Comparison of coronary plaque characteristics between diabetic and non-diabetic subjects: An in vivo optical coherence tomography study

Abstract

Aims: Postmortem series have reported that subjects with diabetes mellitus have coronary plaques with larger necrotic cores and increased macrophage infiltration. Optical coherence tomography (OCT) is a high-resolution imaging modality that allows in vivo characterization of atherosclerotic plaques. Using OCT imaging, we compared in vivo plaque characteristics between diabetic and non-diabetic subjects.

Methods: Sixty-three patients undergoing cardiac catheterization were enrolled. OCT imaging was performed in culprit coronary arteries. Assessment of plaque lipid content, fibrous cap thickness and frequency of thin-cap fibroatheroma were made independently. Macrophage density was determined from the optical signal within fibrous cap.

Results: Eighty-two plaques in total were imaged (19 diabetic vs. 63 non-diabetic). There were no significant differences in frequency of lipid-rich plaques (68% vs. 71%; P=0.78), thin-cap fibroatheroma (29% vs. 36%; P=0.76) or minimum fibrous cap thickness (66.6microm vs. 62.9microm; P=0.87) between diabetic and non-diabetic patients. Fibrous cap macrophage density was higher in lipid-rich plaques (P=0.01) but showed no difference between diabetic and non-diabetic patients (5.94% vs. 5.94%; P=0.37).

Conclusions: There were no significant differences in culprit vessel plaque characteristics between diabetic and non-diabetic patients presenting with coronary artery disease. This represents the first study to characterize coronary plaques in diabetic patients using OCT.

Figure 1

In vivo optical coherence tomography image of a thin-cap fibroatheroma. Signal-poor regions (L) surrounded by diffuse borders and separated by signal-rich layer are consistent with lipid pools. Lipid is present in half of the whole circumference. Thin-cap fibroatheroma is identified by a thin fibrous cap (black arrow, ↑) overlying a large lipid-rich plaque. Guide-wire artefact is seen at 10 o’clock position (*).

Figure 2

Macrophage density of coronary plaque fibrous caps in (A) lipid-rich and non-lipid rich plaques; and (B) diabetic and non-diabetic subjects. Macrophage density was higher in lipid-rich plaques* but did not differ between diabetic and non-diabetic subjects. Median ± interquartile range. * P=0.01.