THURSDAY, May 15 (HealthDay News) -- Statins appear to be associated with a lower risk of the heart rhythm abnormality known as atrial fibrillation in postmenopausal women with coronary disease.

"Our finding alone doesn't prove that statins prevent atrial fibrillation, but it certainly supports the hypothesis that they may," said study author Dr. Cara Pellegrini, an electrophysiology fellow at the University of California, San Francisco. "Most likely, we will need a randomized, controlled study that includes both men and women to further prove this question."

But as a practitioner, Pellegrini added, "I would have a low threshold for putting a patient in whom I'm concerned about atrial fibrillation on a statin. If they perhaps were somewhat borderline for other reasons, this might tip the scale, even in the absence of a formal clinical trial."

The study findings are to be presented Thursday at the Heart Rhythm Society's annual meeting, in San Francisco.

Atrial fibrillation occurs when the two upper chambers of the heart quiver, rather than beat in a coordinated way. Blood can pool in the chambers, and clots can form that travel to the brain, causing a stroke. One 2006 study put the number of Americans with atrial fibrillation at more than 5 million.

Researchers have been looking at the possibility of using statins in people with atrial fibrillation since the early part of the decade. Most prior studies focused on men, although men and women tend to be affected differently by atrial fibrillation. Women have more frequent episodes and seem to be harder hit by some of the complications, including bleeding and stroke.

The new study looked at nearly 2,700 postmenopausal women with existing coronary disease, following them for an average of about four years. The odds of having atrial fibrillation at the start of the study was 65 percent lower among women taking statins. The risk of developing atrial fibrillation during the study period was 55 percent lower in the statin group, the researchers found.

Dr. Suzanne Steinbaum, director of women and heart disease at Lenox Hill Hospital in New York City, said: "Statins aren't anti-arrhythmic, but they are definitely one of the medications that can be used adjunctively to treat and prevent atrial fibrillation. Trials like this remind us that statins do a lot more than decrease cholesterol. They have this anti-inflammatory component, and when you see a study like this that shows such a decreased incidence of atrial fibrillation, you have to assume that it's through that anti-inflammatory pathway. This is pretty compelling."

Other research being presented at the meeting found no association between the consumption of omega-3 fatty acids or vitamin E and atrial fibrillation in women.

The first study, by researchers at Northwestern University, involved 46,704 women participating in the Women's Health Initiative who completed questionnaires about their intake of omega-3 fatty acids.

The second study looked at 38,933 healthy women over the age of 45 who had been randomly selected to receive either vitamin E or a placebo. The study, which lasted for about a decade, was conducted by researchers at Brigham and Women's Hospital in Boston.

More information

Visit the American Heart Association for more on women and heart disease.

SOURCES: Cara Pellegrini, M.D., electrophysiology fellow, University of California, San Francisco; Suzanne Steinbaum, D.O., director, Women and Heart Disease, Lenox Hill Hospital, New York City; May 15, 2008, presentations, Heart Rhythm Society annual meeting, San Francisco

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