Angioplasty increases coronary sinus F2-isoprostane formation: evidence for in vivo oxidative stress during PTCA.

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 F2alpha-III, isoprostane F2alpha-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 iPF2alpha-III and iPF2alpha-VI at baseline were (mean +/- SEM) 40 +/- 9 pg/ml and 115 +/- 10 pg/ml, respectively. The TxB2 levels were undetectable. Following PTCA, isoprostane levels markedly increased (mean +/- SEM): iPF2alpha-III, 125 +/- 12 pg/ml (p < 0.001); iPF2alpha-VI, 295 +/- 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.