Medical device manufacturers seeking regulatory clearances to expand catheter ablation as a treatment for atrial fibrillation got a boost from a new study published in the Journal of the American Medical Assn.
The 19-center study compared the effectiveness of ablation procedures to one of five different drug therapies in treating irregular heartbeats. It found that 70 of the 106 patients, or 66 percent, receiving ablation procedures remained symptom-free a year later, versus only 10 of 61, or 16 percent, of patients treated with arrythymia drugs. All 167 patients participating in study had previously tried at least one drug to control fibrillatons.
The study was sponsored by BioSense Webster Inc., the catheter-design division of Johnson & Johnson (NYSE:JNJ). The company in February 2009 won marketing approval from U.S. regulators allowing its Navistar ThermoCool catheter to be used as a treatment for paroxysmal atrial fibrillation, relying on data from the same study reviewed this week in JAMA.
The Food & Drug Administration cleared catheter ablation as treatment for other types of irregular heartbeats, such as ventricular tachycardia. The procedure involves threading a catheter with an electrical attachment at its tip through blood vessels and into the heart, where the attachment burns a small area of heart muscle, reducing its ability to start or continue irregular beating.
Ablation has been long considered the “gold standard” among cardiac specialists in treating atrial fibrillaton, although only during open-heart procedures such as valve replacements, in which the surgeon has direct access to the organ rather than through a catheter.
Several other device-makers that produce similar catheter ablation tools — including Boston Scientific (NYSE:BSX), Medtronic (NYSE:MDT) and St. Jude Medical (NYSE:STJ) — either are already or are expected to soon seek FDA approval allowing their devices to also be used to treat atrial fibrillation.
Atrial fibrillation is the most common form of irregular heartbeat, affecting an estimated 2 million Americans. Electrical signals, which regulate the heartbeat, become erratic and cause the upper chambers of the heart to quiver rather than contract normally. The arrythmia keeps blood from fully leaving the atrium, increasing the risk of clots forming and possibly leading to strokes or heart failure.
Another study now underway, known as CABANA, is seeking to determine whether ablation patients live longer than patients receiving medication and will follow about 3,000 subjects for three years. Data from the study published this week by JAMA was presented last year in May by its lead researcher during the Heart Rhythm Society’s Scientific Sessions.