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1.
Circulation ; 114(1 Suppl): I435-40, 2006 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-16820615

RESUMEN

BACKGROUND: The use of saphenous vein grafts (SVG) in coronary artery bypass surgery is established but little is known of SVG remodeling during the first year in vivo. METHODS AND RESULTS: The feasibility of measuring total vessel diameter (lumen plus wall), lumen diameter, and wall thickness by a novel computed tomography (CT) method was established in phantom model tubes (r=0.98 for lumen diameter and r=0.98 for wall thickness) and in an initial clinical study of 14 patients correlating CT and intravascular ultrasound measurements of SVG (r=0.88 for total vessel diameter, r=0.85 for lumen diameter and r=0.89 for wall thickness). In a separate group of 42 patients (aged 66+/-10 years; 36 male, 6 female) undergoing coronary artery bypass grafting, SVG total vessel diameter, lumen diameter, and wall thickness were determined prospectively with multi-slice CT angiography at 1 and 12 months postoperatively. Mean total vessel diameter decreased from 5.95+/-0.83 mm to 5.39+/-0.87 mm, P<0.001 (range, -39% to +8% change). Twenty-six patients (62%) had a decrease of SVG vessel diameter (negative remodeling) >5%. Mean lumen diameter decreased from 3.69+/-0.66 mm to 3.36+/-0.68 mm, P<0.001, (range, -40 to +11% change). Surprisingly, mean wall thickness decreased from 1.14+/-0.27 mm to 1.01+/-0.21 mm (P<0.001; range, -48 to +33% change). CONCLUSIONS: Lumen loss in SVG between postoperative months 1 and 12 is predominantly caused by negative remodeling of the whole vessel rather than to changes in wall thickness. Therapies targeting negative remodeling may be required for optimal maintenance of SVG lumen in the first postoperative year.


Asunto(s)
Puente de Arteria Coronaria/métodos , Reestenosis Coronaria/etiología , Oclusión de Injerto Vascular/etiología , Vena Safena/trasplante , Antagonistas Adrenérgicos beta/farmacología , Anciano , Estudios de Cohortes , Puente de Arteria Coronaria/estadística & datos numéricos , Reestenosis Coronaria/diagnóstico por imagen , Reestenosis Coronaria/epidemiología , Reestenosis Coronaria/patología , Reestenosis Coronaria/fisiopatología , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Oclusión de Injerto Vascular/diagnóstico por imagen , Oclusión de Injerto Vascular/epidemiología , Oclusión de Injerto Vascular/patología , Oclusión de Injerto Vascular/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Metoprolol/farmacología , Persona de Mediana Edad , Fantasmas de Imagen , Periodo Posoperatorio , Vena Safena/diagnóstico por imagen , Vena Safena/patología , Método Simple Ciego , Tomografía Computarizada por Rayos X , Trasplante Heterólogo , Ultrasonografía Intervencional
2.
Radiology ; 235(2): 415-22, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15858083

RESUMEN

PURPOSE: To investigate prospectively the relative accuracy of computed tomographic (CT) angiography, calcium scoring (CS), and both methods combined in demonstrating coronary artery stenoses by using conventional angiography as the reference standard. MATERIALS AND METHODS: The study was approved by the institutional review board Human Research Ethics Committee, and all patients completed written informed consent. Fifty patients (40 men, 10 women) aged 62 years +/- 11 (+/- standard deviation) who were suspected of having coronary artery disease underwent both conventional coronary angiography and multisection coronary CT angiography with CS. Sensitivity and specificity of CS, CT angiography, and both methods combined in demonstrating luminal stenosis greater than or equal to 50% were determined for each arterial segment, coronary vessel, and patient. Receiver operating characteristic (ROC) curves were generated for CS prediction of significant stenosis, and the Mann-Whitney U test was used for comparison of CS between groups. RESULTS: When used with segment-specific electrocardiographic phase reconstructions, CT angiography demonstrated stenosed segments with 79% sensitivity and 95% specificity. Mean calcium score was greater in segments, vessels, and patients with stenoses than in segments, vessels, and patients without stenoses (P < .001 for all); nine (16%) of 56 stenosed segments, however, had a calcium score of 0. The patient calcium score correlated strongly with the number of stenosed arteries (Spearman rho = 0.75, P < .001). CS was more accurate in demonstrating stenosis in patients than in segments (areas under ROC curve were 0.88 and 0.74, respectively). CT angiography, however, was more accurate than CS in demonstrating stenosis in patients, vessels, and segments. The sensitivity and specificity of CS varied according to the threshold used, but when the calcium score cutoff (ie, >150) matched the specificity of CT angiography (95%), the sensitivity of CS in demonstrating stenosed segments was 29% (compared with 79% for CT angiography). Combining CT angiography with CS (at threshold of 400) improved the sensitivity of CT angiography (from 93% to 100%) in demonstrating significant coronary disease in patients, without a loss of specificity (85%); this finding, however, was not statistically significant. CONCLUSION: CT angiography is more accurate than CS in demonstrating coronary stenoses. A patient calcium score of greater than or equal to 400, however, can be used to potentially identify patients with significant coronary stenoses not detected at CT angiography.


Asunto(s)
Calcinosis/diagnóstico por imagen , Calcio/análisis , Angiografía Coronaria/estadística & datos numéricos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Estenosis Coronaria/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Tomografía Computarizada Espiral/estadística & datos numéricos , Adulto , Anciano , Algoritmos , Interpretación Estadística de Datos , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Valores de Referencia , Riesgo , Sensibilidad y Especificidad
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