Increased isoprostane content in coronary plaques obtained from vulnerable patients

8-Iso-prostaglandin F2α (8-iso-PGF2α), a representative isoprostane, is a reliable biomarker for enhanced oxidant stress in vivo. Its urinary excretion has been proposed as a risk marker in patients with coronary heart disease. Isoprostane content has not yet been well elucidated so far in human coronary plaques. The aim of this study was to evaluate content of immunoreactive 8-iso-PGF2α in directional coronary atherectomy (DCA) specimens from patients with coronary heart diseases. Twenty-seven patients with stable angina pectoris (SAP) and 8 vulnerable patients (5 patients with unstable angina pectoris and 3 with recent myocardial infarction) were subjected to DCA. The specimens from SAP consisted of 14 de novo and 13 restenotic lesions, whereas those from the vulnerable patients were all de novo lesions. Total 8-iso-PGF2α content in the DCA specimens from the vulnerable patients was significantly greater than that from patients with SAP (5.48 (2.70–10.43) versus 2.38 (1.19–4.32) ng/g tissue, median (interquartile range), P<0.05). There was no significant difference in total 8-iso-PGF2α content between de novo and restenotic lesions from patients with SAP (3.25 (1.48–5.05) versus 1.57 (0.62–2.47) ng/g tissue, respectively, P=0.895). Total 8-iso-PGF2α content in apparently normal peripheral artery specimens was only 0.34 (0.26–0.46) ng/g tissue. In conclusion, 8-iso-PGF2α was enriched in the DCA specimens from vulnerable patients, suggesting a crucial role of free radicals in formation of vulnerable plaques and a putative benefit of anti-oxidant therapy on these patients.