Level 3: Lacking direct evidence
The Effect of Combination Ezetimibe and High-Dose Simvastatin vs. Simvastatin Alone on the Atherosclerotic Process in Patients with Heterozygous Familial Hypercholesterolemia (ENHANCE) randomized trial evaluated the effect of ezetimibe 10 mg plus simvastatin 80 mg (Vytorin) on arterial plaque growth (Merck/Schering-Plough Manufacturer Press Release. 2008; January 14; full-text available online without charge at: www.sch-plough.com/schering_plough/news/release.jsp?releaseID=1095943. Accessed February 4, 2008). A total of 720 patients were randomized to Vytorin vs. simvastatin (Zocor) 80 mg alone for two years.
Carotid intima-media thickness was measured by ultrasound. At baseline, the mean carotid intima-media thickness was 0.68 mm with Vytorin vs. 0.69 mm with simvastatin. After two years, there was no significant difference in the mean change in carotid intima-media thickness (+0.0111 mm with Vytorin vs. +0.0058 mm with simvastatin). This suggests that ezetimibe may not have a clinical benefit despite a reduction in LDL levels.