Consumption of vitamin E in coronary circulation in patients with variant angina

Objectives: The plasma status of vitamin E has been suggested to be linked to the activity of coronary artery spasm. This study was designed to determ ine whether vitamin E is actually consumed in the coronary circulation in p atients with active variant angina having repetitive spasm-induced transien t myocardial ischemia and reperfusion. Methods: Blood samples were obtained simultaneously from the aortic root, coronary sinus and right atrium in 12 patients with variant angina due to spasm of the left coronary artery, nin e patients with stable effort angina and nine control subjects. Plasma vita min E (alpha- and gamma-tocopherol) concentrations were determined by use o f high-performance liquid chromatography and plasma lipid peroxides were me asured as thiobarbituric acid-reactive substances (TBARS). Results: At base line, both plasma alpha- (p<0.01) and gamma- (p<0.05) tocopherol levels wer e significantly lower in the coronary sinus (5.50+/-0.50 and 0.55+/-0.07 mg /l, mean+/-SEM) than in the aortic root (6.63+/-0.57 and 0.63+/-0.08 mg/l) and also in the right atrium (6.44+/-0.61 and 0.63+/-0.09 mg/l) in the vari ant angina group. The TEARS level was significantly (p<0.05) higher in the coronary sinus than in the aortic root in this group. In contrast, these le vels were not significantly different between the samples from the coronary sinus and the aortic root or the right atrium in the control group and als o in the stable effort angina group. The coronary sinus-aortic difference i n plasma vitamin E levels in the variant angina group was not significantly altered after left coronary artery spasm induced by intracoronary injectio n of acetylcholine. Also, the plasma vitamin E levels in the aortic root, c oronary sinus and right atrium all remained unchanged in the stable effort angina group after pacing-induced angina and in the control group after int racoronary administration of acetylcholine. Conclusions: Transcardiac reduc tion in plasma vitamin E concentrations concomitant with lipid peroxide for mation was demonstrated in patients with active variant angina, suggesting actual consumption of this major endogenous antioxidant. Oxidative stress a nd vitamin E exhaustion may be involved in the pathogenesis of coronary art ery spasm. (C) 1999 Elsevier Science B.V. All rights reserved.