Intravascular Frequency-Domain Optical Coherence Tomography Assessment of Carotid Artery Disease in Symptomatic and Asymptomatic Patients

Abstract

The goal of this study was to investigate carotid plaque characteristics in symptomatic versus asymptomatic patients with the use of nonocclusive optical coherence tomography (OCT). The identification of asymptomatic patients with carotid disease who are at risk of stroke remains a challenge. There is an increasing awareness that plaque characteristics may best risk-stratify this population. We hypothesized that OCT, a new high-resolution (∼ 10 μm) imaging modality, might be useful for the identification of low-risk versus high-risk carotid plaque features and help us to understand the relationship between carotid diameter stenosis and plaque morphology to ischemic stroke. Fifty-three patients undergoing diagnostic carotid angiography were studied with OCT. Data analysis was carried out by imaging experts who were unaware of the clinical characteristics of the study population. Plaque with American Heart Association type VI complicated features was more common in symptomatic than asymptomatic patients (74.1% vs. 36.4%, p = 0.02). This was largely driven by differences in the incidence of thin-cap fibroatheroma with rupture (40.7% vs. 13.6%, p = 0.056) and thrombus (67.7% vs. 36.4%, p = 0.034). Conversely, non-type VI plaques were more common in asymptomatic than symptomatic patients (63.6% vs. 25.9%, p = 0.02). No association between the degree of stenosis and plaque morphology was identified. This retrospective analysis of carotid OCT data supports the hypothesis that the evaluation of carotid plaque characteristics with this high-resolution imaging technique has the potential to alter the understanding and treatment of carotid artery disease.