RELATION OF PLASMA-LIPID AND APOPROTEIN LEVELS TO PROGRESSIVE INTIMAL HYPERPLASIA AFTER ARTERIAL ENDARTERECTOMY

Background. To examine the relation of plasma lipoproteins to the proliferative response after arterial injury in humans, we examined the plasma lipid, lipoprotein, and apoprotein levels of 20 patients with early recurrent stenosis caused by intimal hyperplasia after carotid endarterectomy. These were compared with 20 controls who had no evidence of recurrent stenosis by duplex ultrasound scanning. Methods and Results. By univariate analysis, the reoperated patients had higher levels of plasma cholesterol (251 versus 225 mg/dl, p < 0.05), total triglycerides (173 versus 105 mg/dl, p < 0.03), and low density lipoprotein (LDL) apoprotein B (99.8 versus 77.2 mg/dl, p < 0.003). The ratio of cholesterol to apoprotein B in LDL was lower in patients with restenosis (p < 0.04), suggesting LDL of smaller diameter. High density lipoprotein (HDL) cholesterol level was reduced (45 versus 55 mg/dl, p < 0.01) in patients with restenosis. With statistical adjustment for the correlations between these variables by multivariate analysis, both LDL apoprotein B and HDL cholesterol were independent predictors of the risk of restenosis. Ten patients with restenosis but only two controls had one or two apolipoprotein E4 alleles. Conclusions. Elevated lipid levels usually associated with an increased risk of atherosclerosis may predispose patients to an increased incidence of intimal hyperplasia after endarterectomy.