Abstract 9069: Matrix Metalloproteinase-9 (MMP-9), Myeloperoxidase (MPO), And Soluble Cd40 Ligand (sCD40L) Levels in Patients with Non-calcified Coronary Artery Plaques Without Significant Stenosis by Coronary Computed Tomography Angiography (CCTA)

Abstract

Objective: We aimed to evaluate whether matrix metalloproteinase-9 (MMP-9), myeloperoxidase (MPO), and soluble CD40 ligand (sCD40L) are elevated in patients with non-calcified plaques without significant coronary artery stenosis. These are the plaques that have been called “vulnerable” and may lead to acute coronary syndromes (ACS). Methods: We retrospectively analyzed all subjects who underwent coronary computed tomography angiography (CCTA) at our center between January 2009 and May 2010. All patients were referred for chest pain. After excluding patients who had calcified coronary plaques or significant coronary artery stenosis (stenosis>50%), 174 patients were analyzed. Eighty-four patients who had non-calcified coronary plaques were enrolled in group A. Ninety patients who had no coronary plaque were enrolled in the normal control group (group B). The serum levels of MMP-9, MPO, and sCD40L were compared between the two groups. The relationship between these biomarkers and Framingham risk scores were analyzed. Receiver operating characteristic (ROC) curves were used to evaluate the ability of these biomarkers to predict the presence of non-calcified plaques. Results: A total of 128 non-calcified coronary plaques were found in 84 group A patients. The MMP-9 (641.33 ± 215.38 ng/ml vs 413.90 ± 182.01 ng/ml, p<0.001) and MPO values (1073.69 ± 478.20 ng/ml vs 705.18 ± 289.68 ng /ml, p<0.001) in group A were significantly higher than in group B. No significant difference was found in serum level of sCD40L between the two groups (8.65 ± 3.39 ng/ml vs 8.08 ± 4.00ng /ml, p=0.355). The Framingham risk score was significantly higher in group A than in group B (21 ± 5 vs 16 ± 4, p<0.001). The serum levels of MMP-9 and MPO showed significant correlation with Framingham risk score (r = 0.799, p<0.001; and r = 0.301, p<0.001), but not for sCD40L (r=0.072, p=0.345). In terms of predicting non-calcified plaque, the areas under the ROC curves of MMP-9, MPO and sCD40L were 0.802 (95%CI = 0.735-0.868, p<0.001), 0.738 (95%CI = 0.663-0.812, p<0.001), and 0.575 (95%CI = 0.489-0.661, p=0.086), respectively. Conclusion: The serum levels of MMP-9 and MPO positively correlated with Framingham Risk Score and were significantly increased in patients with non-calcified plaque.