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

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 <.001). No significant differences were found with WBPIA. Conclusions and Clinical Importance: The hyperthyroid cats in this study had evidence of altered hemostasis as assessed by 2 viscoelastic methodologies, and characterized by increased clot amplitude, firmness, and faster coagulation times vs euthyroid controls. [ABSTRACT FROM AUTHOR]