In vitro testing of three clotting agents demonstrates ability to reverse some effects of apixaban
THURSDAY, June 21 (HealthDay News) -- Different factor concentrates can reverse some of the alterations in hemostasis attributed to apixaban, according to a study presented during the American Heart Association's Emerging Science Series Webinar, held on June 20.
To investigate the effectiveness of prothrombin complex concentrates (PCCs), activated PCCs (aPCCs), or recombinant Factor VII (rFVIIa) for reversing the alterations of hemostatic mechanism induced by apixaban, Gines Escolar, M.D., Ph.D., from the University of Barcelona in Spain, and colleagues added 200 ng/ml apixaban in vitro to blood aliquots from healthy donors. Using a cone and plate analyzer (Impact R), modifications in platelet reactivity toward surfaces were measured at elevated shear rates. The authors also assessed the effects on thrombin generation (TG) and on parameters of thromboelastometry (TEM).
The researchers found that, in the Impact R studies, apixaban did not affect platelet reactivity. However, apixaban caused a moderate reduction in TG parameters. Thrombin peak and velocity indexes in TG were improved by the concentrates in the following order of efficacy: PCC ≥ aPCC > rFVIIa. In TEM studies, apixaban prolonged clotting time and decreased maximal clot firmness; these alterations were corrected by concentrates in the following order of efficacy: rFVIIa ≥ aPCC > PCC. In perfusion studies, the quantitative reduction in fibrin and platelet interactions with damaged vascular surfaces were counteracted by the different concentrates in the following order of efficacy: rFVIIa > PCC > aPCC.
"The good news is that the various lab tests applied indicate that these approaches may reverse the effects of apixaban," Escolar said in a statement. "But, even with the favorable results in perfusion studies using a damaged vessel, we're far from knowing what will work best in a bleeding patient."
Several authors disclosed financial ties to Bristol-Myers Squibb, which partially funded the study and manufactures apixaban.