Bleeding prediction by rotational thromboelastometry in chronic hemodialysis patients with non-valvular atrial fibrillation on apixaban

BACKGROUND The use of apixaban in chronic hemodialysis (HD) patients for non-valvular atrial fibrillation (NVAF) is still controversial regarding benefit of stroke protection vs risk of bleeding. Rotational thromboelastometry (ROTEM) is a point of care method that evaluates clot formation in whole blood and has been used as an evaluation tool for bleeding risk assessment in non-HD apixaban users. AIM To determine whether bleeding risk can be predicted using ROTEM activated with tissue factor (EXTEM) in HD patients receiving apixaban for NVAF. METHODS Nineteen HD patients with NVAF treated with apixaban for at least 8 days were enrolled. Four dosing regimens were recorded as prescribed by their physician, from 2.5 mg once daily on a non-dialysis day to 5 mg twice daily. Standard coagulation tests, along with ROTEM and apixaban drug levels (using liquid anti-Xa assay) were performed once on a non-dialysis day before and two hours after apixaban morning pill administration. Patients were subsequently monitored for thrombotic/bleeding events and all-cause mortality. RESULTS Over a median follow-up period of 36 months, six patients experienced a bleeding event (group A) and 13 remained free of bleeding (group B). Six deaths were recorded: Three due to major bleeding, one from thrombotic stroke, and two unrelated to coagulopathy. EXTEM clotting time (CT)-post was the only parameter that significantly differed between group A and group B (P = 0.013). Each 1-second increase in CT-post was linked to an 8% higher likelihood of a bleeding event (odds ratio = 1.08, 95% confidence interval: 1.0-1.17; P = 0.048). A significant progressive increase was observed with the drug’s trough and peak levels (P < 0.05) across the four dosing regimens but no significant relationship was found between CT and apixaban dose groups. CONCLUSION Early detection of bleeding risk in HD patients with NVAF on Apixaban maybe be effectively achieved through frequent monitoring using ROTEM EXTEM post CT, thereby helping to reduce associated morbidity.