Lipoprotein(a) as a determinant of the severity of angiographically defined carotid atherosclerosis.

We measured fasting serum lipids, lipoproteins, apolipoproteins and lipoprotein(a) [Lp(a)] in 49 Caucasian patients with transient ischaemic attacks undergoing carotid angiography. The severity of extracranial cerebrovascular disease was assessed visually by a highly reproducible grading system that focused on the internal carotid artery and carotid bifurcation. Compared with a healthy reference group, patients had significantly higher serum concentrations of: total cholesterol (mean +/- SD), 6.2 +/- 1.6 vs. 5.6 +/- 1.0 mmol/l, p = 0.02; apolipoprotein B, 1.4 +/- 0.5 vs. 1.2 +/- 0.3 g/l, p = 0.03; triglyceride [geometric mean(95% CI)], 2.02(1.75-2.32) vs. 1.66(0.67-4.06) mmol/l, p = 0.03; and Lp(a), 0.33(0.26-0.42) vs. 0.17(0.40-0.76) g/l, p < 0.001. Regression analysis showed that of the lipoprotein-related variables, only Lp(a) was significantly related to the severity of carotid artery disease (p = 0.04) in the patients; this association remained significant after adjusting for age, sex, blood pressure, and a history of stroke. Serum Lp(a) concentration was significantly higher in patients with carotid artery disease severity score above the median value of the sample population compared with those below the median: 0.45 vs. 0.24 g/l (95% CI for difference 0.35-0.88), p = 0.01. Elevated serum Lp(a) is a significant determinant of the extent of carotid atherosclerosis and may be useful in identifying patients most at risk of stroke.