42. The effect of ticagrelor on coronary blood after primary PCI when compared with clopidogril

Primary PCI (PPCI) has been established as the best treatment for acute MI when it is used appropriately. It is known to give better TIMI III flow and better frame count when compared with thrombolytics. Loading with P2Y12 inhibitors in the ER prior to primary PCI is an important step in antiplatelet therapy for acute myocardial infarction. In this study We report the effect of loading with two different P2Y12 inhibitors (ticagrelor and clopidogril) on the TIMI frame count in the culprit artery after successful PPCI. Ticagrelor may affect coronary microcirculation and coronary blood flow through faster and stronger platelet inhibition. We randomized 44 patient who presented to our center with acute MI into two groups. The first group received a loading with 180mg of ticagrelor and the second group received a loading with 600 mg of clopidogril. The mean door to balloon time was 98 ± 12 min. All patients in both groups received a loading with 162 mg of aspirin. GP IIb/IIIa inhibitors were used in all cases together with adjusted dose heparin. Stent usage was 100%. No thrombectomy or thrombus aspiration device was used in any of these cases. TIMI III flow after stenting was achieved in all culprit arteries. Then we calculated the TIMI frame count in the culprit artery after successful primary PCI. The mean corrected TIMI frame count in the culprit artery post PCI was 18.34 ± 3.16 frames in group 1 (Ticagrelor group) and 28.73 ± 3.92 in group 2 (clopidogril group) (p = 0.02). Loading with ticagrelor gives faster flow after successful primary PCI in the culprit artery of acute MI when compared with clopidogril. This can be explained by the fact that ticagrelor therapy give faster P2Y12 inhibition thus faster antiplatelet therapy causing less platelet aggregation resulting in less distal embolization and reduced production of inflammatory mediators and adhesion molecules which may result in faster restoration of normal endothelial function. This finding may partially explain the mortality benefit of ticagrelor in a previous ACS study. A larger prospective randomized study is needed to confirm this finding