Prolonged Dual Antiplatelet Therapy in Acute Myocardial Infarction Patients Without Revascularization: China Acute Myocardial Infarction Registry Study.

At least 12 months of dual antiplatelet therapy (DAPT) is 1 of the standards of care following percutaneous coronary intervention in patients with acute coronary syndrome. However, study on prolonged DAPT for patients with acute myocardial infarction (AMI) without revascularization is limited. We studied 1,744 patients with AMI without revascularization from the China Acute Myocardial Infarction registry between January 2013 and September 2014. These patients were on DAPT and did not experience AMI, stroke, or bleeding events at the 12-month follow-up. We divided them into 2 groups: 12-month DAPT group (DAPT for at least 12 months but <18 months) and 18-month DAPT group (DAPT for at least 18 months). The primary outcome was 24-month all-cause death. Overall, 1,221 patients (70.0%) took DAPT for ≥12 months but <18 months, whereas 523 patients (30.0%) took DAPT for ≥18 months. The proportion of patients at high ischemic risk and the proportion of patients at high bleeding risk were similar in the 2 groups. At 24 months, the all-cause mortality rate of the 18-month DAPT group was significantly lower than that for the 12-month DAPT group (3.7% vs 5.9%, p = 0.0471). The adjusted hazard ratio for all-cause death also showed statistical significance (0.59, 95% confidence interval 0.35 to 0.99, p = 0.0444). In conclusion, DAPT for at least 18 months appears to be associated with lower 24-month mortality for non-revascularization AMI patients without events within 12 months after onset.