Following a report out yesterday that the blood thinner rivaroxaban is at least as good as warfarin at preventing strokes in patients with erratic heartbeats, doctors and analysts are abuzz with predictions about which new stroke-prevention drugs will come to dominate the marketplace.

The success of rivaroxaban — based on a 14,000-plus patient study and reported Monday at the American Heart Association’s annual meeting in Chicago — comes on the heels of last month’s approval by the US Food and Drug Administration of a similar anti-clotting agent called Dabigatran for the same condition. “Both of these drugs are game-changers,” Douglas Zipes, a cardiologist at the Indiana University School of Medicine in Bloomington, told the LA Times.

Three more pills for treating atrial fibrillation, a heartbeat irregularity disease that can lead to bleeding complications and ultimately stroke, are also moving toward possible marketing approval in the next few years, and it remains unclear which drug will come out on top. More than two million Americans suffer from atrial fibrillation, and analysts estimate that sales for medicines in this class could top $20 billion a year.

Comparing the two leading contenders, rivaroxaban, which is marketed as Xarelto by Bayer and Johnson & Johnson, performed slightly worse than Boehringer Ingelheim’s Dabigatran, also known as Pradaxa, in relation to warfarin. But the two trials considered different study populations and the drugs have not been tested head-to-head.

Rivaroxaban has the advantage of only requiring one pill per day, compared to Dabigatran’s twice daily dose. But Dabigatran, by being the first to market, could have the leg up over it’s as-yet unapproved counterpart.

Image: NHLBI