A deep-learning model for the assessment of coronary heart disease and related risk factors via the evaluation of retinal fundus photographs / 中华心血管病杂志

Objective: To develop and validate a deep learning model based on fundus photos for the identification of coronary heart disease (CHD) and associated risk factors. Methods: Subjects aged>18 years with complete clinical examination data from 149 hospitals and medical examination centers in China were included in this retrospective study. Two radiologists, who were not aware of the study design, independently evaluated the coronary angiography images of each subject to make CHD diagnosis. A deep learning model using convolutional neural networks (CNN) was used to label the fundus images according to the presence or absence of CHD, and the model was proportionally divided into training and test sets for model training. The prediction performance of the model was evaluated in the test set using monocular and binocular fundus images respectively. Prediction efficacy of the algorithm for cardiovascular risk factors (e.g., age, systolic blood pressure, gender) and coronary events were evaluated by regression analysis using the area under the receiver operating characteristic curve (AUC) and R2 correlation coefficient. Results: The study retrospectively collected 51 765 fundus images from 25 222 subjects, including 10 255 patients with CHD, and there were 14 419 male subjects in this cohort. Of these, 46 603 fundus images from 22 701 subjects were included in the training set and 5 162 fundus images from 2 521 subjects were included in the test set. In the test set, the deep learning model could accurately predict patients' age with an R2 value of 0.931 (95%CI 0.929-0.933) for monocular photos and 0.938 (95%CI 0.936-0.940) for binocular photos. The AUC values for sex identification from single eye and binocular retinal fundus images were 0.983 (95%CI 0.982-0.984) and 0.988 (95%CI 0.987-0.989), respectively. The AUC value of the model was 0.876 (95%CI 0.874-0.877) with either monocular fundus photographs and AUC value was 0.885 (95%CI 0.884-0.888) with binocular fundus photographs to predict CHD, the sensitivity of the model was 0.894 and specificity was 0.755 with accuracy of 0.714 using binocular fundus photographs for the prediction of CHD. Conclusion: The deep learning model based on fundus photographs performs well in identifying coronary heart disease and assessing related risk factors such as age and sex.

Evaluation of myocardial perfusion and systolic function in patients with coronary heart disease by myocardial contrast echocardiography and 2-dimensional speckle tracking imaging / 中南大学学报(医学版)

OBJECTIVES@#The high prevalence and high fatality rate of coronary heart disease seriously endanger the safety of human life. The key to its treatment is to restore the perfusion of the narrowed coronary arteries as soon as possible. Two-dimensional echocardiography is limited for assessment of postoperative myocardial function. Myocardial contrast echocardiography (MCE) and 2-dimensional speckle tracking imaging (2D-STI) possess good value in assessing myocardial perfusion and systolic function. We used MCE and 2D-STI to explore the changes of myocardial perfusion and systolic function after percutaneous coronary intervention (PCI) in patients with coronary heart disease, and to evaluate the clinical value of MCE and 2D-STI.@*METHODS@#Twenty patients with coronary heart disease undergoing PCI were selected. MCE was performed before and one day after PCI, and 2D-STI and conventional ultrasound were performed before and a month after PCI. The recovery of left ventricular wall motion was used as a standard to evaluate the ability of MCE semi-quantitative analysis and to predict the recovery of myocardial segment motion.@*RESULTS@#The quantitative value of MCE (signal intensity of contrast medium in plateau phase, slope of curve, and their product) one day after PCI and the contractile function of one month after PCI were significantly improved (all @*CONCLUSIONS@#MCE and 2D-STI can evaluate the improvement of myocardial perfusion and systolic function in patients with coronary heart disease after PCI, and MCE semi-quantitative analysis can effectively predict the ability of ventricular wall recovery.

Estudio de la deformación miocárdica longitudinal en pacientes con cardiopatía isquémica / Study of longitudinal myocardial deformation in patients with ischemic cardiopathy

Resumen Introducción: Las enfermedades cardiovasculares constituyen la primera causa de muerte en Cuba y la mayoría de los países desarrollados. La ecocardiografía con speckle tracking bidimensional (ST 2D) es una técnica reciente en la evaluación de la función cardíaca. Objetivos: Determinar la relación entre la deformación miocárdica medida por ST 2D y el estado de la circulación coronaria en pacientes con cardiopatía isquémica, en el CIMEQ, durante un año. Material y método: Se realizó un estudio analítico y transversal con 55 pacientes con indicación de coronariografía sometidos a ecocardiograma bidimensional y estudio de ST 2D con medición de la deformación longitudinal (DLG). Se crearon dos grupos: enfermedad coronaria significativa (ECS = 32) y no significativa (ECNS = 23). Se utilizó SSPS para análisis de los resultados. Resultados: La edad promedio fue mayor en la ECS (55.6 ± 9.3 vs. 61.8 ± 8.8; p = 0.014). Predominaron los hombres con ECS (47.3%), los hipertensos (ECS = 90.6% y ENCS = 65.2%; p = 0.02) y los fumadores (ECS = 59.4% y ENCS = 17.4%; p = 0.002). El diagnóstico más frecuente fue la angina crónica estable (87%). En la ECS predominó la enfermedad de tres vasos (75%). La DLG fue menor en la ECS [(-20.0 ± 3.2 vs. -22.1 ± 3.6; p = 0.035); AUC = 0.458]. No hubo diferencias en la DLG según el número de vasos significativamente afectados. Conclusiones: Los resultados encontrados no justifican el empleo del ST 2D para diferenciar la ECS.

Abstract Introduction: Cardiovascular diseases are the leading cause of death in Cuba and most of the developed countries. Two-dimensional speckle tracking echocardiography (2D ST) is a recent technique in the evaluation of cardiac function. Objectives: To determine the relationship between myocardial deformation measured by 2D ST and coronary circulation in patients with ischemic heart disease, in the CIMEQ, for 1 year. Material and method: An analytical, cross-sectional study was carried out with 55 patients with an indication for coronary angiography who underwent 2D echocardiography and 2D ST study with longitudinal strain measurement (LSM). Two groups significant coronary disease (SCD = 32) and not significant (NSCD = 23) were created. SSPS was used to analyze the results. Results: The average age was higher in SCD (55.6 ± 9.3 vs. 61.8 ± 8.8, p = 0.014). Men with SCD (47.3%), hypertensive (SCD = 90.6% and NSCD = 65.2%, p = 0.02) and smokers (SCD = 59.4% and NSCD = 17.4%, p = 0.002) predominated. The most frequent diagnosis was chronic stable angina (87%). Three-vessel disease (75%) prevailed in SCD. The LMS was lower in SCD ([−20.0 ± 3.2 vs. −22.1 ± 3.6, p = 0.035]; AUC = 0.458). There were no differences in LSM according to the number of significantly diseased vessels. Conclusions: The results found do not justify the use of 2D ST to discriminate SCD.

Estudio Descriptivo: Dosis Efectiva de Radiación en Angiotomografías Coronarias Multidetector de Enero del 2013 a Diciembre del 2015 en el Hospital de Especialidades José Carrasco Arteaga

INTRODUCCIÓN: La coronariografia convencional sigue siendo el patrón de referencia para cuantificar y guiar el tratamiento en la enfermedad coronaria sin embargo con la introducción de la angiotomografía coronaria multidetector en la valoración de placas ateromatosas coronarias y con esto la exposición a la radiación ha permanecido como área de constante preocupación. En la práctica diaria se recomienda basarse en lo que se conoce como As Low As Reasonably Achievable que significa optimizar la radiación sin perjuicio de la calidad del estudio. MÉTODOS: Se trata de un estudio descriptivo retrospectivo en el Hospital de Especialidades José Carrasco Arteaga de Cuenca ­ Ecuador, durante el periodo de tiempo comprendido entre el 01 enero del 2013 y 31 diciembre del 2015. Para este estudio se incluyeron todos los pacientes a quienes se les realizó angiotomografía coronaria multidetector, se recolectaron los datos clínicos y la dosis efectiva de radiación de cada paciente. RESULTADOS: La edad promedio fue de 63.2 años. Con una probabilidad pre-test intermedia-baja para enfermedad coronaria en más del 94 % de los pacientes, de los cuales el promedio de dosis de radiación efectiva en angiotomografía coronaria multidetector es de 13.0276 mSv (0.9002 ­ 20.657).CONCLUSION: Se trata del primer estudio en el medio donde investiga la dosis de radiación utilizada en angiotomografía coronaria multidetector permitiendo conocer la media de dosis efectiva y así optimizar la misma mediante técnicas de reducción.

INTRODUCTION: The conventional coronography continues to be the standard used to quantify and manage the treatment of coronary disease. However, with the introduction of the multidetector coronary angiothomography in the evaluation of coronary atheromatous plaque, the exposure to radiation has continued to be an area of constant concern. It is recommended that in daily practice the As Low as Reasonably Achievable guidelines be used, which means optimizing the amount of radiation without affecting the quality of the study. METHOD: This a descriptive retrospective study that took place at the José Carrasco Arteaga Specialties Hospital in Cuenca ­ Ecuador, covering the time period between January 1, 2013 from December 31, 2015. The clinical data and effective dose of radiation of each patient who underwent a multidetector coronary angiothomography during this time span were included in the study. RESULTS: The average age was 63.2 years, with a low to intermediate pre-test probability of coronary disease in over 94 % of the patients. The average dose of effective radiation in multidetector coronary angiothomography was of 13.0276 mSv (0.9002-20.657). CONCLUSIONS: This is the first study in our area where the dose of radiation used in multidetector coronary angiothomography has been investigated, making it possible to identify the effective half dose, in this way optimizing the same through the use of reduction techniques.

Seguridad de la angiografía por tomografía computada coronaria en pacientes con dolor torácico agudo para el alta del servicio de urgencias / Safety of coronary computed tomography angiography in patients with acute chest pain in the Emergency Department

Objetivo: Determinar la relación entre la angiografía por tomografía computada (angio-TC) coronaria y el desarrollo de un evento coronario agudo en los primeros 6 meses en pacientes adultos con dolor torácico agudo, atendidos en el servicio de urgencias de una clínica de nivel iv de atención. Materiales y métodos: Entre febrero de 2012 y de 2014, se realizó un estudio descriptivo y retrospectivo en pacientes adultos que consultaron al servicio de urgencias por un dolor torácico agudo. Todos (n = 62) fueron estudiados por angio-TC coronaria en un tomógrafo Siemens de 40 detectores. Del total, se incluyeron para el análisis a 46 pacientes con resultado negativo o estenosis menor del 50%, a los que se les realizó un seguimiento telefónico o por historia clínica de 6 meses de duración. Se excluyeron los casos a los que no se les pudo hacer un control en los 6 meses posteriores o que tuvieron una estenosis mayor del 50%. Resultados: En la angio-TC se encontraron coronarias sanas en 37 (80%) pacientes y placas no obstructivas en 9 (20%). De los 46 casos incluidos, ninguno presentó un evento coronario agudo o muerte secundaria a este durante los 6 meses de seguimiento. Conclusión: La angio-TC coronaria es una ayuda diagnóstica útil para la valoración de pacientes con dolor torácico agudo. Constituye una herramienta segura y de rápida realización, que permite definir los resultados negativos o la existencia de placas no obstructivas desde el mismo servicio de urgencias

Objective: To determine the relationship between the results of coronary computed tomography (CT) angiography and the development of acute coronary events during the first six months of following in adult patients with acute chest pain seen in the emergency department of an iv level hospital. Materials and methods: A retrospective and descriptive study was conducted that included patients with chest pain that were seen in the emergency department, between February 2012 and February 2014. All of them (n = 62) underwent coronary CT angiography in a 40 detector Siemens CT scanner. The 46 patients who had a negative result or a non-obstructive plaque were included in the analysis, and were followed up over 6 months through medical records or by telephone. Patients who were not able to be tracked during the 6 months, or who had a coronary obstructive plaque greater than 50%, were excluded. Results: Coronary CT angiography was performed on 46 patients, finding healthy coronary arteries in 37 (80%) cases and non-obstructive plaques in 9 (20%). There were no acute coronary events or deaths secondary to this during the follow-up period of 6 months. Conclusión: Coronary CT angiography is a useful diagnostic aid for the evaluation of patients with acute chest pain. It is a safe tool and rapid to perform, which allows defining negative results or the existence of a non-obstructive plaque in the emergency department itself.

Paro cardiorespiratorio secundario a hematoma coronario intramural en arteria descendente anterior / Cardiac arrest associated to intramural hematoma of the anterior descending coronary artery

Background: A 43 year old woman presented with chest pain followed by cardiac arrest recovered after defibrillation. Coronary angiography revealed a narrowed anterior descending coronary artery but no intraluminal thrombi. Optic coherence tomography showed intramural hematoma and the patient was treated medically with aspirin, clopidogrel and atorvastatin. Two weeks later the pain recurred and coronary angiography revealed similar findings. After medical treatment with heparin followed by aspirin and clopidogrel she has remained stable.

Impaired Coronary Flow Reserve Is the Most Important Marker of Viable Myocardium in the Myocardial Segment-Based Analysis of Dual-Isotope Gated Myocardial Perfusion Single-Photon Emission Computed Tomography

OBJECTIVE: The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), 201Tl perfusion status at rest, 201Tl 24 hours redistribution and systolic wall thickening of 99mTc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery. MATERIALS AND METHODS: A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 +/- 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. RESULTS: The left ventricular ejection fraction (LVEF) significantly increased from 37.8 +/- 9.0% to 45.5 +/- 12.3% (p < 0.001) in 22 patients who had a pre-CABG LVEF lower than 50%. Among 590 myocardial segments in the re-vascularized area, 115 showed abnormal wall motion before CABG and 73.9% (85 of 115) had wall motion improvement after CABG. In the univariate analysis (n = 115 segments), stress/rest reversibility (p < 0.001) and 201Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). CONCLUSION: Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

multi slice computed tomography coronary angiographic study of coronary artery disease in soldiers with chest pain

The study is sought to highlight the role and results of MSCT angiography in scenario of acute chest pain to determine or exclude significant coronary artery disease in patients who do not have high risk features for significant coronary disease. Descriptive study. Computed topography department, Armed Forces Institute of Cardiology, National Institute of Heart Diseases Rawalpindi from September 2013 to December 2013. A total of 150 patients [soldiers] who were referred to this hospital with chest pain and who did not have high risk features were evaluated by multi slice computed coronary angiography. One hundred and fifty patients who reported to this hospital with chest pain were evaluated by multi slice computed tomography [MSCT] angiography. Their age ranged from 20 to 53 years. Cases studied were those having low probability of coronary artery disease. Patients having high probability of coronary disease, acute coronary syndrome or definite coronary artery disease were excluded from this study and were evaluated by conventional coronary angiography, 114 [76%] patients showed normal coronary arteries. 6 [4%] had subcritical coronary disease, 5 [3.33%] had only minor irregularity in coronary arteries, 4 [2.66%] had significant coronary artery disease that necessitated coronary angiogram. 16 [10.66%] cases had muscle bridge in left anterior descending artery. One [0.66%] patient had patent graft after coronary artery bypass graft surgery. Three [2%] patient's had patent stents in coronary arteries. While 1[0.66%] patient had aberrant origin of coronary artery. There were no side effects observed during study. Patients presenting with chest pain with low risk features can be studied conveniently with MSCT angiography. Prevalence of significant coronary artery disease is low. MSCT angiography is a very useful, convenient and safe tool to screen low risk patients to rule out presence of significant coronary artery disease

Coronary angiography findings in lung injured patients with sulfur mustard compared to a control group.

Aims and Objectives: We evaluated the incidence of coronary artery disease (CAD) in Sulfur mustard (SM) exposed veterans. We also evaluated the relationship between exposure to SM and angiography findings and compared angiography findings of SM exposed individuals with unexposed ones after two decades from the time of exposure to SM. Materials and Methods: A case-control study was conducted on 200 consecutive patients (100 SM exposed vs. 100 unexposed) undergoing angiographic assessments due to CAD. Results: The coronary angiography findings between two groups were significantly different ( P < 0.001). Ninety two (92%) patients in SM exposed group and 82 (82%) in unexposed group had abnormal findings in their coronary arteries ( P = 0.031). Conclusions: The incidence of CAD and angiographic changes were significantly increased with exposure to SM. Further studies on cardiovascular effects of SM are needed.

High-Definition Computed Tomography for Coronary Artery Stent Imaging: a Phantom Study

OBJECTIVE: To assess the performance of a high-definition CT (HDCT) for imaging small caliber coronary stents (< or = 3 mm) by comparing different scan modes of a conventional 64-row standard-definition CT (SDCT). MATERIALS AND METHODS: A cardiac phantom with twelve stents (2.5 mm and 3.0 mm in diameter) was scanned by HDCT and SDCT. The scan modes were retrospective electrocardiography (ECG)-gated helical and prospective ECG-triggered axial with tube voltages of 120 kVp and 100 kVp, respectively. The inner stent diameters (ISD) and the in-stent attenuation value (AVin-stent) and the in-vessel extra-stent attenuation value (AVin-vessel) were measured by two observers. The artificial lumen narrowing (ALN = [ISD - ISDmeasured]/ISD) and artificial attenuation increase between in-stent and in-vessel (AAI = AVin-stent - AVin-vessel) were calculated. All data was analyzed by intraclass correlation and ANOVA-test. RESULTS: The correlation coefficient of ISD, AVin-vessel and AVin-stent between the two observers was good. The ALNs of HDCT were statistically lower than that of SDCT (30 +/- 5.7% versus 35 +/- 5.4%, p < 0.05). HDCT had statistically lower AAI values than SDCT (15.7 +/- 81.4 HU versus 71.4 +/- 90.5 HU, p < 0.05). The prospective axial dataset demonstrated smaller ALN than the retrospective helical dataset on both HDCT and SDCT (p < 0.05). Additionally, there were no differences in ALN between the 120 kVp and 100 kVp tube voltages on HDCT (p = 0.05). CONCLUSION: High-definition CT helps improve measurement accuracy for imaging coronary stents compared to SDCT. HDCT with 100 kVp and the prospective ECG-triggered axial technique, with a lower radiation dose than 120 kVp application, may be advantageous in evaluating coronary stents with smaller calibers (< or = 3 mm).

Assessment of Left Ventricular Function and Volume in Patients Undergoing 128-Slice Coronary CT Angiography with ECG-Based Maximum Tube Current Modulation: a Comparison with Echocardiography

OBJECTIVE: To compare multi-detector CT (MDCT) using 128-slice coronary CT angiography (Definition AS+, Siemens Medical Solution, Forchheim, Germany) with ECG-based maximum tube current modulation with echocardiography for the determination of left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), as well as assessing coronary artery image quality and patient radiation dose. MATERIALS AND METHODS: Thirty consecutive patients (M:F = 20:10; mean age, 57.9 +/- 11.4 years) were referred for MDCT for evaluation of atypical chest pain. EF, EDV and ESV were determined for both MDCT and echocardiography, and the correlation coefficients were assessed. Coronary artery segment subjective image quality (1, excellent; 4, poor) and radiation dose were recorded. RESULTS: Left ventricular EF, EDV, and ESV were calculated by MDCT and echocardiography and the comparison showed a significant correlation with those estimated by echocardiography (p < 0.05). Consistently, the LVEFs calculated by MDCT and echocardiography were not statistically different. However, LV, EDV and ESV from MDCT were statistically higher than those from echocardiography (p < 0.05). The average image quality score of the coronary artery segment was 1.10 and the mean patient radiation dose was 3.99 +/- 1.85 mSv. CONCLUSION: Although LV volume was overestimated by MDCT, MDCT provides comparable results to echocardiography for LVEF and LVV, with a low radiation dose.

Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

OBJECTIVE: We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). MATERIALS AND METHODS: The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses (> or = 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. RESULTS: The mean heart rate was 89 +/- 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. CONCLUSION: 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

Paraoxonase 1 gene polymorphisms contribute to coronary artery disease risk among north Indians.

Background: Polymorphisms in paraoxonase 1 (PON1) coding for PON1 enzyme have been studied as genetic markers of coronary artery disease (CAD). PON1 Q192R and PON1 L55M polymorphisms have been analyzed extensively, but data on association and role of these polymorphisms in the etiology of CAD are conflicting. In this study, we tested the genetic association between PON1 Q192R and PON1 L55M polymorphisms and CAD among north Indians. Materials and Methods: Two hundred eighty-five angiographically proven patients with coronary artery disease and 200 sex-matched and ethnically matched controls were genotyped for 2 PON1 polymorphisms by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Genotype/ allele frequencies were compared in patients and controls using the chi-square test. Results: At PON1-192 locus, there were significant differences between patients and controls (P< 0.05), leading to significant odds ratios for RR genotype (OR= 1.92, CI: 1.19-3.10) and *R allele (OR= 1.30, CI: 1.00-1.70). These odds ratios were higher in the sub-sample of smokers (2.84 and 1.45, respectively). Binary logistic regression analysis also confirmed that *R allele carriers (QR and RR) have a higher risk of CAD (OR= 3.54, CI: 1.67-5.53). PON1-55 locus did not show significant differences between patients and controls, but LL genotype and *L allele were significant risk factors in the nonsmoker group. RL haplotype was also significantly associated with CAD risk (OR= 1.44, CI: 1.08-1.93). Conclusions: PON1-192R allele and RR genotype are significantly associated with CAD patients from the north Indian population (Uttar Pradesh). This association was stronger in smokers, supporting the conclusion that an interaction between PON1 activity and smoking augments CAD risk. Further studies with larger sample size are warranted to confirm these associations in different Indian populations.

Effect of Heart Rate and Coronary Calcification on the Diagnostic Accuracy of the Dual-Source CT Coronary Angiography in Patients with Suspected Coronary Artery Disease

OBJECTIVE: To evaluate the diagnostic accuracy of a dual-source computed tomography (DSCT) coronary angiography, with a particular focus on the effect of heart rate and calcifications. MATERIALS AND METHODS:One hundred and nine patients with suspected coronary disease were divided into 2 groups according to a mean heart rate ( or = 70 bpm) and into 3 groups according to the mean Agatston calcium scores ( 400). Next, the effect of heart rate and calcification on the accuracy of coronary artery stenosis detection was analyzed by using an invasive coronary angiography as a reference standard. Coronary segments of less than 1.5 mm in diameter in an American Heart Association (AHA) 15-segment model were independently assessed. RESULTS: The mean heart rate during the scan was 71.8 bpm, whereas the mean Agatston score was 226.5. Of the 1,588 segments examined, 1,533 (97%) were assessable. A total of 17 patients had calcium scores above 400 Agatston U, whereas 50 had heart rates > or = 70 bpm. Overall the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) for significant stenoses were: 95%, 91%, 65%, and 99% (by segment), respectively and 97%, 90%, 81%, and 91% (by artery), respectively (n = 475). Heart rate showed no significant impact on lesion detection; however, vessel calcification did show a significant impact on accuracy of assessment for coronary segments. The specificity, PPV and accuracy were 96%, 80%, and 96% (by segment), respectively for an Agatston score less than 100% and 99%, 96% and 98% (by artery). For an Agatston score of greater to or equal to 400 the specificity, PPV and accuracy were reduced to 79%, 55%, and 83% (by segment), respectively and to 79%, 69%, and 85% (by artery), respectively. CONCLUSION: The DSCT provides a high rate of accuracy for the detection of significant coronary artery disease, even in patients with high heart rates and evidence of coronary calcification. However, patients with severe coronary calcification (> 400 U) remain a challenge to diagnose.

Correlation between 64-slice CT angiography and conventional coronary angiography

64-slice CT coronary angiography is now available as a valuable technology in evaluating patients, both with and without symptoms for the detection of coronary lesions and in making decision whether or not further invasive testing is needed. The aim of our study was to evaluate the diagnostic performance of 64-slice CT angiography for detection of significant coronary artery stenoses in comparison with conventional coronary angiography. During a period of 20 months [April 2007-November 2008] we studied 565 patients with 64-slice CT angiography of coronary arteries who fulfilled following criteria; having a positive stress test such as thallium-scan or stress echocardiography if symptomatic, sinus heart rhythm and able to hold breath for 15 seconds. We scheduled coronary angiography for 58 of these patients with mean age of 52 +/- 10.5 years [37 men and 21 women] who have one or more significant stenoses of coronary arteries. A significant lesion was assumed if the diameter reduction of vessel was = 50%. The overall sensitivity and specificity of 64-slice CT for detection of significant coronary artery stenoses in this study were 95% and 94% respectively. The positive predictive value was 85% and negative predictive value was 94%. We found that 64-slice CT correctly identified all patients with three vessel disease. This technique was reliable to classify 90% of patients [52/58] as having one, two or three vessel disease correctly. In conclusion 64-slice CT coronary angiography has a high degree of both sensitivity and specificity in detection of significant coronary artery stenoses