Formation of prostacyclin-sensitive platelet aggregates in human whole blood in vitro. Part II. The occurrence of the phenomenon in males suffering from acute myocardial infarction

The de-aggregatory effect of prostacyclin (PGI2) and the rate of spontaneous platelet aggregation (SPA) were studied in vitro in whole blood of 24 males with acute myocardial infarction (MI) and 18 males, patient controls (PC). The de-aggregatory effect of PGI2 and the rate of SPA (measured as a percentage of changes in free platelet number in whole blood) were higher (p<0.01) in MI than PC. The de-aggregatory effect of PGI2 in whole blood was higher (p<0.05) on the first day of MI than on day 14 following MI. The highest de-aggregatory effect of PGI2 was found in whole blood of patients with MI complicated by ventricular fibrillation. In neither of the groups did the de-aggregatory effect of PGI2 correlate with patients' age, haematocrit, erythrocyte and leucocyte counts, triglycerides, HDL, LDL or total cholesterol levels. In the MI group, de-aggregatory effect of PGI2 was correlated with free platelet concentration (r=-0.59, p<0.05), elevation of glutamic oxalacetic transaminase (r=0.53, p<0.05) and cr...