To demonstrate the substantial equivalence (SE) of Pefakit® PiCT® UC (test device, T) to aPTT-SP (Hemosil) (predicate device, P) in determining heparin levels in subjects undergoing heparin therapy in support of a United States Food and Drug Administration (FDA) 510(k) submission.

Standard of Care Study. Objective is to monitor the patients' heparin levels under treatment with continuous unfractionated heparin infusions. Blood samples collections (4 ml) are required routinely. A proportion of this standard sample (leftover plasma) will be used for study purposes. About three samples will be analyzed which are collected within 2 - 4 days. Time points for blood sample collections will be defined by the treating physician according the local standard of care and will be associated exclusively to clinical considerations. Results of the Pefakit® PiCT® UC assay will NOT be used to take therapeutic decisions for study subjects.

Inclusion Criteria:

• Subjects receiving a continuous infusion with UFH
• Subjects who have given written informed consent (unless written informed consent is waived by local regulations or local EC/IRB)

Exclusion Criteria:

• Subjects treated with any other anticoagulants other than UFH
• Subjects who have been undergoing fibrinolytic therapy within the previous 4 weeks
• Subjects who are known to have a congenital bleeding disorder
• Subjects known to present unexplained prolongations of clotting time
• Subjects known to have coagulation factor deficiencies
• Patient participating or who has participated within one month from enrolment in another investigational study

Subjects undergoing UFH anticoagulation therapy will are needed for this study. Typically, such patients are undergoing cardiovascular surgery, are being treated for thromboembolic events, or are receiving heparin intravenously for thrombosis prophylaxis due to its more advantageous pharmacokinetic profile in some situations.

144 subjects signed ICF. 4 out of 144 failed in/exclusion criteria 123 subjets are part of the AVS (all valid subjects) population. All 123 UFH treated study subjects had previous and concomitant medications and treatments.

Adverse events were collected from the date of FPI (first patient in) until LPO (last patient out).

In the US the study meets the requirements for exemption as defined in the Investigational Device Exemption regulations (21 CFR Part 812.2(c)).

In the EU, national regulations were followed regarding adverse event reporting for IVD studies.