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 acute myocardial infarction (AMI) has been recognized. However, there is very limited knowledge of the baseline TXB₂ and 6-keto-PGF(1a) plasma levels in patients with AMI before therapy has been administered. We compared plasma levels of TXB, and 6-keto-PGF(1a) by enzyme immunoassay in 18 AMI patients 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) were heterogeneous, but significantly higher in the AMI patients than in controls (175.92 ± 17.29 pg/ml and 192.08 ± 26.11 pg/ml, respectively). In some patients, long-term aspirin therapy mildly inhibits baseline prostanoid levels, however, limited data prevents us from further speculations on this issue. Although, the contributions by prostanoids to the pathogenesis of AMI have been well proposed, their plasma concentrations are not uniformly elevated, and it is still unclear whether the resultant changes are indicative of clinically meaningful effects.