Background: Patients with type 2 diabetes mellitus (DM) exhibit a higher frequency of atherosclerotic cardiovascular events. Their atherosclerotic feature is characterized as the presence of large lipid core. Given that the accumulation of excessive lipids within vessel wall promotes cholesterol crystallization, leading to the upregulation of atherogenic inflammatory cascades, cholesterol crystal may be another important feature associated with vulnerable disease substrate in diabetic patients. We investigated the features of atherosclerotic plaques harbouring cholesterol crystal in patients with and without DM by optical coherence tomography (OCT).
Methods: Culprit lesions in 99 patients with coronary artery disease (CAD) were imaged by OCT prior to percutaneous coronary intervention. Cholesterol crystal was defined as a thin, linear region with high signal intensity and backscattering. OCT-derived plaque features were compared in diabetic and non-diabetic subjects stratified according to the presence of cholesterol crystal.
Results: Around 76 and 66% of study subjects received a stain prior to OCT imaging (p=0.28) and their LDL-C level was 87±28 and 98±38 mg/dl (p=0.15), respectively. On OCT imaging, 68% of diabetic and 54% of non-diabetic subjects had cholesterol crystal (p=0.17). In non-diabetic patients, there were no significant differences in any plaque features between patients with and without cholesterol crystal (Figure). By contrast, culprit lesions with cholesterol crystals were more likely to exhibit vulnerable features reflected by a larger arc (p=0.038) and a longer longitudinal length of lipid (p=0.051), and a higher frequency of thrombus (p=0.018) (Figure).
Conclusions: The presence of cholesterol crystal was associated with more vulnerable features in diabetic but not non-diabetic subjects. This observation suggests cholesterol crystal as a potential target to modulate atherosclerotic plaques in patients with DM.