In vivo production of prostacyclin and thromboxane in patients with acute myocardial infarction.

The in vivo production of prostacyclin and thromboxane was monitored by measuring their major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha in ten patients with acute myocardial infarction, five on standard treatment and five receiving prostacyclin infusion. During acute myocardial infarction excretion of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha, measured by a gas chromatography-mass spectrometry method with deuterated internal standards, was significantly increased. This indicates that thromboxane and prostacyclin synthesis are increased during the development of acute myocardial infarction. The excretion data for 2,3-dinor-thromboxane B2 showed that after administration of aspirin there was less pronounced and more variable inhibition than expected. Prostacyclin infusion did not markedly affect the excretion of the thromboxane metabolite.