Vitamin intervention for stroke prevention (VISP) trial: Rationale and design

Elevated plasma levels of homocyst(e)ine [H(e)] are surprisingly common and strongly associated with endothelial dysfunction and a marked increase in vascular risk. Treatment with a combination of folic acid, pyridoxine (vita min B-6) and cobalamin (vitamin B-12) reduces plasma H(e) levels in most ca ses, restores endothelial function, and regresses carotid plaque, but there is no evidence that such treatment will reduce clinical events. The Vitami n Intervention for Stroke Prevention (VISP) study is a double-masked, rando mized, multicenter clinical trial designed to determine if, in addition to best medical/surgical management, high-dose folic acid, vitamin Bg, and Vit amin B12 supplements will reduce recurrent stroke compared to lower doses o f these vitamins. Patients at least 35 years old with a nondisabling ischem ic stroke within 120 days, and screening plasma H(e) > the 25th percentile of benchmark population data are eligible. Secondary endpoints are myocardi al infarction or fatal coronary heart disease. This paper describes the des ign and rationale of the study. Copyright (C) 2001 S. Karger AG, Basel.