PURPOSE: Statins reduce cardiovascular events by more than can be explained by 
their effects on lipids. We conducted a systematic review of how statins affect 
vascular structure and function, differences among statins, and correlations 
between the effects of statins on vascular outcomes and either lipid levels or 
cardiovascular outcomes.
METHODS: We primarily searched MEDLINE (1980 to March 2004) to identify all 
studies with at least 10 subjects that reported the effects of currently 
available statins on coronary artery stenosis, carotid intima-media thickness, 
and endothelial function (excluding studies of drug combinations and subjects 
with organ transplants). Meta-analyses were performed when feasible.
RESULTS: Statins decrease the progression and increase the regression of 
coronary artery lesions and luminal narrowing. Compared with placebo, statins 
decrease the likelihood of coronary artery restenosis (summary risk ratio = 
0.85; 95% confidence interval: 0.77 to 0.95). Statins appear to slow the 
progression of carotid artery intima-media thickness. Although the effect of 
statins on coronary endothelial function is uncertain, statins appear to improve 
peripheral endothelial function. There is no conclusive evidence to suggest that 
individual statins differ in their effects on these outcomes. Studies generally 
found weak or no correlation between the effects of statins on vascular outcomes 
and lipid levels. No study showed a correlation between vascular effect and 
clinical outcome.
CONCLUSION: Statins slow the progression of, and may reverse, atherosclerosis. 
The magnitude of these effects, however, is small compared with the effects of 
statins on cardiovascular events. Statins also improve measures of vascular 
function, which may contribute to their clinical benefits. There is insufficient 
evidence to suggest that individual statins differ in their vascular effects.