November 20, 2009

Study tests treatments for atrial fibrillation

Study tests treatments for atrial fibrillation

The Vanderbilt Heart & Vascular Institute (VHVI) is participating in a trial to determine which treatment for atrial fibrillation — drugs or ablation — is superior in reducing mortality.

The Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) is a multi-center, randomized trial to determine if drug therapy or percutaneous catheter ablation is better at reducing mortality. It will also look at whether ablation has a favorable effect on survival, stroke, quality of life, and health care costs, none of which have been studied extensively.

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with an increased risk of stroke and death. It affects about 3 million people in the United States, but this number is expected to increase to nearly 12 million in 2050.

Dawood Darbar, M.D.

Dawood Darbar, M.D.

“Despite advances in drug therapy, atrial fibrillation continues to impose substantial health and economic burdens on society,” said Dawood Darbar, M.D., director of the Vanderbilt Arrhythmia Service.

Drug therapy is the first line of treatment to help restore normal heart rhythm in people with AF. At best it works in 65 percent of cases. In recent years, percutaneous catheter-based ablation procedures have been developed to treat AF. Ablation, performed via a catheter placed in the groin, applies radiofrequency energy to the pulmonary veins, common sites for triggers that can initiate an episode of AF.

VHVI will also be the coordinating center for a sub-study that will assess if specific therapy for atrial fibrillation can be 'tailored' for each individual patient based on their genetic make-up.

“This sub-study will be important as it will allow us to determine whether patients respond better to ablation or drug treatment,” Darbar said.

“Vanderbilt and VHVI are ideally positioned to carry out this study because of our institutional focus on personalized medicine and our ongoing work developing personalized therapies for atrial fibrillation.”

Patients eligible for the study are individuals with documented episodes of AF that last at least one hour and who have had two or more episodes over a four-month period. The patients must also be 65 years or older or younger than 65 providing they have a history of high blood pressure, diabetes, heart failure or prior stroke. The study will recruit 3,000 patients from 140 centers in North America, Asia, Europe and Australia. Patients will be enrolled for three years and followed for a minimum of two years.

More information about this study can be found on the VHVI Web site or through the Vanderbilt Heart Center for Atrial Fibrillation at 322-2342.