The drug helped stop irregular heartbeats (arrhythmias) known as atrial fibrillation (AF). AF is a disorder in which the two small, upper chambers of the heart quiver instead of beating effectively. Blood that isn't pumped out may pool and clot. If a piece of clot leaves the heart and lodges in an artery to the brain, a stroke results.

Irbesartan is in a class of drugs called angiotensin II antagonists, or blockers. They are used to treat several cardiovascular disorders such as high blood pressure and heart failure.

AF is considered the most common sustained heart arrhythmia, and its incidence rises with age to about 10 percent in people over age 75, says study author Concepcin Moro, M.D., professor of medicine at the University of Alcala and director of the arrhythmia unit at the Ramon y Cajal hospital in Madrid, Spain.

"AF is believed to double the risk of death and quadruple the risk of strokes," she says. "In addition, AF may accompany many cardiac conditions such as valvular heart disease, cardiomyopathies and ischemic heart disease. It can also appear along with high blood pressure and other systemic diseases such as hyperthyroidism, although in many patients the cause is unknown."

AF is typically treated with antiarrhythmic drugs such as amiodarone, anti-clotting agents, and electrical cardioversion, a procedure that uses an electrical impulse to destroy areas of heart tissue where the rhythm disturbances originate. However, AF often recurs despite these treatments, so new options are needed, Moro says.

"The clue for this work was evidence that patients treated with angiotensin II antagonists for other conditions developed fewer atrial arrhythmias than expected," she explains.
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Contact: Maggie Francis
maggie.francis@heart.org
214-706-1397
American Heart Association
24-Jun-2002