Does Activated Clotting Time Help to Predict Innate Coagulopathy in End-Stage Liver Disease Patients?

Measuring activated clotting time (ACT) is widely performed to monitor heparin therapy. Regardless of anticoagulant use, ACT is affected by coagulopathies such as coagulation factor deficiency and thrombocytopenia. However, its use in end-stage liver disease (ESLD) with complex coagulopathy is not well characterized. We evaluated whether ACT could be used to detect innate coagulopathy in ESLD patients.

We retrospectively assessed Hemochron (International Technidyne, Edison, NJ, USA) ACT (FTCA 510, normal range 105-167 seconds) and INTEM clotting time (CT) of rotational thromboelastometry (ROTEM; ROTEM delta, Pentapharm GmbH, Munich, Germany) (100-240 seconds) in 366 liver transplantation (LT) recipients, simultaneously measured before anesthetic induction for LT. Multiple linear regression analyses helped identify the factors related to ACT in ESLD patients. The relationship between ACT and INTEM CT was evaluated by Spearman rank correlation analysis and receiver operating characteristic curve.

Median ACT was 143 seconds (range 73-295 seconds), and 60 patients (16.4%) had ACTs of >167 seconds. Multiple regression analyses revealed that prolonged prothrombin time, activated partial thromboplastin time, low antithrombin III, and young age were associated with high ACT levels. INTEM CT was associated with ACT independent of liver disease severity, while EXTEM CT was not. ACT was moderately correlated with INTEM CT (r = 0.535), and the optimal cutoff value of ACT for predicting INTEM CT >240 seconds was 151 seconds (area under the curve = 0.787).

In ESLD patients, ACT is effective in detecting prolonged INTEM CT. Therefore, ACT may be used to predict intrinsic pathway defects with a cutoff value of 151 seconds, suggesting feasibility when ROTEM is unavailable.