This is a 105-week clinical study in patients with heterozygous familial hypercholesterolemia on intensive Low Density Lipoprotein-cholesterol (LDL-C) lowering therapy intended to assess the affects of MK0524A on carotid intima media thickening using ultrasound compared to patients taking placebo. There will be 12 scheduled clinic visits involving review of medical history, physical exam, vital signs, laboratory testing, ultrasound imaging, and electrocardiograms.