Anti-Malondialdehyde Low-Density Lipoprotein Antibodies and Valvular Calcification: A Substudy of the SCOT-HEART Trial.

BACKGROUND: Coronary computed tomography-derived valve calcification is becoming increasingly important in the multi-modality assessment of valvular disease, especially in aortic and mitral valve disease. Separately, natural antibodies targeted against malondialdehyde-modified low-density lipoprotein (MDA-LDL), an important subset of all oxidized LDLs, are related to fewer atherosclerosis and cardiovascular events. This study sought to investigate the association between the prevalence of aortic and mitral valve calcification with IgG and IgM anti-MDA-LDL antibodies. METHODS: In a substudy of the multicenter randomized controlled SCOT-HEART trial (Scottish computed tomography of the heart), blood biomarkers were measured using laboratory-developed enzyme-linked immunosorbent assays and assessed in tertiles, with adjustment for the ASSIGN cardiovascular risk score. RESULTS: In 830 patients (53% male, 57.6±9.8 years) with a heavy burden of cardiovascular risk factors, the highest tertile of IgM anti-MDA-LDL was associated with a lower prevalence of aortic valve calcification (odds ratio, 0.59 [95% CI, 0.36-0.96], P=0.04) and mitral valve calcification (odds ratio, 0.26 [95% CI, 0.07-0.72], P=0.02). The highest tertile of IgG anti-MDA-LDL was associated with a lower prevalence of mitral valve calcification (odds ratio, 0.36 [95% CI, 0.10-0.99], P=0.05), but not aortic calcification. CONCLUSIONS: Anti-MDA-LDL antibody levels were associated with a lower prevalence of aortic and mitral valve calcification. Assessment of these novel biomarkers may be useful in screening patients for valve calcification, as well as providing novel insights into potential pathological relationships.