Intracranial Bleed Risk Compared for Warfarin, Apixaban in Afib Patients
Apixaban and warfarin lower the risk of stroke, but also raise the risk of uncontrolled bleeding.
A new study published in the journal Blood has found that apixaban was superior to warfarin for decreasing the risk of intracranial hemorrhage in patients with atrial fibrillation. Findings from the study also showed that taking aspirin increased the risk of intracranial hemorrhage, particularly in older patients.
Clinical practice guidelines currently recommend the use of oral anticoagulants in patients with atrial fibrillation who are at high risk for stroke. These drugs, while lowering the risk of stroke, also raise the risk of uncontrolled bleeding. Lead study author Renato D. Lopes, MD, PhD, from the Duke Clinical Research Institute, and colleagues examined the frequency and characteristics of intracranial hemorrhage, factors associated with the risk of hemorrhage, and overall outcomes post-hemorrhage and by randomized treatment.
Patients from the ARISTOTLE study with intracranial hemorrhage who received at least one dose of the study drug (n=18,140) were included. Study authors found that intracranial hemorrhage occurred in 174 patients — most of these events were spontaneous vs. traumatic (71.2% vs. 28.8%).
Patients taking apixaban showed significantly less intracranial hemorrhage (0.33% per year) vs. patients taking warfarin (0.80% per year) no matter the type and location. Factors associated with higher intracranial hemorrhage risk included: enrollment in Asia or Latin America, older age, prior stroke/transient ischemic attack, and aspirin use at baseline.
For patients treated with warfarin, the median time from most recent INR to intracranial hemorrhage was 13 days; 78.5% of patients had an INR <3.0 before the event.
No differences were noted between treatments with regards to all-cause death post intracranial hemorrhage.
"This highlights the clinical relevance of reducing ICH [intracranial hemorrhage] by using apixaban rather than warfarin and avoiding concomitant aspirin, especially in patients with older age," the authors concluded.
Lopes RD, Guimarães PO, Kolls BJ, et al. Intracranial hemorrhage in patients with atrial fibrillation receiving anticoagulation therapy [published online March 29, 2017]. Blood. doi:10.1182/blood-2016-08-731638