9791. Anti-Factor Xa activity (blood plasma)
Description
The anti-Xa activity test measures the degree of inhibition of coagulation factor Xa (Stuart-Prower factor) during the use of unfractionated heparin, low-molecular-weight heparins, and direct oral anticoagulants.
Heparin-based medications and direct oral anticoagulants (DOACs – apixaban, edoxaban, rivaroxaban, betrixaban, or fondaparinux), which exhibit anti-Xa activity, are widely used for the treatment and prevention of thrombosis and thromboembolic complications. Among heparins, unfractionated heparin (UFH) and low-molecular-weight heparins (LMWH) are commonly used. Possible complications associated with heparin therapy (more often with UFH than LMWH) include bleeding, heparin-induced thrombocytopenia, and several other side effects. To reduce the risk of bleeding and optimize treatment, individualized dosing of heparins and DOACs is used, taking into account the patient’s age, body weight, drug interactions, comorbidities, and laboratory monitoring of therapy.
The plasma anti-Xa activity assay is a laboratory test that allows indirect measurement of the activity of heparins and direct oral anticoagulants (DOACs).
When and who needs the test?
- Monitoring therapy with low-molecular-weight heparin (LMWH);
- Assessing the effectiveness of treatment in patients receiving low-molecular-weight and unfractionated heparins (after aPTT testing);
- Comprehensive evaluation of coagulation system disorders in pregnant women;
- Treatment of cardiovascular diseases (acute myocardial infarction, unstable angina, acute coronary syndrome);
- After percutaneous coronary bypass grafting and other cardiac surgeries; • Treatment and prevention of thrombosis (deep vein thrombosis, pulmonary embolism, cavernous sinus thrombosis, Budd-Chiari syndrome, portal vein thrombosis).
Blood sampling should be performed 2-4 hours after drug administration (unless otherwise directed by the physician). Simultaneous assessment of plasma antithrombin III levels is also useful.
The test result should be interpreted in accordance with the treatment protocol prescribed to the patient (type of heparin, dosage, route of administration, blood draw timing, etc.) and the desired therapeutic effect.
Biological material
- Venous blood
Preparing for a blood test
In order to exclude factors that may affect the test results, we recommend to follow the preparation rules:
- an important condition for laboratory tests is to take blood on an empty stomach.
- 6-12 hours before the test, you should avoid eating, drinking alcohol, smoking, and limit physical activity. Drinking...