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.