DOACs safer than warfarin for atrial fibrillation

In general, direct oral anticoagulants (DOACs) pose less risk of bleeding than do warfarin for the treatment of atrial fibrillation (AF), a new study suggests.

Researchers enrolled 423,450 AF patients, of whom 177,318 were on warfarin, 40,994 were taking rivaroxaban, 32,737 were taking dabigatran and 17,971 were on apixaban. The remaining 154,430 were not taking any such medication. Study outcomes included time to first major bleeding, intracranial haemorrhage (ICH) and major gastrointestinal bleedings (GIBs).

Over a median follow-up of 1.4±0.6 years, 29,459 major bleeding events occurred in 6.9 percent of the participants. Of these, 3,303 were ICH episodes, 11,455 were major GIBs and 22,401 were cases of other major bleedings.

Comparing across all the different types of medication, warfarin showed the highest adjusted rate of any major bleeding, while dabigatran users saw the lowest (6.7 percent vs 4.8 percent per year). The same was true for ICH and GIB, both of which occurred most frequently in the warfarin group and least with dabigatran.

Further risk analysis confirmed that dabigatran users were at a significantly lower risk of major bleeding than their warfarin counterparts (hazard ratio [HR], 0.79, 95 percent confidence interval [CI], 0.75–0.82). Apixaban likewise exhibited a significant protective effect (HR, 0.86, 95 percent CI, 0.80–0.93), while rivaroxaban did not (HR, 0.99, 95 percent CI, 0.95–1.04).

Moreover, rivaroxaban appeared to confer a greater risk of GIB than warfarin (HR, 1.20, 95 percent CI, 1.12–1.27). However, all three DOACs showed superior safety outcomes to warfarin in terms of ICH risk.