Peripheral arterial disease in heterozygous familial hypercholesterolemia: no difference between patients with and without partial ileal bypass

Abstract

We evaluated lower limb arterial circulation in 37 patients with heterozygous familial hypercholesterolemia using strain-gauge plethysmography. Nineteen patients were initially allocated to surgical therapy (ileal bypass operation), and 18 control patients were treated conservatively. After a follow-up period of 3–12 years (mean 10 yrs) the surgically treated patients had significantly lower serum total (9.4 vs. 11.9 mmol/1, P < 0.001) and LDL (6.2 vs. 8.1 mmol/1, P < 0.01) cholesterol and apoprotein B levels and higher HDL cholesterol (1.2 vs. 1.0 mmol/1, P < 0.05) and apoprotein A-I levels compared with controls. There was no significant difference in the prevalence of intermittent claudication (16 vs. 6%) or coronary heart disease (68 vs. 61%) between the operated and control groups. The ankle-arm systolic blood pressure ratio was pathologically low in 53% of the operated and 72% of the control patients, and the toe-arm pressure ratio in 50% and 44%, respectively. These differences or the differences in the mean ankle-arm and toe-arm pressure ratios between the groups were not significant. The toe-ankle pressure gradient was normal in all but 2 patients indicating that atherosclerotic changes predominantly affect the more proximal arteries in familial hypercholesterolemia. Patients with peripheral arterial disease could not be differentiated by serum lipoprotein levels, blood pressure or the presence of coronary heart disease. However, smoking was more prevalent (38% vs. 0%, P < 0.05) in patients with impaired peripheral circulation. We conclude that asymptomatic peripheral arterial disease is quite common in familial hypercholesterolemia, and that smoking increases its risk. It seems to be a relatively stable disease, not easily affected by hypocholesterolemic treatment.