College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
National Institute of Animal Science, Rural Development Administration, Wanju, Republic of Korea.
J Vet Intern Med. 2019 May;33(3):1322-1330. doi: 10.1111/jvim.15478. Epub 2019 Mar 11.
The chromogenic anti-Xa assay, the gold standard for monitoring the anti-Xa effect of rivaroxaban, is not available as a cage-side diagnostic test for use in a clinical setting.
HYPOTHESIS/OBJECTIVES: To evaluate clinical modalities for measuring the anticoagulant effects of rivaroxaban using a point-of-care prothrombin time (PT) and thromboelastography (TEG).
Six healthy Beagle dogs.
Prospective, experimental study. Four different doses of rivaroxaban (0.5, 1, 2, and 4 mg/kg) were administered PO to dogs. Single PO and 3 consecutive dosing regimens also were assessed. Plasma rivaroxaban concentration was determined using a chromogenic anti-Xa assay, point-of-care PT, and TEG analysis with 4 activators (RapidTEG, 1 : 100 tissue factor [TF100], 1 : 3700 tissue factor [TF3700], and kaolin), and results were compared. Spearman correlation coefficients were calculated between ratios (peak to baseline PT; peak reaction time [R] of TEG to baseline [R] of TEG) and anti-Xa concentration.
Anti-Xa concentration had a significant correlation with point-of-care PT (R = 0.82, P < .001) and RapidTEG-TEG, TF100-TEG, and TF3700-TEG (R = 0.76, P < .001; R = 0.82, P < .001; and R = 0.83, P < .001, respectively).
Overall, a 1.5-1.9 × delay in PT and R values of TEG 3 hours after rivaroxaban administration is required to achieve therapeutic anti-Xa concentrations of rivaroxaban in canine plasma. The R values of TEG, specifically using tissue factors (RapidTEG, TF100, TF3700) and point-of-care PT for rivaroxaban can be used practically for therapeutic monitoring of rivaroxaban in dogs.
显色抗 Xa 测定法是监测利伐沙班抗 Xa 作用的金标准，但不能作为临床 cage-side 诊断试验。
假设/目的：评估使用即时凝血酶原时间 (PT) 和血栓弹力图 (TEG) 测量利伐沙班抗凝作用的临床方法。
六只健康的比格犬。
前瞻性、实验性研究。给狗口服给予四种不同剂量的利伐沙班 (0.5、1、2 和 4 mg/kg)。还评估了单次口服和连续 3 个疗程的情况。使用显色抗 Xa 测定法、即时凝血酶原时间 (PT) 和 TEG 分析（使用 4 种激活剂：快速 TEG、1:100 组织因子 [TF100]、1:3700 组织因子 [TF3700] 和高岭土）来确定血浆利伐沙班浓度，并进行比较。计算了比值（峰值至基线 PT；TEG 的峰值反应时间 [R] 与 TEG 的基线 [R]）与抗 Xa 浓度之间的 Spearman 相关系数。
抗 Xa 浓度与即时凝血酶原时间 (R=0.82，P<0.001) 和快速 TEG-TEG、TF100-TEG 和 TF3700-TEG 显著相关 (R=0.76，P<0.001；R=0.82，P<0.001；R=0.83，P<0.001)。
总体而言，利伐沙班给药后 3 小时，PT 和 TEG 的 R 值需要延迟 1.5-1.9 倍，才能达到犬血浆中利伐沙班的治疗性抗 Xa 浓度。TEG 的 R 值，特别是使用组织因子 (快速 TEG、TF100、TF3700) 和即时凝血酶原时间 (PT)，可实际用于监测犬利伐沙班的治疗效果。
