Mayo is on the case
to determine best AF treatment

AF Trial to Compare Catheter Ablation With Drugs

June 16, 2009
by Lynn Shapiro, Writer
Mayo Clinic received $48 million in grants from the National Heart, Lung, and Blood Institute (NHLBI), a component of the National Institutes of Health (NIH), and from industry, to compare drugs with catheter ablation in the treatment of AF in 3,000 patients and 140 centers around the world.

The Catheter Ablation Versus Anti-arrhythmic Drug Therapy for Atrial Fibrillation (CABANA) Trial is designed to determine whether catheter ablation is more effective than drug therapy for the treatment of atrial fibrillation, says Douglas Packer, M.D., the trial's principal investigator and a cardiologist at Mayo Clinic.

The study, which will take six years from beginning to releasing results, is a collaborative effort among Dr. Packer and Richard Robb, Ph.D., at Mayo Clinic, Kerry Lee, Ph.D., and Daniel Mark, M.D., at Duke Clinical Research Institute in Durham, N.C., and the NHLBI.

Funding for the trial consists of $18 million from NHLBI/NIH, $20 million from St. Jude Medical and $10 million from Biosense Webster.

Atrial fibrillation is the most common cardiac arrhythmia seen by physicians and affects more than 2 million Americans.

Most individuals with atrial fibrillation have identifiable risk factors, such as high blood pressure or structural heart disease, and tend to be elderly. Long-term complications resulting from atrial fibrillation and its treatment can include death, disabling stroke, serious bleeding and/or cardiac arrest.

The trial will determine whether left atrial catheter ablation, which involves inserting long, narrow tubes to reach and apply energy (hot or cold) to destroy abnormal heart tissue to eliminate atrial fibrillation, is better than current state-of-the-art drug therapy, Dr. Packer says.

The trial also will examine atrial fibrillation recurrence, stroke risk, quality of life and cost-effectiveness.

The study will randomize patients over three years, with half undergoing catheter ablation and half receiving rate control or rhythm control drug therapy (used to keep the heart in normal rhythm). Further information about this trial (NCT00911508) can be found at

According to Dr. Packer, the trial is needed because:

* Atrial fibrillation is on a rapid rise and particularly increasing in individuals over 60 years of age.
* Multiple recent trials have shown the inadequacy of drug therapy to maintain normal heart rhythm and reduce death.
* The use of catheter ablation is rapidly increasing, but a large clinical trial such as CABANA is necessary to answer important questions about effectiveness and safety.
* Atrial fibrillation has a large impact on a patient's quality of life and on health care costs.

"While prior trials have investigated the effectiveness of ablation in treating AF, their value in guiding the treatment of patients is limited by the small size of the studies, relatively short follow-up periods, and the exclusion of older patients with more long-standing AF as well as underlying disease. CABANA will include these patients and follow them for a much longer time period to more clearly define optimal therapy for AF," Dr. Packer says. "We believe that CABANA will be a landmark trial that will guide therapy in the atrial fibrillation arena for years to come."

In atrial fibrillation, the heart's two upper chambers beat irregularly and out of coordination with the two lower chambers. The resulting irregular and often rapid heart rate can lead to poor blood flow to the body. A person can experience symptoms such as heart palpitations, shortness of breath and fatigue, and may be at an increased risk of stroke. Treatment focuses on preventing stroke through the use of blood thinners or aspirin and controlling symptoms with medications or invasive procedures.

Before these grants were awarded, Mayo Clinic led a 10-center, 60-patient pilot study. Those results will be announced later this summer.

The CABANA Trial will be conducted as a collaboration between the Heart Rhythm Service and Biomedical Imaging Resource Center at Mayo Clinic, Duke Clinical Research Institute, and CABANA investigators from the 140 centers around the world.

Mayo Clinic and Drs. Packer and Robb have a financial interest in a mapping technology that may or may not be used in this research. In accordance with the Bayh-Dole Act, this technology has been licensed to St. Jude Medical and Mayo Clinic, and Drs. Packer and Robb have received annual royalties greater than $10,000, the federal threshold for significant financial interest.

Mayo Clinic and Dr. Robb also have a financial interest in Analyze-AVW technology that will be used to analyze some of the heart images in this research. In accordance with the Bayh-Dole Act, this technology has been licensed to commercial entities, and both Mayo Clinic and Dr. Robb have received royalties greater than $10,000, the federal threshold for significant financial interest. In addition, Mayo Clinic holds an equity position in the company to which the AVW technology has been licensed.

Source: Mayo Clinic