Initial patency of the infarct-related artery in patients with acute ST elevation myocardial infarction is related to platelet response to aspirin

Abstract

Introduction A proportion of patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary angiography (PCI) presents with patent infarct-related artery (IRA) on initial angiography. We tested the hypothesis that stronger platelet response to aspirin in these patients at admission might be associated with higher initial coronary flow in the IRA. Methods Platelet response to aspirin was assessed with Multiplate ® ASPI-test before coronary angiography in 70 patients on previous aspirin treatment admitted for acute STEMI. Coronary flow on initial angiogram was evaluated quantitatively according to the Thrombolysis in Myocardial Infarction (TIMI) grading system. Depending on the degree of arachidonic acid (AA) induced platelet aggregation in ASPI-test, patients were stratified into four quartiles and compared according to initial TIMI flow. Results When TIMI flow was compared according to quartiles of platelet aggregation in ASPI-test, we have found significantly higher frequency of TIMI-2 and TIMI-3 flow among patients with low values of ASPI-test, i.e. with stronger aspirin response ( P = 0.014). None of the patients in the highest quartile of ASPI-test had TIMI flow of 2 or 3. Conclusions Patients with stronger antiplatelet response to aspirin therapy in acute STEMI are more likely to present with spontaneous IRA recanalization.