Anticoagulation in Acute Coronary Syndrome: Review of Major Therapeutic Advances

BACKGROUND: In patients with acute coronary syndrome (ACS), a persistent hypercoagulable state has been demonstrated and antithrombin therapy in addition to platelet inhibition has been proposed. AREAS OF UNCERTAINTY: Vitamin K antagonists (VKAs) were used as oral anticoagulant (OAC) therapy and produced mixed results whereas trials are still ongoing with non-vitamin K OACs (NOACs). DATA SOURCES: A literature search regarding benefits and risks of different OAC therapies in ACS was conducted through MEDLINE and EMBASE (last 20 years until September 2018). THERAPEUTIC ADVANCES: Patients receiving dual antiplatelet therapy (DAPT) in combination with NOAC are to be considered at high bleeding risk. Rivaroxaban 2.5 mg BID in triple therapy with DAPT, rivaroxaban 15 mg, or dabigatran 110/150 mg BID in dual therapy with P2Y12 inhibitor (mainly clopidogrel) is safer in terms of bleeding risk than triple therapy with VKA plus DAPT. The reduction in ischemic events by NOACs was most promising when added to single antiplatelet therapy. Ongoing trials with apixaban and edoxaban could clarify whether dual therapy NOACs with P2Y12 inhibitor sufficiently protect against stent thrombosis or myocardial infarction and are safer in terms of bleeding risk than a dual therapy with a VKA and clopidogrel. In the absence of randomized trials, it is unknown whether dual therapy with NOAC and aspirin could be an alternative to NOAC and a P2Y12 inhibitor. Thus, the overall benefit of adding NOAC to antiplatelet treatment after ACS in patients without clear indication for long-term OAC is still unknown. CONCLUSIONS: Different OACs have been tested as antithrombotic therapy after ACS in combination with single or DAPT and led to a modest reduction in ischemic events. Further studies evaluating NOACs in combination with single antiplatelet therapy or shorter duration of triple antithrombotic therapy are warranted.