Apixaban may not prevent stroke in patients on maintenance dialysis patients who have new-onset nonvalvular atrial fibrillation, and it may increase the risk of bleeding, a new study suggests.
Recent research on apixaban, a direct oral anticoagulant (DOAC), showed it outperformed warfarin, a vitamin K antagonist, in patients with kidney failure. In their retrospective study, Thomas A. Mavrakanas, BS, MB, of Brigham & Women’s Hospital in Boston, and colleagues, matched 521 apixaban recipients from the 2012-2015 US Renal Data System (USRDS) to 1561 patients not treated with any anticoagulant by demographics, relevant comorbidities, and use of antihypertensives, statins, and antiplatelets. The database did not capture aspirin use, blood pressure control, body mass index, residual kidney function, dialysis prescription, and anticoagulation prescription during dialysis.
Apixaban use was not significantly associated with a lower incidence of the primary end point: hospital admission for a new ischemic or hemorrhagic stroke, transient ischemic attack, or systemic thromboembolism, the investigators reported in the Clinical Journal of the American Society of Nephrology. The investigators observed a trend toward fewer ischemic strokes with apixaban, but it was offset by more hemorrhagic strokes.
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In addition, apixaban also did not significantly lower the risk for a composite outcome of ischemic stroke or myocardial infarction.
Dr Mavrakanas’ team did find a significant 2.7-fold higher incidence of fatal or intracranial bleeding with apixaban compared with no treatment: 4.9 vs 1.6 events per 100 patient-years or 1 fatal or intracranial bleeding event per 30 treated patients per year. They also observed a similar incidence of clinically important bleeding, defined as resulting in death, occurring at a critical site, or occurring in the gastrointestinal, urinary tract, or gynecologic regions, and requiring hospitalization: 59.2 vs 56.9 per 100 patient-years, respectively.
In subgroup analyses, the standard apixaban dose (5 mg twice daily) was significantly associated with a higher rate of the primary outcome and a higher incidence of fatal or intracranial bleeding and hemorrhagic stroke but the reduced apixaban dose (2.5 mg twice daily) was not.
Stroke mechanisms seem to be different in patients with kidney failure, with more hemorrhagic stroke, the investigators noted. Randomized trials are currently examining apixaban at the standard and lower dose versus warfarin versus no anticoagulation.
“Awaiting randomized data, prudence in prescribing apixaban to patients on maintenance dialysis, especially at the standard dose, is warranted,” Dr Mavrakanas’ team stated.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Reference
Mavrakanas TA, Garlo K, Charytan DM. Apixaban versus no anticoagulation in patients undergoing long-term dialysis with incident atrial fibrillation [published online May 22, 2020]. Clin J Am Soc Nephrol. doi: 10.2215/CJN.11650919
