There are significant differences in risk of gastrointestinal bleeding across direct oral anticoagulant (DOAC) agents, a new study shows.
Apixaban has the most favorable GI safety profile and rivaroxaban the least favorable, according to the population-based study.
The study also found that GI bleeding events among patient taking DOACs increased with age, with the risk greatest in adults aged 75 and older.
DOACs, including dabigatran, rivaroxaban, apixaban and edoxaban, have been shown to be at least as effective as warfarin for preventing stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF).
"With their convenient, fixed-dose and no requirement for monitoring, DOACs have gained broad acceptance and are increasingly the preferred anticoagulant for patients with AF," Dr. Neena Abraham of the Mayo Clinic in Scottsdale, Arizona, and colleagues note in their report online December 31 in Gastroenterology.
"Randomized controlled trials, systematic reviews and observational studies have demonstrated a 25% to 30% increased risk of GI bleeding with DOACs when compared to warfarin. However, relatively little is known about the comparative risk of GI bleeding across the FDA-approved DOACs," they point out.
To investigate, the researchers did a retrospective study using administrative claims data of privately and Medicare insured individuals. They created three propensity-matched cohorts of patients with AF exposed to dabigatran, rivaroxaban, or apixaban. They compared data on rivaroxaban vs. dabigatran for 31,574 patients, data on apixaban vs. dabigatran for 13,084 patients, and data on apixaban vs. rivaroxaban for 13,130 patients.
The researchers found that GI bleeding occurred more often in patients on rivaroxaban than dabigatran (hazard ratio, 1.20; 95% CI, 1.00-1.45). Apixaban was associated with a lower risk of GI bleeding than dabigatran (HR, 0.39; 95% CI, 0.27-0.58) or rivaroxaban (HR, 0.33; 95% CI, 0.22-0.49).
Of all DOACs examined, apixaban appeared to be the safest for patients aged 75 and older, the researchers report.
Median times to GI bleeding were less than 90 days for apixaban and rivaroxaban and less than 120 days for dabigatran.
GI bleeding is a "significant source of morbidity" in patients starting anticoagulation and is "one of the key issues to consider when assessing the risk-benefit trade-offs," the authors note in their paper.
"This is especially important among the elderly as GI bleeding often has a poor prognosis and may significantly affect the quality of life. As DOACs become more commonly prescribed amongst patients with AF, assessing the risk of GI bleeding becomes more critical. To date, there has been very limited information to guide clinicians when comparing the DOACs in the context of risk. In this paper, we find that apixaban may be the preferred agent when GI bleeding is an important consideration in guiding treatment decisions," they conclude.
The study had no commercial funding and the authors have declared no conflicts of interest.