What test is used to monitor heparin therapy?

The appropriate test used to monitor heparin therapy is the activated partial thromboplastin time (APTT). This test evaluates the intrinsic and common pathways of coagulation, which are particularly affected by heparin. When a patient is receiving heparin, it is crucial to ensure that the anticoagulation effect is within a therapeutic range to prevent thromboembolic events without risking excessive bleeding.

APTT measures the time it takes for blood to clot after certain reagents are added, providing a direct correlation to the efficacy of heparin. A prolonged APTT indicates a higher level of anticoagulation, which is expected during heparin therapy. This makes it an essential tool for clinicians to adjust heparin dosages appropriately based on an individual’s response to the medication.

Other tests, such as the international normalized ratio (INR), thrombin time (TT), and prothrombin time (PT), are utilized for monitoring different anticoagulants or specific aspects of coagulation but are not suitable for heparin therapy monitoring. For instance, INR is primarily used for monitoring vitamin K antagonists like warfarin, while PT assesses the extrinsic pathway coagulation, which is not significantly impacted by heparin