Apixaban vs rivaroxaban in patients with atrial fibrillation at high or low bleeding risk: A population-based cohort study.

BACKGROUND

Despite many atrial fibrillation (AF) patients being at risk of bleeding, very limited data are available on bleeding rates of different direct oral anticoagulants based on the spectrum of bleeding risk.

OBJECTIVE

We aimed to compare the risk of major bleeding and thromboembolic events with apixaban vs rivaroxaban for AF patients stratified by bleeding risk.

METHODS

We conducted a population-based, retrospective cohort study of all adult patients (66 years or older) with AF in Ontario, Canada, who were treated with apixaban or rivaroxaban between April 1, 2011, and March 31, 2020. Bleeding risk was estimated by the HAS-BLED score, with high bleeding risk defined as a score of ≥3. The primary safety outcome was major bleeding, and the primary efficacy outcome was thromboembolic events. Comparisons were adjusted for baseline comorbidities by inverse probability of treatment weighting.

RESULTS

This study included 18,156 AF patients with high bleeding risk and 55,186 AF patients with low bleeding risk. Apixaban use was more common in patients with high bleeding risk; 63% of high-risk patients used apixaban compared with 56% of low-risk patients. Apixaban users had lower rates of major bleeding in high-risk patients (2.9% vs 4.2% per year; hazard ratio [HR], 0.69; 95% CI, 0.58-0.81) and in low-risk patients (1.8% vs 2.9% per year; HR, 0.63; 95% CI, 0.56-0.70) compared with rivaroxaban. There were no differences in rates of thromboembolic events, 3.1% vs 3.0% per year (HR, 1.02; 95% CI, 0.86-1.22) in high-risk patients and 1.9% vs 1.9% per year (HR, 1.00; 95% CI, 0.89-1.14) in low-risk patients.

CONCLUSION

In older AF patients with high or low bleeding risk, treatment with apixaban was associated with lower rates of major bleeding with no difference in risk for thromboembolic events compared with rivaroxaban.