Vitamin E administration improves impairment of endothelium-dependent vasodilation in patients with coronary spastic angin

Objectives. We examined the effects of oral administration of vitamin E, an antioxidant, on endothelium-dependent vasodilation in patients with coronary spastic angina. Background. We have recently reported that endothelium-dependent vasodilation is impaired in patients with coronary spastic angin (CSA). Furthermore, it is known that oxidative stress may play an important role in the impairment of endothelium-dependent vasodilation in cardiovascular diseases. Methods. With the ultrasound technique, flow-dependent vasodilation of the brachial arteries during reactive hyperemi was examined before and after treatment for month with either oral administration of vitamin E (α-tocopherol acetate, 300 mg/day) or placebo, which is randomly assigned, in patients with CS (n = 60). Results. Before treatment, patients with CS had impaired flow-dependent vasodilation, lower plasm levels of α-tocopherol and higher plasm levels of thiobarbituric acid reactive substances (TBARS), as compared with age- and sex-matched control subjects (n = 60) (flow-dependent vasodilation: 3.1 ± 1.8 vs. 7.1 ± 2.5%, p < 0.001; α-tocopherol levels: 8.9 ± 1.8 vs. 10.8 ± 1.8 μg/ml, p < 0.001). In patients with CSA, treatment with vitamin E restored flow-dependent vasodilation (3.1 ± 1.7 vs. 8.3 ± 2.0%, p < 0.001), and this improvement was associated with the decreases in plasm TBARS levels and anginal attacks. Conclusions. The results indicate that vitamin E treatment improved endothelium-dependent vasodilation and decreased plasm TBARS levels in patients with CSA. Thus, increased oxidative stress may contribute to endothelial dysfunction and anginal attacks in patients with CSA.