ABSTRACT

INTRODUCTION - Optimal dual antiplatelet therapy (DAPT) duration for medically managed acute coronary syndrome (ACS) (MMACS) patients is still unknown. We explored the efficacy and safety of ≥ 12-month DAPT among MMACS patients.

METHODS - In this sub-analysis of the optimal antiplatelet therapy for Chinese Patients with Coronary Artery Disease study (NCT01735305), clinical outcomes among MMACS patients were compared between the < 12-month and ≥ 12-month DAPT groups. The primary efficacy endpoint was a composite of cardiac death, myocardial infarction, and stroke. Safety endpoints included the Bleeding Academic Research Consortium (BARC) 2–5, BARC 3–5, and all bleeding events. Propensity score matching (PSM) was used to compare baseline characteristics between the < 12-month and ≥ 12-month DAPT groups.

RESULTS - In this cohort of ACS patients (n = 10,016), MMACS patients (n = 2967) were less likely to use DAPT at 12 (31.64% vs. 67.47%, P < 0.0001) and 24 (13.82% vs. 18.71%, P < 0.0001) months and experienced more ischemic events at 12 (4.55% vs. 3.40%, P = 0.006) and 24 (6.88% vs. 5.08%, P = 0.0004) months than those treated with percutaneous coronary intervention (n = 7049). Among MMACS patients, the rate of primary efficacy endpoint occurring within the second year was significantly higher in the < 12-month DAPT group than in the ≥ 12-month group both before (2.88% vs. 1.60%, P = 0.040) and after (3.19% vs. 1.71%, P = 0.045) PSM. After PSM, no significant differences in all bleeding, BARC 2–5, and BARC 3–5 bleeding were found between the groups.

CONCLUSION - MMACS patients with insufficient DAPT management experienced relatively more ischemic events. DAPT for at least 1 year may be beneficial to this special population without significantly increasing the bleeding risks.