Dual Antiplatelet Therapy for Long-term Secondary Prevention of Atherosclerotic Cardiovascular Events

Purpose: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ inhibitor is currently recommended to prevent further ischemic events after percutaneous coronary intervention and acute coronary syndrome (ACS). Guidelines currently recommend a minimum of 6 months after elective drug-eluting stent placement and at least 12 months of DAPT after ACS; however, the benefits of prolonged treatment are unclear. The purpose of this review was to conduct a detailed examination of the data refuting or supporting the use of DAPT beyond 1 year in patients with ACS and in patients receiving percutaneous coronary intervention with stenting. Methods: A search of PubMed was performed to identify articles published in the last 20 years that addressed the role of DAPT beyond 12 months’ duration. Findings: A number of studies have shown ischemic benefits associated with prolonging DAPT beyond 12 months, but this finding is dependent on the patient population studied and the quality of the study design. Many studies also show that longer duration therapy has been associated with increased bleeding risk. In patients with previous myocardial infarction completing at least 1 year of DAPT, continuing DAPT with a reduced dose of ticagrelor 60 mg BID is a regimen to be considered for these patients; in general ACS patients, a reduced dose of 60 mg BID of ticagrelor after the first year of DAPT should be considered; and in the post–percutaneous coronary intervention patients, DAPT beyond 1 year should be considered after careful evaluation of the patient's thrombotic and bleeding risks. Implications: The duration of DAPT, and the choice of P2Y₁₂ inhibitor, should be tailored to the individual patient. To optimize patient outcomes, the benefits and risks associated with prolonging DAPT need to be evaluated, considering comorbidities and the presence of bleeding and ischemic risk factors. Despite some limitations, risk scores, such as the DAPT score, are available to help guide decisions for the best approach for each patient.