Evaluation of Point‐of‐Care Coagulation Measurement Systems for Activated Clotting Time and Partial Thromboplastin Time in Heparinized and Non‐Heparinized Equine Blood

OBJECTIVES: To compare the performance of one point-of-care activated clotting time (ACT) machine (Vet-Tube), one point-of-care activated partial thromboplastin time (aPTT) machine (Coagulation DX), and one bench-top ACT machine (Medtronic ACT II plus) with previously published measurements from stationary devices in whole blood from healthy horses. DESIGN: Prospective, observational study SETTING: University veterinary teaching hospital, from August 2023 to September 2023. ANIMALS: Thirty healthy university-owned horses. METHODS: ACT and aPTT were measured via point-of-care analyzers (ACT POC, aPTT POC) and by conventional stationary analyzers (ACT Stationary, aPTT Stationary) in non-heparinized and heparinized blood collected from healthy horses. Samples were analyzed within 30 min of collection. RESULTS: Moderate correlation (r = 0.5), acceptable bias, and a low intraassay coefficient of variation (<5%) were seen for the ACT stationery device and ACT POC coagulation tubes. The ACT stationery and ACT POC showed no significant difference for both non-heparinized (n = 30, p = 0.64) and heparinized samples (n = 15, p = 0.43). Strong correlation but high bias and a high intraassay coefficient of variation (>5%) were seen for the aPTT POC device, with the aPTT stationary device being within previously published ranges. The aPTT stationary chemistry analyzer and aPTT POC showed a significant difference for non-heparinized samples (n = 30, p = 0.0002) but had no significant difference for heparinized samples (n = 15, p = 0.03). CLINICAL RELEVANCE: The results of this study provide proof of concept for the use of low-cost POC monitoring of ACT in equine patients with coagulopathy or undergoing heparin therapy. Rigorous evaluation in patients with clinical disease is still necessary.