Burning sections of the heart works far better than drugs at treating patients with an irregular heartbeat condition called atrial fibrillation, a common heart rhythm disorder that affects more than 2 million Americans, U.S. researchers said on Tuesday.
The findings suggest that the procedure called catheter ablation is especially effective in patients with an early form of atrial fibrillation.
"Once a drug fails, catheter ablation is far better than continuing to pursue more drug trials," said Dr. David Wilber of Loyola University Chicago Stritch School of Medicine in Chicago, whose study appears in the Journal of the American Medical Association.
Wilber studied patients with an early form of the disease called paroxysmal or intermittent atrial fibrillation, an irregular heart rhythm originating in the small upper chambers of the heart that can lead to strokes and heart failure.
Symptoms include heart palpitations, dizziness, chest pain, fatigue, shortness of breath, fainting, and lightheadedness.
Worldwide, 10 million people have atrial fibrillation, yet fewer than 80,000 are treated with catheter ablation, according to Johnson & Johnson, a manufacturer of ablation devices that sponsored the study.
In the study, 167 patients were treated with either drugs to control their heartbeats or catheter ablation, in which doctors cauterize parts of the heart muscle causing erratic electrical signals.
The procedure involves inserting a thin tube into a blood vessel, usually through a site in the upper leg or neck, then threading it though the body until it reaches the heart. When it reaches the area causing abnormal rhythms, a device emits radiofrequency energy to destroy the tissue.
In the study, 66 percent of patients with atrial fibrillation who got the ablation procedure were free of any recurrent symptoms a year after treatment, compared with only 16 percent of those treated with drugs. None of the ablation patients had any serious complications, such as heart attacks or strokes.
The results were so convincing the trial was halted early.
"One of the implications of the study is you get good results with ablation, particularly if you intervene early," Wilber said in a telephone interview.
"Sometimes people tend to wait until atrial fibrillation has been persistent for awhile. At that time, the problem may be irreversible," he said.
Last year, J&J won U.S. Food and Drug Administration approval to sell its ablation devices specifically to treat atrial fibrillation, becoming the first manufacturer to win approval for that use in the United States.
Several other companies, including St. Jude Medical, Boston Scientific, and Medtronic, make ablation devices for other heart rhythm problems. Many are seeking FDA approval to market their devices for atrial fibrillation, Wilber said.
"Although the (J&J device) was the one that was used, I think in many ways these results could be generated by other catheters as well," Wilber said.
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