Efficacy and safety of long-term ezetimibe/simvastatin treatment in patients with familial hypercholesterolemia

Abstract

Aim. Patients with heterozygous familial hypercholesterolemia (FH) have an increased risk of premature myocardial infarction, stroke, and surgical revascularization, and an increased rate of progression of carotid intima-media thickness (IMT). The most commonly used drugs for cholesterol lowering, statins, have a limited action in these patients. Ezetimibe, a novel compound, selectively inhibits cholesterol uptake and when associated with statins has an additional low-density lipoprotein cholesterol (LDL-C) reducing effect. The aim of this study is to evaluate the effects of long-term combined Ezetimibe/Simvastatin (EZE/SIMVA) therapy (30 months) on the lipidic pattern, inflammatory markers, and carotid IMT in patients with FH subdivided into two groups: one with a history of acute myocardial infarction (IMA) and the other with carotid atherosclerotic plaques but no history of cardiovascular events. Methods. All patients enrolled in this study (group A: patients with a history of IMA; group B, patients with carotid lesions but no history of cardiovascular events) were submitted to a 6-week period of isocaloric diet and to a 4-week lipid-lowering wash-out period before study entry. After the wash-out period at baseline (time 0) and then every two months total cholesterol, triglycerides, highdensity lipoprotein cholesterol (HDL-C), and apolipoprotein B and A1 were determined. LDL-C levels were calculated. Fibrinogen and hs-CRP at baseline and at 6, 18, and 30 months were determined. All patients were submitted to an ultrasonographic evaluation of the carotid intimamedia thickness at baseline, 18 and 30 months. The scheduled duration time of the study was 30 months. At the beginning of the study all patients were assigned to receive the combined EZE/SIMVA treatment 10/20 mg per day. After two months, patients who had not reached the respective LDL-C targets proposed by NCEP ATPIII (<70 mg/dL for patients with a history of IMA and <100 mg/dL for patients with carotid lesions) were assigned to receive EZE/SIMVA 10/40 mg per day and, after four months, patients who had not reached the respective LDL-C targets were assigned to receive EZE/SIMVA 10/80 mg per day. Results. At the end-point, significant reductions (P<0.001) of about 70% in LDL-C, of 57% in total cholesterol (TC), of 46% in Apo-B, and of 46% in hs-C-reactive protein (hs-CRP) were observed in both groups compared to baseline. Also, triglyceride and fibrinogen levels were significantly (P<0.01) reduced, respectively by 26% and 15% compared to baseline. The EZE/SIMVA association resulted in significant increases in HDL-C (P<0.01) of 11% and in Apo-A1 (P<0.05) by 9% and in significant (P<0.001) reductions of the mean of the carotid IMT in both groups. The EZE/SIMVA treatment was generally well-tolerated, with a safety profile on laboratory parameters. During the 30-month scheduled period of the study, no patient in either group presented any further cardiovascular events. Conclusion. In patients with FH, combined EZE/SIMVA treatment resulted in a significant LDL-C lowering, achieving the goals proposed by NCEP ATP HI, in a significant improvement of all the lipidic and inflammatory patterns, and above all in a progressive decrease of the carotid IMT. Although the results of ongoing randomized controlled trials are required before making any definitive conclusions, our results support the hypothesis of stabilizing effect of EZE/SIMVA on the atherosclerotic disease both in primary and in secondary prevention.