Vasomotor effects and pathophysiologic relevance of F-2-isoprostane formation in vascular diseases

OBJECTIVES Isoprostanes, stable end-products of oxygen free radical mediated–lipid peroxidation, were measured in the coronary vessels during percutaneous transluminal coronary angioplasty (PTCA) to provide direct evidence for enhanced oxidative stress in a local milieu in vivo. BACKGROUND Percutaneous transluminal coronary angioplasty is associated with complications such as myocardial stunning and accelerated restenosis, which at least in part are mediated by oxygen free radicals. Because isoprostanes are markers of oxidant stress and potent vasoactive compounds, the formation of which is not inhibited by aspirin treatment in vivo, it is possible that these mediators are increased locally during PTCA. METHODS In 12 coronary artery disease patients who were given aspirin and ticlopidine, blood samples from coronary sinus were taken immediately before and immediately upon balloon deflation during PTCA. Isoprostane F2a-III, isoprostane F2a-VI, and TxB2 were quantified after extraction and chromatography using a stable dilution isotope gas chromatography/mass spectrometry assay. RESULTS Coronary sinus and left main coronary artery levels of iPF2a-III and iPF2a-VI at baseline were (mean 6 SEM) 40 6 9 pg/ml and 115 6 10 pg/ml, respectively. The TxB2 levels were undetectable. Following PTCA, isoprostane levels markedly increased (mean 6 SEM): iPF2a-III, 125 6 12 pg/ml (p , 0.001); iPF2a-VI, 295 6 20 pg/ml (p , 0.001), whereas TxB2 levels remained undetectable. CONCLUSIONS These results indicate that PTCA induces coronary sinus increase in F2-isoprostane formation, and they also provide direct evidence for enhanced oxidative stress in a local milieu in vivo. Thus, an increased F2-isoprostane formation could play a role in the pathogenesis of some PTCA-associated untoward events. (J Am Coll Cardiol 2001;37:76–80) © 2001 by the American College of Cardiology