ADP-induced platelet aggregation and metoprolol treatment of myocardial infarction patients. A controlled study.

The effect of metoprolol on platelet aggregation was investigated in a group of postmyocardial infarction (MI) patients. The study was double-blind and included 63 subjects; 30 patients were maintained on metoprolol and 33 received placebo treatment. Adenosine diphosphate (ADP)-induced platelet aggregation was carried out in each subject close to 4 weeks after the acute MI. It was demonstrated that metoprolol as compared to placebo did not influence ADP-induced platelet aggregation in the present clinical setting.