Assessment of hemostasis in hyperthyroid and euthyroid cats using two viscoelastic assays and platelet aggregometry

Abstract

Background: Hyperthyroidism in humans is associated with a hypercoagulable state and an increased risk of thromboembolism. Objective: To evaluate hemostatic variables in hyperthyroid and euthyroid cats with the hypothesis that hyperthyroid cats will have evidence of altered hemostasis consistent with a potential hypercoagulable state. Animals: Client-owned hyperthyroid (n = 16) and euthyroid (n = 15) cats over 8 years of age. Methods: Prospective observational study. Hyperthyroid and euthyroid cats were enrolled. Rotational thromboelastometry (ROTEM), whole-blood platelet impedance aggregometry (WBPIA) and a point-of-care viscoelastic coagulation monitor (VCM-Vet) were performed immediately after minimally traumatic venipuncture under sedation. Results: Hyperthyroid cats had significantly higher values for variables as assessed by VCM-Vet: A10 (34 [17-47] vs 25 [17-38], P =.003); A20 (39.5 [23-55] vs 31 [21-45], P =.003); and MCF (41 [24-58] vs 35 [22-49], P =.03). Hyperthyroid cats had significantly different values versus the euthyroid cohort as assessed by different ROTEM channels: increased A10, INTEM (61.5 [39-75] vs 54 [23-66], P =.007) and FIBTEM (18 [10-35] vs 13 [2-27], P =.01); increased A20, INTEM (68 [45-78] vs 61 [30-70], P =.006) and FIBTEM (17 [10-34] vs 11 [2-25], P =.002); increased MCF, EXTEM (72 [65-81] vs 69 [34-78], P =.04), INTEM (70 [45-85] vs 62 [35-71], P =.01) and FIBTEM (18 [13-37] vs 14 [3-27], P =.02); increased alpha angle, EXTEM (80 [68-85] vs 76 [41-84], P =.01); shortened CT, EXTEM (52.5 [29-73] vs 60 [52-92], P =.003) and FIBTEM (52.5 [16-75] vs 65 [53-165], P =.001); and decreased ML, FIBTEM (20 [1-36] vs 33 [19-59], P