2022 年 39 巻 3 号 p. 357-360
Dual antiplatelet therapy (DAPT) reduces the risk of ischemic events, including stent thrombosis, in patients undergoing percutaneous coronary intervention (PCI), while oral anticoagulants are superior to antiplatelet therapy for preventing thromboembolic events, including ischemic stroke, in patients with atrial fibrillation (AF). Reportedly, the AF population accounts for approximately 10% of patients undergoing percutaneous PCI. From a theoretical viewpoint, combination therapy of DAPT and oral anticoagulation (OAC) was previously recommended in patients with AF undergoing PCI. However, long–term triple therapy (OAC+DAPT) carries the risk of major bleeding. Recent clinical trials demonstrated the advantage of dual therapy with an oral anticoagulant (warfarin or direct oral anticoagulant) plus a single antiplatelet agent, which decreased the rate of major bleeding in the acute phase in AF patients who underwent PCI. These results affected guidelines, which now recommend that the duration of triple therapy should be limited, and dual therapy should be considered an alternative regimen when considering the bleeding risk. The current guidelines recommend monotherapy with an oral anticoagulant after 12 months of combination therapy, or in patients with AF and stable coronary artery diseases not requiring intervention. However, this approach has yet to be validated by randomized, controlled trials. The AFIRE trial demonstrated that rivaroxaban (a direct inhibitor of Factor Xa) monotherapy was noninferior to dual therapy in terms of efficacy and superior in terms of safety in this population. Thrombin Induces fibrin generation and platelet activation, leading to thrombus formation. Using a treatment that inhibits thrombin generation may provide an effective inhibition of thrombosis. Accumulating evidence demonstrate that there has been a paradigm shift in antithrombotic therapy of a “less is more” regimen.
