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

Background: 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. Methods: 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. Results: 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). Conclusions: 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.