Urinary 11-dehydro-thromboxane B2 levels are associated with vascular inflammation and prognosis in atherosclerotic cardiovascular disease.

Cyclooxygenase-derived thromboxane (TxA2) and prostacyclin (PGI2) regulate atherogenesis in preclinical models. However, the relationship between TxA2 and PGI2 biosynthesis, vascular inflammation, and atherosclerotic cardiovascular disease (ASCVD) progression in humans remains unclear. The association between stable urine metabolites of thromboxane (TxA2-M) and prostacyclin (PGI2-M), circulating levels of cellular adhesion molecules (CAMs: E-selectin, P-selectin), chemokines and C-reactive protein, and the incidence of major adverse cardiovascular events (MACE) were evaluated in 120 patients with stable ASCVD on aspirin therapy. Urinary TxA2-M levels were significantly correlated with circulating P-selectin (r=0.319, p<0.001) and E-selectin (r=0.245, p=0.007) levels, and associated with higher risk of MACE (p=0.043). In contrast, PGI2-M levels were not significantly associated with CAM levels or MACE. These results provide insight into the contribution of TxA2 biosynthesis to ASCVD progression in humans, and suggest that patients with elevated TxA2-M levels may be predisposed to advanced platelet and endothelial activation and higher risk of adverse cardiovascular outcomes.

Cytochrome P450-derived eicosanoids and vascular dysfunction in coronary artery disease patients.

OBJECTIVE: Accumulating preclinical and epidemiologic evidence has emerged to suggest that modulation of cytochrome P450 (CYP)-mediated eicosanoid metabolism may be a viable vascular protective therapeutic strategy for the secondary prevention of coronary artery disease (CAD). The functional relationship between CYP-derived eicosanoid metabolite levels and vascular dysfunction in humans with established CAD, however, has not been evaluated. Therefore, we characterized the relationship between inter-individual variation in soluble epoxide hydrolase (sEH) and CYP ω-hydroxylase metabolism and established vascular function phenotypes predictive of prognosis in a cohort of patients with atherosclerotic cardiovascular disease. METHODS: Plasma epoxyeicosatrienoic acid (EET), dihydroxyeicosatrienoic acid (DHET), and 20-hydroxyeicosatetraenoic acid (20-HETE) levels were quantified by HPLC-MS/MS in 106 patients with stable, angiographically-confirmed CAD. Relationships between biomarkers of CYP-mediated eicosanoid metabolism and vascular function phenotypes were evaluated by Pearson's correlation. RESULTS: A significant inverse association was observed between 20-HETE levels (a biomarker of CYP ω-hydroxylase metabolism) and brachial artery flow-mediated dilation (r = -0.255, p = 0.010). An inverse association was also observed between 14,15-EET:DHET ratios (a biomarker of sEH metabolism) and both monocyte chemoattractant protein-1 levels (r = -0.252, p = 0.009) and a consolidated cellular adhesion molecule 'score' reflecting the levels of E-selectin and P-selectin (r = -0.216, p = 0.027). No associations with C-reactive protein or epithelial neutrophil-activating protein-78 levels were observed. CONCLUSIONS: Collectively, these findings demonstrate that enhanced CYP ω-hydroxylase and sEH metabolic function are associated with more advanced endothelial dysfunction and vascular inflammation, respectively, in patients with established atherosclerotic cardiovascular disease. These findings lay the foundation for future clinical research in this area.