If you’ve ever treated a patient with atrial fibrillation, you may have followed with interest the trials of ximelagatran, an oral direct thrombin inhibitor. After all, an alternative to warfarin with fewer side effects would be a good thing. You may have even cheered when two studies—one, open-label, followed by another, double-blinded—reported that ximelagatran was just as effective as warfarin in preventing strokes.
You might have been disappointed, then, when in October 2004, the U.S. Food