Autoantibodies to oxidized low-density lipoprotein in patients with aortic regurgitation: association with aortic diameter size.

BACKGROUND Aortic regurgitation (AR) is a condition associated with volume overload, causing left-ventricular (LV) remodeling, eccentric LV hypertrophy and eventually heart failure. LV remodeling associated with AR is regulated by mechanical stress, neurohormonal activation, inflammation and oxidative stress. Since anti-oxidized low-density lipoprotein (LDL) antibodies (Abs) are a measurable marker of oxidative stress, we hypothesized that an increased level of circulating oxidized LDL (oxLDL) Abs may be related to remodeling of the left ventricle in patients with significant AR. METHODS We assessed IgG anti-oxLDL Abs in 31 patients with significant AR and compared them to 30 patients with similar risk factors and no valvular disease. Abs to oxLDL were determined by ELISA. RESULTS The 2 groups had similar clinical characteristics. There was no difference between patients with AR and patients with no AR in the level of anti-oxLDL Abs. However, in all patients and controls, anti-oxLDL Abs correlated positively with the diameter of the ascending aorta (AA; r = 0.32, p = 0.016) and the level of oxLDL Abs was significantly higher in patients with an AA diameter ≥39 mm. On multivariate analysis, only white blood cell count and AA diameter were related to anti-oxLDL Abs in all patients. CONCLUSIONS We did not find a difference in the level of anti-oxLDL Abs between patients with AR and controls; however, there was a strong correlation between anti-oxLDL Abs and AA diameter.