Juan Felipe Betancur Pulgarin
CES University, Colombia
Posters & Accepted Abstracts: Intern Med
The antiphospholipid syndrome (APS) is an autoimmune disorder characterized by venous and arterial thrombosis and recurrent fetal losses, frequently accompanied by a moderate thrombocytopenia and the presence of persistent circulating anti-phospholipid antibodies (aPL). The medical management of patients with APS aims mainly at avoiding the thrombotic and/or obstetric recurrences. To reach that, the current mainstay of treatment are: Bridge therapy for at least 5 days with heparin (un-fractioned or low molecular weight heparin) followed by long-term anticoagulation with vitamin K antagonist (VKA) such as warfarin with a recommended target international normalized ratio (INR) of 2.5. The intensity of continuous anticoagulation is still debated. Treatment with VKA is complicated because it has several pitfalls including numerous food and drug interactions (i.e., immunosuppressive agents such as azathioprine), which require frequent INR monitoring. Furthermore, the effective evaluation of the anticoagulation effect may be difficult by the variable response of thromboplastin reagents to aPL (particularly LA), that would make the estimation of anticoagulation intensity with prothrombin time (PT)/INR uncertain. To overcome these and other limitations, a group of relatively new class of drugs that inhibit a single enzyme of the coagulation cascade called direct oral anticoagulants (DOACs) has been introduced. Major phase III prospective and randomized controlled trials (RCT) have shown the efficacy and safe profile of DOACs for venous thromboembolism (VTE) treatment. However, these results are not generalizable to patients with APS, despite these trials probably included patients with this syndrome. There are many available case reports and case series that support the use of DOAC therapy for secondary thrombo prophylaxis for APS patients with previous VTE who require an INR target of 2-3. The use of DOACs in patients with previous arterial thrombosis or in patients requiring a target INR >3 is still matter of discussion. It is unclear if DOACs can replace warfarin for the long-term secondary thrombosis prevention in APS patients with VTE. The necessity for controlled outcome trials of DOACs in APS patients will depend on the results of the ongoing trials.
Email: [email protected]