Oxidized low-density lipoprotein is localized in the ventricles of hearts from patients with coronary heart disease

The present study was designed to investigate whether oxidized low-density lipoprotein is accumulated in the left and right ventricular walls of patients with coronary heart disease (n=10) compared with patients with dilated cardiomyopathy (n=9) or healthy heart donors (controls, n=5). Sections from both ventricles of explanted hearts and coronary arteries of the same patients were analyzed by semiquantitative immunohistochemistry for the presence of oxidized low-density lipoprotein. Oxidized low-density lipoprotein was enriched in the left and right ventricular walls from coronary heart disease patients compared with patients with dilated cardiomyopathy (P=0.0012 for left ventricle and P=0.103 for right ventricle) or controls (P=0.0012 for the left ventride and P<0.05 for the right ventricle). The accumulation of oxidized low-density lipoprotein was higher in the left than in the right ventricles in all three groups. Positive immunoreactivity for oxidized low-density lipoprotein was mainly identified in the endocardium and the subendocardial areas of the ventricles and co-localized with macrophages. Accumulation of oxidized low-density lipoprotein in the ventricles significantly correlated with the enrichment in the respective coronary arteries, whereas only poor correlations were observed between various hemodynamic parameters and ventricular oxidized low-density lipoprotein accumulation. Ventricular accumulation of oxidized low-density lipoprotein seems to be a generalized pathophysiological process which does not exclusively involve the coronary arteries. Higher oxidative stress in combination with impaired oxygen supply in the endocardium could have favored low-density lipoprotein deposition and oxidation.