Antibodies to malondialdehyde oxidized low-density lipoproteins predict long term cardiovascular mortality in high risk patients.

AIMS. Antibodies to oxidized low-density lipoproteins (oxLDLAbs) are detectable in the serum of patients with and without atherosclerosis, but it is unclear if they play a pathogenic or a protective role in atherogenesis or if they are simply a marker of atherosclerosis. Therefore, in a prospective cohort study we investigated if oxLDLAbs titer predicts cardiovascular (CV) events in high-risk coronary artery disease patients. METHODS AND RESULTS: The titer of IgG antibodies to malondialdehyde modified oxidized low-density lipoproteins was measured in 748 randomly selected patients of the GENICA study who underwent coronary angiography and assessment of incident CV events at follow-up. Patients were classified by oxLDLAbs into a low and a high titer group, corresponding to the first three and the last quartile, respectively. Cardiovascular event-free survival was compared between oxLDLAbs groups by Kaplan-Meier and multivariate technique including propensity score matching analysis. During long-term follow-up (median 7.2years) CV deaths were observed in 65 patients (11.6%), more commonly in the high than in the low oxLDLAbs group (patients free from CV death 83.1% vs. 89% respectively, p=0.025). The incidence of CV events was also higher in the former than in latter (event-free survival 69.2% vs. 77.7% respectively, p=0.030). CONCLUSIONS: An oxLDLAbs titer above the 75th percentile is a marker of LDL oxidation which predicts a worse CV prognosis at long term follow-up in high-risk Caucasian patients referred for coronary angiography.