Thromboembolic and bleeding events with rivaroxaban in clinical practice in Spain: impact of inappropriate doses (the EMIR study)

Aim: To analyze the frequency and variables related to inappropriate rivaroxaban dosage in clinical practice and its impact on outcomes after 2 years. Materials & methods: Postauthorization, observational, multicenter study, in which atrial fibrillation patients, treated with rivaroxaban >= 6 months were included. Results: A total of 1421 patients (74.2 +/- 9.7 years, CHA(2)DS(2)-VASc 3.5 +/- 1.6) were included. Overall, 22.9% received rivaroxaban 15 mg. The proper dose of rivaroxaban was taken by 83.3% (9.7% underdosed, 7.0% overdosed). Older age and renal insufficiency were associated with inadequate rivaroxaban dosage. There was a trend toward higher all-cause mortality among underdosed patients (adjusted hazard ratio 1.39; 95% CI 0.75-2.58), and more bleedings in overdosed patients (2.29 vs 0.80 events/100 patient-years; p = 0.14). Conclusion: In clinical practice, rivaroxaban is properly dosed in most patients.

Automated summary

In clinical practice, most patients receive the appropriate dosage of rivaroxaban. However, older age and renal insufficiency are associated with inadequate dosing. Underdosed patients had a slightly higher all-cause mortality rate, while overdosed patients had a higher rate of bleeding events.