Safety of apixaban compared to warfarin in hemodialysis patients: Do antiplatelets make a difference?

BACKGROUND: Data on the safety of apixaban compared to warfarin in hemodialysis (HD) patients are accumulating, but the impact of concomitant antiplatelet use is unknown. OBJECTIVES: Compare hemorrhagic risk and impact of antiplatelets in HD patients receiving oral anticoagulants (OAC). METHODS: Retrospective, multi-center study of HD patients started on OAC inpatient over 5 years. RESULTS: 707 patients were included: 563 received warfarin, and 144 received apixaban. 197 had bleeding, most in the warfarin group (173 [30.1%] vs 24 [16.7%] in the apixaban group), P-value < .01). However, with concomitant antiplatelet use, frequencies were similar (31.4% vs 25.0%; P-value = .292). Cumulative incidence using bleeding as event of interest and death as competing risk showed higher rates of bleeding with warfarin. In a multivariate model, apixaban was associated with a lower hemorrhagic risk (hazard ratio [HR] 0.55 [95% confidence interval {CI} 0.35-0.86}). Apixaban showed lower hemorrhagic risk alone (HR 0.24, 95% CI 0.10-0.55) and similar risk when administered with antiplatelets (HR 0.93, 95% CI 0.55-1.56). CONCLUSIONS: Apixaban is associated with less bleeding in HD patients compared to warfarin, but concomitant antiplatelet use may negate the safety advantage. Prospective trials are warranted to determine the impact of antiplatelets on apixaban safety.

Bartonella Endocarditis Mimicking Crescentic Glomerulonephritis with PR3-ANCA Positivity.

Bartonella henselae is a fastidious organism that causes cat scratch disease, commonly associated with fever and lymphadenopathy but, in rare instances, also results in culture-negative infectious endocarditis. We describe a patient who presented with flank pain, splenic infarct, and acute kidney injury with an active urinary sediment, initially suspicious for vasculitis, which was subsequently diagnosed as B. henselae endocarditis. Bartonella endocarditis may present with a crescentic glomerulonephritis (GN) and elevated PR3-ANCA antibody titers, mimicking ANCA-associated GN, with 54 cases reported in the literature. Unique to our case in this series is a positive PR3-ANCA antibody despite a negative IIF-ANCA. Thus, the presentation of Bartonella can mimic ANCA-associated GN, and renal biopsy showing immune complex deposition is critical for diagnosis and appropriate treatment.