Coagulation Biomarkers and Clinical Outcomes in Elderly Patients With Nonvalvular Atrial Fibrillation: ANAFIE Subcohort Study

Background

Little is known about the relationship between coagulation biomarkers and clinical outcomes in patients with atrial fibrillation (AF) treated with anticoagulants, especially direct oral anticoagulants (DOACs) and warfarin.

Objectives

This subcohort study evaluated the association between coagulation biomarkers and clinical outcomes in elderly Japanese patients with nonvalvular AF using the ANAFIE (All Nippon AF In the Elderly) Registry.

Methods

Patients with a definitive diagnosis of nonvalvular AF and aged ≥75 years at enrollment were included. At enrollment, biomarker levels for D-dimer, thrombin-antithrombin complex (TAT), prothrombin fragment 1+2 (F1+2), and soluble fibrin monomer complex (SFMC), along with data on anticoagulant use, were recorded.

Results

Of the 3,194 patients, 95.1% were using oral anticoagulants (OACs) (71.7% DOACs, 23.4% warfarin). D-dimer, TAT, and F1+2 levels, as well as the proportion of patients with a positive SFMC, were lower among those receiving OACs compared with those not receiving OACs. In the DOAC group, higher levels of D-dimer (≥1.0 μg/mL) and TAT (>3 ng/mL) were significantly associated with increased incidences of cardiovascular (CV) events (stroke, myocardial infarction, cardiac intervention, heart failure, and CV death), all-cause death, and CV death. In the warfarin group, higher levels of D-dimer were significantly associated with increased rates of all-cause death, higher levels of TAT with increased major bleeding, and positive SFMC with increased major bleeding and CV events.

Conclusions

Higher levels of coagulation biomarkers were associated with a higher risk of worse clinical outcomes, and the relationships between the coagulation biomarkers and outcomes differed between the DOAC and warfarin groups. (Prospective Observational Study in Late-Stage Elderly Patients with Non-Valvular Atrial Fibrillation All Nippon AF In Elderly Registry-ANAFIE Registry; UMIN000024006).

Idarucizumab does not have procoagulant effects: Assessment of thrombosis biomarkers in healthy volunteers

Idarucizumab, a humanised monoclonal antibody fragment, binds dabigatran with high affinity and immediately, completely and sustainably reverses dabigatran-induced changes on blood coagulation. The present analysis focuses on the evaluation of potential procoagulant properties of idarucizumab when administered in the absence of dabigatran. As part of two Phase I studies conducted in healthy Caucasian and Japanese male volunteers, the effect of idarucizumab (8 g as a 1-hour [h] infusion and 4 g as a 5-minute [min] infusion) and placebo on calibrated automated thrombography (CAT) was assessed using platelet-poor plasma samples. Measures were made before and 15 min after the end of infusion in Caucasian subjects, as well as pre-dose, 15 min, 4 h and 8 h in Japanese subjects. The levels of the thrombosis markers D-dimer and prothrombin fragment 1 + 2 (F1.2) were assessed over time in plasma samples up to 72 h after the end of infusion of idarucizumab and placebo. Idarucizumab had no apparent effect on endogenous thrombin formation as measured by CAT. D-dimer and F1.2 levels were highly variable in all dose groups but did not increase when compared with placebo or pre-dose levels. In conclusion, idarucizumab had no effect on endogenous thrombin generation. Additional markers of thrombosis, F1.2 and D-dimer, did not differ between placebo and idarucizumab, indicating a lack of procoagulant properties of idarucizumab.