High doses of heparin may mask other coagulation disorders. Bleeding may be prevented when non- heparin related coagulation disorders are detected early enough. Also accidental exposure to heparin (e.g. leakage from catheters) may lead to bleeding problems.

In the HEPTEM assay (heparinase modified TEM), coagulation is triggered via the intrinsic pathway. During the assay, heparinase degrades heparin and allows for the assessment of haemostasis in heparinised patients (e.g. during cardio-pulmonary bypass) or the specific detection of heparin (when HEPTEM and INTEM are used simultaneously). Heparinase is also able to degrade LMWH, danaparoid or pentasaccharide.

The difference of INTEM and HEPTEM is a measure of the heparin load of the patient.