Utility of GRACE and ACUITY-HORIZONS risk scores to guide dual antiplatelet therapy in Korean patients with acute myocardial infarction undergoing drug-eluting stenting

•Both ischemic and bleeding risks are correlated with mortality post-percutaneous coronary intervention.•GRACE and ACUITY-HORIZONS scores may help guide dual antiplatelet therapy (DAPT) in patients with acute myocardial infarction (MI).•The optimal DAPT regimen in Asian patients with acute MI needs to be determined. Dual antiplatelet therapy (DAPT) is recommended in patients receiving drug-eluting stents (DES). However, bleeding risk should be weighed against ischemic risk. Utility of GRACE risk score and ACUITY-HORIZONS bleeding risk score was assessed in patients with acute myocardial infarction (MI) according to use of P2Y12 blocker. From the Korea Acute Myocardial Infarction Registry-National Institute of Health database, 7791 patients with acute MI receiving DES were divided into ticagrelor (n=1554) and clopidogrel (n=6237) groups. Propensity-matched 12-month mortality and bleeding event rates were compared according to GRACE and ACUITY-HORIZONS scores. Patients who received thrombolysis, prasugrel or anticoagulants, or who discontinued or switched DAPT were excluded. In all patients, high-risk patients more often received clopidogrel. After propensity score matching (n=1553 in each group), 12-month mortality was not different, but TIMI major bleeding rate was higher with ticagrelor (2.8% vs. 1.4%, p=0.007). On subgroup analysis, 12-month mortality was lower with ticagrelor in patients with high (>140) compared to low-to-moderate risk GRACE score (5.1% vs. 7.9%, p=0.04). When combined with ACUITY-HORIZONS bleeding score, 12-month mortality was lower with ticagrelor in patients with high GRACE score but without very high (≥20) ACUITY-HORIZONS score (2.4% vs. 5.3%, p=0.03). In patients with acute MI receiving DES, GRACE and ACUITY-HORIZONS scores may help guide DAPT. In patients with high GRACE score, a more potent P2Y12 blocker may be considered, particularly in the subset not at very high risk of bleeding.