RESUMEN
BACKGROUND: While the current methodology for determining fibrous cap (FC) thickness of lipid plaques is based on manual measurements of arbitrary points, which could lead to high variability and decreased accuracy, it ignores the three-dimensional (3-D) morphology of coronary artery disease. OBJECTIVE: To compare, utilizing optical coherence tomography (OCT) assessments, volumetric quantification of FC, and macrophage detection using both visual assessment and automated image processing algorithms in non-culprit lesions of STEMI and stable angina pectoris (SAP) patients. METHODS: Lipid plaques were selected from 67 consecutive patients (1 artery/patient). FC was manually delineated by a computer-aided method and automatically classified into three thickness categories: FC < 65 µm (i.e., thin-cap fibroatheroma [TCFA]), 65-150 µm, and >150 µm. Minimum thickness, absolute categorical surface area, and fractional luminal area of FC were analyzed. Automated detection and quantification of macrophage was performed within the segmented FC. RESULTS: A total of 5,503 cross-sections were analyzed. STEMI patients when compared with SAP patients had more absolute categorical surface area for TCFA (0.43 ± 0.45 mm(2) vs. 0.15 ± 0.25 mm(2) ; P = 0.011), thinner minimum FC thickness (31.63 ± 17.09 µm vs. 47.27 ± 26.56 µm, P = 0.012), greater fractional luminal area for TCFA (1.65 ± 1.56% vs. 0.74 ± 1.2%, P = 0.046), and greater macrophage index (0.0217 ± 0.0081% vs. 0.0153 ± 0.0045%, respectively, P < 0.01). CONCLUSION: The novel OCT-based 3-D quantification of the FC and macrophage demonstrated thinner FC thickness and larger areas of TCFA coupled with more inflammation in non-culprit sites of STEMI compared with SAP.
Asunto(s)
Angina Estable/diagnóstico , Vasos Coronarios/patología , Inflamación/diagnóstico , Infarto del Miocardio/diagnóstico , Tomografía de Coherencia Óptica , Anciano , Algoritmos , Angina Estable/metabolismo , Angina Estable/patología , Automatización , Vasos Coronarios/química , Femenino , Fibrosis , Humanos , Interpretación de Imagen Asistida por Computador , Imagenología Tridimensional , Inflamación/metabolismo , Inflamación/patología , Lípidos/análisis , Macrófagos/patología , Masculino , Persona de Mediana Edad , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Placa Aterosclerótica , Valor Predictivo de las Pruebas , Estudios RetrospectivosRESUMEN
Optical coherence tomography (OCT) is a novel imaging technology based on low-coherence interferometry that uses scattering of near-infrared light as a signal source to provide vascular cross-sectional imaging with definition far superior to any other available modality. With spatial resolution of up to 10 microm, OCT provides 20-fold higher resolution than intravascular ultrasound (IVUS), currently the most used modality for intra-coronary imaging. OCT has the capacity to provide invaluable insight into the various phases of atherosclerotic disease and vascular response to therapeutics. Studies have shown the ability of OCT to detect arterial structures and assist in the determination of different histological constituents. Its capacity to distinguish different grades of atherosclerotic changes and the various types of plaques, as compared to histology, has recently been demonstrated with acceptable intra-observer and inter-observer correlations for these findings. OCT provides unrivaled real-time in vivo endovascular resolution, which has been exploited to assess the vascular structures and response to device deployment. While depth remains a limitation for OCT plaque characterization beyond 2-mm, near-histological resolution can be achieved within the first millimeter of the vessel wall allowing unique assessment of fibrous cap characteristics and thickness. In addition, assessment of neointimal coverage, para-strut tissue patterns and stent apposition can now be scrutinized for individual struts on the micron scale, the so-called strut-level analysis. OCT has propelled intravascular imaging into micron-level in vivo vascular analysis and is expected to soon become a valuable and indispensable tool for the cardiologists on both clinical and research applications.
Asunto(s)
Aterosclerosis/patología , Tomografía de Coherencia Óptica/métodos , HumanosRESUMEN
A Tomografia de Coerência Ótica (TCO) é uma nova tecnologia de imagem baseada em interferometria de baixa coerência que utiliza a dispersão de luz quase-infravermelha como uma fonte de sinal para fornecer imagens transversais vasculares com definição muito superior à de qualquer outra modalidade disponível. Com uma resolução espacial de até 10μm, a TCO fornece uma resolução 20 vezes maior do que o ultrassom intravascular (USIV), a modalidade atualmente mais utilizada para obter imagens intra-coronárias. A TCO tem uma capacidade de fornecer um entendimento das várias fases da doença aterosclerótica e a resposta vascular ao tratamento. Estudos tem mostrado a capacidade da TCO em detectar estruturas arteriais e ajudar na determinação de diferentes constituintes histológicos. Sua capacidade de distinguir diferentes graus de alterações ateroscleróticas e os vários tipos de placas, quando comparada à histologia, tem sido recentemente demonstrada com correlações inter e intra-observador aceitáveis para esses achados. A TCO fornece uma resolução endovascular excepcional em tempo real in vivo, que tem sido explorada para avaliar as estruturas vasculares e a resposta ao uso do equipamento. Embora a profundidade permaneça uma limitação para a caracterização de placa além de 2 mm através da TCO, uma resolução próxima à histológica pode ser obtida dentro do primeiro milímetro da parede do vaso, permitindo uma avaliação extraordinária das características e espessura da capa fibrosa. Além disso, a avaliação da cobertura de neoíntima, padrões de tecido para-haste e aposição de stent podem agora ser escrutinizados para hastes individuais na escala de mícrons, a assim chamada análise em nível de haste. A TCO levou a imagem intravascular ao nível de mícron na análise vascular in vivo e espera-se que breve se torne uma ferramenta valiosa e indispensável para cardiologistas em aplicações clínicas e de pesquisa.
Optical coherence tomography (OCT) is a novel imaging technology based on low-coherence interferometry that uses scattering of near-infrared light as a signal source to provide vascular cross-sectional imaging with definition far superior to any other available modality. With spatial resolution of up to 10μm, OCT provides 20-fold higher resolution than intravascular ultrasound (IVUS), currently the most used modality for intra-coronary imaging. OCT has the capacity to provide invaluable insight into the various phases of atherosclerotic disease and vascular response to therapeutics. Studies have shown the ability of OCT to detect arterial structures and assist in the determination of different histological constituents. Its capacity to distinguish different grades of atherosclerotic changes and the various types of plaques, as compared to histology, has recently been demonstrated with acceptable intra-observer and inter-observer correlations for these findings. OCT provides unrivaled real-time in vivo endovascular resolution, which has been exploited to assess the vascular structures and response to device deployment. While depth remains a limitation for OCT plaque characterization beyond 2-mm, near-histological resolution can be achieved within the first millimeter of the vessel wall allowing unique assessment of fibrous cap characteristics and thickness. In addition, assessment of neointimal coverage, para-strut tissue patterns and stent apposition can now be scrutinized for individual struts on the micron scale, the so-called strut-level analysis. OCT has propelled intravascular imaging into micron-level in vivo vascular analysis and is expected to soon become a valuable and indispensable tool for the cardiologists on both clinical and research applications.
La Tomografía de Coherencia Óptica (TCO) es una nueva tecnología de imagen basada en interferometría de baja coherencia que utiliza la dispersión de luz casi infrarroja como una fuente de señal para suministrar imágenes transversales vasculares con definición muy superior a la de cualquier otra modalidad disponible. Con una resolución espacial de hasta 10 μm, la TCO ofrece una resolución 20 veces mayor que la ecografía intravascular (EIV), la modalidad actualmente más utilizada para obtener imágenes intracoronarias. La TCO tiene capacidad de suministrar comprensión de las varias fases de la enfermedad aterosclerótica y la respuesta vascular al tratamiento. Estudios han mostrado la capacidad de la TCO para detectar estructuras arteriales y ayudar en la determinación de diferentes constituyentes histológicos. Su capacidad para distinguir diferentes grados de alteraciones ateroscleróticas y los varios tipos de placas, cuando se la compara con la histología, ha sido demostrada recientemente con correlaciones inter e intra observador aceptables para esos hallazgos. La TCO ofrece una resolución endovascular excepcional en tiempo real in vivo, que se ha explorado para evaluar las estructuras vasculares y la respuesta al auso del equipamiento. Aunque la profundida continúe siendo una limitación para la caracterización de placa más allá de 2 mm a través de la TCO, una resolución próxima a la histológica puede obtenerse dentro del primer milímetro de la pared del vaso, permitiendo una evaluación extraordnaria de las característica y espesor de la capa fibrosa. Además de ello, la evaluación de la cobertura de neoíntima, patrones de tejido para vástago y aposición de stent pueden ahora ser escrutados para vástagos individuales en la escala de micrones, el llamado análisis a nivel de vástago.