The blood thinner Pradaxa (dabigatran) is approved for the prevention of strokes in patients with an abnormal heart rhythm known as atrial fibrillation, but experts say because of the bleeding risk, it may not be the best anticoagulant to use in patients undergoing ablation therapy.
Ablation therapy is a procedure used to treat atrial fibrillation. During ablation therapy, a thin wire, or catheter, is positioned inside the heart near the pulmonary veins. Radio energy is applied to the tip of the catheter and is used to cauterize, or abate, the heart tissue around each pulmonary vein.
This electrically “disconnects” the pulmonary vein from the left atrium. As a result, the abnormal electrical signals from the pulmonary vein can no longer reach the rest of the heart and trigger atrial fibrillation.
Researchers from the University of Kansas Hospital and Medical Center in Kansas City found that patients taking periprocedural Pradaxa had significantly higher rates of major bleeding and total bleeding compared to patients on uninterrupted doses of warfarin. Warfarin (Coumadin) is a blood thinner that has been on the market for more than 50 years.
A study published online in the Journal of the American College of Cardiology also found that the use of Pradaxa during atrial fibrillation ablation was an independent predictor of bleeding or thromboembolic complications with an odds ratio of 2.76.
Pradaxa was approved by the Food and Drug Administration (FDA) in October 2010 and has since come under scrutiny after reports of serious bleeding events. Not only does Pradaxa carry a greater risk for internal bleeding than warfarin, there is also no antidote for the drug, which means there is little doctors can do to stop these bleeds once they occur.