Background: Apheresis of low-density lipoprotein (LDL) is an effective lipid-lowering treatment in hypercholesterolemic patients who have coronary artery disease and are refractory to drugs. More aggressive lipid-lowering therapy may further slow the progression of atherosclerosis.
Objective: To compare the effect of LDL apheresis and simvastatin therapy with the effect of simvastatin therapy alone on the progression of peripheral vascular disease.
Design: Open, randomized, single-center study.
Setting: University hospital.
Patients: 42 men with primary hypercholesterolemia (total cholesterol level > 8.0 mmol/L) and extensive coronary atherosclerosis.
Intervention: Biweekly apheresis of LDL plus simvastatin, 40 mg/d (n = 21), or simvastatin, 40 mg/d (n = 21), for 2 years.
Measurements: Lipid and lipoprotein levels, changes in hemodynamically significant stenoses in the aortotibial tract (measured by ankle:arm systolic blood pressure ratio combined with Doppler spectrum analysis of the femoral artery), and changes in the mean intima-media thickness of three carotid artery segments.
Results: Mean baseline LDL cholesterol levels decreased from 7.8 to 3.0 mmol/L in the apheresis and simvastatin group and from 7.9 to 4.1 mmol/L in the simvastatin-only group; mean lipoprotein(a) levels decreased from 57.0 to 44.5 mg/dL (change, −19%)in the former group and increased from 38.4 to 44.5 mg/dL (change, 15%) in the latter group. In the apheresis group, the number of patients with hemodynamically significant stenoses in the aortotibial tract decreased from 9 to 7; in the simvastatin-only group, the number increased from 6 to 13 (P = 0.002). Mean intima-media thickness decreased by a mean ±SD of 0.05 ± 0.34 mm in the apheresis group and increased by 0.06 ± 0.38 mm in the simvastatin-only group (P < 0.001). According to multiple regression analysis, changes in apolipoprotein B, total cholesterol, and lipoprotein(a) levels accounted for changes in the aortotibial tract (R2 = 0.36); changes in lipoprotein(a) and apolipoprotein A1 levels accounted for changes in the intima-media thickness of the carotid artery (R2 = 0.49).
Conclusions: Aggressive lipid lowering with simvastatin and LDL apheresis decreased the intima-media thickness of the carotid artery and prevented an increase in the number of hemodynamically significant stenoses in the lower limbs. Therapy with simvastatin alone did not prevent progression of carotid or aortotibial vascular disease.