Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001)2026; doi: 10.1111/vec.70127

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

Hobbs, KJ
·
Ueda, Y
·
Qu, Y
·
Cooper, BL
·
Sheats, MK
·
Burke, MJ

Abstract: 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. Methods: Prospective, observational study SETTING: University veterinary teaching hospital, from August 2023 to September 2023. Methods: 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 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). Conclusions: 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.

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Publication Date: 2026-06-09 PubMed ID: 42262260DOI: 10.1111/vec.70127Google Scholar: Lookup

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Overview

This study evaluates the accuracy and reliability of point-of-care (POC) devices for measuring activated clotting time (ACT) and activated partial thromboplastin time (aPTT) in horse blood, both with and without heparin anticoagulation, by comparing them to established stationary laboratory analyzers.

Background and Rationale

Coagulation tests such as ACT and aPTT are important for monitoring the blood’s clotting ability, especially in patients receiving anticoagulants like heparin.
In veterinary medicine, particularly for horses, quick and reliable clotting tests at the point of care are valuable to guide therapy and detect coagulopathies.
Traditional laboratory analyzers can be time-consuming and less accessible in clinical settings; hence, evaluating faster POC devices is needed.

Study Objectives

To compare the performance of one POC ACT device (Vet-Tube) and one POC aPTT device (Coagulation DX) against benchmark stationary analyzers (Medtronic ACT II plus for ACT and a conventional stationary chemistry analyzer for aPTT) in healthy horse blood samples.
To assess the accuracy, correlation, bias, and variability of POC measurement systems in both non-heparinized and heparinized blood conditions.

Methodology

Study Type: Prospective, observational study conducted at a university veterinary teaching hospital.
Participants: 30 healthy university-owned horses.
Blood Sampling: Each horse provided samples of whole blood, both untreated (non-heparinized) and treated with heparin (heparinized).
Testing: ACT and aPTT were measured using:
- POC analyzers (Vet-Tube for ACT, Coagulation DX for aPTT).
- Stationary analyzers (Medtronic ACT II plus for ACT, standard chemistry analyzer for aPTT).
Samples were processed within 30 minutes to minimize sample degradation.
Statistical Analysis: Correlation coefficients (r), bias assessment, intraassay coefficient of variation, and significance testing for differences between POC and stationary devices.

Key Results

ACT Measurements:
- Moderate correlation (r = 0.5) between the stationary and POC ACT devices.
- Low intraassay variability (<5%), indicating good precision within the POC ACT device.
- No statistically significant differences between the stationary and POC ACT measurements in both non-heparinized (n=30, p=0.64) and heparinized samples (n=15, p=0.43).
- Acceptable bias suggests POC ACT devices provide results comparable to stationary analyzers.
aPTT Measurements:
- Strong correlation between stationary and POC aPTT devices but accompanied by high bias.
- High intraassay coefficient of variation (>5%), indicating more variability and less precision in the POC aPTT device.
- The stationary aPTT analyzer results were within published reference ranges for horses.
- Significant difference found between stationary and POC aPTT devices for non-heparinized samples (n=30, p=0.0002), suggesting less agreement in normal blood.
- No significant difference for heparinized samples (n=15, p=0.03), showing better agreement when heparin affects coagulation.

Conclusions and Implications

The POC ACT device (Vet-Tube) shows promise as a low-cost, rapid, and reliable tool for coagulation monitoring in equine clinical scenarios, including those involving heparin therapy or bleeding disorders.
The POC aPTT device (Coagulation DX) demonstrated less consistent performance, with higher variability and bias, limiting its current clinical utility without further refinement and validation.
Though proof of concept is established, additional studies investigating POC coagulation devices in clinical equine patients (those with actual disease or undergoing therapy) are necessary to fully validate their clinical usefulness.
Adopting validated POC coagulation testing could enhance veterinary care by enabling more rapid and accessible coagulation monitoring in horses.

Cite This Article

APA

Hobbs KJ, Ueda Y, Qu Y, Cooper BL, Sheats MK, Burke MJ. (2026). Evaluation of Point-of-Care Coagulation Measurement Systems for Activated Clotting Time and Partial Thromboplastin Time in Heparinized and Non-Heparinized Equine Blood. J Vet Emerg Crit Care (San Antonio). https://doi.org/10.1111/vec.70127

Publication

Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001)

ISSN: 1476-4431

NlmUniqueID: 101152804

Country: United States

Language: English

Researcher Affiliations

Hobbs, Kallie J

Department of Clinical Sciences, Texas A&M University, College Station, Texas, USA.

Ueda, Yu

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.

Qu, Yang

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.

Cooper, Bethanie L

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.

Sheats, M Katie

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.

Burke, Megan J

Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.

Grant Funding

North Carolina State University Intramural Fund
Thoroughbred Education and Research Foundation Young Investigator Grant

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