New drugs may be better at preventing stroke

New oral anticoagulants that have been approved by NICE are at least as effective, and may be more effective at preventing strokes in people with atrial fibrillation than the widely used drug warfarin. This finding published in Clinical Pharmacology & Therapeutics (DOI: 10.1038/CLPT.2013.83) may help to inform decisions about treatment options for different patients who are at risk of strokes.

Atrial fibrillation is characterized by an irregular heartbeat and increases the risk of stroke and, until recently, warfarin has been the only form of anticoagulation treatment available. The relative effectiveness of new anticoagulants that work through different mechanisms is unknown, and there are currently no plans for trials to compare these drugs.

To help guide treatment selection, Dyfrig Hughes and colleagues from Bangor University’s Centre for Health Economics and Medicines Evaluation performed an indirect comparison, using the findings of previous trials and adjusting for differences in trial designs, populations, and their potential impacts on estimated comparative effectiveness. The results suggest that, on average, apixaban is the most effective oral anticoagulant, followed by dabigatran, rivaroxaban, then warfarin. The authors suggest that differences were driven primarily by stroke rates and major bleeding events, which were lower for all the newer agents compared to warfarin.

The team cautions that these indirect comparisons cannot replace evidence from randomised controlled trials. However, given that warfarin increases the risk of bleeds, interacts with many drugs, and requires careful monitoring due to variability in patient response, these new anticoagulants offer more treatment options and may prove to be better alternatives.

The study was funded by the Medical Research Council, as part of the North West Hub for Trial Methodological Research (NWHTMR).

Publication date: 26 April 2013