Antithrombotic Therapy for Acute Coronary Syndrome.

Acute coronary syndrome (ACS) encompasses a spectrum of cardiovascular emergencies, including unstable angina and myocardial infarction, that require immediate and effective management to reduce morbidity and mortality. Antithrombotic therapy, including antiplatelet and anticoagulant medications, is fundamental in ACS management. We sought to organize the current status of antithrombotic management of ACS, including the concept of high bleeding risk (HBR), in line with the clinical diagnostic flow. ACS is an ever-changing condition; therefore, its diagnosis and treatment are conducted in parallel. While primarily a coronary artery disease, the diagnosis of ACS also includes conditions such as myocardial infarction with nonobstructive coronary arteries as a working diagnosis. This review collates the mechanisms and classification of ACS, showing the diagnostic flow and the antithrombotic agents used at each stage. It discusses strategies for dual antiplatelet therapy (DAPT) duration and de-escalation in patients undergoing percutaneous coronary intervention and addresses the management of patients requiring oral anticoagulation alongside antiplatelet therapy, highlighting the shift toward dual therapy to reduce bleeding risk. Antithrombotic agents are key treatments for ACS, with various available options. Their mechanisms and the approved dosing regimens differ regionally, especially between Japan and other countries. This review synthesizes the regional availability of each agent and compares the latest recommendations from Japanese and international guidelines for ACS management. The field of antithrombotic therapy in ACS is dynamic, influenced by the findings of ongoing clinical trials and emerging evidence. Key considerations include balancing antithrombotic benefits against bleeding risks, particularly in patients with HBR. Recent studies have explored shorter DAPT durations and novel antithrombotic agents, offering new insights for diverse patient populations. In this review, we provide a comprehensive comparison of guidelines and insights from the neuro-interventional field to assist clinicians in making informed decisions regarding ACS management. As ACS management evolves, continued international, cross-sectional collaboration and research are essential to refine guidelines and improve clinical practice.