Inflammatory markers and plaque morphology: an optical coherence tomography study

Abstract

Background: OCT with its unique image resolution is the ideal method to detect culprit lesion characteristics in different clinical presentations. The identification of inflammatory markers related to plaque characteristics may be of clinical importance.

Methods: Thirty-two patients with acute coronary syndromes (ACS) and fourteen patients with stable angina pectoris (SAP) were enrolled in this study. Culprit lesion morphology was assessed by optical coherence tomography (OCT) in patients with ACS and SAP. The possible relations between serum levels of high sensitivity-C reactive protein (hs-CRP) and interleukin-18 (IL-18) with plaque characteristics were investigated in those patients.

Results: Plaque rupture and thin-cap fibroatheroma (TCFA) were detected more frequently in ACS patients compared with SAP patients, (78.6% vs. 14.3%, p<0.001, 92.9% vs. 14.3%, p<0.001, respectively). Higher levels of serum hs-CRP and IL-18 were found in patients with plaque rupture vs. those with no plaque rupture (median value: 19.2mg/L vs. 1.6 mg/L, p<0.001 and 219.5 pg/ml vs. 127.5 pg/ml, p=0.001 respectively), and TCFA vs. those without TCFA (median value: 15.2mg/L vs. 1.6 mg/L, p=0.004 and 209.0 pg/ml vs.153.2 pg/ml, p=0.03 respectively). Serum hs-CRP was the only independent predictor of plaque rupture (p=0.02, odds ratio 1.1, 95% confidence interval 1.0 to 1.2). A cut-off value of hs-CRP>4.5mg/L could detect ruptured plaque with a sensitivity of 91.7% and a specificity of 77.8%.

Conclusions: OCT detected plaque rupture and TCFA more frequent in ACS patients compared with SAP. Elevated hs-CRP and IL-18 were positively related to plaque instability and rupture.