Incremental Prognostic Value of Coronary Computed Tomography Angiography: High-Risk Plaque Characteristics in Asymptomatic Patients

Abstract

Aim: Coronary computed tomography angiography (CCTA) findings of positive remodeling (index > 1.1) and low-attenuation plaque (< 30 Hounsfield units) are recognized as CT-verified high-risk plaque (CT-HRP). Therefore, we investigated the incremental prognostic value of evaluation of plaque characteristics using CCTA in asymptomatic patients.Methods: Overall, 495 consecutive patients without any known coronary artery disease who underwent CCTA were included in this study. Patients who underwent revascularization within 30 days of CCTA or had scans with poor image quality were excluded. Clinical follow-up data (716.5 ± 262.6 days) were available for 339 patients, who were analyzed for the current study. Framingham risk score (FRS), coronary artery calcium score (CACS), and CT-HRP were investigated as predictors of cardiac events by multivariable analysis using Cox proportional hazard model. Improvement of predictive accuracy by including CT findings was evaluated from reclassification [net reclassification indices (NRI) and integrated discrimination improvement (IDI)] standpoints.Results: During the follow-up period, 9 cardiac events (cardiac death: 0, nonfatal myocardial infarction: 2, hospitalization for unstable or progressive angina: 7) occurred. Multivariate Cox proportional hazard analysis demonstrated that CACS (HR, 13.23; 95% CI, 1.62–107.78, p < 0.0164) and CT-HRP (HR, 11.27; 95% CI, 1.24–102.12, p < 0.0321) were the independent predictors of cardiac events. NRI was 0.9556 (p < 0.0007) and IDI was 0.2582 (p < 0.0203), and the diagnostic performance improved by CT-HRP added to the combination of CACS and FRS.Conclusion: Although the cardiac event rate was low, the evaluation of CCTA plaque characteristics may provide incremental prognostic value to CACS in asymptomatic patients.

Noninvasive Coronary Plaque Imaging

“…Hoffman et al 34 ) reported that a significantly larger plaque area and positive remodeling were found in culprit lesions of patients with ACS, compared with patients with stable CAD. Positive remodeling has been recognized as a surrogate marker of plaque vulnerability 35 ) . In a landmark study, Motoyama et al 36 ) found that culprit lesions of patients with ACS more frequently had positive remodeling, low-attenuation plaque (< 30 HU), and spotty calcifications.…”

Noninvasive Assessment of Stenotic Severity and Plaque Characteristics by Coronary CT Angiography in Patients Scheduled for Carotid Artery Revascularization

“…Coronary computed tomographic angiography (CTA) provides valuable information not only about luminal stenosis but also about plaque characteristics. High-risk plaque (HRP: positive remodeling and/or low attenuation) determined by CTA was associated with a high risk of acute coronary syndrome (ACS) 8 – 10 ) . Modern CT equipment provides excellent images with less radiation exposure and lower contrast medium dose requirement, extending the potential use of CTA in preoperative assessment.…”

Diagnostic Aspects of Unstable Atherosclerotic Plaque in Carrying Out Multislice Computed Tomography

“…Предполагается, что неоваскуляризация атеросклеротической бляш-ки является причиной «кольцевидного усиле-ния» [27]. Впоследствии исследователи подтвердили наличие «кольцевидного» усиления в АСБ симп-том-связанной коронарной артерии [28,29]. Manubu Kashiwagi et al сопоставили результаты КТ и ОКТ, в которых феномен «кольцевидного усиления» чаще наблюдался в АСБ (тонкокап-сульная фиброатерома) при КТ (специфичность 97%, чувствительность 44%), чем положитель-ное ремоделирование артерии и наличие участ-ка низкой рентгеновской плотности.…”

“…Более того, это трудно охарактеризовать гистологически [25]. Послед-ние исследования МСКТ-АГ показывают, что «napkin-ring» демонстрирует различную частоту в зависимости от исследуемой популяции [29,33]. Тем не менее, в популяциях, где «napkin ring» распространен, признак был связан с не-стабильными АСБ [29,33].…”

“…В работе Takamura et al МСКТ-АГ у паци-ентов с ОКС выявила микрокальцификации АСБ, связанные с нестабильными бляшками, эти результаты были впоследствии подтвер-ждены при ВСУЗИ [29].…”