Quantitative analysis of pulmonary perfusion with dual-energy CT angiography: comparison of two quantification methods in patients with pulmonary embolism.

The study aimed to evaluate a quantification method of pulmonary perfusion with Dual-Energy CT Angiography (DE-CTA) normalized by lung density in the prediction of outcome in acute pulmonary embolism (PE). In this prospective study with CTA scans acquired with different breathing protocols, two perfusion parameters were calculated: %PBV (relative value of PBV, expressed per unit volume) and PBVm (PBV normalized by lung density, expressed per unit mass). DE-CTA parameters were correlated with simplified pulmonary embolism severity index (sPESI) and with outcome groups, alone and in combinationwith tomographic right-to-left ventricular ratios (RV/LV). PBVm showed significant correlation with sPESI. PBVm presented higher accuracy than %PBV In the prediction of ICU admission or death in patients with PE, with the best performance when combined with RV/LV volumetric ratio.

Lobar pulmonary perfusion quantification with dual-energy CT angiography: Interlobar variability and relationship with regional clot burden in pulmonary embolism.

Purpose: Semi-automated lobar segmentation tools enable an anatomical assessment of regional pulmonary perfusion with Dual-Energy CTA (DE-CTA). We aimed to quantify lobar pulmonary perfusion with DE-CTA, analyze the perfusion distribution among the pulmonary lobes in subjects without cardiopulmonary diseases and assess the correlation between lobar perfusion and regional endoluminal clots in patients with acute pulmonary embolism (PE). Methods: We evaluated 151 consecutive subjects with suspected PE and without cardiopulmonary comorbidities. DE-CTA derived perfused blood volume (PBV) of each pulmonary lobe was measured applying a semi-automated lobar segmentation technique. In patients with PE, blood clot location was assessed, and CT-based vascular obstruction index of each lobe (CTOIlobe) was calculated and classified into three groups: CTOIlobe= 0, low CTOIlobe (1-50%) and high CTOIlobe (>50%). Results: Among patients without PE (103/151, 68.2%), median lobar PBV was 13.7% (IQR 10.2-18.0%); the right middle lobe presented lower PBV when compared to all the other lobes (p < .001). In patients with PE (48/151, 31.8%), lobar PBV was 12.6% (IQR 9.6-15.7%), 13.7% (IQR 10.1-16.7%) and 6.5% (IQR 5.1-10.2%) in the lobes with CTOIlobe= 0, low CTOIlobe and high CTOIlobe scores, respectively, with a significantly decreased PBV in the lobes with high CTOIlobe score (p < .001). ROC analysis of lobar PBV for prediction of high CTOIlobe score revealed AUC of 0.847 (95%CI 0.785-0.908). Conclusion: Pulmonary perfusion was heterogeneously distributed along the pulmonary lobes in patients without cardiopulmonary diseases. In patients with PE, the lobes with high vascular obstruction score (CTOIlobe> 50%) presented a decreased lobar perfusion.

Stent evaluation by coronary computed tomography angiography: a comparison between Iopamidol-370 and Ioversol-320 hypo-osmolar iodine concentration contrasts.

OBJECTIVE: Qualitative and quantitative image analysis between Iopamidol-370 and Ioversol-320 in stents´ evaluation by coronary computed tomography angiography (CTA). METHODS: Sixty-five patients with low-risk stable angina undergoing stent follow-up with coronary CTA were assigned to Iopamidol I-370 (n = 33) or Ioversol I-320 (n = 32) in this prospective, double-blind, non-inferiority, randomized trial. Stent lumen image quality was graded by 5-point Likert Scale. Lumen mean attenuation was measured at native coronary segments: pre-stent, post-stent, distal segments and at coronary plaques. Lumen attenuation increase (LAI) ratio was calculated for all stents. Heart rate (HR) variation, premature heart beats (PHB), heat sensation (HS), blooming and beam hardening were also assessed. RESULTS: Image quality was similar between groups, with no significant difference (Likert score 4.48 ± 0.75 vs 4.54 ± 0.65, p = 0.5). There were similarities in LAI ratio between I-370 and I-320 (0.39 ± 0.42 vs 0.48 ± 0.44 HU, p = 0.08). Regarding lumen mean attenuation at native coronary segments, a significant difference was observed, with I-320 presenting lower values, including contrast mean attenuation in distal segments. After statistical multivariate analysis, three variables correlated with stent image quality: 1) stent diameter, 2) HR variation and 3) stent lumen LAI ratio. CONCLUSIONS: There was no significant difference between Iopamidol-370 mgI ml-1 and Ioversol-320 mgI ml-1 contrasts regarding overall stent lumen image quality, which was mainly influenced by stent diameter, HR and LAI ratio.Advances in knowledge:Coronary CTA allows adequate stents' visualization and image quality is influenced by stent diameter, HR variation and LAI ratio.Stents' image quality showed no difference between different concentration contrasts (I-370 vs. I-320); however, higher concentration contrasts may provide an improved overall visualization, especially regarding coronary distal segments.

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.

Clinical evaluation of left ventricular function and morphology using an accelerated k-t sensitivity encoding method in cardiovascular magnetic resonance.

OBJECTIVES: To provide clinical validation of a recent 2D SENSE-based accelerated cardiovascular magnetic resonance (CMR) sequence (accelerated k-t SENSE), investigating whether this technique accurately quantifies left ventricle (LV) volumes, function, and mass as compared to 2D cine steady-state free precession (2D-SSFP). METHODS: Healthy volunteers (n = 16) and consecutive heart failure patients (n = 26) were scanned using a 1.5 T MRI system. Two LV short axis (SA) stacks were acquired: (1) accelerated k-t SENSE (5-6 breath-holds; temporal/spatial resolution: 37 ms/1.82 × 1.87 mm; acceleration factor = 4) and (2) standard 2D-SSFP (10-12 breath-holds; temporal/spatial resolution: 49 ms/1.67 × 1.87 mm, parallel imaging). Ascending aorta phase-contrast was performed on all volunteers as a reference to compare LV stroke volumes (LVSV) and validate the sequences. An image quality score for SA images was used, with lower scores indicating better quality (from 0 to 18). RESULTS: There was a high agreement between accelerated k-t SENSE and 2D-SSFP for LV measurements: bias (limits of agreement) of 2.4% (- 5.4% to 10.1%), 6.9 mL/m2 (- 4.7 to 18.6 mL/m2), - 1.5 (- 8.3 to 5.2 mL/m2), and - 0.2 g/m2 (- 11.9 to 12.3 g/m2) for LV ejection fraction, end-diastolic volume index, end-systolic volume index, and mass index, respectively. LVSV by accelerated k-t SENSE presented good agreement with aortic flow. Interobserver and intraobserver variabilities for all LV parameters were also high. CONCLUSION: The accelerated k-t SENSE CMR sequence is clinically feasible and accurately quantifies LV volumes, function, and mass, with short acquisition time and good image quality.

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.

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

OBJECTIVES: Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography (82RbPET) MPI. Thus, this study aimed to evaluate agreement between 82RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. METHODS: Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. RESULTS: There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). CONCLUSIONS: There was a significant agreement between dipyridamole stress 320-CT MPI and 82RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. KEY POINTS: • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block / Perfusão Miocárdica de Estresse com Dipiridamol por Tomografia Computadorizada em Pacientes com Bloqueio de Ramo Esquerdo

Abstract Background: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods: Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee. Results: The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion: The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

Resumo Fundamentos: Testes funcionais possuem limitada acurácia para identificar isquemia miocárdica em pacientes com bloqueio de ramo esquerdo (BRE). Objetivo: Utilizando tomógrafo com 320 detectores foi avaliado a acurácia diagnóstica da perfusão miocárdica de estresse com dipiridamol pela tomografia (PMT) em pacientes com BRE utilizando a angiografia coronária quantitativa invasiva (QCA) (estenose ≥ 70%) como referência. Procurou-se também investigar o valor adicional da PMT sobre a angiotomografia coronariana (ATC) comparando a acurácia com a cintilografia perfusional miocárdica (SPECT). Métodos: Trinta pacientes com BRE e SPECT prévio em investigação de doença arterial coronariana foram encaminhados para realização do protocolo de estresse na tomografia. Observadores independentes realizaram avaliação por paciente e por território coronariano. Todos os pacientes assinaram um termo de consentimento livre e esclarecido aprovado pelo Comitê de Ética da Instituição. Resultados: A média de idade foi 62 ± 10 anos. A dose média de radiação do protocolo de tomografia foi 9,3 ± 4,6 mSv. Em relação a PMT, na análise por paciente, a sensibilidade, especificidade, valores preditivos positivos e negativos e acurácia foram, respectivamente, 86%, 81%, 80%, 87%, 83% p = 0,001. Na análise por território os valores foram, respectivamente, 63%, 86% a 65%, 84%, 79% p < 0,001. Em ambas as análises, a adição da PMT a ATC determinou maior acurácia diagnóstica para detecção de isquemia miocárdica quando comparado com o SPECT (p < 0,001). Conclusão: O uso do protocolo de estresse na tomografia é viável e tem boa acurácia diagnóstica na pesquisa de isquemia miocárdica nos pacientes com BRE.

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.

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block.

BACKGROUND: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). OBJECTIVE: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. METHODS: Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution's ethics committee. RESULTS: The patients' mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). CONCLUSION: The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

Diferenças entre as dimensões sistólica e diastólica do anel valvar aórtico naangiotomografia computadorizada em pacientes submetidos a implantepercutâneo de prótese valvar aórtica por cateter / Differences between systolic and diastolic dimensions of the aortic valve annulus in computed tomography angiography in patients undergoing percutaneous implantation of aortic valve prosthesis by catheter

Introdução: A medida acurada do tamanho do anel valvar aórtico tem importância fundamental para o planejamento do implante percutâneo de prótese valvar aórtica transcateter (TAVI) em pacientes comestenose valvar aórtica grave. Embora haja recomendação de se realizar a medida na sístole, pouco se sabe sobre a importância das diferenças entre as dimensões sistólica e diastólica do anel. Métodos: Pacientes consecutivos referidos para TAVI foram avaliados com tomografia computadorizada para medida do anel valvar na sístole e na diástole. Área, circunferência, diâmetros máximo e mínimo, e seus diâmetros médios derivados foram obtidos em ambas as fases do ciclo cardíaco. Gráficos de Bland Altman foram construídos para se avaliarem as diferenças entre as medidas.Resultados: Foram incluídos na análise 41 pacientes com estenose aórtica grave. As médias da área, circunferência e diâmetros médios foram discretamente maiores na sístole. No entanto, em 35% dos pacientes, as dimensões diastólicas foram maiores. Essas diferenças, embora estatisticamente significantes, foram pequenas (a maior diferença de 0,6 mm no diâmetro médio). Gráficos de Bland Altman revelaram bons níveis de concordância entre as medidas sistólicas e diastólicas em todos os parâmetros avaliados.Conclusões: Observamos pequenas diferenças nas dimensões sistólicas e diastólicas no anel valvar aórtico à tomografia computadorizada, as quais, embora estatisticamente significantes, provavelmente não impactam na seleção da prótese e nem no resultado do procedimento.

Background: Accurate aortic valve annulus sizing has critical importance for the planning of percutaneous transcatheter aortic valve implantation (TAVI) in patients with severe aortic valve stenosis. Although there is a recommendation to perform the measurement during systole, little is known about the importance of the differences between systolic and diastolic dimensions of the annulus. Methods: Consecutive patients referred for TAVI were evaluated with computed tomography for valve annulus sizing during systole and diastole. Area, circumference, minimum and maximum diameters, and their mean derived diameters were obtained in both phases of the cardiac cycle. Bland-Altman plots were constructed to evaluate the differences between the measures. Results: The analysis included 41 patients with severe aortic stenosis. Mean area, circumference, and diameters were slightly greater in systole. However, in 35% of patients, diastolic dimensions were greater.These differences, although statistically significant, were small (the greatest difference of 0.6 mm in mean diameter). Bland-Altman plots showed good agreement between systolic and diastolic measurements on all parameters evaluated Conclusions: Small differences were observed in the systolic and diastolic dimensions of the aortic valve annulus with computed tomography scan, which, although statistically significant, probably do not impact the selection of prosthesis or the procedure outcome.

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.

Exercise-induced decrease in myocardial high-energy phosphate metabolites in patients with Chagas heart disease.

BACKGROUND: The influence of exercise on cardiac metabolic response in patients with Chagas disease is incompletely understood. METHODS AND RESULTS: Changes in cardiac energetic metabolism were investigated in Chagas disease patients before and during isometric handgrip exercise with (31)P magnetic resonance spectroscopy (MRS). Twenty-eight patients (10 with systolic dysfunction: group I; 10 with normal systolic function and electrocardiogram (ECG) abnormalities: group II; and 8 asymptomatic without ECG abnormalities: group III) and 8 healthy control subjects (group C) were evaluated by electrocardiogram, echocardiogram, functional tests for coronary artery disease, and image-selected localized cardiac (31)P-MRS. The myocardial phosphocreatine to [ß-phosphate]adenosine triphosphate ratio (PCr/ß-ATP) was measured at rest and during isometric handgrip exercise. Exercise testing or 99mTc-sestamibi scintigraphy were negative for myocardial ischemia in all individuals. At rest, cardiac PCr/ß-ATP was decreased in all Chagas groups (1.23 ± 0.37) versus group C (1.88 ± 0.08; P < .001) and was lower in group I (0.89 ± 0.24) versus groups II (1.44 ± 0.23) and III (1.40 ± 0.37; P < .001). There was no stress-induced change in cardiac PCr/ß-ATP (1.88 ± 0.08 at rest vs 1.89 ± 0.08 during exercise; P = NS) in group C. Mean cardiac PCr/ß-ATP was 0.89 ± 0.24 and 0.56 ± 0.21 at rest and during exercise, respectively, in group I (37% decrease; P < .001). In group II, PCr/ß-ATP was 1.44 ± 0.23 at rest and 0.97 ± 0.37 during exercise (33% decrease; P < .001). In group III, PCr/ß-ATP was 1.40 ± 0.37 at rest and 0.60 ± 0.19 during exercise (57% decrease; P < .001). CONCLUSIONS: Myocardial high-energy phosphates are reduced at rest in Chagas heart disease patients, and the reduction is greater in patients with left ventricular dysfunction. Regardless of left ventricular function, Chagas patients exhibit an exercise-induced decline in cardiac high-energy phosphates consistent with myocardial ischemia, suggesting the possibility that this metabolic approach may offer a tool to probe new interventions in Chagas disease patients.

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.

Hypotheses, rationale, design, and methods for prognostic evaluation in type 2 diabetic patients with angiographically normal coronary arteries. The MASS IV-DM Trial.

BACKGROUND: The MASS IV-DM Trial is a large project from a single institution, the Heart Institute (InCor), University of São Paulo Medical School, Brazil to study ventricular function and coronary arteries in patients with type 2 diabetes mellitus. METHODS/DESIGN: The study will enroll 600 patients with type 2 diabetes who have angiographically normal ventricular function and coronary arteries. The goal of the MASS IV-DM Trial is to achieve a long-term evaluation of the development of coronary atherosclerosis by using angiograms and coronary-artery calcium scan by electron-beam computed tomography at baseline and after 5 years of follow-up. In addition, the incidence of major cardiovascular events, the dysfunction of various organs involved in this disease, particularly microalbuminuria and renal function, will be analyzed through clinical evaluation. In addition, an effort will be made to investigate in depth the presence of major cardiovascular risk factors, especially the biochemical profile, metabolic syndrome inflammatory activity, oxidative stress, endothelial function, prothrombotic factors, and profibrinolytic and platelet activity. An evaluation will be made of the polymorphism as a determinant of disease and its possible role in the genesis of micro- and macrovascular damage. DISCUSSION: The MASS IV-DM trial is designed to include diabetic patients with clinically suspected myocardial ischemia in whom conventional angiography shows angiographically normal coronary arteries. The result of extensive investigation including angiographic follow-up by several methods, vascular reactivity, pro-thrombotic mechanisms, genetic and biochemical studies may facilitate the understanding of so-called micro- and macrovascular disease of DM.