Symptomatic Carotid Plaques Demonstrate Less Leaky Plaque Microvasculature Compared With the Contralateral Side: A Dynamic Contrast-Enhanced Magnetic Resonance Imaging Study. Crombach et al., J Am Heart Assoc. 2019 Apr 16;8(8):e011832.
Atherosclerotic plaques present themselves in various phenotypes, with variable risk of becoming clinically manifest. Intraplaque hemorrhage and intraplaque vasculature are generally considered as indicators for plaque instability, particularly in histologic studies of symptomatic ruptured lesions. In this study by the group of Prof. M. Eline Kooi from the Maastricht University Medical Center, symptomatic and non-symptomatic (ipsilateral) plaques of 88 patients with cerebral ischemic events were analysed by Magnetic Resonance Imaging (MRI). Pharmacological modelling of contrast agent transmission into the plaques resulted in a parameter “Ktrans” that represents microvascular leakiness. Interestingly, the symptomatic plaques showed a significantly lower Ktrans than the non-symptomatic ipsilateral plaques, indicating a less leaky phenotype. However, the symptomatic plaques showed increased prevalence of a lipid-rich necrotic core. The authors hypothesized that although microvascular leakiness is generally regarded as an indicator of decreased plaque stability, less microvasculature might also lead to increased cell death resulting in a larger necrotic core.
The study is of particular interest because it focused on relating the phenotypes of plaques to the occurrence of symptoms in living human patients, thereby using the non-symptomatic plaques as controls.