Aspirin therapy in angina pectoris: Effects on platelet aggregation, exercise tolerance, and electrocardiographic manifestations of ischemia*

Summary If altered platelet function contributes to poorly perfused zones of myocardium in patients with angina pectoris, then specific antiplatelet therapy might improve cardiovascular function and exercise performance. Exercise tolerance on a bicycle ergometer, heart rate-blood pressure product, and ischemic ECG changes at exercise end-point were compared before and during oral aspirin therapy (2.4 Gm. per day for 2 weeks) in 11 normal subjects and in 11 patients with stable angina pectoris. Platelet aggregation threshold in response to ADP and epinephrine was measured. Untreated patients had increased platelet aggregability when compared to normal subjects. Mean concentration of ADP for aggregation threshold was 1.80 μM * in patients and 4.1 μM * in normal subjects (p * in patients and 11.0 μM * in normal subjects (p