice formation while leaving the connective tissue intact.
Six-month data from a 20-patient study using the Arctic Front suggests that success rates could range well above traditional point-to-point radio frequency ablation techniques, the company said. The new device's balloon design allows the entire surface area of the encircling atrial tissue of the pulmonary vein to be ablated at one time, reducing the number of lesions required and shortening procedural times, the company said.
There currently are no FDA-approved cryoablation devices for treating AF. The most common treatment for AF – and for which the CryoCath technology would provide an important alternative – is a highly invasive surgical intervention, termed the Maze (or Cox-Maze) procedure.
Jean-Pierre Desmarais, CryoCath's chief scientific officer, called the cryo-treatment of AF the company's "holy grail," and that same designation could readily be applied to the entire "cryo" sector if such a device therapy reaches commercial maturity.
The initial stage of Cryocath's new trial will treat about 25 patients at three centers in the U.S., with enrollment expected to be completed by the end of the second quarter of this year, the company said.
CryoCath said it anticipates initial three-month follow-up data to be available in the fourth quarter. The trial's endpoints are safety (stenosis) and efficacy (freedom from AF, with or without drugs).
Following discussions with the FDA, CryoCath said it plans to use the data from the initial stage of the trial as well as ongoing European data to apply for FDA approval to begin the pivotal trials for the treatment of AF.
The Arctic Front catheter has been designed, CryoCath said, to overcome the three principal obstacles in providing a commercially viable ablation solution for treating the disorder: safety limitations, inappropriate chronic success rates and lengthy/complex procedures.
Based on clinical results from the prior use of cryoenergy in and around the pulmonary veins, the company said it believes this energy source does not generate serious adverse events such as stenosis (narrowing of the vein), thrombosis (clot formation), and esophageal perforation, which are three complications that have been consistently reported with alternative heat-based ablation systems.
Procedures are expected to be completed in less than two-and-a-half hours, as opposed to surgical procedure times which average four or five hours, Arless said.
In November 2004, Freezor MAX was approved in the U.S. for minimally invasive cardiac surgery procedures, including the treatment of cardiac arrhythmias (Medical Device Daily, Nov. 12, 2004).