Anti-Xa activity in oral factor Xa inhibitor-treated patients with atrial fibrillation and a higher risk of bleeding: a pilot study

The number of patients with nonvalvular atrial fibrillation (NV-AF) who require long-term anticoagulation and also have a higher risk of bleeding is increasing. Recently, there is no information regarding real on-treatment anti-Xa activity in patients with NV-AF and a higher risk of bleeding who receive oral factor Xa inhibitors. The aim of this study was to determine trough and peak anti-Xa activity in these patients. This single-centre pilot study enrolled 41 patients with NV-AF and a higher risk of bleeding defined as Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly score at least 3 points. Twenty-one patients were treated with rivaroxaban and 17 patients were treated with apixaban. The trough and peak samples of these patients were tested for anti-Xa activity with factor Xa-calibrated anti-Xa chromogenic analysis. The detected trough anti-Xa activity was 63.2 ± 44.4 ng/ml. There was a significant increase in peak anti-Xa activity up to 170.3 ± 99.6 ng/ml (P 
Source: Blood Coagulation and Fibrinolysis - Category: Hematology Tags: Original Articles Source Type: research