A study finds that a new and easier-to-use blood thinner prevents strokes in people with a common heart rhythm problem as well as Coumadin does, and without an increase in bleeding or side effects.

The drug is called rivaroxaban. It was tested against warfarin, the generic version of Coumadin, in more than 14,000 people with atrial fibrillation. That's the most common heart rhythm problem in America.

It occurs when the upper parts of the heart quiver instead of beating normally. This raises the risk of clots that can cause a stroke.
Johnson & Johnson and Bayer Healthcare plan to seek federal approval to sell the drug later this year. Doctors gave results of the study Monday at a heart conference in Chicago.