Effects of a single subcutaneous dose of enoxaparin on veterinary viscoelastic coagulation monitor variables in healthy cats: Double blind, placebo controlled cross-over trial.

Abstract

BACKGROUND: Cats placed on anticoagulant medication require frequent monitoring. The veterinary viscoelastic coagulation monitor (VCM-Vet) could provide a convenient and cost-effective monitoring, enabling therapeutic decision making. HYPOTHESIS/OBJECTIVES: Enoxaparin will lead to changes in VCM-Vet variables and these will correlate with antiXa activity. ANIMALS: Twenty-one healthy cats. METHODS: Cats were randomized to receive either enoxaparin (1&#xa0;mg/kg) subcutaneously or 0.9% NaCl (equal volume) and crossed over with a 7-day washout period. The investigators were blinded to group allocation until data analysis. Jugular blood samples were drawn at time 0, and 2, 4, and 8&#xa0;hours after injection for VCM-Vet analysis within 2&#xa0;min of collection. Citrated plasma was frozen at -80&#xb0;C for antiXa activity analysis. A Generalized Linear Model was completed to assess changes between baseline measurements and all time points. RESULTS: Significant differences between the enoxaparin-treated cats and controls at for T0h and T2h were found and presented as mean&#x2009;&#xb1;&#x2009;SD for clotting time (enoxaparin, 593.4&#x2009;&#xb1;&#x2009;78.0&#xa0;s; control, 448.5&#x2009;&#xb1;&#x2009;50.3&#xa0;s, P&#x2009;<&#x2009;.001), clot formation time (enoxaparin, 183.1&#x2009;&#xb1; 41.7&#xa0;s; control, 155.4&#x2009;&#xb1;&#x2009;28.0&#xa0;s, P&#xa0;=&#xa0;.001), and alpha angle (enoxaparin, 52.4&#x2009;&#xb1; 6.1&#xb0;; control, 56.9&#x2009;&#xb1;&#x2009;3.7&#xa0;s, P&#xa0;=&#xa0;.003). AntiXa activity was significantly different between T0 and all other timepoints for the enoxaparin group (P&#x2009;<&#x2009;.001). There was no correlation between changes in clotting time and antiXa activity. CONCLUSIONS AND CLINICAL IMPORTANCE: The VCM-Vet detects a difference at 2&#xa0;hours after single-dose enoxaparin administration and it can be useful for anticoagulant therapy monitoring in cats.