Diagnosis of obstructive coronary artery disease using computed tomography angiography in patients with stable chest pain depending on clinical probability and in clinically important subgroups: meta-analysis of individual patient data.

OBJECTIVE: To determine whether coronary computed tomography angiography (CTA) should be performed in patients with any clinical probability of coronary artery disease (CAD), and whether the diagnostic performance differs between subgroups of patients. DESIGN: Prospectively designed meta-analysis of individual patient data from prospective diagnostic accuracy studies. DATA SOURCES: Medline, Embase, and Web of Science for published studies. Unpublished studies were identified via direct contact with participating investigators. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Prospective diagnostic accuracy studies that compared coronary CTA with coronary angiography as the reference standard, using at least a 50% diameter reduction as a cutoff value for obstructive CAD. All patients needed to have a clinical indication for coronary angiography due to suspected CAD, and both tests had to be performed in all patients. Results had to be provided using 2×2 or 3×2 cross tabulations for the comparison of CTA with coronary angiography. Primary outcomes were the positive and negative predictive values of CTA as a function of clinical pretest probability of obstructive CAD, analysed by a generalised linear mixed model; calculations were performed including and excluding non-diagnostic CTA results. The no-treat/treat threshold model was used to determine the range of appropriate pretest probabilities for CTA. The threshold model was based on obtained post-test probabilities of less than 15% in case of negative CTA and above 50% in case of positive CTA. Sex, angina pectoris type, age, and number of computed tomography detector rows were used as clinical variables to analyse the diagnostic performance in relevant subgroups. RESULTS: Individual patient data from 5332 patients from 65 prospective diagnostic accuracy studies were retrieved. For a pretest probability range of 7-67%, the treat threshold of more than 50% and the no-treat threshold of less than 15% post-test probability were obtained using CTA. At a pretest probability of 7%, the positive predictive value of CTA was 50.9% (95% confidence interval 43.3% to 57.7%) and the negative predictive value of CTA was 97.8% (96.4% to 98.7%); corresponding values at a pretest probability of 67% were 82.7% (78.3% to 86.2%) and 85.0% (80.2% to 88.9%), respectively. The overall sensitivity of CTA was 95.2% (92.6% to 96.9%) and the specificity was 79.2% (74.9% to 82.9%). CTA using more than 64 detector rows was associated with a higher empirical sensitivity than CTA using up to 64 rows (93.4% v 86.5%, P=0.002) and specificity (84.4% v 72.6%, P<0.001). The area under the receiver-operating-characteristic curve for CTA was 0.897 (0.889 to 0.906), and the diagnostic performance of CTA was slightly lower in women than in with men (area under the curve 0.874 (0.858 to 0.890) v 0.907 (0.897 to 0.916), P<0.001). The diagnostic performance of CTA was slightly lower in patients older than 75 (0.864 (0.834 to 0.894), P=0.018 v all other age groups) and was not significantly influenced by angina pectoris type (typical angina 0.895 (0.873 to 0.917), atypical angina 0.898 (0.884 to 0.913), non-anginal chest pain 0.884 (0.870 to 0.899), other chest discomfort 0.915 (0.897 to 0.934)). CONCLUSIONS: In a no-treat/treat threshold model, the diagnosis of obstructive CAD using coronary CTA in patients with stable chest pain was most accurate when the clinical pretest probability was between 7% and 67%. Performance of CTA was not influenced by the angina pectoris type and was slightly higher in men and lower in older patients. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42012002780.

Applicability and accuracy of pretest probability calculations implemented in the NICE clinical guideline for decision making about imaging in patients with chest pain of recent onset.

OBJECTIVES: To analyse the implementation, applicability and accuracy of the pretest probability calculation provided by NICE clinical guideline 95 for decision making about imaging in patients with chest pain of recent onset. METHODS: The definitions for pretest probability calculation in the original Duke clinical score and the NICE guideline were compared. We also calculated the agreement and disagreement in pretest probability and the resulting imaging and management groups based on individual patient data from the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT). RESULTS: 4,673 individual patient data from the CoMe-CCT Consortium were analysed. Major differences in definitions in the Duke clinical score and NICE guideline were found for the predictors age and number of risk factors. Pretest probability calculation using guideline criteria was only possible for 30.8 % (1,439/4,673) of patients despite availability of all required data due to ambiguity in guideline definitions for risk factors and age groups. Agreement regarding patient management groups was found in only 70 % (366/523) of patients in whom pretest probability calculation was possible according to both models. CONCLUSIONS: Our results suggest that pretest probability calculation for clinical decision making about cardiac imaging as implemented in the NICE clinical guideline for patients has relevant limitations. KEY POINTS: • Duke clinical score is not implemented correctly in NICE guideline 95. • Pretest probability assessment in NICE guideline 95 is impossible for most patients. • Improved clinical decision making requires accurate pretest probability calculation. • These refinements are essential for appropriate use of cardiac CT.

Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT).

BACKGROUND: Coronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780). METHODS/DESIGN: The analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest likelihood of coronary artery disease. A bivariate random-effects model will be used to calculate pooled mean negative and positive predictive values as well as sensitivity and specificity. The primary outcome of interest will be positive and negative predictive values of coronary computed tomography angiography for the presence of coronary artery disease as a function of pretest likelihood of coronary artery disease, analyzed by meta-regression. As a secondary endpoint, factors that may influence the diagnostic performance and clinical value of computed tomography, such as heart rate and body mass index of patients, number of detector rows, and administration of beta blockade and nitroglycerin, will be investigated by integrating them as further covariates into the bivariate random-effects model. DISCUSSION: This collaborative individual patient data meta-analysis should provide answers to the pivotal question of which patients benefit most from noninvasive coronary computed tomography angiography and thus help to adequately select the right patients for this test.

Asociación entre algunos factores de riesgo cardiovascular y el puntaje de calcio coronario en pacientes sintomáticos / Association between some cardiovascular risk factors and coronary calcium scoring in symptomatic patients

Introducción: el conocimiento de la carga aterosclerótica global individual es de alta importancia. Su asociación con los factores de riesgo cardiovascular no está bien establecida. Objetivo: determinar la asociación entre algunos factores de riesgo cardiovascular y el puntaje de calcio coronario. Métodos: se estudiaron 169 pacientes sintomáticos con sospecha de cardiopatía isquémica, que de forma consecutiva se realizaron el puntaje de calcio, se identificaron los factores de riesgo y para determinar su asociación se utilizó el modelo de regresión logística. Resultados: el estudio incluyó 106 mujeres y 63 hombres, edad media 59,6 ± 10,8 años vs. 59,5 ± 11,0 años, respectivamente. El 51,9 pociento de las mujeres y el 34,9 porciento de los hombres tuvieron un score = 0. La dosis media de radiación efectiva fue de 0,82 mSv. Las variables sexo masculino > 55 años, femenino > 65 años, hábito de fumar, diabetes mellitus, edad, número de factores de riesgo, VLDL, triglicéridos y HDL, mostraron asociación significativa con algunos de los valores de corte del puntaje de calcio establecidos. En el análisis multivariado, la edad, el hábito de fumar, los triglicéridos y la HDL como factor protector, tuvieron coeficientes significativamente diferentes de 0, siendo la edad la que tuvo mayor influencia en el valor del score de calcio > 0 y ³ 100 y la HDL en el valor ³ 400. Conclusiones: solamente algunos factores de riesgo muestran asociación con el puntaje de calcio coronario, fundamentalmente la edad y los niveles de HDL como factor protector

Introduction: knowledge of an individual's overall atherosclerotic burden is extremely important. Its association with cardiovascular risk factors has not been well established. Objective: determine the association between some cardiovascular risk factors and coronary calcium scoring. Methods: a study was conducted of 169 symptomatic patients with suspected ischemic heart disease. The patients consecutively underwent calcium scoring and risk factor identification. Association between the two values was determined by logistic regression modeling. Results: 106 patients were women and 63 were men; mean age was 59.6 ± 10.8 and 59.5 ± 11.0, respectively. 51.9 percent of the women and 34.9 percent of the men had a score = 0. Mean effective radiation dose was 0.82 mSv. The variables male patient aged > 55, female patient aged > 65, smoking, diabetes mellitus, age, number of risk factors, VLDL, triglycerides and HDL showed a significant association with some of the calcium score cut-off values established. In the multivariate analysis, age, smoking, triglycerides and HDL as a protective factor, exhibited coefficients significantly different from 0, with age exerting the greatest influence upon the calcium score > 0 and ³ 100 value, and HDL upon the ³ 400 value. Conclusions: only some risk factors show an association with coronary calcium score, particularly age and HDL levels as a protective factor

[Accuracy of the 64 multislice computed tomography in the diagnosis of coronary stent restenosis]. / Precisión de la tomografía de 64 cortes en el diagnóstico de reestenosis de stent coronario.

OBJECTIVE: To determine the accuracy of coronary angiography through 64-slice computed tomography in detecting in-stent restenosis. METHOD: Fifty-two patients with 76 coronary stents and suspicion of restenosis were examined. Initially, they underwent coronary angiography through 64-slice computed tomography, and subsequently invasive coronary angiography as gold standard. Diagnostic efficiency indexes were calculated. RESULTS: In the stents of 3 mm or more of diameter, tomography sensitivity, specificity, positive and negative predictive value were 95, 98, 95 and 98% respectively, with positive likelihood ratio of 42 (CI95%, 6 to 290) and negative of 0.05 (CI95%, .01 to .35), validity of 97% and Kappa of 0.93 (CI95%, .83 to 1), (p ? 0.00001). In the stents smaller than 3 mm, the indexes of diagnostic efficiency and Kappa considerably decreased, loosing the statistical significance (p >0.05). CONCLUSIONS: Coronary angiography through 64-slice computed tomography is an accurate, non-invasive clinical technique for the detection of in-stent restenosis, especially with stents of 3 mm or more of diameter, and reliable allows identification of patients who need to undergo or not control invasive coronary angiography.

Precisión de la tomografía de 64 cortes en el diagnóstico de reestenosis de stent coronario / Accuracy of the 64 multislice computed tomography in the diagnosis of coronary stent restenosis

Objetivo: Determinar la precisión de la coronariografía por tomografía de 64 cortes para la detección de la reestenosis de los stents. Método: Se examinaron 52 pacientes portadores de 76 stents coronarios con sospecha de reestenosis. Inicialmente se les realizó coronariografía mediante tomógrafo de 64 cortes y posteriormente coronariografía invasiva como patrón de referencia. Se calcularon los índices de eficiencia diagnóstica. Resultados: En los stents valorables de 3 mm o más de diámetro, la sensibilidad, especificidad, valor predictivo positivo y negativo de la tomografía fueron de 95, 98, 95 y 98% respectivamente, con razón de verosimilitud positiva de 42 (IC95%, 6 a 290) y negativa de 0.05 (IC95%, 0.01 a 0.35), validez de 97% y Kappa de 0.93 (IC95%, 0.83 a 1), (p ≤ 0.00001). En los stents valorables menores que 3 mm, disminuyeron apreciablemente los índices de eficiencia diagnóstica y de Kappa, perdiendo la significancia estadística (p > 0.05). Conclusión: La coronariografía por tomografía de 64 cortes es una técnica clínica no invasiva precisa, en la detección de la reestenosis de los stents, sobre todo en los stents de 3 mm o más, y segura, ya que permite identificar a los pacientes que necesitan o no la realización de una coronariografía invasiva de control.

Objective: To determine the accuracy of coronary angiography through 64-slice computed tomography in detecting in-stent restenosis. Method: Fifty-two patients with 76 coronary stents and suspicion of restenosis were examined. Initially, they underwent coronary angiography through 64-slice computed tomography, and subsequently invasive coronary angiography as gold standard. Diagnostic efficiency indexes were calculated. Results: In the stents of 3 mm or more of diameter, tomography sensitivity, specificity, positive and negative predictive value were 95, 98, 95 and 98% respectively, with positive likelihood ratio of 42 (CI95%, 6 to 290) and negative of 0.05 (CI95%, .01 to .35), validity of 97% and Kappa of 0.93 (CI95%, .83 to 1), (p ≤ 0.00001). In the stents smaller than 3 mm, the indexes of diagnostic efficiency and Kappa considerably decreased, loosing the statistical significance (p >0.05). Conclusions: Coronary angiography through 64-slice computed tomography is an accurate, non-invasive clinical technique for the detection of in-stent restenosis, especially with stents of 3 mm or more of diameter, and reliable allows identification of patients who need to undergo or not control invasive coronary angiography.

[Volume of coronary calcified plaques by computed tomography and presence of significant stenosis by coronary angiography]. / Volumen de placas coronarias calcificadas por tomografía computarizada y presencia de estenosis significativa por angiografía coronaria.

BACKGROUND: Coronary artery calcium is almost pathognomonic of atherosclerosis. In 1990, Agatston designed a method to measure the coronary calcium score by computed tomography. Our aim was to establish the association between coronary calcified plaque volumes calculated by 64 slice computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography. METHOD: 150 consecutive patients, 66.6% male, scheduled for invasive coronary angiography were studied. Coronary calcium score was measured per patient and per artery by computed tomography previous to invasive coronary angiography. 128 calcified plaques were enrolled and volume was determined by Callister method introduced in 1998. According to the volume, the plaques were classified in two groups: small if volume ≤ 10 mm3 and big if > 10 mm3. RESULTS: In 79% of plaques with a volume > 10 mm3, significant coronary stenosis was detected by invasive coronary angiography versus 17% with small volume (p < 0.0001). More than 75% of plaques with volume > 10 mm3 in circumflex artery, anterior descending artery and right coronary artery were associated with significant coronary stenosis (p < 0.0001). Spearman correlation was 0.8. The sensitivity and specificity of significant coronary stenosis were 98.7% and 71.7% respectively for a cut off value of 6,5 mm3, area under the curve of 0,88 ± 0,32 (CI 95%, 0.815 to 0.940). CONCLUSIONS: Association between coronary calcified plaque volume diagnosed by computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography was observed.

Utilidad del score de calcio en el diagnóstico de enfermedad coronaria obstructiva / Usefulness of the calcium score in the diagnosis of obstructive coronary disease

Introducción: La presencia de calcio en las coronarias es prácticamente patognomónica de aterosclerosis. En el año 1990, Agatston diseño un método para cuantificar el calcio a través de la tomografía. El objetivo del presente trabajo fue determinar el valor del puntaje de calcio coronario para confirmar o descartar obstrucción coronaria significativa. Métodos: Se incluyeron 276 pacientes (80 por ciento del sexo masculino y edad media de 56±10 años) con sospecha de cardiopatía isquémica, a los que inicialmente se les realizó cuantificación del calcio coronario a través de la tomografía de 64 cortes y luego coronariografía por cateterismo. Se determinó sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo, razones de verosimilitudes, índice de kappa y validez diagnóstica para puntos de corte 0, 25, 50, 100 y 400 Unidades Agatston (UA) de puntaje de calcio por pacientes y arterias para diagnosticar estenosis coronaria significativa tomando como patrón de referencia la coronariografía invasiva, así como el área bajo la curva ROC. Se consideró significativo una p<0,05 y un índice de confiabilidad del 95 por ciento. Resultados: La sensibilidad, especificidad y el valor predictivo negativo fueron 96 por ciento, 51 por ciento y 92,4 por ciento respectivamente y kappa de 0,46 (IC 95 por ciento, 0,37-0,56), (p<0,0001) para punto de corte 0 UA, y para punto de corte 50 UA fueron 84 por ciento; 80 por ciento y 84 por ciento respectivamente con kappa de 0,64 (IC 95 por ciento, 0,56-0,74), (p<0,0001). El área bajo la curva ROC en el análisis por pacientes fue 0,887±0,020 (0,848-0,926)...

Introduction: The presence of calcium in coronary arteries is practically pathognomonic of the atherosclerosis. In 1990, Agatston designed a method for to quantify the calcium by tomography. The aim of present paper was to determine the coronary calcium score to confirm or to rule out a significant coronary obstruction. Methods: In present study authors included 276 patients (80 percent of male sex and a mean age of 56 ± 10 years) with suspect of ischemic heart disease, who initially underwent a quantification of coronary calcium by 64 scans tomography and then a catheterization coronariography. The sensitivity, specificity, positive and negative predictive value, credibility reasons, Kappa index and diagnostic validity for scan points 0, 25, 50, 100 and 400 Agatston (AU) of calcium score for patients and arteries to diagnose a significant coronary stenosis taking as reference pattern the invasive coronary one, as well as the area under the ROC curve. A p <0,05 and a reliability rate of 95 percent were considered as significant. Results: The sensitivity, specificity and negative predictive value were of 96 percent, 51 percent and 92,4 percent, respectively and a Kappa index of 0,46 (95 percent CI, 0,37-0,56), (p <0,0001) for a scan point 0 UA and for a scan point 50 UA were of 84, percent, 80 percent and 84 percent, respectively with a Kappa index of 0,64 (95 percent CI, 0,56-0,74),(<0,0001). In analysis by patients the area under the ROC curve, the sensitivity, specificity and negative predictive value were of 91 percent, 66 percent and 96 percent, respectively with a Kappa index of 0,43 (95 percent CI, 0,39-0,48), (p<0,0001) and for the scan point 25 UA 83 percent and 94 percent, respectively with a Kappa index of 0,58 (95 percent CI, 0,52-063), (p<0,0001)...

Volumen de placas coronarias calcificadas por tomografía computarizada y presencia de estenosis significativa por angiografía coronaria / Volume of coronary calcified plaques by computed tomography and presence of significant stenosis by coronary angiography

Introducción: La presencia de calcio en las arterias coronarias es prácticamente patognomónica de aterosclerosis. En 1990, Agatston diseñó un método para cuantificar el puntaje de calcio coronario a través de la tomografía computarizada. Nuestro objetivo fue determinar la asociación entre el volumen de las placas calcificadas en las arterias coronarias determinado por tomografía de 64 cortes y la presencia de estenosis coronaria significativa diagnosticada por coronariografía invasiva. Método: Se estudiaron consecutivamente 150 pacientes, 66.6% varones, programados para coronariografía invasiva. Previo a este procedimiento, se les cuantificó el puntaje de calcio por arteria y por paciente a través de la tomografía. Se incluyeron 128 placas calcificadas, a las que se les determinó el volumen a través del método de Callister introducido en el año 1998. Las placas se consideraron pequeñas si el volumen era ≤ 10 mm³ y grandes si >10 mm³. Resultados: Se asociaron a estenosis coronaria significativa 79% de las placas con volumen mayor a 10 mm³, contra 17% con volumen pequeño (p < 0.0001). Más de 75% de las placas con volumen mayores de 10 mm³ en las arterias circunfleja, descendente anterior y coronaria derecha, se asociaron a estenosis coronaria significativa en el segmento de la placa (p < 0.0001). Correlación de Spearman 0.8. La sensibilidad y especificidad diagnóstica de estenosis coronaria significativa fueron 98.7% y 71.7 % respectivamente para un valor de corte 6.5 mm³ con un área bajo la curva de 0.88 ± 0.32 (IC 95%, 0.815 a 0.940). Conclusiones: Se observó asociación entre el volumen de las placas calcificadas circunscritas en las arterias coronarias diagnosticada por tomografía computada y la presencia de estenosis coronaria significativa diagnosticada por coronariografía invasiva.

Background: Coronary artery calcium is almost patognomonic of atherosclerosis. In 1990, Agatston designed a method to measure the coronary calcium score by computed tomography. Our aim was to establish the association between coronary calcified plaque volumes calculated by 64 slice computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography. Method: 150 consecutive patients, 66.6% male, scheduled for invasive coronary angiography were studied. Coronary calcium score was measured per patient and per artery by computed tomography previous to invasive coronary angiography. 128 calcified plaques were enrrolled and volume was determined by Callister method introduced in 1998. According to the volume, the plaques were classified in two groups: small if volume ≤ 10 mm³ and big if > 10 mm³. Results: In 79% of plaques with a volume > 10 mm³, significant coronary stenosis was detected by invasive coronary angiography versus 17% with small volume (p < 0.0001). More than 75% of plaques with volume > 10 mm³ in circumflex artery, anterior descending artery and right coronary artery were associated with significant coronary stenosis (p < 0.0001). Spearman correlation was 0.8. The sensitivity and specificity of significant coronary stenosis were 98.7% and 71.7% respectively for a cut off value of 6,5 mm³, area under the curve of 0,88 ± 0,32 (CI 95%, 0.815 to 0.940). Conclusions: Association between coronary calcified plaque volume diagnosed by computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography was observed.

[Accuracy of 64 slice computed tomography angiography in the diagnosis of ischemic coronary artery disease]. / Precisión de la tomografía de 64 cortes en el diagnóstico de la cardiopatía isquémica.

INTRODUCTION AND OBJECTIVES: Multislice computed tomography coronary angiography (MSCT-CA) has been developed in the last years. One of the advantages is to supply information of the lumen and wall of the vessels. The aim was to assess the diagnostic accuracy of MSCT - CA to detect significant coronary stenoses taking as gold standard the invasive coronary angiography (ICA). PATIENTS AND METHODS: We studied, after informed consent, 64 consecutive patients (50 males). First MSCT - CA was performed and afterwards with a media of 45 days the ICA. Sensitivity (SENS), specificity (ESP), positive predictive value (PPV), negative predictive value (NPV) and predictive precision (PP) were assessed per patients, per arteries and per segments. RESULTS: The SENS, ESP, PPV, PNV and PP were 96.4, 91.2, 87, 96.8, 93.5% respectively per patients and 95.7, 97, 88.2, 98.9, 96.7% respectively per arteries and 91, 99, 89, 99.6, 98.7% respectively per segments. The diagnostic accuracy decreased in patients with heart rate higher than 65 beats per minute, as well as in patients with calcium scoring higher than 400 Agatston Units or body mass index with or higher than 30 kg/m2 CS. CONCLUSIONS: Our results suggest that MSCT - CA has a good accuracy, especially in the ESP and NPV for the diagnosis of significant coronary stenoses in selected patients with calcium scoring of 400 Agatston Units or lower, heart rate with 65 beats per minute or lower with regular rhythm and body mass index lower than 30 kg/m2 CS.

Precisión de la tomografía de 64 cortes en el diagnóstico de la cardiopatía isquémica / Accuracy of 64 slice computed tomography angiography in the diagnosis of ischemic coronary artery disease

INTRODUCTION AND OBJECTIVES: Multislice computed tomography coronary angiography (MSCT-CA) has been developed in the last years. One of the advantages is to supply information of the lumen and wall of the vessels. The aim was to assess the diagnostic accuracy of MSCT - CA to detect significant coronary stenoses taking as gold standard the invasive coronary angiography (ICA). PATIENTS AND METHODS: We studied, after informed consent, 64 consecutive patients (50 males). First MSCT - CA was performed and afterwards with a media of 45 days the ICA. Sensitivity (SENS), specificity (ESP), positive predictive value (PPV), negative predictive value (NPV) and predictive precision (PP) were assessed per patients, per arteries and per segments. RESULTS: The SENS, ESP, PPV, PNV and PP were 96.4, 91.2, 87, 96.8, 93.5% respectively per patients and 95.7, 97, 88.2, 98.9, 96.7% respectively per arteries and 91, 99, 89, 99.6, 98.7% respectively per segments. The diagnostic accuracy decreased in patients with heart rate higher than 65 beats per minute, as well as in patients with calcium scoring higher than 400 Agatston Units or body mass index with or higher than 30 kg/m2 CS. CONCLUSIONS: Our results suggest that MSCT - CA has a good accuracy, especially in the ESP and NPV for the diagnosis of significant coronary stenoses in selected patients with calcium scoring of 400 Agatston Units or lower, heart rate with 65 beats per minute or lower with regular rhythm and body mass index lower than 30 kg/m2 CS.

Precisión de la tomografía de 64 cortes en el diagnóstico de estenosis coronaria significativa / Accuracy of 64-slice computed tomography in the diagnosis of significant coronary stenosis

La coronariografía invasiva (CI) constituye el patrón de referencia para el estudio de las arterias coronarias. Se ha planteado que la tomografía computarizada de múltiples cortes (TCMC) puede evitar la CI. Se estudiaron 62 pacientes, 50 del sexo masculino, edad media 56 ± 8 años para evaluar la precisión diagnóstica de la TCMC de 64 cortes en la detección de estenosis coronarias significativas (ECS), comparándola con la CI. Se les realizó la CI por presentar ECS o persistencia de los síntomas. Se determinó sensibilidad (S), especificidad (E), valor predictivo positivo (VPP), valor predictivo negativo (VPN) y precisión predictiva (PP) por pacientes y por arterias. La S, la E, el VPP, el VPN y la PP fueron 96,4; 91,2; 87; 96,8 y 93,5 por ciento, respectivamente, por pacientes, y 95,7; 97; 88,2; 98,9 y 96,7 por ciento, respectivamente, por arterias. Se concluyó que la TCMC puede sustituir la CI en pacientes seleccionados.

Invasive coronariography (IC) is the reference pattern for the study of coronary arteries. It has been stated that multiple slice computed tomography (MSCT) may avoid IC. 62 patients, 50 of whom were males, with mean age 56 ± 8, were studied to evaluate the diagnostic accuracy of the 64-slice MSCT in the detection of significant coronary stenoses (SCS), comparing it with IC. IC was performed due to the presence of SCS or persistence of the symptoms. Sensitivity (S), specificity (E), positive predictive value (PPV), negative predictive value (NPV) and predictive accuracy (PA) were determined by patients and arteries. S, E, PPV, NPV and PA were 96.4; 91.2; 87; 96.8 and 93.5 percent per patient, respectively; whereas they were 95.7; 97; 88.2; 98.9 and 96.7 percent by artery, respectively. It was concluded that MSCT may replace IC in selected patients.

Puntuación de calcio en arterias coronarias y presencia de estenosis angiográficamente significativas / Calcium scoring in coronary arteries and presence of angiographically significant stenosis

La presencia de calcio en las arterias coronarias es patognomónica de aterosclerosis. Agatston diseñó un método para cuantificar el puntaje de calcio coronario mediante la tomografía para determinar la asociación entre el grado de calcificación en las arterias coronarias determinado por tomografía de 64 cortes y la presencia de estenosis coronarias significativas (ECS) diagnosticadas por coronariografía invasiva (CI). Se estudiaron 153 pacientes, los cuales estaban programados para CI. Previo a la CI se les cuantificó el puntaje de calcio por arteria y por paciente. El 91,7 por ciento de los pacientes con puntaje ≤ 10 UA (unidades Agatston) no presentó ECS contra 8,3 por ciento con puntaje ≥ 401 UA (p < ,0001). El 2,4 por ciento con puntaje ≤ 10 UA en el tronco de la coronaria izquierda presentó ECS contra el 75 por ciento con puntaje ≥ 401 UA (p< 0,0001). El 5,5 por ciento con puntaje ≤ 10 UA en la arteria descendente anterior tenía ECS contra el 87,5 por ciento con puntaje ≥ 401 UA (p< 0,0001). Similar comportamiento se observó en las demás arterias. Se concluyó que existía asociación entre el grado de puntaje de calcio en las arterias coronarias diagnosticado por tomografía y la presencia de ECS diagnosticadas por CI.

The presence of calcium in the coronary arteries is pathognomonic of atherosclerosis. Agatston designed a method to quantify the coronary calcium scoring by tomography to determine the association between the degree of calcification in the coronary arteries by 64-slice computed tomography and the presence of significant coronary stenosis (SCS) diagnosed by invasive coronariography (IC). 153 patients that were scheduled for IC were studied. The calcium scoring was quantified by patient and by artery before performing the IC. 91.7 percent of the patients with scoring £10 UA (Agatston units) did not present SCS versus 8.3 percent with scoring ³ 401 UA (p< .0001). 2.4 percent with scoring 10 UA in the trunk of the left coronary presented SCS versus 75 percent with scoring 401 UA (p < 0.0001). 5.5 percent with scoring 10 UA in the anterior descending artery has SCS versus 87.5 percent with scoring 401 UA (p < 0.0001). Similar behavior was observed in the rest of the arteries. It was concluded that there was association between the calcium degree scoring in the coronary arteries diagnosed by computed tomography and the presence of SCS diagnosed by IC.

Coronariografía por tomografía de 64 cortes: Precisión diagnóstica según puntaje de calcio y frecuencia cardíaca / Coronariography by 64-Slice Computed Tomography: Diagnostic Accuracy According to Calcium Score and Heart Rate

Introducción y Objetivos La coronariografía invasiva (CI) es el patrón estándar para el estudio de las coronarias con un bajo índice de complicaciones. La tomografía computarizada multicorte (TCMC) permite el estudio mínimamente invasivo del árbol coronario. El objetivo del presente trabajo estuvo dirigido a determinar la precisión de la TCMC para detectar estenosis coronaria significativa (ECS) según puntaje de calcio y frecuencia cardíaca. Material y métodos Se estudiaron 62 pacientes, 50 del sexo masculino, a los que se les realizó primero la coronariografía por TCMC y luego la CI, con una media de 45 días, previo consentimiento informado. Se determinaron la sensibilidad (S), la especificidad (E), el valor predictivo positivo (VPP), el valor predictivo negativo (VPN) y la precisión predictiva (PP) por paciente y arterias según puntaje de calcio y frecuencia cardíaca. Resultados La S, la E, el VPP, el VPN y la PP por arterias fueron, respectivamente, con puntaje de calcio menor o igual a 400 UA del 98%, 98%, 89%, 99% y 98% y con puntaje mayor de 400 UA, del 75%, 50%, 75%, 50% y 67%. En los 54 pacientes con frecuencia cardíaca menor o igual a 65 latidos por minuto, la S, la E, el VPP, el VPN y la PP fueron del 100%, 96%, 96%, 100% y 98,1% y en los 8 pacientes con frecuencia cardíaca mayor de 65 latidos por minuto fueron del 50%, 66,7%, 33%, 80% y 62,5%, respectivamente. Conclusiones El puntaje de calcio por encima de 400 UA por paciente y arterias, como también la frecuencia cardíaca mayor de 65 latidos por minuto, disminuyen la precisión diagnóstica de ECS a través de la TCMC.

Introduction and Objectives Invasive coronariography (IC) is the gold standard for the study of coronary arteries with a low percentage of complications. Multislice computerized tomography (MSCT) allows the minimally invasive study of the coronary tree. The objective of the present study was aimed at determining the accuracy of MSCT in the detection of significant coronary stenosis (SCS) by calcium score and heart rate. Material and Methods The 62 patients enrolled in the study (50 males) underwent a coronariography with MSCT, and later the IC, with a mean of 45 days, after signature of an informed consent. Sensitivity (Se) was assessed, as well as specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and predictive accuracy (PA) per patient and arteries, according to calcium score and heart rate. Results Se, Sp, PPV, NPV and PA per arteries, with a calcium score lower or equal to 400 AU were, respectively 98%, 98%, 89%, 99% and 98%, and with a score higher than 400 AU, of 75%, 50%, 75%, 50% and 67%. In 54 patients with heart rate lower or equal to 65 beats per minute, Se, Sp, PPV, NPV and PA were 100%, 96%, 96%, 100% and 98,1% and in the 8 patients with heart rate higher than 65 beats per minute were 50%, 66.7%, 33%, 80% and 62.5%, respectively. Conclusions Calcium score above 400 AU per patient and arteries, as well as the heart rate over 65 beats per minute, decrease the diagnostic accuracy of SCS by means of MSCT.