In vivo platelet hyperactivity and factor VIII related antigen increase long after myocardial infarction. A controlled effect of sulfinpyrazone.

In the Anturane Reinfarction Italian Study the trend of some specific and quantitative haemostatic parameters is being investigated in different series of patients balanced for sulfinpyrazone and placebo. In a series of young male patients who had had myocardial infarction 6 months previously, it has been shown that the placebo treatment subsample presented shortened platelet production time (PPT), increased levels of plasma β-thrombo-globulin (β-TG) and platelet factor 4 (PF4), and increased factor VIII related antigen (VIII:RAg) compared with a matched control group. A close correlation between plasma concentration of VIILRAg and PPT was evidenced in the same treatment subsample. The sulfinpyrazone treatment subsample presented normalized PPT accompanied by reduction of VIII:RAg but not of β-TG or PF4 levels.