Dual antiplatelet treatment with aspirin and a P2Y₁₂antagonist is similar to treatment with either drug alone. Laser-induced injury was performed in cremaster muscle arterioles of wild-type mice treated with vehicle (blue), aspirin alone (1.25 mg/d, red), cangrelor alone (0.75 µg prior to each injury, green), or aspirin plus cangrelor (magenta) as described in “Materials and methods.” (A) CD41-positive area over time (mean ± SEM). (B) Graph shows the area under the CD41 vs time curve (AUC). The line and error bars show the median and interquartile range. (C) P-selectin–positive area over time (mean ± SEM). (D) Area under the P-selectin vs time curve. The line and error bars show the median and interquartile range. Vehicle, n = 39 injuries in 8 mice; aspirin alone, n = 42 injuries in 9 mice; cangrelor alone, n = 21 injuries in 5 mice; aspirin plus cangrelor, n = 21 injuries in 5 mice.