ADP-induced platelet aggregation in young female survivors of acute myocardial infarction and their female controls.

Adenosine diphosphate (ADP)-induced platelet aggregation was studied in 35 young female survivors of acute myocardial infarction (AMI) 14-46 (median 30) months after the infarction. The results were compared to those obtained for 35 control females of comparable age. Five different final ADP concentrations (0.2-1.0 microM) were employed, and the object was to assess the slope for the primary wave of aggregation as well as the threshold ADP concentration for secondary aggregation. The results showed that AMI patients and control subjects did not differ with respect to the primary wave of aggregation. However, secondary platelet aggregation was recorded to a significantly higher extent (p less than 0.02) in AMI patients than in their controls. The results therefore support the concept that enhanced platelet reactivity is present in patients with documented ischemic heart disease.