From the Guidelines
Asymptomatic antiphospholipid antibody–positive patients without thrombosis or obstetric complications should be treated with prophylactic aspirin, 81 or 100 mg daily, during pregnancy as preeclampsia prophylaxis, starting early in pregnancy (before 16 weeks) and continuing through delivery 1.
Key Considerations
- The presence of antiphospholipid antibodies (aPL) is considered a risk factor for the development of preeclampsia, regardless of clinical history 1.
- In pregnant women with positive aPL who do not meet criteria for obstetric or thrombotic APS, prophylactic aspirin is conditionally recommended to prevent preeclampsia 1.
- For patients with thrombotic APS, treatment with low-dose aspirin and therapeutic-dose heparin (usually LMWH) throughout pregnancy and postpartum is strongly recommended 1.
- The management of APS in pregnancy involves a combination of anticoagulation therapy and low-dose aspirin, with the goal of preventing recurrent clots and promoting a healthy pregnancy outcome 1.
Treatment Options
- Low-dose aspirin (81-100mg daily) for primary prevention in patients with antibodies but no clotting history 1.
- Low molecular weight heparin (such as enoxaparin 40mg daily) plus low-dose aspirin for patients with thrombotic APS 1.
- Adjusted-dose vitamin K antagonist (target INR, 2.5) over direct-acting oral anticoagulant therapy during the treatment phase for patients with confirmed APS 1.
From the Research
Antiphospholipid Syndrome (APS) Information
- APS is a systemic autoimmune disorder characterized by recurrent venous or arterial thrombosis with or without pregnancy morbidity in the presence of persistent antiphospholipid (aPL) autoantibodies 2.
- The mainstay of anticoagulation in patients with thrombotic APS is warfarin or an alternative vitamin K antagonist (VKA) and, in certain situations, low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) 3.
- Accurate assessment of anticoagulation intensity underpins optimal anticoagulant dosing for thrombus treatment or primary/secondary prevention 3.
Diagnosis and Management of APS
- The diagnosis of APS includes testing for antiphospholipid antibodies (aPL) and which tests to do 4.
- Clinical practice points on the management of venous, arterial, and small vessel thrombosis, in the context of first and recurrent thrombotic events, are considered 4.
- An approach to recurrent thrombosis and anticoagulant-refractory APS is discussed, with options including increasing the anticoagulation intensity of vitamin K antagonists, switching to low-molecular-weight-heparin, the use of fondaparinux and/or the addition of antiplatelet treatment 4.
Anticoagulation Therapy in APS
- Antithrombotic drugs are the therapeutic cornerstone for patients with APS and thrombosis 5.
- Choosing the specific agent (vitamin K antagonists or antiplatelet drugs), the intensity of anticoagulation (e.g., international normalized ratio [INR] range 2.0 to 3.0 or 3.0 to 4.0), and the duration of treatment has been a recurrent matter of debate 5.
- A recent consensus document recommends warfarin to an INR range of 2.0 to 3.0 for patients with a first venous thromboembolic event 5.
- Higher anticoagulation intensity is recommended for patients presenting with arterial events 5.
Secondary Thromboprophylaxis in Patients with aPL
- Patients with venous events and a single test for aPL showed a low recurrence rate while receiving oral anticoagulation at a target international normalized ratio (INR) of 2.0-3.0 6.
- Patients with stroke and a single positive aPL test had no increased risk compared with those without aPL 6.
- Recurrence rates in patients with definite antiphospholipid syndrome (APS) and previous venous thromboembolism were lower than in patients with arterial and/or recurrent events, both with and without therapy 6.