Medtronic Inc. Monday released the first results of a pivotal clinical study that claims its method of using cold temperatures to treat atrial fibrillation (AF) is far more effective than drugs.
Of the 245 patients enrolled in the company’s STOP-AF trial, nearly 70 percent of people treated with Medtronic’s Artic Front Cardiac CyroAbalation Catheter System had no AF one year after treatment compared to just 7.3 percent of patients who received drugs but do not respond well to such therapy. Medtronic presented the study to the American College of Cardiologists’ scientific meeting.
“We’re excited about the promise these technologies represent,” Reggie Groves, Medtronic vice president and general manager of AF Solutions, said in an interview. “AF is the most common and most poorly treated rhythmic disturbances of the heart.”
About 2.2 million Americans suffer from AF, in which the two small upper chambers of the heart quiver instead of beat normally, according to the American Heart Association. When the patient’s heart is not pumping effectively, blood pools clot and get lodged in the brain, causing strokes.
Normal treatments include drugs like beta blockers (atenolol, metoprolol, propranolol) that slow down rapid heart rate. Companies like Johnson & Johnson and St. Jude Medical Inc. also sell devices that use radio frequency waves to kill diseased tissue causing the AF or that interrupt abnormal electrical pathways.
Medtronic has high hopes that its Artic Front therapy, the first of its kind in the United States, can grab a significant piece of the estimated $2 billion global AF market, which has been growing at a double-digit rate the past few years.
The company acquired the technology in 2008 when it purchased CryoCath Technologies Inc. for about $380 million. The Canadian company makes catheters (tubes) and balloons that can deliver subzero temperatures to the heart. The technology restores normal electric signals by freezing the tissue or pathways behind the irregular quivering.
While the STOP-AF trial does not compare cyroablation to radio frequency, Dr. Kevin Wheelan, the trial’s investigator, believes more doctors will embrace Medronic’s technology. While there aren’t many doctors trained in radio frequency, Artic Front will appeal to physicians already familiar with catheter-balloon technology, said Wheelan, chief of staff at Baylor Heart and Vascular in Dallas.
Medtronic hopes to win pre-market approval from the Food and Drug Administration in the fall.