Takeaway
- In patients with atrial fibrillation (AF), standard-dose rivaroxaban (20 mg/day) was associated with an increased risk of gastrointestinal bleeding (GIB) compared with aspirin in the UK, but not in Hong Kong.
- However, low-dose rivaroxaban (≤15 mg/day) had a similar GIB risk vs aspirin in both cohorts.
Why this matters
- Findings suggest that any increased GIB risk associated with standard-dose rivaroxaban remains uncertain, and further studies are warranted to investigate this association.
Study design
- This population-based cohort study used separate data from the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority and The Health Improvement Network (THIN) database in the UK.
- Patients with AF newly prescribed aspirin or rivaroxaban were included:
- CDARS (n=29213 [rivaroxaban: n=1052; aspirin: n= 28161]); and
- THIN (n=11549 [rivaroxaban: n=3496; aspirin: n=8053]).
- Funding: None disclosed.
Key results
- Crude GIB rates for aspirin and rivaroxaban users were:
- 3.0 and 2.6 per 100 patient-years, respectively, in CDARS; and
- 1.3 and 2.4 per 100 patient-years, respectively, in THIN.
- No significant difference was observed in overall GIB risk between rivaroxaban and aspirin in CDARS (HR, 1.04; 95% CI, 0.76-1.42; P=.815) and THIN (HR, 1.40; 95% CI, 1.00-1.98; P=.052).
- In THIN, rivaroxaban 20 mg/day vs aspirin showed an increased risk of GIB (HR, 1.57; 95% CI, 1.08-2.29).
- In CDARS, no significant difference was observed in GIB risk between rivaroxaban 20 mg/day and aspirin (HR, 1.21; 95% CI, 0.84-1.74).
- No significant difference was observed in GIB risk between rivaroxaban ≤15 mg/day vs aspirin in CDARS (HR, 0.80; 95% CI, 0.44-1.45) and THIN (HR, 1.00; 95% CI, 0.56-1.30).
Limitations
- GIB event rates were small in both cohorts; therefore, results should be interpreted with caution.
This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.
