Circulating osteoglycin and NGAL/MMP9 complex concentrations predict 1-year major adverse cardiovascular events after coronary angiography.

Previous proteomics experiments have demonstrated that several proteins are differentially expressed in vulnerable human carotid plaques compared with stable plaques. This study aims to investigate the prognostic value of 13 such circulating biomarkers in patients with coronary artery disease. Between 2008 and 2011, 768 patients who underwent coronary angiography for acute coronary syndrome or stable angina pectoris were included in a prospective biomarker study. Plasma concentrations of 13 biomarkers were measured in 88 patients who experienced a major adverse cardiovascular event (MACE) within 1 year and 176 control patients without MACE who were matched on age, sex, and number of diseased coronary vessels. MACE comprised all-cause mortality, acute coronary syndrome, unplanned coronary revascularization, and stroke. After adjustment for established cardiovascular risk factors, osteoglycin (OGN; odds ratio per SD increase in ln-transformed OGN, 1.53; 95% confidence interval, 1.11-2.11; P=0.010) and neutrophil gelatinase-associated lipocalin/matrix metalloproteinase 9 (NGAL/MMP9; odds ratio per SD increase in ln-transformed NGAL/MMP9, 1.37; 95% confidence interval, 1.01-1.85; P=0.042) complex were independently associated with MACE during follow-up. These associations were independent of C-reactive protein levels. Adding OGN or NGAL/MMP9 to a model containing conventional risk factors did not significantly improve discriminatory power (OGN: area under receiver operating characteristic curve, 0.75 versus 0.67; NGAL/MMP9: 0.73 versus 0.67) but did significantly improve risk reclassification (OGN: net reclassification index=0.29; 95% confidence interval, 0.05-0.53; P<0.019; NGAL/MMP9: net reclassification index=0.44; 95% confidence interval, 0.20-0.69; P<0.001). Circulating OGN and NGAL/MMP9 complex are promising biomarkers that are expressed in vulnerable atherosclerotic plaques and may have incremental value for prediction of MACE within 1 year after coronary angiography.