Mayo gets $48 mln to study heart disorder treatment

* Famed clinic will conduct atrial fibrillation trial

* Trial to examine ablation to treat heart disorder

CHICAGO (Reuters) - The Mayo Clinic said it has received $48 million from the U.S. government and industry to expand a study investigating a catheter-based treatment for atrial fibrillation, the most common serious heart rhythm abnormality in people over the age of 65.

The trial, dubbed CABANA, will include 3,000 patients in 140 centers around the world and is designed to determine whether catheter ablation is more effective than drug therapy to treat the condition.

Atrial fibrillation -- marked by a rapid, irregular heart rhythm originating in the small upper chambers of the heart -- affects more than 2 million Americans and is on the rise. It can lead to stroke, serious bleeding, cardiac arrest and death.

The trial will determine whether left atrial catheter ablation to eliminate atrial fibrillation, which involves inserting long, narrow tubes to reach and apply energy to destroy abnormal heart tissue, is better than current drug therapy.

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

Rochester, Minnesota-based Mayo is doing a pilot trial that is evaluating catheter ablation for atrial fibrillation. The pilot includes 60 patients at 10 centers in the United States.

The expanded study, which will enroll patients for three years and follow up for at least two years, is being paid for by the National Heart, Lung and Blood Institute, a part of the National Institutes of Health, which will contribute $18 million, and St Jude Medical Inc and Johnson & Johnson's Biosense Webster, which will contribute $20 million and $10 million, respectively.