The U.S. Food and Drug Administration released the results of a study on the safety and efficacy of dabigatran (Pradaxa) in 134,000 Medicare recipients with nonvalvular atrial fibrillation. New users of dabigatran — versus warfarin (blood thinner) — had reduced risks of ischemic stroke, intracranial hemorrhage and death. The risk of major gastrointestinal (GI) bleeding was higher with dabigatran, but there was no difference in the risk of heart attack. Via Medpage. Posted May 13, 2014.