The factor VIII complex in atherosclerosis: Effects of aspirin

Sixty patients with well-documented previous myocardial infarction were treated with either 1 gm of aspirin daily or a placebo (AMIS trial). The factor VIII-von Willebrand factor complex was measured at 3-4-month intervals during the first 12-16 months of the trial. The levels of the complex did not change appreciably during this period, and the mean values for all but seven patients fell within 2 S.D. of the mean values obtained in normal laboratory controls. The concentrations of the factor VIII-von Willebrand complex in patients with a variety of vascular occlusive events did not differ from those in patients without such events. Finally, the mean values in patients treated with aspirin were virtually identical to those receiving placebo. We conclude that plasma levels of the factor VIII-von Willebrand factor complex are not altered in patients with atherosclerotic vascular disease, and are unaffected by aspirin therapy.