Increased levels of the oxidative stress marker, nitrotyrosine in patients with provocation test-induced coronary vasospasm

Abstract Background Endothelial dysfunction of the coronary arteries caused by oxidative stress plays an important role in the pathogenesis of coronary vasospasm. However, it is not clear whether circulating biomarkers for oxidative stress are altered after coronary vasospasm. We investigated temporal changes in the levels of oxidative stress biomarkers after coronary vasospasm induced by intracoronary acetylcholine provocation testing, resulting in transient myocardial ischemia. Methods and results Thirty consecutive patients with suspected vasospastic angina pectoris (VSAP) were enrolled in the study. Patients were categorized into the VSAP-positive group ( n  = 14) and the VSAP-negative group ( n  = 16) on the basis of test results. Serum samples were examined for the levels of the oxidative stress markers 4-hydroxynonenal (HNE) and nitrotyrosine (NT) before, and 15 min, 3 h, and 12 h after the provocation test. The serum HNE levels did not change in either group after the test. The serum NT levels in the VSAP-positive group significantly increased at 3 h and 12 h after the test (11.3 ± 3.3 μg/ml at 3 h, p  = 0.015, and 12.1 ± 5.7 μg/ml at 12 h, p  = 0.03), as compared with baseline (8.1 ± 3.2 μg/ml). In the VSAP-negative group, the serum NT levels significantly decreased from baseline at each of the 3 time points. Conclusions Serum NT significantly increased after coronary vasospasm induced by acetylcholine provocation, suggesting that serum NT could be a biomarker of transient myocardial ischemia and could contribute to the development of VSAP.