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1.
Nature ; 603(7901): 488-492, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35102311

RESUMO

The SARS-CoV-2 Omicron variant (B.1.1.529) has multiple spike protein mutations1,2 that contribute to viral escape from antibody neutralization3-6 and reduce vaccine protection from infection7,8. The extent to which other components of the adaptive response such as T cells may still target Omicron and contribute to protection from severe outcomes is unknown. Here we assessed the ability of T cells to react to Omicron spike protein in participants who were vaccinated with Ad26.CoV2.S or BNT162b2, or unvaccinated convalescent COVID-19 patients (n = 70). Between 70% and 80% of the CD4+ and CD8+ T cell response to spike was maintained across study groups. Moreover, the magnitude of Omicron cross-reactive T cells was similar for Beta (B.1.351) and Delta (B.1.617.2) variants, despite Omicron harbouring considerably more mutations. In patients who were hospitalized with Omicron infections (n = 19), there were comparable T cell responses to ancestral spike, nucleocapsid and membrane proteins to those in patients hospitalized in previous waves dominated by the ancestral, Beta or Delta variants (n = 49). Thus, despite extensive mutations and reduced susceptibility to neutralizing antibodies of Omicron, the majority of T cell responses induced by vaccination or infection cross-recognize the variant. It remains to be determined whether well-preserved T cell immunity to Omicron contributes to protection from severe COVID-19 and is linked to early clinical observations from South Africa and elsewhere9-12.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Reações Cruzadas/imunologia , Imunidade Celular , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Vacinas contra COVID-19/imunologia , Convalescença , Hospitalização , Humanos , Pessoa de Meia-Idade , SARS-CoV-2/química , SARS-CoV-2/classificação
2.
PLoS Pathog ; 19(11): e1011772, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37943890

RESUMO

The impact of previous SARS-CoV-2 infection on the durability of Ad26.COV2.S vaccine-elicited responses, and the effect of homologous boosting has not been well explored. We followed a cohort of healthcare workers for 6 months after receiving the Ad26.COV2.S vaccine and a further one month after they received an Ad26.COV2.S booster dose. We assessed longitudinal spike-specific antibody and T cell responses in individuals who had never had SARS-CoV-2 infection, compared to those who were infected with either the D614G or Beta variants prior to vaccination. Antibody and T cell responses elicited by the primary dose were durable against several variants of concern over the 6 month follow-up period, regardless of infection history. However, at 6 months after first vaccination, antibody binding, neutralization and ADCC were as much as 59-fold higher in individuals with hybrid immunity compared to those with no prior infection. Antibody cross-reactivity profiles of the previously infected groups were similar at 6 months, unlike at earlier time points, suggesting that the effect of immune imprinting diminishes by 6 months. Importantly, an Ad26.COV2.S booster dose increased the magnitude of the antibody response in individuals with no prior infection to similar levels as those with previous infection. The magnitude of spike T cell responses and proportion of T cell responders remained stable after homologous boosting, concomitant with a significant increase in long-lived early differentiated CD4 memory T cells. Thus, these data highlight that multiple antigen exposures, whether through infection and vaccination or vaccination alone, result in similar boosts after Ad26.COV2.S vaccination.


Assuntos
Ad26COVS1 , COVID-19 , Humanos , COVID-19/prevenção & controle , SARS-CoV-2 , Anticorpos , Vacinação , Imunidade Adaptativa , Anticorpos Antivirais , Anticorpos Neutralizantes , Imunidade Humoral
3.
J Virol ; 96(15): e0055822, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35867572

RESUMO

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, several variants of concern (VOCs) have arisen which are defined by multiple mutations in their spike proteins. These VOCs have shown variable escape from antibody responses and have been shown to trigger qualitatively different antibody responses during infection. By studying plasma from individuals infected with either the original D614G, Beta, or Delta variants, we showed that the Beta and Delta variants elicit antibody responses that are overall more cross-reactive than those triggered by D614G. Patterns of cross-reactivity varied, and the Beta and Delta variants did not elicit cross-reactive responses to each other. However, Beta-elicited plasma was highly cross-reactive against Delta Plus (Delta+), which differs from Delta by a single K417N mutation in the receptor binding domain, suggesting that the plasma response targets the N417 residue. To probe this further, we isolated monoclonal antibodies from a Beta-infected individual with plasma responses against Beta, Delta+, and Omicron, which all possess the N417 residue. We isolated an N417-dependent antibody, 084-7D, which showed similar neutralization breadth to the plasma. The 084-7D MAb utilized the IGHV3-23*01 germ line gene and had somatic hypermutations similar to those of previously described public antibodies which target the 417 residue. Thus, we have identified a novel antibody which targets a shared epitope found on three distinct VOCs, enabling their cross-neutralization. Understanding antibodies targeting escape mutations, such as K417N, which repeatedly emerge through convergent evolution in SARS-CoV-2 variants, may aid in the development of next-generation antibody therapeutics and vaccines. IMPORTANCE The evolution of SARS-CoV-2 has resulted in variants of concern (VOCs) with distinct spike mutations conferring various immune escape profiles. These variable mutations also influence the cross-reactivity of the antibody response mounted by individuals infected with each of these variants. This study sought to understand the antibody responses elicited by different SARS-CoV-2 variants and to define shared epitopes. We show that Beta and Delta infections resulted in antibody responses that were more cross-reactive than the original D614G variant, but they had differing patterns of cross-reactivity. We further isolated an antibody from Beta infection which targeted the N417 site, enabling cross-neutralization of Beta, Delta+, and Omicron, all of which possess this residue. The discovery of antibodies which target escape mutations common to multiple variants highlights conserved epitopes to target in future vaccines and therapeutics.


Assuntos
Anticorpos Antivirais , Reações Cruzadas , Epitopos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/virologia , Reações Cruzadas/imunologia , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Humanos , Evasão da Resposta Imune/imunologia , Testes de Neutralização , SARS-CoV-2/química , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
4.
NMR Biomed ; : e4992, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37401341

RESUMO

The global disparity of magnetic resonance imaging (MRI) is a major challenge, with many low- and middle-income countries (LMICs) experiencing limited access to MRI. The reasons for limited access are technological, economic and social. With the advancement of MRI technology, we explore why these challenges still prevail, highlighting the importance of MRI as the epidemiology of disease changes in LMICs. In this paper, we establish a framework to develop MRI with these challenges in mind and discuss the different aspects of MRI development, including maximising image quality using cost-effective components, integrating local technology and infrastructure and implementing sustainable practices. We also highlight the current solutions-including teleradiology, artificial intelligence and doctor and patient education strategies-and how these might be further improved to achieve greater access to MRI.

5.
J Cardiovasc Magn Reson ; 25(1): 21, 2023 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973744

RESUMO

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has affected nearly 600 million people to date across the world. While COVID-19 is primarily a respiratory illness, cardiac injury is also known to occur. Cardiovascular magnetic resonance (CMR) imaging is uniquely capable of characterizing myocardial tissue properties in-vivo, enabling insights into the pattern and degree of cardiac injury. The reported prevalence of myocardial involvement identified by CMR in the context of COVID-19 infection among previously hospitalized patients ranges from 26 to 60%. Variations in the reported prevalence of myocardial involvement may result from differing patient populations (e.g. differences in severity of illness) and the varying intervals between acute infection and CMR evaluation. Standardized methodologies in image acquisition, analysis, interpretation, and reporting of CMR abnormalities across would likely improve concordance between studies. This consensus document by the Society for Cardiovascular Magnetic Resonance (SCMR) provides recommendations on CMR imaging and reporting metrics towards the goal of improved standardization and uniform data acquisition and analytic approaches when performing CMR in patients with COVID-19 infection.


Assuntos
COVID-19 , Cardiopatias , Imageamento por Ressonância Magnética , Humanos , COVID-19/complicações , Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/normas , Espectroscopia de Ressonância Magnética , Miocardite/diagnóstico por imagem , Valor Preditivo dos Testes , Cardiopatias/diagnóstico por imagem , Cardiopatias/etiologia
7.
J Biomech Eng ; 145(11)2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37470483

RESUMO

Rheumatic heart disease (RHD) is a neglected tropical disease despite the substantial global health burden. In this study, we aimed to develop a lower cost method of modeling aortic blood flow using subject-specific velocity profiles, aiding our understanding of RHD's consequences on the structure and function of the ascending aorta. Echocardiography and cardiovascular magnetic resonance (CMR) are often used for diagnosis, including valve dysfunction assessments. However, there is a need to further characterize aortic valve lesions to improve treatment options and timing for patients, while using accessible and affordable imaging strategies. Here, we simulated effects of RHD aortic valve lesions on the aorta using computational fluid dynamics (CFD). We hypothesized that inlet velocity distribution and wall shear stress (WSS) will differ between RHD and non-RHD individuals, as well as between subject-specific and standard Womersley velocity profiles. Phase-contrast CMR data from South Africa of six RHD subjects with aortic stenosis and/or regurgitation and six matched controls were used to estimate subject-specific velocity inlet profiles and the mean velocity for Womersley profiles. Our findings were twofold. First, we found WSS in subject-specific RHD was significantly higher (p < 0.05) than control subject simulations, while Womersley simulation groups did not differ. Second, evaluating spatial velocity differences (ΔSV) between simulation types revealed that simulations of RHD had significantly higher ΔSV than non-RHD (p < 0.05), these results highlight the need for implementing subject-specific input into RHD CFD, which we demonstrate how to accomplish through accessible methods.


Assuntos
Cardiopatia Reumática , Humanos , Cardiopatia Reumática/diagnóstico por imagem , Aorta/fisiologia , Valva Aórtica/diagnóstico por imagem , Imageamento por Ressonância Magnética , Hemodinâmica/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia
8.
Heart Fail Rev ; 27(1): 357-368, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-32653980

RESUMO

Rheumatic heart disease (RHD) is a major cause of cardiovascular morbidity and mortality in low- and middle-income countries, where living conditions promote spread of group A ß-haemolytic streptococcus. Autoimmune reactions due to molecular mimicry of bacterial epitopes by host proteins cause acute rheumatic fever (ARF) and subsequent disease progression to RHD. Despite knowledge of the factors that predispose to ARF and RHD, determinants of the progression to valvular damage and the molecular events involved remain incompletely characterised. This review focuses on altered protein expression in heart valves, myocardial tissue and plasma of patients with RHD and pathogenic consequences on RHD. Proteins mainly involved in structural organization of the valve matrix, blood homeostasis and immune response were altered due to RHD pathogenesis. Study of secreted forms of these proteins may aid the development of non-invasive biomarkers for early diagnosis and monitoring outcomes in RHD. Valve replacement surgery, the single evidence-based strategy to improve outcomes in severe RHD, is costly, largely unavailable in low- and middle-income countries (LMIC) and requires specialised facilities. When diagnosed early, penicillin prophylaxis may be used to delay progression to severe valvular damage. Echocardiography and cardiovascular magnetic resonance and the standard imaging tools recommended to confirm early diagnosis remain largely unavailable and inaccessible in most LMIC and both require expensive equipment and highly skilled persons for manipulation as well as interpretation of results. Changes in protein expression in heart valves and myocardium are associated with progressive valvular deformation in RHD. Understanding these protein changes should shed more light on the mechanisms of pathogenicity, while secreted forms of these proteins may provide leads towards a biomarker for non-invasive early detection of RHD.


Assuntos
Febre Reumática , Cardiopatia Reumática , Progressão da Doença , Ecocardiografia , Valvas Cardíacas , Humanos
9.
Trop Med Int Health ; 27(6): 564-573, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35411997

RESUMO

OBJECTIVES: The objective was to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, assess the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection and determine whether protection against severe disease conferred by prior infection and/or vaccination was maintained. METHODS: In this cohort study, we included public sector patients aged ≥20 years with a laboratory-confirmed COVID-19 diagnosis between 14 November and 11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalisation or death and any hospitalisation or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection. RESULTS: We included 5144 patients from wave four and 11,609 from prior waves. The risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted hazard ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR: 0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58). CONCLUSIONS: In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for a modest reduction in risk of severe hospitalisation or death compared to the Delta-driven wave.


Assuntos
COVID-19 , Técnicas de Laboratório Clínico , SARS-CoV-2 , Adulto , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/virologia , Teste para COVID-19 , Vacinas contra COVID-19/administração & dosagem , Estudos de Coortes , Feminino , Humanos , Masculino , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Estudos Soroepidemiológicos , África do Sul/epidemiologia , Adulto Jovem
10.
BMC Infect Dis ; 22(1): 559, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35725387

RESUMO

BACKGROUND: There is still a paucity of evidence on the outcomes of coronavirus disease 2019 (COVID-19) among people living with human immunodeficiency virus (PWH) and those co-infected with tuberculosis (TB), particularly in areas where these conditions are common. We describe the clinical features, laboratory findings and outcome of hospitalised PWH and human immunodeficiency virus (HIV)-uninfected COVID-19 patients as well as those co-infected with tuberculosis (TB). METHODS: We conducted a multicentre cohort study across three hospitals in Cape Town, South Africa. All adults requiring hospitalisation with confirmed COVID-19 pneumonia from March to July 2020 were analysed. RESULTS: PWH comprised 270 (19%) of 1434 admissions. There were 47 patients with active tuberculosis (3.3%), of whom 29 (62%) were PWH. Three-hundred and seventy-three patients (26%) died. The mortality in PWH (n = 71, 26%) and HIV-uninfected patients (n = 296, 25%) was comparable. In patients with TB, PWH had a higher mortality than HIV-uninfected patients (n = 11, 38% vs n = 3, 20%; p = 0.001). In multivariable survival analysis a higher risk of death was associated with older age (Adjusted Hazard Ratio (AHR) 1.03 95%CI 1.02-1.03, p < 0.001), male sex (AHR1.38 (95%CI 1.12-1.72, p = 0.003) and being "overweight or obese" (AHR 1.30 95%CI 1.03-1.61 p = 0.024). HIV (AHR 1.28 95%CI 0.95-1.72, p 0.11) and active TB (AHR 1.50 95%CI 0.84-2.67, p = 0.17) were not independently associated with increased risk of COVID-19 death. Risk factors for inpatient mortality in PWH included CD4 cell count < 200 cells/mm3, higher admission oxygen requirements, absolute white cell counts, neutrophil/lymphocyte ratios, C-reactive protein, and creatinine levels. CONCLUSION: In a population with high prevalence of HIV and TB, being overweight/obese was associated with increased risk of mortality in COVID-19 hospital admissions, emphasising the need for public health interventions in this patient population.


Assuntos
COVID-19 , Infecções por HIV , Tuberculose , Adulto , COVID-19/epidemiologia , Estudos de Coortes , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hospitalização , Humanos , Masculino , Obesidade/complicações , Sobrepeso , Prevalência , África do Sul/epidemiologia , Tuberculose/complicações , Tuberculose/epidemiologia
11.
Int J Equity Health ; 20(1): 28, 2021 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-33422065

RESUMO

BACKGROUND: Whilst global health research often involves international collaborations, achieving or promoting equity within collaborations remains a key challenge, despite established conceptual approaches and the development of frameworks and guidelines to promote equity. There have also been several empirical studies documenting researchers' experiences of inequity and views on what is required to advance equity in global health collaborations. While these empirical studies provide critical insights, there has been no attempt to systematically synthetize what constitutes equity and how it can be achieved. To address this gap, we conducted a scoping review of qualitative studies, opinion and editorial pieces about what equity is and how it can be promoted in international collaborations. METHODS: We conducted a scoping review to explore domains of equity in international health collaborations. This review included qualitative studies and opinion pieces or editorial pieces on equity in international health collaborations. We mapped the data and identified common themes using a thematic analysis approach. RESULTS: This initial search retrieved a total of 7611 papers after removing duplicates. A total of 11 papers were included in this review, 10 empirical studies and 1 editorial piece. We conducted our search between October - November 2019. We identified 10 key domains which are important for promoting equity in international collaborations: funding; capacity building; authorship; sample ownership and export; trust; research agreement; acknowledging inequality; recognition and communication. DISCUSSION: Our findings suggest that for international collaborations to be considered more equitable, it must at least consider the 10 domains we highlighted. The 10 domains map onto five key aspects of social justice theory, namely avoiding unequal power relations like subordination, group recognition and affirmation, promoting the well-being of all, inclusion in decision-making and ensuring self-development.


Assuntos
Fortalecimento Institucional/normas , Saúde Global/normas , Equidade em Saúde/normas , Disparidades nos Níveis de Saúde , Política de Saúde , Humanos , Cooperação Internacional , Pesquisa Qualitativa , Justiça Social , Organização Mundial da Saúde
12.
J Infect Dis ; 222(Suppl 1): S63-S69, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32645158

RESUMO

BACKGROUND: People with human immunodeficiency virus (PWH) face increased risks for heart failure and adverse heart failure outcomes. Myocardial steatosis predisposes to diastolic dysfunction, a heart failure precursor. We aimed to characterize myocardial steatosis and associated potential risk factors among a subset of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) participants. METHODS: Eighty-two PWH without known heart failure successfully underwent cardiovascular magnetic resonance spectroscopy, yielding data on intramyocardial triglyceride (IMTG) content (a continuous marker for myocardial steatosis extent). Logistic regression models were applied to investigate associations between select clinical characteristics and odds of increased or markedly increased IMTG content. RESULTS: Median (Q1, Q3) IMTG content was 0.59% (0.28%, 1.15%). IMTG content was increased (> 0.5%) among 52% and markedly increased (> 1.5%) among 22% of participants. Parameters associated with increased IMTG content included age (P = .013), body mass index (BMI) ≥ 25 kg/m2 (P = .055), history of intravenous drug use (IVDU) (P = .033), and nadir CD4 count < 350 cells/mm³ (P = .055). Age and BMI ≥ 25 kg/m2 were additionally associated with increased odds of markedly increased IMTG content (P = .049 and P = .046, respectively). CONCLUSIONS: A substantial proportion of antiretroviral therapy-treated PWH exhibited myocardial steatosis. Age, BMI ≥ 25 kg/m2, low nadir CD4 count, and history of IVDU emerged as possible risk factors for myocardial steatosis in this group. CLINICAL TRIALS REGISTRATION: NCT02344290; NCT03238755.


Assuntos
Cardiomiopatias/epidemiologia , Cardiomiopatias/patologia , Tecido Adiposo , Antirretrovirais/uso terapêutico , Índice de Massa Corporal , Contagem de Linfócito CD4 , Feminino , Infecções por HIV/tratamento farmacológico , Fatores de Risco de Doenças Cardíacas , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Triglicerídeos
14.
Clin Infect Dis ; 71(10): e672-e679, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-32285090

RESUMO

BACKGROUND: Human immunodeficiency virus (HIV) and antiretroviral therapy (ART) confer cardiovascular disease (CVD) risk in adults with HIV. Few studies have assessed endothelial dysfunction (ED), an early marker of subclinical CVD risk, in youth living with perinatally acquired HIV (YLPHIV). METHODS: Using peripheral arterial tonometry, we compared ED in YLPHIV and age-matched youth without HIV. A reactive hyperemic index ≤1.35 was defined as ED. Eligible participants included those aged 9-14 years and on ART ≥6 months at enrollment. RESULTS: Overall, 431 YLPHIV and 93 youth without HIV with a median age of 14.1 versus 13.9 years, respectively, were included. YLPHIV had a lower BMI z score (BMIZ; -0.2 vs 0.4; P < .01) but higher rates of hypercholesterolemia (10% vs 1%; P = .01) than youth without HIV. Among YLPHIV, mean log viral load (VL) was 4.83 copies/mL with 21.7% having a CD4 count <500 cell/mm3; median duration on ART was 9.8 years with 38% initiating at <2 years of age. YLPHIV had higher rates of ED than youth without HIV (50% vs 34%; P = .01); this relationship persisted after adjusting for age, sex, BMIZ, elevated BP, and hypercholesterolemia (RR, 1.43; P = .02). Among YLPHIV, CD4 count >500 cell/mm3 (RR, 1.04; P = .76), VL (RR, 1.01; P = .78), and current ART class (protease inhibitor based vs nonnucleoside inhibitor based: relative risk, 0.90; P = .186) were not associated with ED after adjustment. CONCLUSIONS: Even after adjusting for physiologic differences, YLPHIV appear to be at increased risk of ED compared with age-matched youth without HIV. These findings have important implications for the life course of YLPHIV who may be at increased risk of premature CVD and complications.


Assuntos
Infecções por HIV , Adolescente , Adulto , Antirretrovirais/uso terapêutico , Contagem de Linfócito CD4 , Criança , HIV , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Carga Viral
15.
J Cardiovasc Magn Reson ; 22(1): 71, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32981527

RESUMO

The presentation and identification of cardiovascular disease in women pose unique diagnostic challenges compared to men, and underrecognized conditions in this patient population may lead to clinical mismanagement.This article reviews the sex differences in cardiovascular disease, explores the diagnostic and prognostic role of cardiovascular magnetic resonance (CMR) in the spectrum of cardiovascular disorders in women, and proposes the added value of CMR compared to other imaging modalities. In addition, this article specifically reviews the role of CMR in cardiovascular diseases occurring more frequently or exclusively in female patients, including Takotsubo cardiomyopathy, connective tissue disorders, primary pulmonary arterial hypertension and peripartum cardiomyopathy. Gaps in knowledge and opportunities for further investigation of sex-specific cardiovascular differences by CMR are also highlighted.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Disparidades nos Níveis de Saúde , Imageamento por Ressonância Magnética , Saúde da Mulher , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Fatores Sexuais , Adulto Jovem
17.
Magn Reson Med ; 73(5): 1864-71, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24934930

RESUMO

PURPOSE: To investigate for the first time the feasibility of aortic four-dimensional (4D) flow at 7T, both contrast enhanced (CE) and non-CE. To quantify the signal-to-noise ratio (SNR) in aortic 4D flow as a function of field strength and CE with gadobenate dimeglumine (MultiHance). METHODS: Six healthy male volunteers were scanned at 1.5T, 3T, and 7T with both non-CE and CE acquisitions. Temporal SNR was calculated. Flip angle optimization for CE 4D flow was carried out using Bloch simulations that were validated against in vivo measurements. RESULTS: The 7T provided 2.2 times the SNR of 3T while 3T provided 1.7 times the SNR of 1.5T in non-CE acquisitions in the descending aorta. The SNR gains achieved by CE were 1.8-fold at 1.5T, 1.7-fold at 3T, and 1.4-fold at 7T, respectively. CONCLUSION: The 7T provides a new tool to explore aortic 4D flow, yielding higher SNR that can be used to push the boundaries of acceleration and resolution. Field strength and contrast enhancement at all fields provide significant improvements in SNR.


Assuntos
Aorta/fisiologia , Aortografia/métodos , Velocidade do Fluxo Sanguíneo/fisiologia , Meios de Contraste , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Meglumina/análogos & derivados , Compostos Organometálicos , Adulto , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Razão Sinal-Ruído , Adulto Jovem
18.
J Cardiovasc Magn Reson ; 16: 21, 2014 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-24593856

RESUMO

BACKGROUND: Systemic sclerosis (SSc) is characterised by multi-organ tissue fibrosis including the myocardium. Diffuse myocardial fibrosis can be detected non-invasively by T1 and extracellular volume (ECV) quantification, while focal myocardial inflammation and fibrosis may be detected by T2-weighted and late gadolinium enhancement (LGE), respectively, using cardiovascular magnetic resonance (CMR). We hypothesised that multiparametric CMR can detect subclinical myocardial involvement in patients with SSc. METHODS: 19 SSc patients (18 female, mean age 55 ± 10 years) and 20 controls (19 female, mean age 56 ± 8 years) without overt cardiovascular disease underwent CMR at 1.5T, including cine, tagging, T1-mapping, T2-weighted, LGE imaging and ECV quantification. RESULTS: Focal fibrosis on LGE was found in 10 SSc patients (53%) but none of controls. SSc patients also had areas of myocardial oedema on T2-weighted imaging (median 13 vs. 0% in controls). SSc patients had significantly higher native myocardial T1 values (1007 ± 29 vs. 958 ± 20 ms, p < 0.001), larger areas of myocardial involvement by native T1 >990 ms (median 52 vs. 3% in controls) and expansion of ECV (35.4 ± 4.8 vs. 27.6 ± 2.5%, p < 0.001), likely representing a combination of low-grade inflammation and diffuse myocardial fibrosis. Regardless of any regional fibrosis, native T1 and ECV were significantly elevated in SSc and correlated with disease activity and severity. Although biventricular size and global function were preserved, there was impairment in the peak systolic circumferential strain (-16.8 ± 1.6 vs. -18.6 ± 1.0, p < 0.001) and peak diastolic strain rate (83 ± 26 vs. 114 ± 16 s-1, p < 0.001) in SSc, which inversely correlated with diffuse myocardial fibrosis indices. CONCLUSIONS: Cardiac involvement is common in SSc even in the absence of cardiac symptoms, and includes chronic myocardial inflammation as well as focal and diffuse myocardial fibrosis. Myocardial abnormalities detected on CMR were associated with impaired strain parameters, as well as disease activity and severity in SSc patients. CMR may be useful in future in the study of treatments aimed at preventing or reducing adverse myocardial processes in SSc.


Assuntos
Cardiomiopatias/diagnóstico , Edema Cardíaco/diagnóstico , Imagem Cinética por Ressonância Magnética , Miocardite/diagnóstico , Miocárdio/patologia , Esclerodermia Difusa/complicações , Idoso , Cardiomiopatias/etiologia , Cardiomiopatias/patologia , Cardiomiopatias/fisiopatologia , Estudos de Casos e Controles , Meios de Contraste , Diástole , Edema Cardíaco/etiologia , Edema Cardíaco/patologia , Edema Cardíaco/fisiopatologia , Inglaterra , Feminino , Fibrose , Humanos , Masculino , Pessoa de Meia-Idade , Miocardite/etiologia , Miocardite/patologia , Miocardite/fisiopatologia , Valor Preditivo dos Testes , Estudos Prospectivos , Índice de Gravidade de Doença , Função Ventricular Esquerda , Função Ventricular Direita
19.
J Cardiovasc Magn Reson ; 16: 9, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24447690

RESUMO

BACKGROUND: Cardiovascular magnetic resonance (CMR) is regarded as the gold standard for clinical assessment of the aorta, but normal dimensions are usually referenced to echocardiographic and computed tomography data and no large CMR normal reference range exists. As a result we aimed to 1) produce a normal CMR reference range of aortic diameters and 2) investigate the relationship between regional aortic size and body surface area (BSA) in a large group of healthy subjects with no vascular risk factors. METHODS: 447 subjects (208 male, aged 19-70 years) without identifiable cardiac risk factors (BMI range 15.7-52.6 kg/m2) underwent CMR at 1.5 T to determine aortic diameter at three levels: the ascending aorta (Ao) and proximal descending aorta (PDA) at the level of the pulmonary artery, and the abdominal aorta (DDA), at a level 12 cm distal to the PDA. In addition, 201 of these subjects had aortic root imaging, allowing for measurements at the level of the aortic valve annulus (AV), aortic sinuses and sinotubular junction (STJ). RESULTS: Normal diameters (mean ±2 SD) were; AV annulus male(♂) 24.4 ± 5.4, female (♀) 21.0 ± 3.6 mm, aortic sinus♂ 32.4 ± 7.7, ♀27.6 ± 5.8 mm, ST-junction ♂25.0 ± 7.4, ♀21.8 ± 5.4 mm, Ao ♂26.7 ± 7.7, ♀25.5 ± 7.4 mm, PDA ♂20.6 ± 5.6, +18.9 ± 4.0 mm, DDA ♂17.6 ± 5.1, ♀16.4 ± 4.0 mm. Aortic root and thoracic aortic diameters increased at all levels measured with BSA. No gender difference was seen in the degree of dilatation with increasing BSA (p>0.5 for all analyses). CONCLUSION: Across both genders, increasing body size is characterized by a modest degree of aortic dilatation, even in the absence of traditional cardiovascular risk factors.


Assuntos
Aorta/patologia , Aneurisma Aórtico/etiologia , Tamanho Corporal , Imageamento por Ressonância Magnética , Nomogramas , Obesidade/complicações , Adulto , Fatores Etários , Idoso , Aneurisma Aórtico/patologia , Índice de Massa Corporal , Superfície Corporal , Estudos Transversais , Dilatação Patológica , Feminino , Humanos , Imageamento por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Variações Dependentes do Observador , Valor Preditivo dos Testes , Valores de Referência , Reprodutibilidade dos Testes , Fatores Sexuais , Adulto Jovem
20.
J Acquir Immune Defic Syndr ; 95(1): 82-89, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37851954

RESUMO

BACKGROUND: Youth living with perinatally acquired HIV infection (YLPHIV) are at risk of developing atherosclerotic cardiovascular disease. METHODS: We determined the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) coronary arteries (CA) and abdominal aorta (AA) risk scores among YLPHIV who are ≥15 years old in Cape Town Adolescent and Antiretroviral Cohort. PDAY score was calculated using non-high-density lipoprotein, high-density lipoprotein cholesterol, hyperglycemia, hypertension, obesity, and smoking; a score ≥1 was considered elevated. HIV viremia was categorized as sustained (SV) = viral load (VL) >50 copies/mL, transient (TV) = mix of VL >50 and ≤50 copies/mL, or sustained-virologic suppression = VL <50 copies/mL throughout the study. Among YLPHIV, logistic models were fit to assess factors associated with elevated PDAY. RESULTS: Overall, 218 YLPHIV [median age 16.8 (interquartile range: 15.9-17.8) years, male 47%] were included. Among YLPHIV, 8% (n = 17) had SV, and 54% (n = 118) had TV. Median antiretroviral therapy (ART) duration was 12 (interquartile range: 8-14) years. Among YLPHIV, 30.3% and 18.4% had elevated PDAY for CA and AA, respectively.Among YLPHIV, SV [adjusted odds ratio (aOR) = 18.4, P < 0.01] and TV (aOR = 2.10, P = 0.04) compared with virologic suppression and ART duration in years (aOR = 1.12, P = 0.03) were associated with elevated CA. Male sex was associated with both elevated CA and AA (aOR = 2.14, P = 0.02, and aOR = 3.43, P = 0.01, respectively) and association of SV with elevated AA (aOR = 3.24, P = 0.09). CONCLUSIONS: A substantial proportion of YLPHIV have PDAY scores reflecting increased aggregate atherosclerotic risk. Among YLPHIV, viremia, lifetime ART duration, and male sex contribute to this risk, highlighting the importance of HIV control and the need to monitor cardiometabolic health.


Assuntos
Aterosclerose , Infecções por HIV , Humanos , Masculino , Adolescente , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , África do Sul/epidemiologia , Viremia/tratamento farmacológico , Fatores de Risco , Aterosclerose/epidemiologia , Antirretrovirais/uso terapêutico
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