Aim: To evaluate the effect of statin therapy on the decrease of common carotid artery intima-media thickness (CCA-IMT) compared to placebo or usual care.
Methods: A systematic search of electronic databases (MEDLINE, EMBASE, and Cochrane Center Register) up to December 2011 was performed. Two reviewers independently determined the eligibility of randomized controlled trials (RCTs) comparing statin therapy with a placebo or usual care with a minimum follow-up of 6 months.
Results: Twenty-one RCTs involving 6317 individuals were included in this review. The pooled weighted mean difference (WMD) between statin therapy and placebo or usual care on CCA-IMT was −0.029 mm (95%CI: −0.045, −0.013). Subgroup analyses showed significant effects of lovastatin (WMD: −0.077; 95%CI: −0.082, −0.073) and simvastatin (WMD: −0.069; 95%CI: −0.094, −0.045), followed by pravastatin and rosuvastatin, but no significant benefits of atorvastatin, fluvastatin, or cerivastatin. A greater decrease in mean CCA-IMT was observed in the setting of secondary prevention versus primary prevention (WMD: −0.045 vs. −0.004), in younger patients versus older patients (WMD: −0.057 vs. −0.041), and in studies where the patient proportion was males ≥ females (−0.044 vs. −0.008). Meta-regression analysis showed a significant association between changes in mean CCA-IMT with decreasing triglyceride levels. A similar, but not statistically significant trend was also found between CCA-IMT decrease and the decrease in LDL-C levels or increase in HDL-C levels.
Conclusion: Statin therapy is associated with a favorable decrease in CCA-IMT, an effect that seems to be mainly driven by the CCA-IMT at baseline and the extent of lipid decrease, specifically triglycerides.