Aspirin dose in prevention of transient ischaemic attacks

Acetylsalicylic acid-induced prolongation of bleeding time in healthy men

Bleeding times were determined in 25 healthy men using the Thrombolette bleeding time device. The median bleeding times prior to low and high doses of acetylsalicylic acid (ASA), 245 and 230 s, were not significantly different (P = 0.12). 2 h after randomized ingestion of 0.44 and 3.96 g ASA, the median bleeding times rose to 450 and 430 s, respectively. Both increased in bleeding time were significant (P less than 0.001), but the difference was not significant (P = 0.29). The maximum increase in bleeding time was estimated to occur 2.6 h after ingestion of a single low ASA dose, and 2.4 h after a single high dose. Following ingestion of 0.44 as well as 3.96 g ASA the bleeding time returned to basal levels within 5-6 d. Compared to the younger ones, volunteers with a higher age showed a tendency to have lower plasma salicylate levels as well as smaller increases in bleeding times following ASA ingestion.

Anticoagulant vs anti-platelet therapy as prophylactic against cerebral infarction in transient ischemic attacks

156 patients with transient ischemic attacks (TIA) or reversible ischemic neurological deficit (RIND) were given prophylactic anticoagulant (AC) treatment against cerebral infarction in a prospective multicenter study from 5 hospitals in southern Sweden. After 2 months of AC treatment, 135 patients remained in the study and were randomized into 2 groups; one continued with AC treatment and one changed to anti-platelet therapy. The patients were followed for 12 months. No significant difference was seen between the 2 groups but 3 completed cerebral infarctions occurred during anti-platelet therapy against one during AC treatment. One cerebral hemorrhage was seen during AC treatment. All completed strokes occurred in men who initially had carotid symptoms. The number of patients with TIA/RIND was somewhat higher in the anti-platelet group whereas myocardial infarctions occurred more often during AC treatment. Compared to the natural history of untreated TIA/RIND both treatments were found to have a prophylactic effect against cerebral infarction.