Comparison of short-term clinical outcomes between ticagrelor versus clopidogrel in patients with acute myocardial infarction undergoing successful revascularization; From Korea Acute Myocardial Infarction Registry - National Institute of Health

Background Although ticagrelor has been well-known to improve clinical outcomes in patients with acute myocardial infarction (AMI) without increased bleeding risk, its clinical impacts have not been well established in East Asian patients. Methods Between November 2011 and June 2015, a total of 8010 patients (1377 patients were prescribed ticagrelor and 6633 patients clopidogrel) undergoing successful revascularization were analyzed from Korea Acute Myocardial Infarction Registry - National Institute of Health. The patients who discontinued or occurred in-hospital switching between two antiplatelet agents were excluded. Results After propensity score matching (1377 pairs), no difference in the composite of cardiac death, MI, stroke, or target vessel revascularization at 6 months was observed between two groups (4.2% vs. 4.9%, p = 0.499). However, the incidences of in-hospital Thrombolysis In Myocardial Infarction (TIMI) major and minor bleeding were higher in ticagrelor than clopidogrel (2.6% vs. 1.2%, p = 0.008; 3.8% vs. 2.5%, p = 0.051). The in-hospital mortality was higher in patients with than those without TIMI major bleeding (11.3% vs. 0.9%, p < 0.001). In a subgroup analysis, a higher risk for in-hospital TIMI major bleeding with ticagrelor was observed in patients ≥ 75 years or with body weight < 60 kg (odd ratio [OR] = 3.209; 95% confidence interval [CI] = 1.356-7.592) and in those received trans-femoral intervention (OR = 1.996; 95% CI = 1.061-3.754). Conclusions Our study shows that ticagrelor did not reduce ischemic events yet, however, was associated with increased risk of bleeding complications compared with clopidogrel. Further large-scale, long-term, randomized trials should be required to assess the outcomes of ticagrelor for East Asian patients with AMI.