Distinct lipoprotein contributions to valvular heart disease: Insights from genetic analysis

The per-particle pathogenicity of very-low-density lipoprotein (VLDL) and lipoprotein(a) [Lp(a)] with risk of valvular heart diseases (VHD) other than aortic stenosis compared with low-density lipoprotein (LDL) remains unclear.

Single-nucleotide polymorphism specific clusters associated with LDL cholesterol (LDL-C), VLDL cholesterol (VLDL-C) and Lp(a) were identified. The relationships of genetically predicted variation in apolipoprotein B (apoB) in these lipoproteins with risk of VHD and its major types (aortic stenosis, aortic regurgitation, and mitral regurgitation) were evaluated to determine the comparative pathogenicity by Mendelian randomization (MR) analyses.

The VHD odds ratio (OR) per 1 g/L higher apoB was 1.09 [95 % confidence interval (CI) 1.04-1.15] in LDL vs. 1.45 (95 % CI 1.25-1.69) in VLDL vs. 2.71 (95 % CI 1.92-3.82) in Lp(a) based on the cluster-based MR analyses. The polygenic scores for each lipoprotein weighted by apoB similarly showed a greater OR of VHD per 1 g/L apoB in VLDL [1.20 (95 % CI 1.06-1.37)] and in Lp(a) [2.54, (95 % CI 1.95-3.32)] compared with that in LDL [1.05 (95 % CI 1.01-1.08)]. Multivariable MR analyses further revealed the strong effects of VLDL-C and Lp(a) on VHD risk independent of LDL-C. In addition, significant associations between Lp(a) and all three major types of VHD were observed, while LDL and VLDL had no impact on aortic and mitral regurgitation.

VLDL and Lp(a) appear to have significantly greater per-particle pathogenicity in VHD compared to LDL. The distinct impacts of lipoproteins on different VHD subtypes suggest the inadequacy of just focusing on LDL-lowering treatment for valve disorders.