Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.073
Filtrar
2.
J Comput Assist Tomogr ; 44(5): 790-795, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936580

RESUMO

BACKGROUND: The state-of-art motion correction algorithm is inadequate for correcting motion artifacts in coronary arteries in cardiovascular computed tomography angiography (CCTA) for children with high heart rates, and even less effective for heart structures beyond coronary arteries. PURPOSE: This study aimed to evaluate the effectiveness of a second-generation, whole-heart motion correction algorithm in improving the heart image quality of CCTA for children with high heart rates. MATERIALS AND METHODS: Forty-two consecutive symptomatic cardiac patients with high heart rates (122.6 ± 18.8 beats/min) were enrolled. All patients underwent CCTA on a 256-row CT using a prospective electrocardiogram-triggered single-beat protocol. Images were reconstructed using a standard algorithm (STD), state-of-the-art first-generation coronary artery motion correction algorithm (MC1), and second-generation, whole-heart motion correction algorithm (MC2). The image quality of the origin of left coronary, right coronary, aortic valve, pulmonary valve, mitral valve, tricuspid valve, aorta root, pulmonary artery root, ventricular septum (VS), and atrial septum (AS) was assessed by 2 experienced radiologists using a 4-point scale (1, nondiagnostic; 2, detectable; 3, measurable; and 4, excellent); nonparametric test was used to analyze and compare the differences among 3 groups; and post hoc multiple comparisons were used between different methods. RESULTS: There were group differences for cardiac structures except VS and AS, with MC2 having the best image quality and STD having the worst image quality. Post hoc multiple comparisons showed that MC2 was better than MC1 and STD in all structures except VS and AS where all 3 algorithms performed equally, whereas MC1 was better than STD only in the origin of left coronary, right coronary, and mitral valve. CONCLUSIONS: A second-generation, whole-heart motion correction algorithm further significantly improves cardiac image quality beyond the coronaries in CCTA for pediatric patients with high heart rates.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Frequência Cardíaca/fisiologia , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Algoritmos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos
3.
N Z Med J ; 133(1522): 128-132, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32994622

RESUMO

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is an increasingly recognised condition and it accounts for approximately 10% of all cases of MI. Despite the absence of obstructive coronary artery disease, patients with MINOCA are at increased risk of morbidity and mortality compared to the general population. While many well recognised conditions can present as MINOCA, it can be difficult to reach a final diagnosis with certainty due to the relative infrequency of these conditions in the general population and the lack of diagnostic gold-standard tests. The most common causes of MINOCA are myocarditis, coronary vasospasm, coronary plaque disruption and coronary thrombus or embolism. These can be assessed by way of cardiac magnetic resonance imaging, intra-coronary imaging modalities and clinically relevant diagnostic blood tests, respectively. There are less common and rarer aetiologies which should be considered in the absence of an apparent cause, each with a unique diagnostic standard. By following a systematic approach of diagnostic tests, an underlying cause of MINOCA can be found in the majority of cases, allowing a directed management strategy to be pursued.


Assuntos
Doença das Coronárias , Infarto do Miocárdio , Algoritmos , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Diagnóstico por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/etiologia
4.
PLoS One ; 15(7): e0236035, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673354

RESUMO

PURPOSE: Systemic inflammation and coronary microvascular dysfunction (CMD) may be causal drivers of heart failure with preserved ejection fraction (HFpEF). We tested the hypothesis that subclinical inflammation is associated with non-endothelial dependent CMD and diastolic dysfunction. METHODS: In a cross-sectional study of 336 women with angina but no flow limiting coronary artery stenosis (180 with diabetes) and 95 asymptomatic controls, blood samples were analysed for 90 biomarkers of which 34 were part of inflammatory pathways. CMD was assessed as coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography and defined as CFVR<2.5. We used E/e' as an indicator of diastolic function in age-adjusted linear regressions to assess correlations between biomarkers, CFVR and diastolic function. RESULTS: CMD was found in 59% of participants whereas only 4% fulfilled strict criteria for diastolic dysfunction. Thirty-five biomarkers, 17 of them inflammatory, were negatively correlated with CFVR and 25, 15 inflammatory, were positively correlated with E/e'. A total of 13 biomarkers, 9 inflammatory, were associated with both CFVR and E/e'. CFVR and E/e' were only correlated in the subgroup of patients with CMD and signs of increased filling pressure (E/e'>10) (p = 0.012). CONCLUSION: This is the first study to link a large number of mainly inflammatory biomarkers to both CMD and E/e', thus confirming a role of inflammation in both conditions. However, despite a high prevalence of CMD, few patients had diastolic dysfunction and the data do not support a major pathophysiologic role of non-endothelial dependent CMD in diastolic dysfunction.


Assuntos
Angina Pectoris/epidemiologia , Circulação Coronária , Vasos Coronários/fisiopatologia , Diástole , Inflamação/fisiopatologia , Volume Sistólico , Adulto , Idoso , Idoso de 80 Anos ou mais , Angina Pectoris/etiologia , Angina Pectoris/metabolismo , Angina Pectoris/patologia , Biomarcadores/metabolismo , Estudos de Casos e Controles , Estudos Transversais , Feminino , Seguimentos , Humanos , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico
5.
Rev Cardiovasc Med ; 21(2): 157-162, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32706205

RESUMO

Cardiovascular disease, and in particular coronary artery disease (CAD), remains an important contributor of morbidity and mortality among patients with chronic kidney disease (CKD). Classic symptomatology of CAD and effectiveness of established therapeutic measures is less frequent in patients with CKD. This suggests unique characteristics of CAD among patients with CKD. Two important features of CAD in CKD include increased calcific density of atherosclerotic plaques and of the vessels themselves (coronary artery calcification -- CAC), as well as a decrease in microcirculatory function -- or coronary microcirculatory dysfunction. A multitude of pathophysiologic pathways have been identified that contribute to CAC in CKD; less is known about the pathophysiology of microcirculatory dysfunction. It is not well established if these two processes are directly related to each other, but the combination results in a greater severity of effect on overall myocardial function and may in part explain the greater preponderance of silent myocardial infarction. Further investigation is needed to better understand these unique aspects of CAD in CKD as well as the role they play in overall CVD in this group, and ultimately therapeutics that may lessen the burden of disease.


Assuntos
Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Vasos Coronários/fisiopatologia , Rim/fisiopatologia , Microcirculação , Insuficiência Renal Crônica/fisiopatologia , Calcificação Vascular/fisiopatologia , Animais , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/terapia , Vasos Coronários/diagnóstico por imagem , Progressão da Doença , Taxa de Filtração Glomerular , Hemodinâmica , Humanos , Placa Aterosclerótica , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/terapia , Medição de Risco , Fatores de Risco , Fatores de Tempo , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/epidemiologia , Calcificação Vascular/terapia
6.
PLoS One ; 15(6): e0234861, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603330

RESUMO

OBJECTIVE: To examine whether the cardiac, renal and uterine physiological hemodynamic changes during gestation are altered in rats with an early and prolonged exposure to a high fat diet (HFD). METHODS: Arterial pressure and cardiac, renal, uterine and radial arteries hemodynamic changes during gestation were examined in adult SD rats exposed to normal (13%) (n = 8) or high (60%) (n = 8) fat diets from weaning. Plethysmography, high-resolution high-frequency ultrasonography and clearance of an inulin analog were used to evaluate the arterial pressure and hemodynamic changes before and at days 7, 14 and 19 of gestation. RESULTS: Arterial pressure was higher (P<0.05) in rats with high than in those with normal (NFD) fat diet before pregnancy (123 ±3 and 110 ±3 mmHg, respectively) and only decreased at day 14 of gestation in rats with NFD (98±4 mmHg, P<0.05). A significant increment in stroke volume (42 ±10%) and cardiac output (51 ±12%) was found at day 19 of pregnancy in rats with NFD. The changes in stroke volume and cardiac output were similar in rats with NFD and HFD. When compared to the values obtained before pregnancy, a transitory elevation in renal blood flow was found at day 14 of pregnancy in both groups. However, glomerular filtration rate only increased (P<0.05) in rats with NFD at days 14 (20 ±7%) and 19 (27 ±8%) of gestation. The significant elevations of mean velocity, and velocity time integral throughout gestation in radial (127 ±26% and 111 ±23%, respectively) and uterine (91 ±16% and 111 ±25%, respectively) arteries of rats with NFD were not found in rats with an early and prolonged HFD. SUMMARY: This study reports novel findings showing that the early and prolonged exposure to a HFD leads to a significant impairment in the renal, uterine and radial arteries hemodynamic changes associated to gestation.


Assuntos
Artérias/fisiopatologia , Vasos Coronários/fisiopatologia , Dieta Hiperlipídica/efeitos adversos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Artérias/diagnóstico por imagem , Pressão Sanguínea/fisiologia , Vasos Coronários/diagnóstico por imagem , Feminino , Taxa de Filtração Glomerular/fisiologia , Rim/irrigação sanguínea , Modelos Animais , Gravidez , Ratos , Fluxo Sanguíneo Regional/fisiologia , Volume Sistólico/fisiologia , Ultrassonografia , Útero/irrigação sanguínea , Útero/diagnóstico por imagem
7.
Am J Physiol Heart Circ Physiol ; 319(2): H360-H369, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32678708

RESUMO

Proper inlet boundary conditions are essential for accurate computational fluid dynamics (CFD) modeling. We developed methodology to derive noninvasive FFRB using CFD and computed tomography coronary angiography (CTCA) images. This study aims to assess the influence of brachial mean blood pressure (MBP) and total coronary inflow on FFRB computation. Twenty-two patients underwent both CTCA and FFR measurements. Total coronary flow was computed from left ventricular mass (LVM) measured from CTCA. A total of 286 CFD simulations were run by varying MBP and LVM at 70, 80, 90, 100, 110, 120, and 130% of the measured values. FFRB increased with incrementally higher input values of MBP: 0.78 ± 0.12, 0.80 ± 0.11, 0.82 ± 0.10, 0.84 ± 0.09, 0.85 ± 0.08, 0.86 ± 0.08, and 0.87 ± 0.07, respectively. Conversely, FFRB decreased with incrementally higher inputs value of LVM: 0.86 ± 0.08, 0.85 ± 0.08, 0.84 ± 0.09, 0.84 ± 0.09, 0.83 ± 0.10, 0.83 ± 0.10, and 0.82 ± 0.10, respectively. Noninvasive FFRB calculated using measured MBP and LVM on a total of 30 vessels was 0.84 ± 0.09 and correlated well with invasive FFR (0.83 ± 0.09) (r = 0.92, P < 0.001). Positive association was observed between FFRB and MBP input values (mmHg) and negative association between FFRB and LVM values (g). Respective slopes were 0.0016 and -0.005, respectively, suggesting potential application of FFRB in a clinical setting. Inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions.NEW & NOTEWORTHY While brachial mean blood pressure (MBP) and left ventricular mass (LVM) measured from CTCA are the two CFD simulation input parameters, their effects on noninvasive fractional flow reserve (FFRB) have not been systematically investigated. We demonstrate that inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions. This is important in the clinical application of noninvasive FFR in coronary artery disease diagnosis.


Assuntos
Pressão Arterial , Artéria Braquial/fisiopatologia , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Ventrículos do Coração/diagnóstico por imagem , Modelos Cardiovasculares , Tomografia Computadorizada Multidetectores , Modelagem Computacional Específica para o Paciente , Interpretação de Imagem Radiográfica Assistida por Computador , Idoso , Doença da Artéria Coronariana/fisiopatologia , Vasos Coronários/fisiopatologia , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Hidrodinâmica , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos
8.
Int J Cardiovasc Imaging ; 36(10): 2039-2050, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32488454

RESUMO

To explore the superiority of radiomics analysis in the diagnostic performance of coronary computed tomography angiography (CCTA) for identifying myocardial ischaemia and predicting major adverse cardiovascular events (MACE). A total of 105 lesions from 88 patients who underwent CCTA and invasive fractional flow reserve measurement were collected as the training set, and another 31 patients with CCTA and clinical outcome information were used as the validation set. Conventional CCTA features included the stenosis diameter, length, Agatston score and high-risk plaque characteristics. After extracting and selecting radiomics features, the robustness of the radiomics features was examined, and then conventional and radiomics models were established using logistic regressions. The area under the receiver operating characteristic (ROC) curve (AUC) and Net Reclassification Index (NRI) were analysed to compare the discrimination and classification abilities between the two models in both the training and validation sets. A total of 1409 radiomics features were extracted, and three wavelet features were finally screened out. The robustness test showed good stability for the refined radiomics features. Compared with the conventional model, the radiomics model displayed a significantly improved diagnostic performance in the training set (AUC 0.762 vs. 0.631, 95% confidence interval [CI] 0.671-0.853 vs. 0.519-0.742, P = 0.058) but a slightly improved diagnostic performance in the validation set (AUC 0.671 vs. 0.592, 95% CI 0.466-0.875 vs. 0.519-0.742, P = 0.448). The NRI of the radiomics model was increased in both the training and validation sets (NRI 0.198 and 0.238, respectively). Quantitative radiomics analysis was feasible and might help to improve the diagnostic performance of CCTA but is still controversial for predicting MACE.


Assuntos
Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Interpretação de Imagem Radiográfica Assistida por Computador , Idoso , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença , Análise de Ondaletas
9.
Comput Methods Biomech Biomed Engin ; 23(12): 894-905, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32519914

RESUMO

Stenosis in the bifurcated coronary artery has attracted wide attention among the researchers. Many investigations have been carried out by means of Computational Fluid Dynamics (CFD) to better understand the physical mechanism inside the stenotic bifurcated artery. However, the main focus of the existing publications is limited to the variation of hemodynamic parameters affected by the stenosis and bifurcation structure. The present study aims to make further evaluations of stenosis development and diagnostic lesion assessments based on the critical values of hemodynamic and practical diagnostic parameters. The bifurcated coronary artery with initial stenosis source has been studied in 2 D unsteady model. Different locations of initial stenosis source have been found to greatly affect the orientation of the further stenosis development. In addition, different stenosis severities (diameter stenosis: 30%, 50% and 70%), different stenosis lengths (3 mm, 6 mm and 9 mm) and different pulse rates (75 bpm, 100 bpm and 120 bpm) as controlling parameters have been investigated.


Assuntos
Estenose Coronária/diagnóstico , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Análise Numérica Assistida por Computador , Velocidade do Fluxo Sanguíneo , Simulação por Computador , Hemodinâmica , Humanos , Hidrodinâmica , Modelos Cardiovasculares , Estresse Mecânico
10.
J Interv Cardiol ; 2020: 4094121, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508540

RESUMO

While coronary revascularization strategies guided by instantaneous wave-free ratio (iFR) are, in general, noninferior to those guided by fractional flow reserve (FFR) with respect to the rate of major adverse cardiac events at one-year follow-up in patients with stable angina or an acute coronary syndrome, the overall accuracy of diagnosis with iFR in large patient cohorts is about 80% compared with the diagnosis with FFR. So far, it remains incompletely understood what factors contribute to the discordant diagnosis between iFR and FFR. In this study, a computational method was used to systemically investigate the respective effects of various cardiovascular factors on FFR and iFR. The results showed that deterioration in aortic valve disease (e.g., regurgitation or stenosis) led to a marked decrease in iFR and a mild increase in FFR given fixed severity of coronary artery stenosis and that increasing coronary microvascular resistance caused a considerable increase in both iFR and FFR, but the degree of increase in iFR was lower than that in FFR. These findings suggest that there is a high probability of discordant diagnosis between iFR and FFR in patients with severe aortic valve disease or coronary microcirculation dysfunction.


Assuntos
Síndrome Coronariana Aguda , Angina Estável , Valva Aórtica , Angiografia Coronária/métodos , Estenose Coronária , Vasos Coronários , Reserva Fracionada de Fluxo Miocárdico , Revascularização Miocárdica/métodos , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/etiologia , Angina Estável/diagnóstico , Angina Estável/etiologia , Valva Aórtica/patologia , Valva Aórtica/fisiopatologia , Simulação por Computador , Circulação Coronária , Estenose Coronária/diagnóstico , Estenose Coronária/fisiopatologia , Vasos Coronários/patologia , Vasos Coronários/fisiopatologia , Humanos , Seleção de Pacientes , Índice de Gravidade de Doença , Resistência Vascular
11.
Medicina (B Aires) ; 80(3): 253-270, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-32442940

RESUMO

One in every four coronarographies performed to study myocardial ischemia shows coronary angiographic stenosis less than 50%. This data triggered an increasing interest in the medical community. The American Society of Cardiology recently published a position paper about the pathophysiology, diagnosis and treatment of this entity. Our group performed a narrative review reflecting the opinion of cardiology experts from different centers in Argentina. It aims physiopatologic and diagnostic aspect to understand the current approach in patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) e INOCA (demonstrated angina and ischemia but without coronary lesions that justify this syndrome).


Assuntos
Tomada de Decisão Clínica , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Cineangiografia/métodos , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Prognóstico , Fatores de Risco , Tomografia Computadorizada por Raios X/métodos
12.
PLoS One ; 15(5): e0232483, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32392256

RESUMO

BACKGROUND: Percutaneous coronary intervention represents the most important treatment modality of coronary artery stenosis. In-stent restenosis (ISR) is still a limitation for the long-term outcome despite the introduction of drug eluting stents. It has been shown that adipokines directly influence vessel wall homeostasis by influencing the function of endothelial cells and arterial smooth muscle cells. Visceral adipose tissue-derived serpin vaspin was recently identified as a member of serine protease inhibitor family and serveral studies could demonstrate a relation to metabolic diseases. The aim of this study was to investigate a role of vaspin in the development of in-stent restenosis in vivo and on migration of smooth muscle cells and endothelial cells in vitro. METHODS: We studied 85 patients with stable coronary artery disease who underwent elective and successful PCI with implatation of drug eluting stents. Blood samples were taken directly before PCI. Vaspin plasma levels were measured by specific ELISA. ISR was evaluated eight months later by coronary angiography. Human coronary artery smooth muscle cells (HCASMC) and human umbilical vein endothelial cells (HUVEC) migration was analyzed by an in-vitro migration assay with different concentrations (0.004ng/mL up to 40ng/mL) of vaspin as well as by an scratch assay. For proliferation an impedance measurement with specialiced E-Plates was performed. RESULTS: During the follow up period, 14 patients developed ISR. Patients with ISR had significantly lower vaspin plasma levels compared to patients without ISR (0.213 ng/ml vs 0.382 ng/ml; p = 0.001). In patients with plasma vaspin levels above 1.35 ng/ml we could not observe any restenosis. There was also a significant correlation of plasma vaspin levels and late lumen loss in the stented coronary segments. Further we could demonstrate that vaspin nearly abolishes serum induced migration of HCASMC (100% vs. 9%; p<0.001) in a biphasic manner but not migration of HUVEC. Proliferation of HCASMC and HUVEC was not modulated by vaspin treatment. CONCLUSION: We were able to show that the adipokine vaspin selectively inhibits human coronary SMC migration in vitro and has no effect on HUVEC migration. Vaspin had no effect on proliferation of HUVEC which is an important process of the healing of the stented vessel. In addition, the occurrence of ISR after PCI with implantation of drug eluting stents was significantly associated with low vaspin plasma levels before intervention. Determination of vaspin plasma levels before PCI might be helpful in the identification of patients with high risk for development of ISR after stent implantation. In addition, the selective effects of vaspin on smooth muscle cell migration could potentially be used to reduce ISR without inhibition of re-endothelialization of the stented segment.


Assuntos
Adipocinas/fisiologia , Reestenose Coronária/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Serpinas/fisiologia , Adipocinas/sangue , Adipocinas/farmacologia , Idoso , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Cultivadas , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/cirurgia , Reestenose Coronária/patologia , Reestenose Coronária/fisiopatologia , Vasos Coronários/patologia , Vasos Coronários/fisiopatologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Miócitos de Músculo Liso/fisiologia , Serpinas/sangue , Serpinas/farmacologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-32357115

RESUMO

Type 2 diabetic (T2DM) coronary resistance microvessels (CRMs) undergo inward hypertrophic remodeling associated with reduced stiffness and reduced coronary blood flow in both mice and pig models. Since reduced stiffness does not appear to be due to functional changes in the extracellular matrix, this study tested the hypothesis that decreased CRM stiffness in T2DM is due to reduced vascular smooth muscle cell (VSMC) stiffness, which impacts the traction force generated by VSMCs. Atomic force microscopy (AFM) and traction force microscopy (TFM) were conducted on primary low-passage CRM VSMCs from normal Db/db and T2DM db/db mice in addition to low-passage normal and T2DM deidentified human coronary VSMCs. Elastic modulus was reduced in T2DM mouse and human coronary VSMCs compared with normal (mouse: Db/db 6.84 ± 0.34 kPa vs. db/db 4.70 ± 0.19 kPa, P < 0.0001; human: normal 3.59 ± 0.38 kPa vs. T2DM 2.61 ± 0.35 kPa, P = 0.05). Both mouse and human T2DM coronary microvascular VSMCs were less adhesive to fibronectin compared with normal. T2DM db/db coronary VSMCs generated enhanced traction force by TFM (control 692 ± 67 Pa vs. db/db 1,507 ± 207 Pa; P < 0.01). Immunoblot analysis showed that T2DM human coronary VSMCs expressed reduced ß1-integrin and elevated ß3-integrin (control 1.00 ± 0.06 vs. T2DM 0.62 ± 0.14, P < 0.05 and control 1.00 ± 0.49 vs. T2DM 3.39 ± 1.05, P = 0.06, respectively). These data show that T2DM coronary VSMCs are less stiff and less adhesive to fibronectin but are able to generate enhanced force, corroborating previously published computational findings that decreasing cellular stiffness increases the cells' ability to generate higher traction force.NEW & NOTEWORTHY We show here that a potential causative factor for reduced diabetic coronary microvascular stiffness is the direct reduction in coronary vascular smooth muscle cell stiffness. These cells were also able to generate enhanced traction force, validating previously published computational models. Collectively, these data show that smooth muscle cell stiffness can be a contributor to overall tissue stiffness in the coronary microcirculation, and this may be a novel area of interest for therapeutic targets.


Assuntos
Aorta/fisiopatologia , Vasos Coronários/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Músculo Liso Vascular/fisiopatologia , Adulto , Animais , Módulo de Elasticidade , Feminino , Humanos , Masculino , Camundongos , Microcirculação/fisiologia , Microscopia de Força Atômica , Pessoa de Meia-Idade , Miócitos de Músculo Liso/fisiologia
14.
Int J Cardiovasc Imaging ; 36(8): 1407-1416, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32367188

RESUMO

Contrast-flow quantitative flow ratio (cQFR) is a new technology for quantitative evaluation of coronary stenosis using computational fluid dynamics based on angiograms. The aim of this study was to assess the sensitivity and specificity of cQFR to detect myocardial ischemia using stress magnetic resonance imaging (MRI) as a reference standard. Patients who received stress MRI and coronary angiography were selected from the hospital database. Relevant ischemia on stress MRI was defined as a perfusion deficit in ≥ 2 of 16 segments. cQFR was quantitated based on 3-dimensional quantitative coronary angiography using QAngio XA3D1.1 software by two blinded and independent investigators. A cQFR of ≤ 0.80 was considered abnormal. Among 87 patients 230 vessels met the criteria for full analysis by cQFR (88%). In vascular territories with a significant perfusion deficit, cQFR was significantly lower compared to areas with normal perfusion (0.72 (0.62-0.78) vs. 0.96 (0.89-0.99); p < 0.001). The sensitivity of cQFR in detecting significant epicardial stenoses of coronary vessels with documented ischemia in stress MRI was 81% (68-90%), the specificity was 88% (82-92%). Diameter stenoses (DS) and area stenoses (AS) in vessels with positive stress MRI were significantly higher than in vessels without ischemia (DS 59.1% (49.4-68.4%) vs. 34.8% (27.1-46.1%) p < 0.001; AS 75.6% (63.0-85.2%) vs. 45.0% (30.8-63.6%), p < 0.001). The analysis reveals a high correlation between coronary stenosis measured by cQFR and ischemic areas detected by stress MRI. The data set the stage to plan randomized studies assessing cQFR measurements with regard to clinical outcomes.


Assuntos
Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética , Idoso , Velocidade do Fluxo Sanguíneo , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Função Ventricular Esquerda
15.
Int J Cardiovasc Imaging ; 36(8): 1395-1406, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32409977

RESUMO

Immediate assessment of coronary microcirculation during treatment of ST elevation myocardial infarction (STEMI) may facilitate patient stratification for targeted treatment algorithms. Use of pressure-wire to measure the index of microcirculatory resistance (IMR) is possible but has inevitable practical restrictions. We aimed to develop and validate angiography-derived index of microcirculatory resistance (IMRangio) as a novel and pressure-wire-free index to facilitate assessment of the coronary microcirculation. 45 STEMI patients treated with primary percutaneous coronary intervention (pPCI) were enrolled. Immediately before stenting and at completion of pPCI, IMR was measured within the infarct related artery (IRA). At the same time points, 2 angiographic views were acquired during hyperaemia to measure quantitative flow ratio (QFR) from which IMRangio was derived. In a subset of 15 patients both IMR and IMRangio were also measured in the non-IRA. Patients underwent cardiovascular magnetic resonance imaging (CMR) at 48 h for assessment of microvascular obstruction (MVO). IMRangio and IMR were significantly correlated (ρ: 0.85, p < 0.001). Both IMR and IMRangio were higher in the IRA rather than in the non-IRA (p = 0.01 and p = 0.006, respectively) and were higher in patients with evidence of clinically significant MVO (> 1.55% of left ventricular mass) (p = 0.03 and p = 0.005, respectively). Post-pPCI IMRangio presented and area under the curve (AUC) of 0.96 (CI95% 0.92-1.00, p < 0.001) for prediction of post-pPCI IMR > 40U and of 0.81 (CI95% 0.65-0.97, p < 0.001) for MVO > 1.55%. IMRangio is a promising tool for the assessment of coronary microcirculation. Assessment of IMR without the use of a pressure-wire may enable more rapid, convenient and cost-effective assessment of coronary microvascular function.


Assuntos
Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Vasos Coronários/diagnóstico por imagem , Microcirculação , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Resistência Vascular , Idoso , Angioplastia Coronária com Balão/instrumentação , Velocidade do Fluxo Sanguíneo , Cateterismo Cardíaco/instrumentação , Cateteres Cardíacos , Doença da Artéria Coronariana/fisiopatologia , Doença da Artéria Coronariana/terapia , Vasos Coronários/fisiopatologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Stents , Transdutores de Pressão
16.
Int J Cardiovasc Imaging ; 36(9): 1791-1799, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32419092

RESUMO

The aim of this study was to investigate the image quality and radiation dose of different scanning protocols in dual-source CT cardiothoracic angiography for children with tetralogy of Fallot (TOF). Seventy-five consecutive children with known or suspected TOF were enrolled to undergo prospective ECG-triggering sequential dual-source CT (DSCT) cardiothoracic angiography. According to the scanning protocols, these patients were randomly divided into 3 groups: fixed delay time (FDT, n = 25, group A), automatic bolus-tracking (ABT, n = 25, group B) and manual bolus-tracking (MBT, n = 25, group C). Subjective and objective image quality were evaluated. The radiation doses were recorded. The image quality scores of group C were significantly higher than those of group A and B. The absolute value of difference (D-value) on CT attenuation between left (CTLV) and right ventricle (CTRV) in group C was significantly lower than that in group A and B. The total effective dose of groups A, B and C were 0.39 ± 0.06 mSv, 0.40 ± 0.07 mSv and 0.40 ± 0.08 mSv, respectively. There was no significant difference among 3 groups (P = 0.722). Scanning protocol has significantly impacts on the image quality of cardiovascular structures for TOF patients. Compared with the conventional scanning protocols FDT and ABT, the MBT technique provides high image quality and achieves more homogenous attenuation among different patients with TOF.


Assuntos
Angiografia por Tomografia Computadorizada , Angiografia Coronária , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Doses de Radiação , Exposição à Radiação/prevenção & controle , Tetralogia de Fallot/diagnóstico por imagem , Técnicas de Imagem de Sincronização Cardíaca , Angiografia por Tomografia Computadorizada/efeitos adversos , Meios de Contraste/administração & dosagem , Angiografia Coronária/efeitos adversos , Vasos Coronários/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Lactente , Masculino , Tomografia Computadorizada Multidetectores/efeitos adversos , Variações Dependentes do Observador , Valor Preditivo dos Testes , Exposição à Radiação/efeitos adversos , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Tetralogia de Fallot/fisiopatologia
17.
Clin Hemorheol Microcirc ; 76(1): 9-26, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32417765

RESUMO

Cardiovascular disease is now under the influence of several factors that encourage researchers to investigate the flow of these vessels. Oscillation influences the blood circulation in the volume of red blood cells (RBC) strongly. Therefore, in this study, its effects have been considered on hemodynamic parameters in the elastic wall and coronary bifurcation. In this study, a 3D geometry of non-Newtonian and pulsatile blood circulation is considered in the left coronary artery bifurcation. The Casson model with various hematocrits is analyzed in elastic and rigid walls. The wall shear stress (WSS) cannot show the stenosis artery alone, therefore, the oscillatory shear index (OSI) is represented as a hemodynamic parameter of WSS individually of time. The results are determined using two-way fluid-structure interaction (FSI) coupling method using an arbitrary Lagrangian-Eulerian method. The most prominent difference in velocity happened in the bifurcation and at hematocrit 30 with yield stress 6.59E-04 Pa. The backflow and vortex flow in the LCx branch grown with increasing shear rates. The likelihood of plaque generation at the ending of the LM branch is observed in hematocrits 10 and 20, while the WSS magnitude is normal in the hematocrit 60 with the greatest yield stress in the bifurcation. The shear stress among the rigid and elastic models is the highest at the ending of the LM branch. The wall shear stress magnitude among the models decreased at most of 24.49% by dividing the flow. Time-independent results for models showed that there is the highest value of OSI at the bifurcation, which then quickly dropped.


Assuntos
Vasos Coronários/fisiopatologia , Coração/fisiologia , Hematócrito/métodos , Hemodinâmica/fisiologia , Humanos , Modelos Cardiovasculares
18.
Nat Rev Cardiol ; 17(10): 629-640, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32409779

RESUMO

Evidence supporting the use of coronary physiology as an adjunct to coronary angiography to guide percutaneous coronary interventions has accumulated over the past 25 years. The fractional flow reserve has dominated this evolving physiological guidance of coronary intervention and its use is supported by large clinical outcome trials. However, despite clinical practice guidelines advocating its use in most patients with coronary stenosis who are eligible for coronary intervention, the uptake of a physiology-guided approach remains limited. The use of non-hyperaemic coronary pressure measurements to guide coronary interventions was introduced in an attempt to simplify the routine application of coronary physiology-guided intervention in daily practice. Over the past decade, a large scientific effort has focused on the development of several non-hyperaemic pressure ratios. In this Review, we detail the basic principles of coronary physiology in non-hyperaemic conditions, the rationale for the use of non-hyperaemic coronary pressure measurements for stenosis evaluation, the current evidence base for the available non-hyperaemic coronary pressure ratios, the basis for the discordance between non-hyperaemic coronary pressure ratios and fractional flow reserve, and the potential advantages of these new parameters over fractional flow reserve.


Assuntos
Pressão Arterial , Volume Sanguíneo , Estenose Coronária/fisiopatologia , Estenose Coronária/cirurgia , Vasos Coronários/fisiopatologia , Intervenção Coronária Percutânea/métodos , Hemodinâmica , Humanos
19.
Am J Emerg Med ; 38(6): 1185-1191, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32229223

RESUMO

BACKGROUND: Several studies have indicated that acute myocardial infarction (AMI) secondary to coronary artery embolism (CE) has a poor prognosis. However, in the latter studies, CE of tumor origin accounts for a considerable proportion of cases and the clinical features and contribution to overall prognosis of non-tumor CE are unknown and therefore the subject of this study. METHODS: We retrospectively studied 2006 consecutive patients with AMI at our medical center from January 2014 to October 2018. Non-tumor CE was diagnosed based on angiographic, biochemical, and imaging criteria. Patients were divided into two groups: patients without CE (control) and patients with non-tumor CE. RESULTS: Atrial fibrillation was the most frequent etiology (n = 32, 69.6%) in the non-tumor CE group (n = 46). Compared with the control group, the non-tumor CE group had (all p < 0.05): higher incidence of atrial fibrillation; larger left atrial diameter, left ventricular end-diastolic diameter and left ventricular end-systolic diameter; lower left ventricular ejection fraction, ST-segment-elevation myocardial infarction incidence and low density lipoprotein cholesterol level; lower incidence of multivessel coronary stenosis, level of culprit lesion stenosis and proportion of angioplasty; higher ratio of manual thrombectomy and antithrombotic drugs alone therapy; lower thrombolysis in myocardial infarction (TIMI) grade and higher corrected TIMI frame counts (CTFC) after reperfusion; and statistically similar overall survival at median 864 (interquartile range, 413-1272) days. CONCLUSIONS: The overall incidence of non-tumor CE was 2.3%, with atrial fibrillation as its most common etiology. Midterm overall survival was similar between AMI patients secondary to non-tumor CE and those without CE.


Assuntos
Embolia/complicações , Infarto do Miocárdio/etiologia , Prognóstico , Idoso , Fibrilação Atrial/complicações , Fibrilação Atrial/fisiopatologia , Distribuição de Qui-Quadrado , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Eletrocardiografia/métodos , Embolia/epidemiologia , Embolia/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Estudos Retrospectivos
20.
Intern Med ; 59(7): 909-916, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32238661

RESUMO

Objective A positive correlation is observed between the progression of renal impairment and the increasing risk of cardiovascular disease. Our aim was to examine the relationship between the renal resistive index (RRI) assessed by duplex sonography and the extent of atherosclerosis in patients without renal impairment undergoing vascular imaging studies. Methods The RRI was evaluated pre-procedurally among 106 outpatients with an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 undergoing clinically-driven coronary computed tomography angiography (CCTA). In those subjects, a carotid artery ultrasound scan was also performed to evaluate carotid artery disease. We investigated the association between the RRI and the atherosclerotic extent, defined by the presence of coronary artery calcium (CAC) >0 and carotid intima-media thickness (cIMT) ≥1.0 mm. Results Multi-site atherosclerosis (CAC>0 and cIMT≥1.0 mm) was found in 31 patients. The RRI was significantly increased with an increasing number of atherosclerotic vessels (absence of atherosclerosis: 0.65±0.04 vs. single-site atherosclerosis: 0.67±0.06 vs. multi-site atherosclerosis: 0.71±0.05, p<0.001). A multivariate logistic regression analysis showed that RRI>0.70 [odds ratio (OR): 4.05, 95% confidence interval (CI), 1.37-12.0, p=0.01], cardio ankle vascular index (CAVI) ≥9.0 (OR: 8.18, 95% CI: 2.47-27.1, p<0.01), diabetes (OR: 4.34, 95% CI: 1.37-13.7, p=0.01) and an eGFR>90 mL/min/1.73 m2 (OR: 5.89, 95% CI: 1.39-25.1, p=0.01) were associated with multi-site atherosclerosis. Conclusion The RRI, a sub-clinical renal parameter is an atherosclerotic marker in patients without renal impairment.


Assuntos
Aterosclerose/fisiopatologia , Circulação Renal/fisiologia , Insuficiência Renal/complicações , Resistência Vascular , Idoso , Aterosclerose/complicações , Velocidade do Fluxo Sanguíneo , Doenças das Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Feminino , Taxa de Filtração Glomerular , Humanos , Rim/diagnóstico por imagem , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Insuficiência Renal/fisiopatologia , Ultrassonografia Doppler
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA