Which Dose of Apixaban is Suitable for Asian Patients with Atrial Fibrillation Who Have a Serum Creatinine < 1.5 mg/dL but an Estimated Glomerular Filtration Rate < 50 mL/min?

Introduction: Reduced-dose (Low-dose [LD]) apixaban is recommended in patients with atrial fibrillation (AF) who fulfill 2 of 3 criteria: age ≥ 80 years, body weight ≤ 60 kg, and a serum creatinine (sCr) ≥ 1.5 mg/dl. However, the suitable (appropriate) dose for Asian patients who have a sCr < 1.5 mg/dl but an estimated glomerular filtration rate (eGFR) < 50 mL/min is unknown.

Methods: This is a retrospective study using the Chang Gung Memorial hospital medical database in Taiwan. A total of 13,508 AF patients receiving oral anticoagulants (OACs) from 2012 to 2018 were reviewed and 1595 patients with a sCr < 1.5 mg/dL and an eGFR < 50 mL/min who met 1 criterion of dose reduction of apixaban other than sCr (that is, age ≥ 80 years or body weight < 60 kg) were identified. Clinical outcomes were compared between LD and SD apixaban versus warfarin.

Results: Their OACs use was as follows: 343 receiving apixaban (128 patients on standard dose [SD] and 215 on LD), 174 receiving warfarin, and 1078 on other NOACs. Patients with an eGFR < 50 mL/min had higher risk of mortality (adjusted hazard ratio [aHR], 1.264; 95 % confidence interval [CI], 1.086-1.472) and composite endpoint of 'ischemic stroke/systemic embolism (IS/SE) or major bleeding or mortality (aHR, 1.202; 95 % CI, 1.056-1.370) compared to those with an eGFR ≥ 50 mL/min whereas the risk of IS/SE and major bleeding were similar. LD apixaban was associated with lower risk of composite endpoint of IS/SE or major bleeding (aHR, 0.567; 95 % CI, 0.331 - 0.972), mortality (aHR, 0.336; 95 % CI, 0.138 - 0.815), and 'IS/SE or major bleeding or mortality (aHR, 0.551; 95 % CI, 0343 - 0.886) compared to warfarin while the risk was comparable between SD apixaban and warfarin (aHR, 0.745; 95 % CI, 0.402 - 1.378; aHR, 0.407; 95 % CI, 0.145 - 1.143; aHR, 0.619; 95 % CI, 0.354 - 1.084, respectively).

Conclusion: In patients with sCr < 1.5 mg/dL and eGFR < 50 mL/min, SD and LD apixaban were comparable in the prevention of IS/SE, but LD apixaban was superior in reducing the composite endpoint of 'IS/SE or major bleeding or mortality'. Therefore, LD apixaban might be a preferred dose for this population.