Intima-media thickness after cholesterol lowering in familial hypercholesterolemia. A three-year ultrasound study of common carotid and femoral arteries.

Patients with familial hypercholesterolemia (FH) (n = 53) were examined with B-mode ultrasound before and after 3 years of cholesterol-lowering therapy with pravastatin, cholestyramine, or a combination. The aim was to measure the progression rate of intima-media thickening during follow-up in the common carotid and common femoral arteries. Since for ethical reasons it was not possible to perform a randomized placebo controlled study in patients with FH, we chose to recruit an untreated control group with lower risk, matched for sex, age, height and weight, and with serum cholesterol below 6.5 mmol/l. At baseline, intima-media thickness was larger in the hypercholesterolemic group than in the control group in both the common carotid and common femoral arteries. The difference between the change over 3 years observed in the control group and the change observed in the hypercholesterolemic group was calculated and defined as 'net difference'. There was a -32% net difference in low density lipoprotein (LDL) in the hypercholesterolemic group during follow-up. The ultrasound investigation showed a concomitant net difference of -0.06 mm in mean carotid intima-media thickness (95% confidence interval, -0.11 to -0.01 mm) and of -0.09 mm in maximum carotid intima-media thickness (P < 0.05, 95% confidence interval, -0.16 to -0.01 mm), with no net change in lumen diameter. No decrease was recorded in common femoral intima-medial thickness. Seventeen of the patients with FH had a positive history of myocardial infarction (MI) and this subgroup had a significantly larger decrease in mean carotid intima-media thickness during follow-up than the subgroup of patients with a negative history of MI (P < 0.01). In conclusion, the results showed a reduction in common carotid intima-media thickness after long-term cholesterol-lowering therapy in patients with FH. This finding may indicate a beneficial effect on atherosclerosis development in these patients.