Question: Is indicated the use of antioxidant supplements in patients at risk for coronary artery disease?

Context:
We and others have published observational epidemiologic studies in support of vitamins in the primary prevention of CVD, but the results from intervention studies are mixed.
For vitamin E, observational data suggest benefit at doses of 100 to 400 IU/d. Results from recent large-scale trials are mixed, with some showing modest benefit but others suggesting no benefit, especially for secondary prevention. Results for B vitamins are also mixed and further complicated by the recent folate fortification of the flour supply. If greater B vitamin intake does reduce CVD, the benefits are likely to be greatest for primary prevention and in populations with intake below dietary reference standards. 
In the dose-response meta-analysis, each 30 mg/day increase in vitamin C, 30 IU/day increase in vitamin E, and 1 mg/day increase in beta-carotene yielded the estimated overall relative risk for CHD of 1.01 (95% CI, 0.99-1.02), 0.96 (95% CI, 0.94-0.99), and 1.00 (95% CI, 0.88-1.14), respectively. CONCLUSIONS: Our findings in this meta-analysis suggest that an increase in dietary intake of antioxidant vitamins has encouraging prospects for possible CHD prevention.
High levels of α-tocopherol in serum were associated with 30% lower CAD risk in another study (HR 0.71; 95%CI 0.53-0.94). Among minerals (zinc, selenium, and chromium), an inverse association between zinc and CAD was observed; levels lower than 14.1 µmol/L were associated with an increased risk for CAD (RR 1.70; 95%CI 1.21-2.38).
The information available on this issue is scarce. Further prospective studies are needed to elucidate the role of these nutrients in the cardiovascular risk of patients with diabetes.
Coenzyme Q10 supplementation at a dosage of 150 mg appears to decrease the inflammatory marker IL-6 in patients with CAD.
 Coenzyme Q10 supplements at a dose of 150 mg can decrease oxidative stress and increase antioxidant enzyme activity in patients with CAD. A higher dose of coenzyme Q10 supplements (>150 mg/d) might promote rapid and sustainable antioxidation in patients with CAD.
Alpha-tocopherol or beta-carotene supplementation has no protective effect on macrovascular outcomes or total mortality of diabetic male smokers.
Sodium selenite supplementation increases GPx-1 activity in endothelial cells and in CAD patients. Future studies have to demonstrate whether long-term CAD outcome can be improved.
After 7.3 years of treatment and follow-up, a combination pill of folic acid, vitamin B6, and vitamin B12 did not reduce a combined end point of total cardiovascular events among high-risk women, despite significant homocysteine lowering.
 In this population-based study, vitamin E use was unrelated to mortality, but this apparently null finding seems to represent a combination of increased mortality in those with severe cardiovascular disease and a possible protective effect in those without.
 In this large cohort of apparently healthy US male physicians, self-selected supplementation with vitamin E, vitamin C, or multivitamins was not associated with a significant decrease in total CVD or CHD mortality. 
The American Heart Association has recommended consumption of a balanced diet with emphasis on antioxidant-rich fruits and vegetables but has made no recommendations regarding vitamin E supplementation for the general population. Although vitamin E supplementation seems to be safe for most people, recommendations from health care professionals should reflect the uncertainty of established benefit as demonstrated in clinical trials
Recent studies show that supplementation with antioxidant vitamins E and C have benefits in CHD prevention; however, supplementation with beta-carotene may have deleterious effects and is not recommended. Current evidence suggests that patients with CHD would probably benefit from taking vitamin E in a dosage of 400 IU per day and vitamin C in a dosage of 500 to 1,000 mg per day. Clinicians may also want to consider vitamin supplementation for CHD prevention in high-risk patients. Folate lowers elevated homocysteine levels, but evidence for routine supplemental use does not yet exist. 
In patients at high risk for cardiovascular events, treatment with vitamin E for a mean of 4.5 years had no apparent effect on cardiovascular outcomes.

Answer: antioxidant supplementation 
However there are no clear evidencies on the clinical and prognostic benefit of this supplementation. 
Currently there areno recommendation for the antioxidant therapy in patients with coronary artery disease.
Currently the American Heart Association recommends consumption of a balanced diet with emphasis on antioxidant-rich fruits and vegetables but does not recommend antioxidant supplementation for the general population.
Exact answer: no