Duration of Clopidogrel-Based Dual Antiplatelet Therapy and Clinical Outcomes in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention ― A Real-World Observation in Taiwan From 2012 to 2015 ―

BACKGROUND: Little information is available in Asia about the real-world practice of dual antiplatelet therapy (DAPT) duration for acute coronary syndrome (ACS) and its influence on clinical outcomes.Methods and Results:The Taiwan ACS STENT Registry was a prospective, multicenter study to observe ACS patients using clopidogrel-based DAPT after percutaneous coronary intervention (PCI). The primary outcome was a composite of cardiovascular death, myocardial infarction, and stroke. Overall, 2,221 ACS patients (62 years, 83% men) were included. DAPT duration was ≤9 months in 935 (42.1%). The incidence of primary outcome was higher in patients receiving DAPT ≤9 months compared with those receiving DAPT >9 months at 1 year (3.5% vs. 1.6%, P=0.0026). The incidence of stent thrombosis (overall 0.5%) was similar between groups. Multivariable analysis showed that DAPT >9 months was associated with a significantly lower risk of primary outcome (odds ratio 0.725, 95% confidence interval 0.545-0.965). CONCLUSIONS: Our data showed that short duration of DAPT (≤9 months) was common (42.1%) in Taiwan for ACS patients undergoing PCI. DAPT ≤9 months increased the risk of the primary outcome.