Pharmacological Evaluation of Ticagrelor and Aspirin Versus Clopidogrel and Aspirin Pretreatment on Infarct Artery Flow in Patients with Acute STEMI

<b>Background and Objectives</b>: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is standard in ST-segment elevation myocardial infarction (STEMI). Guidelines favor ticagrelor over clopidogrel, but their effect on infarct artery flow prior to percutaneous coronary intervention (PCI) remains debated. Objective was to compare the effects of aspirin + clopidogrel versus aspirin + ticagrelor pretreatment on infarct artery Thrombolysis in Myocardial Infarction (TIMI) flow in STEMI patients. <b>Materials and Methods</b>: This retrospective cohort study included first-time STEMI patients ≥ 18 years admitted to the Military Medical Academy, Belgrade (January 2016-January 2022), who received pretreatment with aspirin + clopidogrel or aspirin + ticagrelor and underwent PCI. TIMI flow was graded before and after PCI. Primary outcomes were pre- and post-PCI TIMI flow; secondary outcome was in-hospital mortality. <b>Results</b>: Of 299 STEMI patients, 174 received aspirin + ticagrelor and 125 received aspirin + clopidogrel. Pre-PCI TIMI flow was significantly higher in the ticagrelor group (<i>p</i> < 0.001), while post-PCI TIMI flow (<i>p</i> = 0.056) and in-hospital mortality (<i>p</i> = 0.083) did not significantly differ between groups. After exclusion of patients receiving glycoprotein IIb/IIIa inhibitors, the difference in PCI TIMI flow grade after PCI became statistically significant (<i>p</i> = 0.007), favoring the aspirin + ticagrelor group. In multivariate analysis, male gender, drug-eluting stent implantation, and glycoprotein IIb/IIIa inhibitor use were independently associated with reduced in-hospital mortality. <b>Conclusions</b>: In STEMI patients, ticagrelor-based DAPT was associated with better initial coronary flow compared to clopidogrel. However, this advantage was not evident after PCI. Male gender, drug-eluting stent implantation, and glycoprotein IIb/IIIa inhibitor use were associated with improved survival.