OXIDIZED LDL AND MALONDIALDEHYDE-MODIFIED LDL IN PATIENTS WITH ACUTE CORONARY SYNDROMES AND STABLE CORONARY-ARTERY DISEASE

Background - The association between oxidative modifications of LDL an d coronary artery disease (CAD) is suspected but not established. Ther efore, the association between plasma levels of oxidized LDL and malon dialdehyde (MDA)-modified LDL and acute coronary syndromes and stable CAD was investigated. Methods and Results - The study population conta ined 63 patients with acute coronary syndromes (45 with acute myocardi al infarction and 18 with unstable angina pectoris), 35 nontransplante d patients with angiographically confirmed stable angina, 28 heart tra nsplant patients with posttransplant CAD, 79 heart transplant patients without CAD, and 65 control subjects. After correction for age, sex, and LDL and HDL cholesterol, plasma levels of oxidized LDL and MDA-mod ified LDL were significantly higher in patients with CAD than in indiv iduals without CAD (r(2) = 0.57 and r(2) = 0.26, respectively; both P = 0.0001). Plasma levels of MDA-modified LDL were significantly higher in patients with acute coronary syndromes than in individuals with st able CAD (r(2) = 0.65; P = 0.0001) and were associated with increased levels of troponin I and C-reactive protein (r(2) = 0.39 and r(2) = 0. 34, respectively; both P = 0.0001), Plasma levels of oxidized LDL were not associated with increased levels of troponin I and C-reactive pro tein (r(2) = 0.089 and r(2) = 0.063, respectively). Conclusions - Elev ated plasma levels of oxidized LDL are associated with CAD. Elevated p lasma levels of MDA-modified LDL suggest plaque instability and may be useful for the identification of patients with acute coronary syndrom es.