Intervention Studies in Humans-Secondary Prevention
Hodis and coworkers have shown a reduction in CHD progression (as measured angiographically) in men given 100 IU vitamin E daily, although no benefit was found for vitamin C. Singh and colleagues found that a combi-nation of vitamins A, C, E, and l3-carotene administered within a few hours after acute MI and continued for 28 d led to significantly fewer cardiac events and a lower prevalence of angina pectoris in the supplemented group. The Cambridge Heart Antioxidant Study (CHAOS), a trial of vitamin E supplementation on 2002 patients with angiographic evidence of coronary disease, was carried out with a mean treatment duration of 1.4 yr. This short-term supplementation with a-toco-pherol (268 or 537 mg/d) reduced CHD morbidity in patients (77% decreased risk of subsequent nonfatal MI). No benefit was found, however, in terms of cardiovascular mortality, with a nonsignificant excess among vitamin E-allocated participants.
The recently published GISSI-P trial investigated the independent and combined effec~ of n-3 PUFA and vitamin E on morbidity and mortality after MI. Although n-3 PUFA reduce the primary combined endpoint of death, nonfatal MI, and stroke, vitamin E had no benefit When each supplement was compared with no treatment in a four-way analysis, however. there was a nonsignificant reduction of 11 % in events by vitamin E (the study was designe' so that only a reduction of 20% in events would be statistically significant).
