Enhanced Expression of Hemoglobin Scavenger Receptor CD163 in Accumulated Macrophages Within Filtered Debris Between Acute Coronary Syndromes and Stable Angina Pectoris

Coronary intraplaque hemorrhage up-regulates hemoglobin scavenger receptor CD163 expression on macrophages, and has an association with vulnerable plaque development. During percutaneous coronary intervention, mechanical plaque disruption exposes potentially embolic atheromatous contents from culprit plaque.In 37 patients with stable angina pectoris (SAP, n = 20) or acute coronary syndrome (ACS, n = 17), atherothrombotic debris was collected using a filter-based distal embolic protection device. We immunohistochemically determined CD14-positive macrophages and CD163-positive macrophages in filtered debris. We also examined the relation of CD14- and CD163-positive macrophages with culprit plaque volume and components evaluated with ultrasonic tissue characterization (VH-IVUS).The only significant difference in clinical characteristics between the two groups was in hs-CRP. In ACS, the percentage of CD14- and CD163-positive macrophages to the whole cells (%CD14 and %CD163, respectively) was significantly higher than that in SAP (20.1 ± 8.2 versus 8.8 ± 6.8%, P < 0.001 and 32.6 ± 18.9 versus 9.0 ± 3.8%, P < 0.001, respectively). In IVUS indices of culprit plaque, the remodeling index was significantly higher in ACS than in SAP. However, necrotic core component (%NC) in ACS was significantly higher than that in SAP. Furthermore, fibrotic component (%Fibrous) in ACS was significantly lower than that in SAP (56.1 ± 4.7 versus 60.1 ± 3.3%, P = 0.03). %CD14 and %CD163 had a significant positive correlation with %NC (%CD14: r = 0.40, P = 0.01 and %CD163: r = 0.45, P = 0.01), but only %CD163 was negatively correlated with %Fibrous (%CD163: r = -0.48, P = 0.01).These findings suggest that the presence of CD14- and CD163-positive macrophages may reflect plaque inflammation, NC expansion, and plaque vulnerability in patients with coronary heart disease.