Association between perivascular inflammation and downstream myocardial perfusion in patients with suspected coronary artery disease.

AIMS: To investigate the association between pericoronary adipose tissue (PCAT) computed tomography (CT) attenuation derived from coronary computed tomography angiography (CTA) and coronary flow reserve (CFR) by positron emission tomography (PET) in patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: PCAT CT attenuation was measured in proximal segments of all major epicardial coronary vessels of 105 patients with suspected CAD. We evaluated the relationship between PCAT CT attenuation and other quantitative/qualitative CT-derived anatomic parameters with CFR by PET. Overall, the mean age was 60 ± 12 years and 93% had intermediate pre-test probability of obstructive CAD. Obstructive CAD (≥50% stenosis) was detected in 37 (35.2%) patients and impaired CFR (<2.0) in 32 (30.5%) patients. On a per-vessel analysis (315 vessels), obstructive CAD, non-calcified plaque volume, and PCAT CT attenuation were independently associated with CFR. In patients with coronary calcium score (CCS) <100, those with high-PCAT CT attenuation presented significantly lower CFR values than those with low-PCAT CT attenuation (2.47 ± 0.95 vs. 3.13 ± 0.89, P = 0.003). Among those without obstructive CAD, CFR was significantly lower in patients with high-PCAT CT attenuation (2.51 ± 0.95 vs. 3.02 ± 0.84, P = 0.021). CONCLUSION: Coronary perivascular inflammation by CTA was independently associated with downstream myocardial perfusion by PET. In patients with low CCS or without obstructive CAD, CFR was lower in the presence of higher perivascular inflammation. PCAT CT attenuation might help identifying myocardial ischaemia particularly among patients who are traditionally considered non-high risk for future cardiovascular events.

Myocardial T1 mapping and extracellular volume quantification in patients with left ventricular non-compaction cardiomyopathy.

Aims: From pathophysiological mechanisms to risk stratification and management, much debate and discussion persist regarding left ventricular non-compaction cardiomyopathy (LVNC). This study aimed to characterize myocardial T1 mapping and extracellular volume (ECV) fraction by cardiovascular magnetic resonance (CMR), and investigate how these biomarkers relate to left ventricular ejection fraction (LVEF) and ventricular arrhythmias (VA) in LVNC. Methods and results: Patients with LVNC (n = 36) and healthy controls (n = 18) were enrolled to perform a CMR with T1 mapping. ECV was quantified in LV segments without late gadolinium enhancement (LGE) areas to investigate diffuse myocardial fibrosis. Patients with LVNC had slightly higher native T1 (1024 ± 43 ms vs. 995 ± 22 ms, P = 0.01) and substantially expanded ECV (28.0 ± 4.5% vs. 23.5 ± 2.2%, P < 0.001) compared to controls. The ECV was independently associated with LVEF (ß = -1.3, P = 0.001). Among patients without LGE, VAs were associated with higher ECV (27.7% with VA vs. 25.8% without VA, P = 0.002). Conclusion: In LVNC, tissue characterization by T1 mapping suggests an extracellular expansion by diffuse fibrosis in myocardium without LGE, which was associated with myocardial dysfunction and VA, but not with the amount of non-compacted myocardium.

On the search of arterial geometry heritability.

BACKGROUND: Geometrical risk factors for CAD have been previously proposed before. To date, however, the effect of those factors is not conclusive, and remains as an open research field. Here, we hypothesize that some of these factors have a genetic component explaining inter-individual variability. OBJECTIVE: To detect heritability indicators of the coronary arterial geometry. MATERIALS AND METHODS: A patient sample of 48 individuals, consisting of 24 siblings, was used. Three dimensional geometry of the LAD, LCx and RCA were reconstructed from standard CCTA. Arterial models were characterized in terms of 20+ geometric descriptors (phenotypes). A comprehensive statistical analysis to detect potential heritability of such phenotypes was employed. Heritability was assessed by means of several statistical indexes. Finally, the association of phenotypes to stenotic lesion is also reported. RESULTS: The RCA scored positive indications for heritability in 15+ phenotypes, while the LAD in 10 and the LCx in only 3 phenotypes. Association between presence of lesion and phenotypes was higher in the LAD, 10+ phenotypes, while for the LCx only 2 phenotypes were significantly associated, and none association was found for the RCA. CONCLUSION: The RCA showed potential heritability for the largest number of phenotypes, followed by the LAD. The LCx presents the weaker association of morphology among siblings. Regarding lesion-geometry associations, the there are hints of an underlying relation in the LAD, the LCx featured a weaker association and the RCA showed none. This difference could be related to the different hemodynamic environments in these arteries.

Myocardial tissue characterization in Chagas' heart disease by cardiovascular magnetic resonance.

BACKGROUND: Chagas' heart disease is an important public health problem in South America. Several aspects of the pathogenesis are not fully understood, especially in its subclinical phases. On pathology Chagas' heart disease is characterized by chronic myocardial inflammation and extensive myocardial fibrosis. The latter has also been demonstrated by late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR). In three clinical phases of this disease, we sought to investigate the presence of LGE, myocardial increase in signal intensity in T2-weighted images (T2W) and in T1-weighted myocardial early gadolinium enhancement (MEGE), previously described CMR surrogates for myocardial fibrosis, myocardial edema and hyperemia, respectively. METHODS: Fifty-four patients were analyzed. Sixteen patients with the indeterminate phase (IND), seventeen patients with the cardiac phase with no left ventricular systolic dysfunction (CPND), and twenty-one patients with the cardiac phase with left ventricular systolic dysfunction (CPD). All patients underwent 1.5 T CMR scan including LGE, T2W and MEGE image sequences to evaluate myocardial abnormalities. RESULTS: Late gadolinium enhancement was present in 72.2 % of all patients, in 12.5 % of IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001). Myocardial increase in signal intensity in T2-weighted images (T2W) was present in 77.8 % of all patients, in 31.3 % of the IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001). T1-weighted myocardial early gadolinium enhancement (MEGE) was present in 73.8 % of all patients, in 25.0 % of the IND, 92.3 % of the CPND and 94.1 % of the CPD (p < 0.0001). A good correlation between LGE and T2W was observed (r = 0.72, and p < 0.001). CONCLUSIONS: Increase in T2-weighted (T2W) myocardial signal intensity and T1-weighted myocardial early gadolinium enhancement (MEGE) can be detected by CMR in patients throughout all phases of Chagas' heart disease, including its subclinical presentation (IND). Moreover, those findings were parallel to myocardial fibrosis (LGE) in extent and location and also correlated with the degree of Chagas' heart disease clinical severity. These findings contribute to further the knowledge on pathophysiology of Chagas' heart disease, and might have therapeutic and prognostic usefulness in the future.

The descending branch of the lateral femoral circumflex artery is a good option in CABG with arterial grafts.

INTRODUCTION: The descending branch of the lateral femoral circumflex artery is an option for coronary artery bypass grafting. OBJECTIVE: To evaluate the early patency and adaptation of lumen diameter using multidetector computed angiotomography. METHODS: Thirty-two patients were selected to undergo coronary artery bypass grafting using the descending branch of the lateral circumflex artery, the internal thoracic artery, and other grafts. Evaluations were carried out through high resolution computed tomography performed on the 7th and 90th postoperative day. Diameters of the descending branch of the lateral circumflex artery and the left internal thoracic artery were measured 3 cm before the distal anastomosis, in the middle portion, and 3 cm after the proximal anastomosis. Diameters were compared using paired t-test (P<0.05). RESULTS: Descending branch of the lateral femoral circumflex artery wDescending branch of the lateral femoral circumflex artery was used in 26 patients, as its use was not viable in six patients (18%). It was used as composite graft in all cases. The anterior descending branch was revascularized by the left internal thoracic artery in all cases. Patency rates of the descending branch of the lateral femoral circumflex artery were 96% and 92%, respectively. No occlusions were observed in the left internal thoracic artery (LITA) and no ischemic events were observed in the descending branch of the lateral circumflex. Descending branch of the lateral femoral circumflex artery increased the lumen diameter in the middle (P=0.001) and distal portions (P=0.006); the left internal thoracic artery (LITA) increased in the middle portion (P=0.001). CONCLUSION: Similar to the left internal thoracic artery, the descending branch of the lateral femoral circumflex artery showed high patency rate and positive luminal adaptation. This early evaluation confirms the descending branch of the lateral femoral circumflex artery as a potential alternative for grafting. Due to anatomical variations, preoperative femoral angiographic evaluation appears to be mandatory.

The descending branch of the lateral femoral circumflex artery is a good option in CABG with arterial grafts / Ramo descendente da artéria circunflexa lateral femoral é boa opção para revascularização do miocárdio com enxertos arteriais

INTRODUCTION: The descending branch of the lateral femoral circumflex artery is an option for coronary artery bypass grafting. OBJECTIVE: To evaluate the early patency and adaptation of lumen diameter using multidetector computed angiotomography. METHODS: Thirty-two patients were selected to undergo coronary artery bypass grafting using the descending branch of the lateral circumflex artery, the internal thoracic artery, and other grafts. Evaluations were carried out through high resolution computed tomography performed on the 7th and 90th postoperative day. Diameters of the descending branch of the lateral circumflex artery and the left internal thoracic artery were measured 3 cm before the distal anastomosis, in the middle portion, and 3 cm after the proximal anastomosis. Diameters were compared using paired t-test (P<0.05). RESULTS: Descending branch of the lateral femoral circumflex artery wDescending branch of the lateral femoral circumflex artery was used in 26 patients, as its use was not viable in six patients (18%). It was used as composite graft in all cases. The anterior descending branch was revascularized by the left internal thoracic artery in all cases. Patency rates of the descending branch of the lateral femoral circumflex artery were 96% and 92%, respectively. No occlusions were observed in the left internal thoracic artery (LITA) and no ischemic events were observed in the descending branch of the lateral circumflex. Descending branch of the lateral femoral circumflex artery increased the lumen diameter in the middle (P=0.001) and distal portions (P=0.006); the left internal thoracic artery (LITA) increased in the middle portion (P=0.001). CONCLUSION: Similar to the left internal thoracic artery, the descending branch of the lateral femoral circumflex artery showed high patency rate and positive luminal adaptation. This early evaluation confirms the descending branch of the lateral femoral circumflex artery as a potential alternative for grafting. Due to anatomical variations, preoperative femoral angiographic evaluation appears to be mandatory.

INTRODUÇÃO: O ramo descendente da artéria circunflexa lateral é um enxerto pouco avaliado e pode ser uma opção para a revascularização do miocárdio. OBJETIVO: Avaliar a perviabilidade e o remodelamento arterial do ramo descendente da artéria circunflexa lateral, em três meses de seguimento, por meio de angiotomografia de artérias coronárias. MÉTODOS: Foram analisados 32 pacientes submetidos à revascularização do miocárdio com ramo descendente da artéria circunflexa lateral, artéria torácica interna esquerda e outros enxertos. A avaliação foi realizada por meio da tomografia computadorizada de alta resolução, realizada no 7º e 90º dias de pós-operatório. O diâmetro do ramo descendente da artéria circunflexa lateral foi medido 3 cm antes da anastomose distal, na porção média e 3 cm após a anastomose proximal. As mesmas medidas foram realizadas para a artéria torácica interna esquerda. Os diâmetros foram comparados pelo método t de Student pareado (significância P<0,05). RESULTADOS: O ramo descendente da artéria circunflexa lateral foi adequado para a utilização em 26 pacientes. Em seis (18%) pacientes, o ramo descendente da artéria circunflexa lateral era inviável. Em todos os casos, o ramo descendente da artéria circunflexa lateral foi empregado sob a forma de enxerto composto. Todos os pacientes receberam artéria torácica interna esquerda para o ramo descendente anterior. A perviabilidade do ramo descendente da artéria circunflexa lateral foi de 96% e 92%, em 7 e 90 dias de pós-operatório, respectivamente. Não foram detectadas oclusões da artéria torácica interna esquerda. Não foram detectados sinais de espasmo do ramo descendente da artéria circunflexa lateral. O ramo descendente da artéria circunflexa lateral apresentou aumento de diâmetro nas porções média (P=0,001) e distal (P=0,006) e a artéria torácica interna esquerda, aumento na porção média (P=0,001). CONCLUSÃO: O remodelamento positivo sugere que o ramo descendente da artéria circunflexa lateral tem comportamento semelhante à artéria torácica interna esquerda e pode ser uma excelente opção para a revascularização do miocárdio com enxertos arteriais. Em virtude das variações anatômicas, estudos de pré-operatório podem auxiliar na seleção de casos.

Late gadolinium enhancement magnetic resonance imaging in the diagnosis and prognosis of endomyocardial fibrosis patients.

BACKGROUND: Endocardial fibrous tissue (FT) deposition is a hallmark of endomyocardial fibrosis (EMF). Echocardiography is a first-line and the standard technique for the diagnosis of this disease. Although late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) allows FT characterization, its role in the diagnosis and prognosis of EMF has not been investigated. METHODS AND RESULTS: Thirty-six patients (29 women; age, 54±12 years) with EMF diagnosis after clinical evaluation and comprehensive 2-dimensional Doppler echocardiography underwent cine-CMR for assessing ventricular volumes, ejection fraction and mass, and LGE-CMR for FT characterization and quantification. Indexed FT volume (FT/body surface area) was calculated after planimetry of the 8 to 12 slices obtained in the short-axis view at end-diastole (mL/m(2)). Surgical resection of FT was performed in 16 patients. In all patients, areas of LGE were confined to the endocardium, frequently as a continuous streak from the inflow tract extending to the apex, where it was usually most prominent. There was a relation between increased FT/body surface area and worse New York Heart Association functional class and with increased probability of surgery (P<0.05). The histopathologic examination of resected FT showed typical features of EMF with extensive endocardial fibrous thickening, proliferation of small vessels, and scarce inflammatory infiltrate. In multivariate analysis, the patients with FT/body surface area >19 mL/m(2) had an increased mortality rate, with a relative risk of 10.8. CONCLUSIONS: Our study provides evidence that LGE-CMR is useful in the diagnosis and prognosis of EMF through quantification of the typical pattern of FT deposition.

[Coronary calcium score as predictor of stenosis and events in pretransplant renal chronic failure].

BACKGROUND: Coronary artery disease (CAD) is the major cause of death among chronic renal failure (CRF) patients. Traditional, non-invasive exams to detect CAD and to predict events have shown insufficient results in this group. CT Scan evaluation of Coronary Calcium Score (CCS) has proven to be of prognostic value for the population reporting no renal condition. OBJECTIVE: To investigate CCS accuracy in detecting obstructive CAD and in predicting cardiovascular events in candidates to renal transplant as compared to quantitative invasive coronary angiography (ICA). METHODS: Ninety-seven (97) CRF patients aged > or =35 were evaluated. Obstructive CAD was considered as > or =50% or > or =70% stenosis on ICA. Descriptive data, concordance, diagnostic tests, Kaplan-Meier, and multivariate analysis were used. RESULTS: Agatston mean score was 580.6 +/- 1,102.2. Minimum and maximum values were 0 and 7,994, with median at 176. Only 14 patients had zero calcium score. No differences were reported in regard to ethnicity. Highest regional calcium was associated to the highest probability of coronary stenosis in the same segment. Agatston calcium score showed high accuracy for the diagnosis of > or =50% and > or =70% stenosis, with area under ROC curve (AUC) of 0.75 and 0.70, respectively. At the threshold of 400, calcium score identified a subgroup with a higher rate of cardiovascular events at an average follow-up time of 29+/-11.0 months. CONCLUSION: CCS proved to have good diagnostic and prognostic performance for cardiovascular events evaluation in CRF patients.

Escore de cálcio coronariano prediz estenose e eventos na insuficiência renal crônica pré-transplante / Score de calcio coronario predice estenosis y eventos en la insuficiencia renal crónica pre trasplante / Coronary calcium score as predictor of stenosis and events in pretransplant renal chronic failure

FUNDAMENTO: A doença arterial coronariana (DAC) é a principal causa de óbito em pacientes com insuficiência renal crônica (IRC). Os exames não invasivos tradicionais para detecção de DAC e predição de eventos têm apresentado resultados insuficientes nesse grupo. A avaliação do escore de cálcio coronariano (ECC) por tomografia computadorizada tem comprovado valor prognóstico na população sem doença renal. OBJETIVO: Avaliar a acurácia do ECC para detectar DAC obstrutiva e prever eventos cardiovasculares em candidatos a transplante renal comparada à angiografia coronariana invasiva (ACI) quantitativa. MÉTODOS: Foram avaliados 97 pacientes com IRC e idade > 35anos. Foi considerada DAC obstrutiva a presença de estenose >50 por cento ou >70 por cento pela ACI. Dados descritivos, concordância, testes diagnósticos, Kaplan-Meier e análise multivariada foram utilizados. RESULTADOS: O escore de Agatston médio foi de 580,6 ± 1.102,2; os valores mínimos e máximos foram 0 e 7.994, e mediana de 176. Apenas 14 pacientes tinham escore de cálcio de zero. Não houve diferenças entre as etnias e a maior presença de cálcio regional associou-se a maior probabilidade de estenose coronária no mesmo segmento. O escore de cálcio de Agatston apresentou boa acurácia para o diagnóstico de estenose, >50 por cento e >70 por cento com área sob a curva ROC de 0,75 e 0,70, respectivamente. No limiar de 400, o escore de cálcio identificou o subgrupo com maior taxa de eventos cardiovasculares em tempo médio de seguimento de 29,1±11,0 meses. CONCLUSÃO: O ECC na avaliação de DAC apresentou boa performance diagnóstica e prognóstica para eventos cardiovasculares em pacientes com insuficiência renal crônica (IRC).

BACKGROUND: Coronary artery disease (CAD) is the major cause of death among chronic renal failure (CRF) patients. Traditional, non-invasive exams to detect CAD and to predict events have shown insufficient results in this group. CT Scan evaluation of Coronary Calcium Score (CCS) has proven to be of prognostic value for the population reporting no renal condition. OBJECTIVE: To investigate CCS accuracy in detecting obstructive CAD and in predicting cardiovascular events in candidates to renal transplant as compared to quantitative invasive coronary angiography (ICA). METHODS: Ninety-seven (97) CRF patients aged > 35 were evaluated. Obstructive CAD was considered as >50 percent or >70 percent stenosis on ICA. Descriptive data, concordance, diagnostic tests, Kaplan-Meier, and multivariate analysis were used. RESULTS: Agatston mean score was 580.6 ± 1,102.2. Minimum and maximum values were 0 and 7,994, with median at 176. Only 14 patients had zero calcium score. No differences were reported in regard to ethnicity. Highest regional calcium was associated to the highest probability of coronary stenosis in the same segment. Agatston calcium score showed high accuracy for the diagnosis of >50 percent and >70 percent stenosis, with area under ROC curve (AUC) of 0.75 and 0.70, respectively. At the threshold of 400, calcium score identified a subgroup with a higher rate of cardiovascular events at an average follow-up time of 29±11.0 months. CONCLUSION: CCS proved to have good diagnostic and prognostic performance for cardiovascular events evaluation in CRF patients.

FUNDAMENTO: La enfermedad arterial coronaria (EAC) es la principal causa de óbito en pacientes con insuficiencia renal crónica (IRC). Los exámenes no invasivos tradicionales para detección de EAC y predicción de eventos vienen presentando resultados insuficientes en este grupo. La evaluación del score de calcio coronario (SCC) por tomografía computarizada ha estado comprobando valor pronóstico en la población sin enfermedad renal. OBJETIVO: Evaluar la exactitud del SCC para detectar EAC obstructiva y prever eventos cardiovasculares en candidatos a trasplante renal comparada a la angiografía coronaria invasiva (ACI) cuantitativa. MÉTODOS: Se evaluaron a 97 pacientes con IRC y edad > 35 años. Se consideró como EAC obstructiva la presencia de estenosis > 50 por ciento o > 70 por ciento por la ACI. Datos descriptivos, concordancia, pruebas diagnósticas, Kaplan-Meier y análisis multivariado se utilizaron. RESULTADOS: El score de Agatston promedio fue de 580,6 ± 1.102,2; los valores mínimos y máximos fueron 0 y 7.994, y mediana de 176. Solamente 14 pacientes tenían score de calcio de cero. No hubo diferencias entre las etnias y la mayor presencia de calcio regional se asoció a la mayor probabilidad de estenosis coronaria en el mismo segmento. El score de calcio de Agatston presentó buena exactitud para el diagnóstico de estenosis, > 50 por ciento y > 70 por ciento con área bajo la curva ROC de 0,75 y 0,70, respectivamente. En el umbral de 400, el score de calcio identificó el subgrupo con mayor tasa de eventos cardiovasculares en tiempo promedio de seguimiento de 29,1 ± 11,0 meses. CONCLUSIÓN: El SCC en la evaluación de EAC presentó una buena performance diagnóstica y pronostica para eventos cardiovasculares en pacientes con insuficiencia renal crónica (IRC).

Relation between visceral fat and coronary artery disease evaluated by multidetector computed tomography.

Visceral abdominal fat has been associated to cardiovascular risk factors and coronary artery disease (CAD). Computed tomography (CT) coronary angiography is an emerging technology allowing detection of both obstructive and nonobstructive CAD adding information to clinical risk stratification. The aim of this study was to evaluate the association between CAD and adiposity measurements assessed clinically and by CT. We prospectively evaluated 125 consecutive subjects (57% men, age 56.0+/-12 years) referred to perform CT angiography. Clinical and laboratory variables were determined and CT angiography and abdominal CT were performed in a 64-slice scanner. CAD was defined as any plaque calcified or not detected by CT angiography. Visceral and subcutaneous adiposity areas were determined at different intervertebral levels. CT angiography detected CAD in 70 (56%) subjects, and no association was found with usual anthropometric adiposity measurements (waist and hip circumferences and body mass index). Otherwise, CT visceral fat areas (VFA) were significantly related to CAD. VFA T12-L1 values > or =145cm(2) had an odds ratio of 2.85 (95% CI 1.30-6.26) and VFA L4-L5 > or =150cm(2) had a 2.87-fold (95% CI 1.31-6.30) CAD risk. The multivariate analysis determined age and VFA T12-L1 as the only independent variables associated to CAD. Visceral fat assessed by CT is an independent marker of CAD determined by CT angiography.

Contrast-enhanced magnetic resonance imaging identifies focal regions of intramyocardial fibrosis in patients with severe aortic valve disease: Correlation with quantitative histopathology.

BACKGROUND: Chronic aortic valve disease (AVD) is characterized by progressive accumulation of interstitial myocardial fibrosis (MF). However, assessment of MF accumulation has only been possible through histologic analyses of endomyocardial biopsies. We sought to evaluate contrast-enhanced magnetic resonance imaging (ce-MRI) as a noninvasive method to identify the presence of increased MF in patients with severe AVD. METHODS: Seventy patients scheduled to undergo aortic valve replacement surgery were examined by cine and ce-MRI in a 1.5-T scanner. Cine images were used for the assessment of left ventricular (LV) volumes, mass, and function. Delayed-enhancement images were used to characterize the regions of MF. In addition, histologic analyses of myocardial samples obtained during aortic valve replacement surgery were used for direct quantification of interstitial MF. Ten additional subjects who died of noncardiac causes served as controls for the quantitative histologic analyses. RESULTS: Interstitial MF determined by histopathologic analysis was higher in patients with AVD than in controls (2.7% +/- 2.0% vs 0.6% +/- 0.2%, P = .001). When compared with histopathologic results, ce-MRI demonstrated a sensitivity of 74%, a specificity of 81%, and an accuracy of 76% to identify AVD patients with increased interstitial MF. There was a significant inverse correlation between interstitial MF and LV ejection fraction (r = -0.67, P < .0001). Accordingly, patients with identifiable focal regions of MF by ce-MRI exhibited worse LV systolic function than those without MF (45% +/- 14% vs 65% +/- 14%, P < .0001). CONCLUSIONS: Contrast-enhanced MRI allows for the noninvasive detection of focal regions of MF in patients with severe AVD. Moreover, patients with identifiable MF by ce-MRI exhibited worse LV functional parameters.

Arsenic removal by electrocoagulation using combined Al-Fe electrode system and characterization of products.

Combination of electrodes, such as aluminum and iron in a single electrochemical cell provide an alternative method for removal of arsenic from water by electrocoagulation. The removal process has been studied with a wide range of arsenic concentration (1-1000 ppm) at different pH (4-10). Analysis of the electrochemically generated by-products by XRD, XPS, SEM/EDAX, FT-IR, and Mössbauer Spectroscopy revealed the expected crystalline iron oxides (magnetite (Fe3O4), lepidocrocite (FeO(OH)), iron oxide (FeO)) and aluminum oxides (bayerite (Al(OH)3), diaspore (AlO(OH)), mansfieldite (AlAsO(4).2(H2O)), as well as some interaction between the two phases. The amorphous or very fine particular phase was also found in the floc. The substitution of Fe3+ ions by Al3+ ions in the solid surface has been observed, indicating an alternative removal mechanism of arsenic in these metal hydroxides and oxyhydroxides by providing larger surface area for arsenic adsorption via retarding the crystalline formation of iron oxides.

CT angiography in highly calcified arteries: 2D manual vs. modified automated 3D approach to identify coronary stenoses.

BACKGROUND: Two-dimensional axial and manually-oriented reformatted images are traditionally used to analyze coronary data provided by multidetector-row computed tomography angiography (MDCTA). While apparently more accurate in evaluating calcified vessels, 2D methods are time-consuming compared with automated 3D approaches. The purpose of this study was to evaluate the performance of a modified automated 3D approach (using manual vessel isolation and different window and level settings) in a population with high calcium scores who underwent coronary half-millimeter 16-detector-row CT angiography (16 x 0.5-MDCTA). METHODS: ECG-gated 16 x 0.5-MDCTA (16 x 0.5 mm cross-sections, 0.35 x 0.35 x 0.35 mm3 isotropic voxels, 400 ms rotation) was performed after injection of iopamidol (120-ml, 300 mg/ml) in 19 consecutive patients (11 male, 62+/-10 years-old). Native arteries were independently evaluated for >or=50%-stenoses using both manual 2D and modified automated 3D approaches. Stents and bypass grafts were excluded. Conventional coronary angiography was visually analyzed by 2 observers. RESULTS: Median Agatston calcium score was 434. Sensitivities, specificities, positive and negative predictive values for detection of >or=50% coronary stenoses using the 2D and modified 3D approaches were, respectively: 74%/63%, 76%/80%, 45%/34%, and 91%/93% (p=NS for all comparisons). Overall diagnostic accuracies were 75 and 78%, respectively (p=NS). Uninterpretable vessels were, respectively: 37% (77/209) and 35% (73/209) - p=NS. Time to analyze a single study was 160+/-23 and 53+/-11 min, respectively (p<0.01). CONCLUSIONS: This modified automated 3D approach is equivalent to and significantly less time consuming than the traditional manual 2D method for evaluation of >or=50%-stenoses by 16 x 0.5-MDCTA in native coronary arteries of patients with high calcium scores.

Myocardial delayed enhancement by magnetic resonance imaging in patients with Chagas' disease: a marker of disease severity.

OBJECTIVES: We sought to investigate whether myocardial delayed enhancement (MDE) by magnetic resonance imaging (MRI) could quantify myocardial fibrosis (MF) in patients with Chagas' heart disease (CHD), thus defining the severity of the disease. BACKGROUND: Myocardial fibrosis secondary to ischemic disease can be imaged using MDE. Advanced CHD is characterized by progressive MF. METHODS: Fifty-one patients with CHD were enrolled: 15 seropositive asymptomatic participants in the indeterminate phase (IND); 26 patients with known clinical CHD; and 10 patients with known CHD and ventricular tachycardia (VT). Using a 1.5-T MRI system, we acquired left ventricular (LV) short-axis slices using cine-MRI (LV function) and inversion-recovery gradient-echo (MDE). RESULTS: Myocardial fibrosis by MRI was present in 68.6% of all patients, in 20% of IND, 84.6% of CHD, and 100% of VT (p < 0.001). Quantified MF increased progressively across disease severity subgroups (0.9 +/- 2.3% in IND; 16.0 +/- 12.3% in CHD; and 25.4 +/- 9.8% in VT, p < 0.001) and New York Heart Association functional classes (I: 7.5 +/- 9.5%; II: 21.9 +/- 13.8%; and III: 25.3 +/- 9.9% of LV mass, p < 0.001). Left ventricular ejection fraction and MF had significant negative correlation (r = -0.78, p < 0.001), similar to the segmental MF and function: 4.9 +/- 15.1% of MF in normal function, 32.5 +/- 32.5% in mildly hypokinetic, 57.8 +/- 31.4% in severely hypokinetic, and 72.3 +/- 36.2% in akinetic and dyskinetic segments, respectively (p < 0.001). CONCLUSIONS: In CHD, MDE by MRI quantifies MF that not only can be detected in the early asymptomatic stages but parallels well-established prognostic factors and provides unique information for clinical disease staging.

Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Comarca Lagunera México.

Arsenic contamination is an enormous worldwide problem. A large number of people dwelling in Comarca Lagunera, situated in the central part of northern México, use well water with arsenic in excess of the water standard regulated by the Secretary of Environment and Natural Resources of México (SEMARNAT), to be suitable for human health. Individuals with lifetime exposure to arsenic develop the classic symptoms of arsenic poisoning. Among several options available for removal of arsenic from well water, electrocoagulation (EC) is a very promising electrochemical treatment technique that does not require the addition of chemicals or regeneration. First, this study will provide an introduction to the fundamental concepts of the EC method. In this study, powder X-ray diffraction, scanning electron microscopy, transmission Mössbauer spectroscopy and Fourier transform infrared spectroscopy were used to characterize the solid products formed at iron electrodes during the EC process. The results suggest that magnetite particles and amorphous iron oxyhydroxides present in the EC products remove arsenic(III) and arsenic(V) with an efficiency of more than 99% from groundwater in a field pilot scale study.

Non-invasive assessment of right ventricular function in the late follow-up of the Senning procedure.

Deteriorating ventricular function is a major concern after the Senning operation. A Doppler-derived non-geometric measurement, the so-called myocardial performance index, has been described for use in adults and children. We aimed to assess the utility of this index as a method for quantification of right ventricular function in patients in the late follow-up of the Senning procedure, and to correlate the right ventricular ejection fraction and the first derivative of right ventricular pressure as derived using echocardiography with the ejection fraction determined using magnetic resonance imaging. We studied 44 patients within a mean postoperative period of 15.3 years. We calculated the right ventricular myocardial performance index by pulsed wave Doppler interrogation of tricuspid inflow and aortic outflow, the ejection fraction by Simpson's rule, and the first derivative of right ventricular pressure by continuous wave Doppler from tricuspid regurgitation. Mean values of right ventricular myocardial performance index, ejection fraction, and the first derivative of right ventricular pressure were 0.50, 39 percent and 1,398 millimetres of mercury per second, respectively. A cut-off value of 0.47 for the right ventricle myocardial performance index was determined, with a sensitivity of 75 percent and a specificity of 62.5 percent. We found no correlation between ejection fraction and the first derivative of right ventricular pressure as estimated by echocardiography and the ejection fraction as shown by magnetic resonance imaging (r2 equal to 0.29 and 0.04 respectively). We concluded, first, that patients with preserved right ventricular function had values for the right ventricular myocardial performance index lower than 0.47, and second, that ejection fraction and the first derivative of right ventricular pressure as determined echocardiographically did not correlate with values derived using magnetic resonance imaging.