The women were randomly assigned to receive either 100 mg of aspirin a day or no aspirin. Over five years of follow-up, aspirin use was found to lower heart attack risk by 47 percent, and mini-stroke (transient ischemic attack) risk by 43 percent. Aspirin did not reduce the risk of larger or persistent strokes from clots or brain bleeds.
Platelet ADP release (Table 3 Table 3 Platelet Size, Nucleotides and ADP Release. ). The patients' platelets released less ADP when incubated with kaolin or when stirred with connective tissue than normal platelets did.
Any of these conditions, even those in which platelets are increased, may cause defective formation of hemostatic plugs and bleeding. The risk of bleeding is inversely proportional to the platelet count and platelet function (see Table: Platelet Count and Bleeding Risk). When platelet function is reduced (eg, as a result of uremia or aspirin use), the risk of bleeding increases.