[Induced platelet aggregation in patients with coronary heart disease as well as trained and untrained control...

Induced in vitro platelet aggregation (adrenaline and collagen) and serum lipid levels were investigated in 21 postinfarction patients, in 11 of these patients subsequent to therapy with 46 +/- 14 mg nifedipine per os daily for one week and in 21 untrained, 16 endurance-trained, and 17 non-endurance-trained healthy male control subjects. Plasma catecholamine levels at rest (patients) and oxygen uptake capacity (control subjects) were determined in subgroups. Mean platelet aggregation was increased in patients (p less than 0.05) and was decreased both in endurance-trained subjects (p less than 0.05) and in the group of 11 patients subsequent to therapy with nifedipine (p less than 0.01), but platelet aggregation was slightly higher in non-endurance-trained individuals. Adrenaline-induced platelet aggregation correlated positively with collagen-induced aggregation (r = 0.72), with LDL-cholesterol fraction (r = 0.51) and negatively with oxygen uptake capacity (r = -0.49). Patients with increased LDL-cholesterol levels also showed increased plasma catecholamine levels (r = 0.49 and r = 0.43). Low aerobic capacity (oxygen uptake capacity), high LDL-cholesterol levels and plasma catecholamine concentrations indicate an increased induced platelet sensitivity in vitro.