Figure 1.

Ticagrelor reduces aggregation and prevents formation of drug-free platelet cores during aggregate formation in vitro. Platelet-rich plasma (PRP) derived from blood preincubated with aspirin (30 μmol/L) and prasugrel active metabolite (PAM; 3 μmol/L) or ticagrelor (1.35 μmol/L) was mixed in a range of proportions with PRP from blood preincubated with respective vehicles or with ticagrelor (1.35 μmol/L) to reflect mid-dose t=6-h levels. Aggregation in response to (A) ADP 20 μmol/L or (B) arachidonic acid 1 mmol/L was determined by light transmission aggregometry. Data presented as mean±SEM and compared by 2-way ANOVA (n=4, **P<0.01, ***P<0.001). C, Multiple images captured by ImageStreamX of aggregates (mixtures of 85% aspirin+PAM-pretreated platelets or aspirin+ticagrelor pretreated platelets plus 15% uninhibited platelets). Each panel contains columns with following image sets: drug-free (green), inhibited platelets (red), merged image. D, Representative confocal images of aggregates (left) formed from mixtures comprising 85% aspirin+PAM-pretreated platelets or aspirin+ticagrelor-pretreated (green) and 15% uninhibited platelets (red). E, Images were analyzed for size of the uninhibited platelet particles. Data are presented as mean±SEM and compared by t test (n=4; **P<0.01).