Arachidonic acid-induced platelet aggregation and thromboxane A2 generation in patients with coronary heart disease.

: Arachidonic acid (AA)-induced platelet aggregation was studied in platelet-rich plasma of 32 male patients who survived myocardial infarction and in 32 healthy men of similar age. Only in three healthy subjects, but in 13 patient, irreversible platelet aggregation was induced consistently with concentrations of AA below 500 micrometer. The rate of conversion of AA to thromboxane A2 (TXA2) by platelets of these patients was augmented, although less endogenous TXA2 was required to trigger aggregation of their platelets as compared to the controls. The results indicate that among patients with coronary heart disease a subgroup can be distinguished which can possibly benefit from the secondary preventive treatment with aspirin and with other anti-platelet drugs which inhibit the generation of TXA2 in platelets.