What are the new therapeutic alternatives to warfarin in atrial fibrillation?

Why are the studies on these newer agents important? atrial fibrillation is associated with an increased risk of stroke (mean= 4.5% per year) and hence necessitates starting the patients on lifelong oral anticoagulants. vitamin k antagonists, like warfarin, have been the mainstay of treatment, but remain grossly underused because of increased bleeding risk, variability in results and the need for therapeutic monitoring. the advent of newer agents like dabigatran, direct factor iia (thrombin) inhibitor and apixaban and rivaroxaban, factor xa inhibitors may make this a little easier. these fast acting, short lived, fixed dosed (unmonitored) agents exhibit limited drug and food interactions and provide consistent and predictable anticoagulation.