Glass bead-activated clotting time (gb-ACT) for monitoring the anticoagulation effects in elderly patients with high risk of venous thromboembolism (VTE)

ABSTRACT

Background

To find a new bedside method to monitor the anticoagulation effects of low-molecular-weight heparins (LMWHs) in patients with a high risk of venous thromboembolism (VTE).

Research design and methods

A total of 32 hospitalized patients (aged ≥60 years) who were at high risk of VTE were assigned to receive subcutaneous LMWH for 5 to 14 days. Plasma anti-factor Xa (anti-Xa) activity was conducted by a chromogenic method, and the glass bead-activated whole blood clotting time (gb-ACT) value was obtained by a Sonoclot Analyzer.

Results

A correlation between the gb-ACT values and the anti-Xa levels was suggested (R = 0.447, p = 0.002), and it was stronger in the older group aged 80 years above (R = 0.467, p = 0.008) and in the group of patients with an eGFR of 30 ~ 60 mL/min (R = 0.565, p = 0.005). The area under the curve (AUC) for gb-ACT by receiver operating characteristic (ROC) curve evaluation was 0.725 (p = 0.011), and the gb-ACT >282.5s provided a sensitivity of 60% and specificity of 74% for anti-Xa >0.800 IU/ml.

Conclusions

The gb-ACT values detected by a Sonoclot Analyzer could act as a novel bedside method in the monitoring of LMWH anticoagulation.

KEYWORDS:

• Venous thromboembolism
• low-molecular-weight heparin
• activated clotting time
• anti-factor Xa
• elderly
• renal dysfunction

Article highlights

• There was a correlation between gb-ACT values and the anti-Xa levels (R = 0.447, p = 0.002).

• There were stronger correlations in the older group aged 80 years above (R = 0.467, p = 0.008) and in the group of patients with an eGFR of 30 ~ 60 mL/min (R = 0.565, p = 0.005).

• The anti-Xa levels were similar when detected on the 2^nd and the 5^th day since LMWH administration, while the gb-ACT values were higher on the 5^th day (p = 0.089, 0.005 respectively).

• Clinicians should be very alert to the risk of hemorrhage when the gb-ACT value was more than 282.5s.

• In these special populations, LMWHs could be used once daily instead of twice a day because they were already in the target range.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

P Pingan performed this study, collected data, and drafted this paper, including drawing the figures and revising the manuscript. C Yiwen and Q Mingzhao designed this study, analyzed part of the data, and revised the paper. Y Guang and X Xiaohan helped to perform the study, collected and analyzed part of data, and made revisions. Z Yujie and Q Mingzhao made some adjustments to the experimental design, revised the figures, and approved the manuscript. All authors agree to be accountable for all aspects of the work.

Ethical approval

The study was approved by the institutional ethics committees of Beijing Anzhen Hospital and was conducted according to the Helsinki Declaration, with written informed consent of all patients.

Additional information

Funding

This work was supported by a grant from the National Key Research and Development Program of China [2022YFC3602500].