Plasma thromboxane and prostacyclin are linearly related and increased in patients presenting with acute myocardial infarction

The role of prostanoids in patients with ischemic heart disease including a cute myocardial infarction (AMI) has been recognized. However, there is ver y limited knowledge of the baseline TXB2 and 6-keto-PGF(1a) plasma levels i n patients with AMI before therapy has been administered. We compared plasm a levels of TXB2 and 6-keto-PGF(1a) by enzyme immunoassay in 18 AMI patient s before thrombolysis, with those of 13 healthy controls. Plasma levels of TXB2 (319.78 +/- 16.50 pg/ml) and 6-keto-PGF(1a) (536.72 +/- 56.71 pg/ml) w ere heterogeneous, but significantly higher in the AMI patients than in con trols (175.92 +/- 17.29 pg/ml and 192.08 +/- 26.11 pg/ml, respectively). In some patients, long-term aspirin therapy mildly inhibits baseline prostano id levels, however, limited data prevents us from further speculations on t his issue. Although, the contributions by prostanoids to the pathogenesis o f AMI have been well proposed, their plasma concentrations are not uniforml y elevated, and it is still unclear whether the resultant changes are indic ative of clinically meaningful effects.