Correlation of Activated Clotting Time and Activated Partial Thromboplastin Time to Plasma Heparin Concentration

Abstract

There are significant statistical linear and log linear correlations between both clotting time tests and plasma heparin concentrations, with aPTT showing stronger correlation than ACT. However, decisions regarding heparin therapy based on ACT may increase a patient's risk of bleeding, whereas decisions based on aPTT may increase the risk of thrombus progression or rethrombosis.