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

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.