[Duration of the effect of acetylsalicylic acid on circulating platelet aggregates in cerebral infarct patients].

The number of "circulating platelet aggregates" was examined in 33 patients who had suffered a cerebral infarct. Examination was done before onset of treatment with acetylsalicylic acid (ASA), 2 hours after ASA medication, and 12 hours after ASA medication, employing a modification of the platelet function measuring method according to the authors Wu and Hoak. The significant increase in the number of circulating platelet aggregates, compared with healthy persons, was found to be significantly reduced 2 and 12 hours after ASA medication. After 2 hours, we found in only 6% of the patients an increase in the number of circulating platelet aggregates above the mean value + triple (simple) standard deviation for n = 71 healthy controls. 12 hours after ASA administration 30% of the patients had again passed beyond the liberally defined standard level of the method.