Antioxidants and atherosclerotic cardiovascular disease: unresolved issues

Does Ginkgo biloba reduce the risk of cardiovascular events?

BACKGROUND

Cardiovascular disease (CVD) was a preplanned secondary outcome of the Ginkgo Evaluation of Memory Study. The trial previously reported that Ginkgo biloba had no effect on the primary outcome, incident dementia.

METHODS AND RESULTS

The double-blind trial randomly assigned 3069 participants over 75 years of age to 120 mg of G biloba EGb 761 twice daily or placebo. Mean follow-up was 6.1 years. The identification and classification of CVD was based on methods used in the Cardiovascular Health Study. Differences in time to event between G biloba and placebo were evaluated using Cox proportional hazards regression adjusted for age and sex. There were 355 deaths in the study, 87 due to coronary heart disease with no differences between G biloba and placebo. There were no differences in incident myocardial infarction (n=164), angina pectoris (n=207), or stroke (151) between G biloba and placebo. There were 24 hemorrhagic strokes, 16 on G biloba and 8 on placebo (not significant). There were only 35 peripheral vascular disease events, 12 (0.8%) on G biloba and 23 (1.5%) on placebo (P=0.04, exact test). Most of the peripheral vascular disease cases had either vascular surgery or amputation.

CONCLUSIONS

There was no evidence that G biloba reduced total or CVD mortality or CVD events. There were more peripheral vascular disease events in the placebo arm. G biloba cannot be recommended for preventing CVD. Further clinical trials of peripheral vascular disease outcomes might be indicated.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00010803.

Classification of systemic therapies for potential stabilization of the vulnerable plaque to prevent acute myocardial infarction

In this editorial, a classification of systemic therapies for potential plaque stabilization of vulnerable plaque to prevent acute myocardial infarction is proposed based on both biologic plausibility (a potential mechanism to explain the effect) and clinical evidence (i.e., whether the agent reduced acute myocardial infarction in well-designed clinical trials). All therapies possess biologic plausibility but are classified into groups I to IV based on clinical data.

Nutrient involvement in preeclampsia

Preeclampsia is a pregnancy-specific condition that increases maternal and infant mortality and morbidity. It is diagnosed by new-onset increased blood pressure and proteinuria during gestation; for many years these markers were the sole targets for study. More recently, increased attention to the multisystemic nature of the syndrome with involvement of almost all organs, activation of coagulation and increased sensitivity to pressor agents has expanded understanding of the disorder. The epidemiology of preeclampsia, being more common in poor women, long ago suggested that nutrients might be involved in the disorder. Numerous conflicting hypotheses were advanced but the testing of these hypotheses has either been done poorly or not at all. Review of the available data indicates very few studies that provide useful insights. In many studies the syndrome is poorly defined and in most studies nutritional data (questionnaires or biomarkers) are obtained on women with the clinical syndrome. In overtly preeclamptic women it is impossible to decipher cause from effect. Nonetheless, current concepts of the genesis of preeclampsia that include endothelial dysfunction, inflammatory activation, oxidative stress and predisposing maternal factors provide targets for well-designed nutritional investigation. In this review the current concepts of the pathogenesis of preeclampsia are reviewed and available data are assessed in light of these concepts. Targets for nutritional investigation based on the current knowledge of pathophysiology are suggested.