November 30, 2009
With atrial fibrillation (AF) as the most widespread cardiac arrhythmia affecting patients, many new clinical trials are testing additional, more effective methods than the frequently prescribed drugs to treat AF, according to research published this month by the Millennium Research Group (MRG).
Research from Decision Resources found that in 2009 six million patients around the globe were diagnosed with AF, and 86 percent of these patients were prescribed some form of drug therapy as a method of treatment.
According to Dan Whalen, analyst at MRG, although drug therapy is seen as the “front-line option” for treatment by organizations, such as the American Heart Association (AHA) and the American College of Cardiology (ACC), evidence has shown that some patients may not fully benefit from drug therapy.
Because studies have found rhythm-control drugs are only effective in 30 to 60 percent of patients, according to Whalen, other treatments such as catheter ablation to treat AF are increasingly being explored.
Catheter ablation devices work to destroy dysfunctional heart tissue that causes cardiac arrhythmias, said Whalen, and the devices’ minimally invasive nature leads to decreased recovery times and has the potential provide a long-term cure for AF.
Two catheter ablation procedures have been explored: one using radiofrequency (RF) energy via an irrigated- or conventional-tip catheter and the other using cryothermal energy with a refrigerant such as liquid nitrogen (cryoablation).
Currently, nearly 99 percent of AF catheter ablation procedures are done using RF energy; however, less risk of thermal heart damage in treatment through cryoablation has led to rapid increases in the latter type of procedures.
A study of 1,000 patients diagnosed with AF who were unable to be treated by antiarrhythmic drugs found that 80 percent of patients who underwent treatment via catheter ablation stayed free of any further AF occurrence. In addition, lower morbidity and mortality were found in these patients compared to independent studies examining drug therapy, according to the report.
In fact, some study results have shown a complication rate of less than 6 percent in patients treated via a catheter ablation device.
From completed research regarding catheter ablation treatments, Whalen cautioned that most studies, while showing promising results, were tested on rather small sample sizes and by highly experienced physicians in leading medical centers, and therefore the results need to be replicated in larger studies.
According to Whalen, catheter ablation treatment for AF patients is a “rapidly expanding market” with companies such as Biosense Webster, Medtronic and C.R. Bard already running several investigational trials using ablation catheter equipment devices. Further, several market competitors have also been active in acquiring smaller electrophysiology-based companies to add to their own ability to address the opportunities in AF treatment by catheter ablation.
According to research, usage of catheter ablation devices for the treatment of AF is expected to account for 42 percent of total device-based AF treatments by 2013. “AF catheter ablation procedures are growing faster than surgical procedures or cardiac rhythm management device implantations,” said Whalen.
Studies analyzing cost effectiveness of the catheter ablation devices in the U.S., U.K. and Canada have found that the devices will have a high initial cost compared to drug therapy, but could be cost-neutral in the long-run.
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