The effect of statins on carotid plaque morphology: a LDL-associated action or one more pleiotropic effect of statins?

Introduction: The early identification of the unstable carotid plaque together with the best medical treatment, are two missing parts of the stroke-prevention puzzle. This review summarizes the available evidence on the effects of statins on carotid plaque morphology.

Methods: A systematic review of the PubMed, Scopus and Cochrane Library databases was performed. Studies evaluating the effect of statins on plaque imaging features other than intima media thickness as well as on the serum inflammatory profile were eligible for inclusion.

Results: Seventeen studies were eligible for inclusion. The majority of the studies used MRI and ultrasound imaging. Plaque composition (fibrous cap and lipid core size), and size (plaque area and volume) were mainly used to evaluate the changes in plaque morphology. All studies showed slower progression, remodelling or even regression of the plaque even after only 1 month of statin administration, although the type, dosage and duration of treatment varied significantly between them. Intensive statin treatment was suggested to have a more pronounced effect on plaque morphology, however, that was mainly associated with maintaining LDL-levels <100 mg/mL and not with the intensity of the dosage. Seven studies measured CRP, four of which found significantly decreased levels with statin use.

Conclusion: This review suggests that statins may have a beneficial effect on plaque morphology and the inflammatory response. Further validation of whether this is an LDL-associated effect or a separate pleiotropic phenomenon of statins is needed. There are significant inherent limitations to the safe extraction of solid conclusions from the studies due to data heterogeneity and publication bias.