Viscoelastic properties of plasma fibrin clots are similar in patients on rivaroxaban and vitamin K antagonists.

Viscoelastic properties of plasma fibrin clots are similar in patients on rivaroxaban and vitamin K antagonists. J Physiol Pharmacol. 2018 Feb;70(1): Authors: Kopytek M, Zabczyk M, Natorska J, Siudut J, Malinowski KP, Ptaszek P, Glajcar A, Goralczyk T, Undas A Abstract Unfavorable fibrin clot features have been observed in patients with venous thromboembolism (VTE). We investigated whether rivaroxaban, a direct factor Xa inhibitor, and vitamin K antagonists (VKAs) can improve plasma clot viscoelastic properties. We studied four age- and sex-matched groups: 25 healthy controls, 15 VTE patients taking rivaroxaban 20 mg/day (blood concentration, 145 (67 - 217) ng/ml), 15 VTE patients taking VKA (INR: 2 - 3), and 15 VTE patients who stopped oral anticoagulant therapy (OAT). Using a hybrid rheometier the storage (G') and loss (G") moduli were evaluated in citrated plasma after addition of 5 pmol/l tissue factor. Fiber thickness within clots was assessed using scanning electron microscopy. Higher G' but not G" was observed for VTE patients taking rivaroxaban (+34%; post hoc, P = 0.029) compared to controls. As reflected by lower G' and G", patients taking rivaroxaban (-19% and -30%; post hoc, P = 0.0013 and P < 0.0001, respectively) formed less stiff and viscous clots compared to VTE patients after OAT withdrawal, also after adjustment for fibrinogen. VTE patients treated with rivaroxaban and VKA had similar clot viscoelastic properties...
Source: Journal of Physiology and Pharmacology - Category: Drugs & Pharmacology Tags: J Physiol Pharmacol Source Type: research