Statins in stroke prevention and carotid atherosclerosis: systematic review and up-to-date meta-analysis

Area of Science:

• Cardiovascular Medicine
• Pharmacology
• Epidemiology

Background:

• Previous meta-analyses on statins and stroke involved ~20,000 patients, showing a 2-30% risk reduction.
• The precise contribution of low-density lipoprotein-cholesterol (LDL-C) reduction to statin efficacy in stroke prevention remained unclear.
• Recent statin trials encompass over 90,000 participants, necessitating an updated analysis.

Purpose of the Study:

• To determine the effect of statins on stroke prevention.
• To elucidate the relationship between LDL-C reduction and stroke risk reduction.
• To analyze the impact of statins on carotid intima-media thickness (IMT) progression.

Main Methods:

• Systematic review and meta-analysis of randomized statin trials published before August 2003.
• Trials identified via PubMed search.
• Analysis stratified by LDL-C reduction to assess impact on stroke incidence and IMT.

Main Results:

• A 21% relative risk reduction for all strokes was observed (OR, 0.79 [0.73-0.85]) with no heterogeneity.
• Fatal strokes showed a non-significant 9% reduction (OR, 0.91 [0.76-1.10]).
• No increase in hemorrhagic strokes (OR, 0.90 [0.65-1.22]). Each 10% LDL-C reduction correlated with a 15.6% stroke risk reduction and 0.73% annual IMT reduction.

Conclusions:

• Statins effectively reduce all stroke incidence without increasing hemorrhagic stroke risk.
• The primary driver of statin-induced stroke risk reduction is the degree of LDL-C lowering.
• Carotid IMT progression is strongly associated with LDL-C reduction, suggesting a mechanistic link.