Maybe.
A small Dutch study showed that heart attack survivors who were taking low-dose aspirin to ward off a second heart attack benefited most when they took aspirin at bedtime.
We know that cardiovascular events are more often to occur in the morning. Platelets help aid blood in clotting and it is thought that platelet activity peaks in the morning hours. Dutch researchers postulated that the timing of the aspirin would not be significant as it is known that aspirin’s effect on blood clotting continues for a few days. But, after the results were found, it may be that the platelet surge inactivity is blunted with nighttime aspirin use.
Certainly, more research is needed but this is promising.
Dr. Leslie Greenberg's Blog 