Invasive coronary angiography findings across the CAD-RADS classification spectrum.

The recently introduced coronary artery disease reporting and data system (CAD-RADS) evaluated by computed tomography and based on stenosis severity, might not adequately reflect the complexity of CAD. We explored the relationship between CAD-RADS and the spatial distribution, burden, and complexity of lesions by invasive coronary angiography (ICA). Stable patients who underwent coronary computed tomography angiography (CCTA) and ICA comprised the study population. Patients were classified according to the CAD-RADS: 0, No plaque; 1, 1-24% stenosis; 2, 25-49%; 3, 50-69%; 4A, 70-99%; 4B, left main stenosis or 3-vessel obstructive disease; and 5, total occlusion. Based on ICA findings, we calculated the SYNTAX score and the CAD extension index. Ninety-one patients were included, with a mean age of 61.4 ± 10.5 years (74% male). We found significant relationships between CAD-RADS and both the SYNTAX score (p < 0.0001) and the CAD extension index (p < 0.0001), although the complexity of coronary anatomy differed among patients with CAD-RADS ≥ 4A. Among patients with CAD-RADS < 4, the mean segment involvement score (SIS) was 8.4 ± 4.0, 52% of them with a SIS > 5. Of the 30 patients with CAD-RADS 5, 9 (30%) affected distal segments or secondary branches, and 9 (30%) had concomitant severe non-extensive disease at ICA. Regarding the spatial distribution of the non-occluded most severe lesions, 27 (44%) comprised distal segments or secondary branches. In the present study including a high-risk population, we identified diverse coronary anatomy complexity scenarios and relevant differences in spatial distribution sharing the same CAD-RADS classification.

Pericardial fat volume is related to atherosclerotic plaque burden rather than to lesion severity.

AIMS: We sought to explore the relationship between pericardial fat volume (PFV) and both coronary atherosclerosis (CA) extent and severity using coronary artery calcium score (CAC), computed tomography coronary angiography (CTCA), and invasive coronary angiography in patients at high to intermediate likelihood of coronary artery disease (CAD). METHODS AND RESULTS: Patients clinically referred to invasive angiography who underwent CTCA and CAC within 1 month before the procedure comprised the study population. PFV, CAC, atherosclerotic burden indexes [segment involvement score (SIS); segment stenosis score; three-vessel plaque; and any left main plaque], and the invasive angiography-derived CAD index were evaluated independently. A total of 75 patients were included in the study. PFV did not differ between patients with or without obstructive (stenosis >70%) CAD defined by invasive angiography (86.4 ± 31.7 vs. 77.1 ± 42.8 cm3, P = 0.34), although patients with obstructive CAD had significantly higher CAC scores [636.0 (IQR 229.5-1101.0) vs. 206.0 (IQR 0.0-675), P < 0.0001] than patients without obstructive CAD. Patients with extensive CA (SIS > 5) had significantly larger PFV (89.9 ± 33.9 vs. 58.7 ± 33.2 cm3, P = 0.003) than patients with non-extensive CA. Significant correlations were found between PFV and CAC (r = 0.49, P < 0.0001), and SIS (r = 0.46, P < 0.0001), whereas very weak correlations were observed between PFV and the CAD index (r = 0.27, P = 0.02), and between PFV and the body mass index (r = 0.33, P = 0.004). CONCLUSION: The main finding of the present study was the identification of PFV as more closely related to atherosclerotic plaque burden rather than to lesion severity in patients referred to invasive coronary angiography.

Extensión y distribución espacial de la carga ateroesclerótica mediante imágenes monocromáticas virtuales derivadas de tomografía computarizada de doble energía / Extension and spatial distribution of atherosclerotic burden using virtual monochromatic imaging derived from dual-energy computed tomography

Introducción y objetivos: Se analizaron las diferencias de carga ateroesclerótica observadas entre la coronariografía invasiva y las imágenes monocromáticas virtuales obtenidas con la tomografía computarizada de doble energía. Métodos: Se examinó con tomografía computarizada de doble energía y se clasificó a 80 pacientes consecutivos remitidos a una coronariografía invasiva según el grado de carga ateroesclerótica utilizando el índice pronóstico de enfermedad coronaria de Duke modificado, la puntuación de extensión de la enfermedad coronaria, la puntuación de afección de segmentos y la puntuación de estenosis de segmentos. Resultados: La media de la puntuación de afección de segmento (8,2 más o menos 3,9 frente a 6,0 más o menos 3,7; p < 0,0001), el índice de Duke modificado (4,33 más o menos 1,6 frente a 4,0 más o menos 1,7; p = 0,003), la puntuación de extensión de la enfermedad coronaria (4,84 más o menos 1,8 frente a 4,43 más o menos 2,1; p = 0,005) y la mediana de la puntuación de estenosis de segmento (13,5 [9,0-18,0] frente a 9,5 [5,0-15,0]; p < 0,0001) fueron significativamente superiores con la tomografía computarizada de doble energía que con la coronariografía invasiva. La tomografía computarizada de doble energía mostró un número de pacientes con alguna lesión del tronco coronario izquierdo significativamente mayor (46 [58%] frente a 18 [23%]; p < 0,0001) y con lesiones proximales graves (0,28 más o menos 0,03 frente a 0,26 más o menos 0,03; p < 0,0001) en comparación con lo observado en la coronariografía invasiva. Los grados de calcificación arterial coronaria por debajo y por encima de la mediana mostraron sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo del 100 y el 97%; el 86 y el 50%; el 93 y el 95% y el 100 y el 67% para la identificación de estenosis más que o igual a 50%. Conclusiones: La angiografía coronaria con tomografía computarizada de energía dual identificó una carga ateroesclerótica significativamente mayor que la observada con la coronariografía invasiva, en especial por lo que respecta a la afección de los segmentos proximales (AU)

Introduction and objectives: We explored the differences between atherosclerotic burden with invasive coronary angiography and virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography. Methods: Eighty consecutive patients referred for invasive coronary angiography underwent dual-energy computed tomography coronary angiography and were categorized according to the atherosclerotic burden extent using the modified Duke prognostic coronary artery disease index, coronary artery disease extension score, segment involvement score, and the segment stenosis score. Results: The mean segment involvement score (8.2 more or less 3.9 vs 6.0 more or less 3.7; P < .0001), modified Duke index (4.33 more or less 1.6 vs 4.0 more or less 1.7; P = .003), coronary artery disease extension score (4.84 more or less 1.8 vs 4.43 more or less 2.1; P = .005), and the median segment stenosis score (13.5 [9.0-18.0] vs 9.5 [5.0-15.0]; P < .0001) were significantly higher on dual-energy computed tomography compared with invasive angiography. Dual-energy computed tomography showed a significantly higher number of patients with any left main coronary artery lesion (46 [58%] vs 18 [23%]; P < .0001) and with severe proximal lesions (0.28 more or less 0.03 vs 0.26 more or less 0.03; P < .0001) than invasive angiography. Levels of coronary artery calcification below and above the median showed a sensitivity, specificity, positive predictive value, and negative predictive value of 100% and 97%; 86% and 50%; 93% and 95%; 100% and 67% for the identification of is greater than or equal to 50% stenosis. Conclusions: Dual-energy computed tomography coronary angiography identified a significantly larger atherosclerotic burden compared with invasive coronary angiography, particularly involving the proximal segments (AU)

Virtual Monochromatic Imaging in Patients with Intermediate to High Likelihood of Coronary Artery Disease: Impact of Coronary Calcification.

RATIONALE AND OBJECTIVES: We sought to explore the image quality and diagnostic performance of virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography (DE-CTCA) in patients with intermediate to high likelihood of coronary artery disease (CAD) and the influence of calcification. MATERIALS AND METHODS: Consecutive symptomatic patients with suspected CAD referred for invasive coronary angiography who underwent DE-CTCA and a coronary artery calcium scoring before the invasive procedure comprised the study population. RESULTS: Sixty-seven patients were included. Image quality was significantly lower at 45 keV reconstructions (mean Likert score 45 keV 3.57 ± 0.6, 65 keV 4.07 ± 0.5, and 85 keV 4.09 ± 0.6; P < .0001). Patients with moderate calcification showed a trend toward a significant improvement in the diagnostic performance with 65 keV vs 45 keV reconstructions (45 keV, area under the curve 0.92 [95% confidence interval 0.89-0.95] vs 65 keV, area under the curve 0.96 [95% confidence interval 0.93-0.98], P = .06). The diagnostic performance of DE-CTCA was significantly lower in segments with higher coronary artery calcium scoring compared to segments with none or mild calcification, independent of the energy level applied. CONCLUSIONS: In patients with intermediate to high likelihood of CAD, DE-CTCA had a good diagnostic performance, although significantly lower in segments with severe calcification.

Extension and Spatial Distribution of Atherosclerotic Burden Using Virtual Monochromatic Imaging Derived From Dual-energy Computed Tomography.

INTRODUCTION AND OBJECTIVES: We explored the differences between atherosclerotic burden with invasive coronary angiography and virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography. METHODS: Eighty consecutive patients referred for invasive coronary angiography underwent dual-energy computed tomography coronary angiography and were categorized according to the atherosclerotic burden extent using the modified Duke prognostic coronary artery disease index, coronary artery disease extension score, segment involvement score, and the segment stenosis score. RESULTS: The mean segment involvement score (8.2 ± 3.9 vs 6.0 ± 3.7; P < .0001), modified Duke index (4.33 ± 1.6 vs 4.0 ± 1.7; P = .003), coronary artery disease extension score (4.84 ± 1.8 vs 4.43 ± 2.1; P = .005), and the median segment stenosis score (13.5 [9.0-18.0] vs 9.5 [5.0-15.0]; P < .0001) were significantly higher on dual-energy computed tomography compared with invasive angiography. Dual-energy computed tomography showed a significantly higher number of patients with any left main coronary artery lesion (46 [58%] vs 18 [23%]; P < .0001) and with severe proximal lesions (0.28 ± 0.03 vs 0.26 ± 0.03; P < .0001) than invasive angiography. Levels of coronary artery calcification below and above the median showed a sensitivity, specificity, positive predictive value, and negative predictive value of 100% and 97%; 86% and 50%; 93% and 95%; 100% and 67% for the identification of ≥ 50% stenosis. CONCLUSIONS: Dual-energy computed tomography coronary angiography identified a significantly larger atherosclerotic burden compared with invasive coronary angiography, particularly involving the proximal segments.

Dual energy imaging and intracycle motion correction for CT coronary angiography in patients with intermediate to high likelihood of coronary artery disease.

We explored whether intracycle motion correction algorithms (MCAs) might be applicable to dual energy computed tomography coronary angiography in patients with intermediate to high likelihood of coronary artery disease. MCA reconstructions were associated with higher interpretability rates (96.7% vs. 87.9%, P<.001), image quality scores (4.12 ± 0.9 vs. 3.76 ± 1.0; P<.0001), and diagnostic performance [area under the curve of 0.95 (95% confidence interval [CI] 0.92-0.97) vs. 0.89 (95% CI 0.86-0.92); P<.0001] compared to conventional reconstructions. In conclusion, application of intracycle MCA reconstructions to dual energy computed tomography acquisitions was feasible and resulted in significantly higher image quality scores, interpretability, and diagnostic performance.

Monochromatic image reconstruction by dual energy imaging allows half iodine load computed tomography coronary angiography.

PURPOSE: To compare image interpretability and diagnostic performance of dual-energy CT coronary angiography (DE-CTCA) performed with 50% iodine load reduction versus single energy acquisitions (SE-CTCA) with full iodine load. MATERIALS AND METHODS: The present prospective study involved patients with suspected coronary artery disease (CAD) clinically referred for CTCA. DE-CTCA with 50% iodine volume load was performed first, and after heart rate returned to baseline SE-CTCA was performed using full iodine volume load. The primary endpoint was to compare image interpretability between groups. DE-CTCA was performed by rapid switching between low and high tube potentials (80-140 kV) from a single source, allowing the generation of monochromatic image reconstructions ranging from 40 to 140 keV. Image quality assessment was performed using a 5-point Likert scale. RESULTS: Thirty-six patients constituted the study population. The mean heart rate before the CT scan (DE-CTCA 57.3 ± 10.7 bpm vs. SE-CTCA 58.5 ± 11.2 bpm, p=0.29) and the mean effective radiation dose (3.5 ± 1.9 mSv vs. 3.8 ± 0.9 mSv, p=0.48) did not differ between groups. Likert image quality scores were similar between groups (DE-CTCA 4.42 ± 0.98 vs. SE-CTCA 4.43 ± 0.84, p=0.67). Signal-to-noise and contrast-to-noise ratios were significantly lower with DE-CTCA, driven by lower signal density levels at 60 keV compared to SE-CTCA. The sensitivity and specificity for the detection of stenosis >50% was indistinguishable between groups (DE-CTCA 84.4% (69.9-93.0%), 87.1% (81.6-91.2%); SE-CTCA 84.4% (69.9-93.0%), 87.1% (81.6-91.2%). CONCLUSIONS: In this pilot, prospective study, dual energy CTCA imaging with half iodine load achieved comparable interpretability than full iodine load with single energy CTCA.

Effect of intracycle motion correction algorithm on image quality and diagnostic performance of computed tomography coronary angiography in patients with suspected coronary artery disease.

RATIONALE AND OBJECTIVES: We sought to explore the impact of intracycle motion correction algorithms (MCA) in the interpretability and diagnostic accuracy of computed tomography coronary angiography (CTCA) performed in patients suspected of coronary artery disease (CAD) referred to invasive coronary angiography. MATERIALS AND METHODS: Patients with suspected CAD referred to invasive coronary angiography previously underwent CTCA. Patients under rate-control medications were advised to withhold for the previous 24 hours. The primary end point of the study was to evaluate image interpretability and diagnostic performance of MCA compared to conventional reconstructions in patients referred to invasive angiography because of suspected CAD. RESULTS: Thirty-five patients were prospectively included in the study protocol. The mean age was 61.4 ± 9.4 years. Twenty-seven (77%) patients were men. A total of 533 coronary segments were evaluated using conventional and MCA reconstructions. MCA reconstructions were associated to higher interpretability rates (525 of 533, 98.5% vs. 515 of 533, 96.6 %; P < .001) and image quality scores (3.88 ± 0.54 vs. 3.78 ± 0.76; P < .0001) compared to conventional reconstructions. Although only mild, a significant difference was observed regarding the diagnostic performance between reconstruction modes, with an area under the curve of 0.90 (0.87-0.92) versus 0.89 (0.86-0.92), respectively, for MCA and conventional reconstructions (P = .0447). CONCLUSIONS: In this pilot investigation, MCA reconstructions performed in patients with suspected CAD were associated to higher interpretability rates and image quality scores compared to conventional reconstructions, although only mild differences were observed regarding the diagnostic performance between reconstruction modes.

Radial artery spasm associated with transradial cardiovascular procedures: results from the RAS registry.

OBJECTIVES: To report the incidence and predictors of moderate/severe radial artery spasm (RAS) in patients undergoing cardiovascular percutaneous procedures through a transradial approach (TRA) in centers with TRA expertise. BACKGROUND: Data regarding the actual rate of clinically meaningful RAS are limited due to difference in study designs and operator expertise. METHODS: The RAS registry, an international (14 centers from Argentina, Chile, India, Indonesia, Macedonia, The Netherlands and United States of America) registry that included 1,868 patients undergoing TRA cardiovascular procedures (63.5% diagnostic and 56.5% therapeutic).All selected centers used TRA as default strategy in the cardiac catheterization laboratory. Throughout 2012, each center included all consecutive TRA cases (during a 2-month period) into a dedicated database covering clinical characteristics as well as procedural topics related to TRA patterns and RAS occurrence. RESULTS: The incidence of moderate/severe RAS was 2.7%. Only 0.7% of patients required crossover (8 to transfemoral and 5 to contralateral TRA). Patients with moderately/severe spasm were more frequently females, had a history of dyslipidemia, received more often a 7F sheath and more puncture attempts than patients without spasm. By multivariate analysis, the need for more than one attempt and the use of a 7 F sheath were independent predictors of the development of moderate/severe RAS. CONCLUSIONS: The incidence of moderate/severe RAS is low in centers with a default TRA. Its development appears to be strongly related to the numbers of puncture attempts and the use of large sheaths.

Problemas y soluciones en la implementación de un Programa de Implante Valvular Aórtico Percutáneo / Problems and Solutions in the Implementation of a Transcatheter Aortic Valve Implantation Program

Introducción La sobrevida de la estenosis aórtica grave sintomática inoperable es baja. El implante percutáneo de válvula aórtica (IVAP) representa una alternativa para estos pacientes. Es nuestra práctica que los candidatos a IVAP ingresen en un programa de evaluación (Programa de IVAP) para determinar su elegibilidad clínica para, luego, solicitar la aprobación a la cobertura de salud. Objetivos Evaluar las causas de la exclusión de pacientes del procedimiento y su impacto clínico. Material y métodos Desde abril de 2009 hasta agosto de 2011, 37 pacientes ingresaron en el Programa de IVAP. Resultados De los 37 pacientes, 29 recibieron el tratamiento o fueron descartados: 14 fueron sometidos a IVAP (grupo IVAP, 48,3%) y 15 fueron descartados (grupo no IVAP 52,7%). Del grupo no IVAP, seis pacientes (40%) fueron descartados por el Programa y cuatro por la cobertura médica, mientras que otros cinco pacientes fallecieron aguardando la autorización. La mediana de EuroSCORE de la población fue del 22% (rango 10-56%) y el promedio de edad fue de 79 ± 8 años. En un seguimiento de 12 meses, la mortalidad del grupo IVAP y no IVAP fue del 7,1% y del 33,3%, respectivamente (p = 0,082). La mortalidad cardiovascular total fue del 17,2%, en todos los casos del grupo no IVAP. Conclusión En nuestro medio, más de la mitad de los pacientes evaluados en un Programa de IVAP no son intervenidos. Razones médicas y socioeconómicas inciden en la toma de decisiones y en la realización o no del IVAP, observándose una mortalidad importante en los pacientes no tratados.

Background Survival of severe symptomatic aortic valve replacement in patients who are not candidates for cardiac surgery is low. Transcatheter aortic valve implantation (TAVI) represents an alternative for these patients. Candidates for TAVI are evaluated in our TAVI Program, firstly to determine if they are clinically eligible and secondly to request the health medical coverage the authorization of the procedure. Objectives To evaluate the reasons for the exclusion of patients from the procedure and its clinical impact. Methods From April 2009 to August 2011, 37 patients were admitted in the TAVI Program. Results From the original 37 patients, 29 were divided into two groups: TAVI group (14 patients undergoing the procedure, 48.3%) and no TAVI group (15 patients rejected for the procedure, 52.7%). In the no TAVI group, six patients (40%) were rejected by the Program and four by the medical coverage, while other five died waiting for the authorization. Median EuroSCORE was of 22% (range 10-56%) and mean age was 79±8 years. After 12 months of follow-up, mortality in the TAVI group and no TAVI group was 7.1% and 33.3%, respectively (p=0.082). Overall cardiovascular mortality was of 17.2%, in all the cases in the no TAVI group. Conclusion In our environment, more than half of the patients evaluated in a TAVI Program do not undergo the procedure. Medical and social and economic reasons influence the decision-making process and carrying out TAVI, with an important mortality in untreated patients.

Problemas y soluciones en la implementación de un Programa de Implante Valvular Aórtico Percutáneo / Problems and Solutions in the Implementation of a Transcatheter Aortic Valve Implantation Program

Introducción La sobrevida de la estenosis aórtica grave sintomática inoperable es baja. El implante percutáneo de válvula aórtica (IVAP) representa una alternativa para estos pacientes. Es nuestra práctica que los candidatos a IVAP ingresen en un programa de evaluación (Programa de IVAP) para determinar su elegibilidad clínica para, luego, solicitar la aprobación a la cobertura de salud. Objetivos Evaluar las causas de la exclusión de pacientes del procedimiento y su impacto clínico. Material y métodos Desde abril de 2009 hasta agosto de 2011, 37 pacientes ingresaron en el Programa de IVAP. Resultados De los 37 pacientes, 29 recibieron el tratamiento o fueron descartados: 14 fueron sometidos a IVAP (grupo IVAP, 48,3%) y 15 fueron descartados (grupo no IVAP 52,7%). Del grupo no IVAP, seis pacientes (40%) fueron descartados por el Programa y cuatro por la cobertura médica, mientras que otros cinco pacientes fallecieron aguardando la autorización. La mediana de EuroSCORE de la población fue del 22% (rango 10-56%) y el promedio de edad fue de 79 ± 8 años. En un seguimiento de 12 meses, la mortalidad del grupo IVAP y no IVAP fue del 7,1% y del 33,3%, respectivamente (p = 0,082). La mortalidad cardiovascular total fue del 17,2%, en todos los casos del grupo no IVAP. Conclusión En nuestro medio, más de la mitad de los pacientes evaluados en un Programa de IVAP no son intervenidos. Razones médicas y socioeconómicas inciden en la toma de decisiones y en la realización o no del IVAP, observándose una mortalidad importante en los pacientes no tratados.(AU)

Background Survival of severe symptomatic aortic valve replacement in patients who are not candidates for cardiac surgery is low. Transcatheter aortic valve implantation (TAVI) represents an alternative for these patients. Candidates for TAVI are evaluated in our TAVI Program, firstly to determine if they are clinically eligible and secondly to request the health medical coverage the authorization of the procedure. Objectives To evaluate the reasons for the exclusion of patients from the procedure and its clinical impact. Methods From April 2009 to August 2011, 37 patients were admitted in the TAVI Program. Results From the original 37 patients, 29 were divided into two groups: TAVI group (14 patients undergoing the procedure, 48.3%) and no TAVI group (15 patients rejected for the procedure, 52.7%). In the no TAVI group, six patients (40%) were rejected by the Program and four by the medical coverage, while other five died waiting for the authorization. Median EuroSCORE was of 22% (range 10-56%) and mean age was 79±8 years. After 12 months of follow-up, mortality in the TAVI group and no TAVI group was 7.1% and 33.3%, respectively (p=0.082). Overall cardiovascular mortality was of 17.2%, in all the cases in the no TAVI group. Conclusion In our environment, more than half of the patients evaluated in a TAVI Program do not undergo the procedure. Medical and social and economic reasons influence the decision-making process and carrying out TAVI, with an important mortality in untreated patients.(AU)

Accuracy of low-dose prospectively gated axial coronary CT angiography for the assessment of coronary artery stenosis in patients with stable heart rate.

BACKGROUND: Desirable methods for cardiac CT angiography would both reduce radiation exposure from cardiac CT angiography and preserve accuracy. OBJECTIVES: We assessed image quality, radiation dose, and diagnostic accuracy of a low-dose, prospectively gated axial cardiac CT angiography protocol for the evaluation of patients with suspected coronary artery disease (CAD). METHODS: Fifty consecutive patients referred for diagnostic invasive coronary angiography (ICA) and with a stable heart rate < 60 beats/min after beta-blocker administration were prospectively enrolled in a single center study. Subjects underwent CT angiography with a 64-row multidetector CT scanner with a prospectively gated axial imaging protocol. If the examination was determined to be nondiagnostic, then a retrospectively gated helical scan was performed. Two reviewers independently assessed image quality and the presence of significant coronary artery stenosis (>50%). RESULTS: Prospectively gated CT angiography was successfully performed in 46 of 50 patients. Of 794 coronary segments, 777 were determined to be of diagnostic image quality. The overall patient-based sensitivity (95% CI), specificity, positive predictive value, negative predictive value, and accuracy for the diagnosis of significant coronary stenosis were 100% (87%-100%), 75% (53%-90%), 81% (64%-93%), 100% (81%-100%), and 88% (81%-95%), respectively. The mean effective radiation dose for CT angiography and ICA were 3.4 +/- 0.4 mSv and 6.9 +/- 0.8 mSv, respectively. CONCLUSIONS: Cardiac CT angiography performed in a prospectively gated axial mode with 64-row multidetector CT provides an accurate, low-dose alternative for the detection of CAD.

Feasibility of 64-slice gadolinium-enhanced cardiac CT for the evaluation of obstructive coronary artery disease.

OBJECTIVE: To assess the feasibility of gadolinium-enhanced 64-slice cardiac CT (CCT) for the diagnosis of obstructive coronary artery disease. DESIGN: Comparative prospective study. SETTING: Outpatient Imaging Diagnostic Centre, Diagnóstico Maipú, Buenos Aires, Argentina. PATIENTS: Twenty patients with suspected coronary artery disease. INTERVENTIONS: Gadolinium-enhanced 64-slice CCT was performed before invasive coronary angiography (ICA). MAIN OUTCOME MEASURES: The feasibility of gadolinium-enhanced 64-slice CCT for detection of obstructive coronary artery disease (>50% diameter reduction) was evaluated, using ICA as the 'gold standard'. Mean lumen attenuation, non-calcified and calcified plaques densities were correlated between gadolinium-enhanced CCT studies and iodine-enhanced CCT studies of a control group. Renal function was strictly monitored. RESULTS: Gadolinium-enhanced CCT demonstrated adequate visualisation of 283/289 coronary segments that were evaluable by ICA, 31 of which had >50% luminal stenosis. In per-segment analysis, gadolinium-enhanced CCT showed a sensitivity of 90.3%, specificity of 96.8%, positive predictive value of 77.8% and negative predictive value of 98.8%. The agreement of coronary stenosis between multidetector CT (MDCT) and ICA was 94.1% (272/289). The mean lumen attenuation, non-calcified and calcified plaques densities in gadolinium-enhanced CCT studies were 140.1 Hounsfield units (HU), 51.1 HU and 523.6 HU, whereas in iodine-enhanced CCT studies the values were 354.1 HU, 101.0 HU and 778.5 HU, respectively (p < 0.001). CONCLUSION: Gadolinium-enhanced CCT is a feasible alternative for patients with severe contraindications to iodinated contrast agents referred for MDCT coronary angiography.

Angiografía coronaria por tomografía computarizada multidetector con gatillado electrocardiográfico prospectivo: análisis de la calidad de imagen y de la dosis de radiación / Prospective Electrocardiogram-Gated Multidetector Row Computed Tomography Coronary Angiography: analysis of Quality Image and Radiation Dose

Introducción La angiografía coronaria por tomografía computarizada multidetector (ACTCM) se ha convertido en una herramienta diagnóstica útil para la cuantificación directa de la estenosis coronaria, la identificación de anomalías coronarias y la evaluación de bypass. Pese a que su valor clínico en ocasiones se ve cuestionado debido a la dosis de radiación efectiva (DRE) que recibe cada paciente, ésta no es mayor que la de otros estudios. No obstante, es motivo de permanente preocupación la búsqueda de diferentes estrategias para reducir la DRE sin detrimento de la calidad de imagen y de la certeza diagnóstica. Objetivos Determinar la calidad de imagen y la dosis de radiación efectiva (DRE) de los estudios de angiografía coronaria por tomografía computarizada multidetector realizados con gatillado electrocardiográfico prospectivo (ACTCM-P) (emisión de radiación sincronizada con la fase diastólica) en comparación con la técnica de adquisición con gatillado retrospectivo (ACTCMR) (emisión durante todo el ciclo cardíaco) y, en forma preliminar, su certeza diagnóstica en relación con la cinecoronariografía digital invasiva (CCG). Material y métodos Cincuenta pacientes consecutivos con sospecha de enfermedad coronaria y ritmo sinusal fueron estudiados con ACTCM-P y comparados con un grupo control al que se le realizó una ACTCM-R. La calidad de imagen fue analizada por dos observadores. Se determinaron la concordancia interobservador y la DRE. En 30 pacientes se evaluó la certeza diagnóstica de la ACTCM-P para la detección de estenosis > 50% en comparación con la CCG. Resultados No hubo diferencias significativas en la calidad de imagen entre los dos grupos. La concordancia interobservador fue: k = 0,92. La DRE media de la ACTCM-P fue de 3,5 mSv en comparación con 12,9 y 9,7 mSv de la ACTCM-R sin modulación del tubo de rayos X y con ella, respectivamente. En el análisis por paciente incluyendo todos los segmentos, la sensibilidad, la especificidad y el valor predictivo positivo y negativo de la ACTCM-P para la detección de estenosis fueron del 94,74%, 81,82%, 90% y 90%, respectivamente. Conclusión Nuestra experiencia inicial demostró que la ACTCM-P brinda una reducción sustancial de la DRE con una calidad de imagen comparable a la de la ACTCM-R en una población seleccionada.

Background Multidetector row computed tomography coronary angiography (MDCT-CA) has become a useful diagnostic tool for the direct quantification of coronary stenosis, for identifying coronary anomalies and for the assessment of coronary artery bypass grafts. Despite its clinical value has been questioned due to the effective radiation dose (ERD) received by each patient, radiation exposure is similar to other studies. However, different strategies are permanently tested in order to reduce the ERD maintaining adequate and diagnostic image quality. Objectives To determine the image quality and effective radiation dose (ERD) of prospective electrocardiogram-gated multidetector row computed tomography coronary angiography (PMDCTCA) (the x-ray beam is turned on for only a short portion of diastole) compared to retrospective ECG gating (RMDCTCA) (the x-ray beam is turned on throughout the cardiac cycle) and a preliminary approach of its diagnostic accuracy compared to digital invasive coronary angiography (CA). Material and Methods Fifty consecutive patients with suspected coronary artery disease and sinus rhythm were evaluated with PMDCT-CA and compared to a control group who underwent RMDCTCA. Image quality was analyzed by two reviewers. Interobserver concordance and ERD were determined. The diagnostic accuracy of PMDCT-CA compared to CA to detect coronary artery stenosis > 50% was assessed in 30 patients. Results There were no significant differences in the image quality between both groups. Agreement between the reviewers for segment image quality scores was k = 0.92. Mean ERD was 3.5 mSv for PMDCT-CA compared to 9.7 and 12.9 mSv for RMDCT-CA with and without tube current modulation, respectively. Individual analysis including all segments showed that the sensitivity, specificity, positive predictive value and negative predictive value of PMDCT-CA for the detection of coronary stenosis were 94.74%, 81.82%, 90% and 90%, respectively. Conclusion Our initial experience demonstrated that PMDCT-CA has similar subjective image quality scores with a substantial reduction of ERD when compared to RMDCT-CA in a selected population.

Reubicación de los vasos del cuello y exclusión endovascular de las disecciones y los aneurismas del arco aórtico / Replacement of Neck Vessels and Endovascular Exclusion of Aortic Arch Dissections and Aneurysms

El tratamiento endovascular de la aorta descendente le brinda a un grupo de pacientes seleccionados de alto riesgo una alternativa para resolver un problema grave de manera segura y efectiva. Sólo el 15% de los enfermos tiene un cuello adecuado para el implante respetando la integridad de la arteria subclavia izquierda y su oclusión intencional origina en hasta un 30% isquemia del brazo, síndrome vertebrobasilar o leaks. Además, los pacientes que presentan compromiso del arco aórtico (extensión retrógrada de la disección, porque ésta se origina allí o por aneurisma de ese sector) constituyen una población aún más seleccionada y de mayor riesgo para el tratamiento quirúrgico habitual. Entre noviembre de 2005 y diciembre de 2006 incluimos 10 pacientes que se presentaban con: 1) disecciones con compromiso de la arteria subclavia izquierda o retrodisecciones hacia el cayado aórtico (n = 7) y 2) aneurismas del cayado aórtico (n = 3). Fueron tratados dentro del período agudo (14 días), todos con un puntaje de riesgo anestésico (ASA) igual a 3 o mayor. Se utilizó una técnica híbrida, de un solo acto en dos etapas (quirúrgica/endovascular) realizadas en el mismo día. En la fase quirúrgica no se requirió paro cardíaco, circulación extracorpórea ni hipotermia profunda y durante la etapa endovascular se utilizaron prótesis autoexpandibles y es aquí donde se notaron las dificultades técnicas que debieron sortearse para llevar adelante el implante. Todos los procedimientos resultaron técnicamente exitosos. Dos pacientes fallecieron, uno en el primer día (taponamiento cardíaco) otro por sepsis en el día 27. No se registraron complicaciones neurológicas ni vasculares. La técnica fue factible y efectiva, con una morbimortalidad adecuada para la población en estudio y similar a la de publicaciones con pacientes de las mismas características.

Endovascular treatment of the descendant aorta is a safe and effective alternative to solve a severe condition in a selected group of high-risk patients. In only 15% of patients the anatomical relations of the aneurysm neck with the left subclavian artery are adequate for the implant, and the incidence of arm ischemia, vertebrobasilar artery syndrome or leaks related to the left subclavian artery intentionally occluded reaches 30%. In addition, patients with compromise of the aortic arch (due to dissections or aneurysms of the aortic arch) are still a more selected high-risk population for surgical treatment. Between November 2005 and December 2006 we included 10 patients with: 1) dissections with compromise of the left subclavian artery or dissections towards the aortic arch (n=7) and, 2) aneurisms of the aortic arch (n=3). All patients had ASA class III or greater, and they were all treated during the acute phase (14 days). A two-stage (surgical/endovascular) hybrid technique was performed during the same day. The surgical approach was carried out without the need for circulatory arrest, extracorporeal circulation, and deep hypothermia, but endovascular self-expanding stent-graft placement presented a few technical difficulties. All procedures were technically successful. Two patients died, one at day 1 (cardiac tamponade) and the other at day 27 (sepsis). No neurologic or vascular complications were reported. The procedure was feasible and effective, with morbidity and mortality rates according to the study population and similar to those reported in other studies performed on comparable patients.

Evaluación de las placas coronarias por tomografía computarizada multidetector de 16 filas: Correlación con ecografía intravascular / Assessment of Coronary Plaques by 16-Row Multidetector Computed Tomography: Correlation with Intravascular Ultrasound

Introducción El 50% de las muertes de etiología cardiovascular se deben a la enfermedad arteriosclerótica. Estudios recientes demostraron que las placas ateromatosas más propensas al desarrollo de un evento coronario son las que presentan ciertas características particulares, como un centro o core lipídico y remodelación positiva, denominadas placas vulnerables. La determinación temprana de la presencia de este tipo de placas ateroscleróticas tendría un impacto clínico de suma importancia y podría ayudar a prevenir el desarrollo de un síndrome coronario agudo en el futuro. Objetivo Determinar la certeza diagnóstica de la angiografía coronaria por tomografía computarizada multidetector de 16 filas (16-ACTCM) en la identificación, la caracterización y la cuantificación de las lesiones arterioscleróticas coronarias en comparación con la ecografía intravascular (EIV). Material y métodos Se estudiaron 45 pacientes con indicación de angiografía coronaria con 16-ACTCM y EIV. En cada segmento coronario se analizaron la carga de placa y las características de la placa aterosclerótica, que se clasificó en blanda, fibrosa y cálcica. La certeza diagnóstica de la 16- ACTCM para determinar la carga de placa y la identificación de placas coronarias se calculó con el método exacto binomial. Sobre la base de un análisis con curvas ROC se determinó el punto de corte para cada tipo de placa, así como la densidad media y la desviación estándar en unidades Hounsfield [UH]). Se evaluó además la certeza diagnóstica de la ACTCM para el diagnóstico de estenosis coronaria ≥ 50%. Resultados Para la detección de carga de placa, la sensibilidad fue del 96,2% y la especificidad fue del 81,9%. Para la detección de placas blandas, fibrosas y calcificadas, la sensibilidad y la especificidad fueron del 94,6% y 92,62%, del 94,9% y 98,5% y del 93,2% y 95,1%, respectivamente. Con un valor de corte de 85 UH, la 16-ACTCM diferenció correctamente el 86% de las placas blandas y fibrosas, con un área ROC = 0,96; con un valor de corte de 196,7 UH diferenció correctamente el 93% de las placas calcificadas y no calcificadas, con un área ROC = 0,98. Para la detección de estenosis coronaria, la sensibilidad fue del 81,58% y la especificidad fue del 93,8%. Conclusión La 16-ACTCM es una modalidad diagnóstica no invasiva promisoria para el estudio de pacientes con enfermedad coronaria, ya que permite la detección y la caracterización de los diferentes tipos de placa.

Background Atherosclerosis counts for 50% of cardiovascular deaths. Recent studies have demonstrated that certain atheromatous plaques with a lipid core and positive remodeling, known as vulnerable plaques, are more likely to develop plaque disruption, resulting in a coronary event. The early identification of these atheromatous plaques would have an extremely important clinical impact and might help to prevent the further development of an acute coronary syndrome. Objective To assess the diagnostic accuracy of coronary angiography with 16-row multidetector computed tomography (16-MCT) for the detection, characterization and quantification of atherosclerotic coronary artery lesions compared to intravascular ultrasound (IVUS). Material and Methods Forty five patients eligible to coronary angiography underwent 16-MCT and IVUS. Plaque burden and the characteristics of atheromatous plaques were analyzed in each coronary segment; plaques were classified in soft, fibrous and calcified. The binomial exact method was used to calculate the diagnostic accuracy of 16-MCT to determine the plaque burden and to identify coronary plaques. ROC curves analysis determined the cut-point for each type of plaque, as well as the mean density and the standard deviation expressed in Hounsfield units (HU). The diagnostic accuracy of the method for the diagnosis of coronary stenosis ≥ 50% was also assessed. Results The sensitivity and specificity of 16-MCT to detect plaque burden were 96.20% and 81.96%, respectively. For the detection of soft, fibrous and calcified plaques, the sensitivity and the specificity were 94.59% and 92.62%, 94.91% and 98.56%, and 93.22% and 95.13%, respectively. Using a cutpoint of 85 HU, 16-MCT properly identified 86% of soft and fibrous plaques, with an area under the ROC curve of 0.96; a cut-point of 196.68 UH resulted in an identification of 93% of calcified and non-calcified plaques, and the area under the ROC curve was 0.98. The sensitivity and specificity of the test for detecting coronary stenosis were 81.58% and 93.86%, respectively. Conclusion 16-MCT is a promising non-invasive diagnostic tool for the assessment of patients with coronary artery disease, useful for the detection and characterization of the different types of plaques.

New approach to noninvasive coronary angiography by multidetector computed tomography: initial experience using gadolinium.

OBJECTIVE: To investigate the gadolinium performance for 16-detector-row coronary computed tomography (CT) angiography. METHODS: Ethics committee approval and informed consent were obtained. Ten patients with coronary artery disease underwent digital coronary angiography and gadolinium-enhanced CT coronary angiography (Gd-CTCA) within the same week. For the Gd-CTCA, each patient received a dose of 0.3 mmol/kg of body weight of 0.5 mmol/mL gadoterate meglumine. Two readers interpreted the CT angiographies independently, and their results were matched with the digital angiography findings. The diagnostic accuracy of Gd-CTCA was calculated by the exact binomial method. RESULTS: Sensitivity, specificity, and positive and negative predictive values were for observer 1: 91.67%, 98.73%, 84.62%, and 99.36%, and for observer 2: 83.33%, 98.73%, 83.33%, and 98.73%, respectively. CONCLUSION: Preliminary results demonstrated that gadolinium chelates may be used as an alternative CT contrast media in coronary CT angiographies, without detriment to diagnosis results.

Feasibility of gadolinium-diethylene triamine pentaacetic acid enhanced multidetector computed tomography for the evaluation of coronary artery disease.

BACKGROUND: Multidetector computed tomography (MDCT) has been proposed as a noninvasive method for the diagnosis of obstructive coronary artery disease (CAD). In patients with high risk of iodinated contrast adverse effects such as acute allergic-type reactions, the use of gadolinium could be an alternative. OBJECTIVE: We sought to evaluate the feasibility of gadolinium-enhanced MDCT for the diagnosis of obstructive CAD. METHODS: Twenty patients (mean age, 61 years; range, 50-73 years) referred for X-ray coronary angiography were studied by both gadolinium and iodine-enhanced 16-row MDCT coronary angiography. The degree of enhancement and the accuracy for detection of obstructive CAD (>50% diameter reduction) were evaluated with X-ray coronary angiography as the standard. Renal nephrotoxicity was strictly monitored. RESULTS: Gadolinium- and iodine-enhanced MDCT showed adequate visualization of the coronary arteries in 310 of the 312 coronary artery segments that were available by X-ray angiography, respectively. The average density of the coronary arteries in both iodine and gadolinium CT scans was 253.65 Hounsfield unit (HU) and 135.20 HU, respectively. In a per-coronary segment analysis, gadolinium- and iodine-enhanced MDCT showed sensitivities of 89% vs 84%, specificities of 96% vs 95%, and negative predictive values of 97% vs 96%, respectively. In a per-patient analysis, both gadolinium- and iodine-enhanced MDCT showed sensitivities of 92.85% vs specificities of 83.33%. Intermethod agreement between gadolinium- and iodine-enhanced MDCT (kappa) was 0.95 (P < 0.0001). CONCLUSION: Our preliminary results indicate lower attenuation with gadolinium but similar diagnostic accuracy for the detection of obstructive CAD when compared with iodine-enhanced MDCT. Therefore, gadolinium is a feasible alternative contrast agent for patients with iodine contrast allergy referred for MDCT coronary angiography.