Characterization of Polyvascular Disease in Heterozygous Familial Hypercholesterolemia: Its Association With Circulating Lipoprotein(a) Levels

Abstract

BACKGROUND: Heterozygous familial hypercholesterolemia (HeFH) more likely exhibits extensive atherosclerotic disease at multiple vascular beds. Lipoprotein(a) (Lp(a)) is an atherogenic lipoprotein that elevates HeFH-related atherosclerotic cardiovascular disease risks. Whether circulating Lp(a) level associates with polyvascular propagation of atherosclerosis in subjects with HeFH remains uncertain. METHODS AND RESULTS: The current study analyzed 370 subjects with clinically diagnosed HeFH who received evaluation of systemic arteries. Polyvascular disease (polyVD) was defined as more than 2 coexisting atherosclerosis conditions including coronary artery disease, carotid stenosis, or peripheral artery disease. Clinical characteristics and lipid features were analyzed in subjects with HeFH and polyVD; 5.7% of patients with HeFH (21/370) had polyVD. They were more likely to have a clustering of risk factors, tendon (P<0.001) and skin xanthomas (P=0.004), and corneal arcus (P=0.026). Furthermore, an elevated Lp(a) level (P=0.006) and a greater frequency of Lp(a) level ≥50 mg/dL (P<0.001) were observed in subjects with HeFH and polyVD. On multivariable analysis adjusting risk factors and lipid-lowering agents, Lp(a) ≥50 mg/dL (odds ratio [OR], 5.66 [95% CI, 1.68– 19.0], P=0.005), age, and family history of premature coronary artery disease independently predicted polyVD in subjects with HeFH. Of note, the prevalence of polyVD rose to 33.3% in patients with HeFH and age >58 years old, family history of premature coronary artery disease, and Lp(a) ≥50 mg/dL (OR, 10.3 [95% CI, 3.12– 33.4], P<0.001). CONCLUSIONS: An increased level of circulating Lp(a) levels predicted concomitance of polyVD in patients with HeFH. The current findings suggest subjects with HeFH and Lp(a) ≥50 mg/dL as a high-risk category who require meticulous screening of systemic vascular beds.