Intravascular frequency-domain optical coherence tomography assessment of carotid artery disease in symptomatic and asymptomatic patients.

Objectives: 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).

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.