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1.
J Am Heart Assoc ; : e020604, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622670

RESUMO

Background Although the association between dysregulated coagulation and atherosclerosis is well recognized, individual assays have been of minimal value in understanding disease susceptibility. Here we investigated the association of global coagulation profiles with coronary artery disease with consideration of sex differences. Methods and Results The study included patients from the BioHEART-CT (The BioHEART Study: Assessing Patients With Suspected Cardiovascular Disease for New Disease Markers and Risk Factors) biobank who had computed tomography coronary angiograms scored for coronary artery calcium score (CACS) and Gensini score. The cohort included 206 adult patients who were referred for clinically indicated computed tomography coronary angiography and had a median of 2 major cardiac risk factors; 50% were women and the average age was 62.6 years (±9.9 years). The overall hemostatic potential (OHP) and calibrated automated thrombography generation assays were performed on platelet-poor plasma. CACS and Gensini score in men were significantly correlated in bivariate analysis with measures from the OHP assay, and regression models predicting disease severity by CACS or Gensini score were improved by adding the OHP assay variables in men but not in women. The calibrated automated thrombography generation assay demonstrated a more hypercoagulable profile in women than in men. The OHP assay showed hypercoagulable profiles in women with hyperlipidemia and men with obesity. Conclusions The OHP assay identified hypercoagulable profiles associated with different risk factors for each sex and was associated with CACS and Gensini score severity in men, emphasizing the associations between increased fibrin generation and reduced fibrinolysis with cardiac risk factors and early atherosclerosis. Registration Information www.anzctr.org.au. Identifier: ACTRN12618001322224.

2.
BMJ Open ; 11(9): e049858, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34588252

RESUMO

INTRODUCTION: There is currently only one approved medication effective at improving walking distance in people with intermittent claudication. Preclinical data suggest that the ß3-adrenergic receptor agonist (mirabegron) could be repurposed to treat intermittent claudication associated with peripheral artery disease. The aim of the Stimulating ß3-Adrenergic Receptors for Peripheral Artery Disease (STAR-PAD) trial is to test whether mirabegron improves walking distance in people with intermittent claudication. METHODS AND ANALYSIS: The STAR-PAD trial is a Phase II, multicentre, double-blind, randomised, placebo-controlled trial of mirabegron versus placebo on walking distance in patients with PAD. A total of 120 patients aged ≥40 years with stable PAD and intermittent claudication will be randomly assigned (1:1 ratio) to receive either mirabegron (50 mg orally once a day) or matched placebo, for 12 weeks. The primary endpoint is change in peak walking distance as assessed by a graded treadmill test. Secondary endpoints will include: (i) initial claudication distance; (ii) average daily step count and total step count and (iii) functional status and quality of life assessment. Mechanistic substudies will examine potential effects of mirabegron on vascular function, including brachial artery flow-mediate dilatation; MRI assessment of lower limb blood flow, tissue perfusion and arterial stiffness and numbers and angiogenesis potential of endothelial progenitor cells. Given that mirabegron is safe and clinically available for alternative purposes, a positive study is positioned to immediately impact patient care. ETHICS AND DISSEMINATION: The STAR-PAD trial is approved by the Northern Sydney Local Health District Human Research Ethics Committee (HREC/18/HAWKE/50). The study results will be published in peer-reviewed medical or scientific journals and presented at scientific meetings, regardless of the study outcomes. TRIAL REGISTRATION NUMBER: ACTRN12619000423112; Results.

3.
Nat Commun ; 12(1): 4992, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404777

RESUMO

Liquid chromatography-mass spectrometry-based metabolomics studies are increasingly applied to large population cohorts, which run for several weeks or even years in data acquisition. This inevitably introduces unwanted intra- and inter-batch variations over time that can overshadow true biological signals and thus hinder potential biological discoveries. To date, normalisation approaches have struggled to mitigate the variability introduced by technical factors whilst preserving biological variance, especially for protracted acquisitions. Here, we propose a study design framework with an arrangement for embedding biological sample replicates to quantify variance within and between batches and a workflow that uses these replicates to remove unwanted variation in a hierarchical manner (hRUV). We use this design to produce a dataset of more than 1000 human plasma samples run over an extended period of time. We demonstrate significant improvement of hRUV over existing methods in preserving biological signals whilst removing unwanted variation for large scale metabolomics studies. Our tools not only provide a strategy for large scale data normalisation, but also provides guidance on the design strategy for large omics studies.


Assuntos
Metabolômica/métodos , Cromatografia Líquida , Humanos , Espectrometria de Massas/métodos , Modelos Biológicos , Fluxo de Trabalho
4.
Hip Int ; : 11207000211038550, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34424780

RESUMO

BACKGROUND: Bony morphology is central to the pathomechanism of femoroacetabular impingement syndrome (FAIS), however isolated radiographic measures poorly predict symptom onset and severity. More comprehensive morphology measurement considered together with patient factors may better predict symptom presentation. This study aimed to determine the morphological parameter(s) and patient factor(s) associated with symptom age of onset and severity in FAIS. METHODS: 99 participants (age 32.9 ± 10.5 years; body mass index (BMI 24.3 ± 3.1 kg/m2; 42% females) diagnosed with FAIS received standardised plain radiographs and magnetic resonance scans. Alpha angle in four radial planes (superior to anterior), acetabular version (AV), femoral torsion, lateral centre-edge, anterior centre-edge (ACEA) and femoral neck-shaft angles were measured. Age of symptom onset (age at presentation minus duration of symptoms), international Hip Outcome Tool-33 (iHOT-33) and modified UCLA activity scores were recorded. Backward stepwise regression assessed morphological parameters and patient factors (age, sex, BMI, symptom duration, annual income, private/public healthcare system accessed) to determine variables independently associated with onset age and iHOT-33 score. RESULTS: Earlier symptom onset was associated with larger superoanterior alpha angle (p = 0.007), smaller AV (p = 0.023), lower BMI (p = 0.010) and public healthcare system access (p = 0.041) (r2 = 0.320). Worse iHOT-33 score was associated with smaller ACEA (p = 0.034), female sex (p = 0.040), worse modified UCLA activity score (p = 0.010) and public healthcare system access (p < 0.001) (r2 = 0.340). CONCLUSIONS: Age of symptom onset was chiefly predicted by femoral and acetabular bony morphology measures, whereas symptom severity predominantly by patient factors. Factors measured explained a small amount of variance in the data; additional unmeasured factors may be more influential.

5.
Sci Rep ; 11(1): 12712, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135432

RESUMO

Despite improvements in revascularization after a myocardial infarction, coronary disease remains a major contributor to global mortality. Neutrophil infiltration and activation contributes to tissue damage, via the release of myeloperoxidase (MPO) and formation of the damaging oxidant hypochlorous acid. We hypothesized that elevation of thiocyanate ions (SCN-), a competitive MPO substrate, would modulate tissue damage. Oral dosing of rats with SCN-, before acute ischemia-reperfusion injury (30 min occlusion, 24 h or 4 week recovery), significantly reduced the infarct size as a percentage of the total reperfused area (54% versus 74%), and increased the salvageable area (46% versus 26%) as determined by MRI imaging. No difference was observed in fractional shortening, but supplementation resulted in both left-ventricle end diastolic and left-ventricle end systolic areas returning to control levels, as determined by echocardiography. Supplementation also decreased antibody recognition of HOCl-damaged myocardial proteins. SCN- supplementation did not modulate serum markers of damage/inflammation (ANP, BNP, galectin-3, CRP), but returned metabolomic abnormalities (reductions in histidine, creatine and leucine by 0.83-, 0.84- and 0.89-fold, respectively), determined by NMR, to control levels. These data indicate that elevated levels of the MPO substrate SCN-, which can be readily modulated by dietary means, can protect against acute ischemia-reperfusion injury.

6.
J Med Imaging Radiat Oncol ; 65(6): 710-718, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34180148

RESUMO

Medical imaging plays a critical role in clinical decision-making across disciplines, and as such, there is frequent need for non-radiologist clinicians to interact with medical imaging. This review examines the literature about the delivery of medical imaging education to non-radiologist clinicians, spanning junior doctors, advanced trainees and specialists. Knowledge of medical imaging among non-radiologist clinicians is paramount to the quality of patient care, with calls for formal implementation of radiology education into non-imaging specialty training programmes. Overall, there is a demand across non-imaging disciplines for greater formalised medical imaging education. Concerns are raised that too great a reliance on informal methods of teaching radiology, for example in ward settings, results in greater variation in the quality and volume of educational opportunities and risks the perpetuation of erroneous attitudes and practices. The evolution of the medical imaging workplace and increasing utilisation of remote reporting has distanced the collaborative relationship between radiologists and their non-imaging colleagues, diminishing opportunities for ad hoc learning and engagement in larger formalised educational collaborations. Ideally, radiologists should be directly involved in the development and delivery of medical imaging education to post-graduate doctors to not only benefit patient care but also foster inter-specialty relationships and respect. Evidence supports the value of structured radiological teaching opportunities, including tutorials, lectures and electronic resources, in improving medical imaging skills among non-radiologist clinicians. There is wide scope for growth in the e-learning arena to address this demand for quality and accessible imaging education for our non-radiology colleagues.

7.
Atherosclerosis ; 333: 100-107, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34045070

RESUMO

BACKGROUND AND AIMS: Targeting the modifiable risk factors for coronary artery disease (CAD) has substantial impact at the community level. However, it is not uncommon for individuals to present with atherosclerosis related events without identified risk factors. We examined sex differences in the association of risk factors and atherosclerotic burden assessed by CT coronary angiography (CTCA). METHODS: We analysed clinical and imaging data in 1002 individuals in the BioHEART cohort. RESULTS: 45% were female, 35% had no CAD identified. Median coronary calcium score was 9.9 Agatston units (IQR: 0-146), and median Gensini Score was 3.5 (IQR: 0-11.5). 26% had a calcified plaque predominant phenotype, and 18% had a non-calcified plaque predominant phenotype. There were no sex differences in the prevalence of risk factors. However, there were notable sex differences in the adjusted associations of risk factors with CAD. Age and hypercholesterolaemia (OR 1.56, 95% CI 1.03-2.36, p = 0.04 in males, and OR 1.75, 95% CI 1.09-2.78, p = 0.02 in females) were associated with the presence of CAD in both genders (p < 0.05). Diabetes and smoking were associated with presence of CAD, calcified CAD, and non-calcified plaque in males (p < 0.05) but not females. In women, none of the standard modifiable risk factors were associated with the amount of plaque present when adjusted for age, BMI, and family history of premature CAD. CONCLUSIONS: CTCA provides an important opportunity for improving the stratification of cohorts to assess underlying biology and risk. We demonstrate sex-specific differences in associations of risk factors with atherosclerosis burden.

8.
Cells ; 10(5)2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922315

RESUMO

Despite effective prevention programs targeting cardiovascular risk factors, coronary artery disease (CAD) remains the leading cause of death. Novel biomarkers are needed for improved risk stratification and primary prevention. To assess for independent associations between plasma metabolites and specific CAD plaque phenotypes we performed liquid chromatography mass-spectrometry on plasma from 1002 patients in the BioHEART-CT study. Four metabolites were examined as candidate biomarkers. Dimethylguanidino valerate (DMGV) was associated with presence and amount of CAD (OR) 1.41 (95% Confidence Interval [CI] 1.12-1.79, p = 0.004), calcified plaque, and obstructive CAD (p < 0.05 for both). The association with amount of plaque remained after adjustment for traditional risk factors, ß-coefficient 0.17 (95% CI 0.02-0.32, p = 0.026). Glutamate was associated with the presence of non-calcified plaque, OR 1.48 (95% CI 1.09-2.01, p = 0.011). Phenylalanine was associated with amount of CAD, ß-coefficient 0.33 (95% CI 0.04-0.62, p = 0.025), amount of calcified plaque, (ß-coefficient 0.88, 95% CI 0.23-1.53, p = 0.008), and obstructive CAD, OR 1.84 (95% CI 1.01-3.31, p = 0.046). Trimethylamine N-oxide was negatively associated non-calcified plaque OR 0.72 (95% CI 0.53-0.97, p = 0.029) and the association remained when adjusted for traditional risk factors. In targeted metabolomic analyses including 53 known metabolites and controlling for a 5% false discovery rate, DMGV was strongly associated with the presence of calcified plaque, OR 1.59 (95% CI 1.26-2.01, p = 0.006), obstructive CAD, OR 2.33 (95% CI 1.59-3.43, p = 0.0009), and amount of CAD, ß-coefficient 0.3 (95% CI 0.14-0.45, p = 0.014). In multivariate analyses the lipid and nucleotide metabolic pathways were both associated with the presence of CAD, after adjustment for traditional risk factors. We report novel associations between CAD plaque phenotypes and four metabolites previously associated with CAD. We also identified two metabolic pathways strongly associated with CAD, independent of traditional risk factors. These pathways warrant further investigation at both a biomarker and mechanistic level.

9.
Neuroimage Clin ; 29: 102555, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33461111

RESUMO

OBJECTIVE: Phenylketonuria (PKU) is an autosomal recessive disorder whereby deficiencies in phenylalanine metabolism cause progressive neurological dysfunction. Managing PKU is challenging, with disease monitoring focussed on short-term phenylalanine control rather than measures of neuronal damage. Conventional imaging lacks sensitivity, however diffusion kurtosis imaging (DKI), a new MRI method may reveal subclinical white matter structural changes in PKU. METHODS: This cohort study involved adults with PKU recruited during routine clinical care. MRI, neurocognitive assessment and historical phenylalanine (Phe) levels were collected. A hypothesis-generating case study comparing diet-compliant and non-compliant siblings confirmed that DKI metrics are sensitive to dietary adherence and prompted a candidate metric (Krad/KFA ratio). We then tested this metric in a Replication cohort (PKU = 20; controls = 43). RESULTS: Both siblings scored outside the range of controls for all DKI-based metrics, with severe changes in the periventricular white matter and a gradient of severity toward the cortex. Krad/KFA provided clear separation by diagnosis in the Replication cohort (p < 0.001 in periventricular, deep and pericortical compartments). The ratio also correlated negatively with attention (r = -0.51 & -0.50, p < 0.05) and positively with 3-year mean Phe (r = 0.45 & 0.58, p < 0.01). CONCLUSION: DKI reveals regionally-specific, progressive abnormalities of brain diffusion characteristics in PKU, even in the absence of conspicuous clinical signs or abnormalities on conventional MRI. A DKI-based marker derived from these scores (Krad/KFA ratio) was sensitive to cognitive impairment and PKU control over the medium term and may provide a meaningful subclinical biomarker of end-organ damage.


Assuntos
Fenilcetonúrias , Substância Branca , Adulto , Encéfalo , Estudos de Coortes , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Humanos , Fenilcetonúrias/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
10.
Eur Heart J ; 42(10): 1004-1015, 2021 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-33517376

RESUMO

BACKGROUND: Silent brain infarcts (SBIs) are frequently identified after transcatheter aortic valve implantation (TAVI), when patients are screened with diffusion-weighted magnetic resonance imaging (DW-MRI). Outside the cardiac literature, SBIs have been correlated with progressive cognitive dysfunction; however, their prognostic utility after TAVI remains uncertain. This study's main goals were to explore (i) the incidence of and potential risk factors for SBI after TAVI; and (ii) the effect of SBI on early post-procedural cognitive dysfunction (PCD). METHODS AND RESULTS: A systematic literature review was performed to identify all publications reporting SBI incidence, as detected by DW-MRI after TAVI. Silent brain infarct incidence, baseline characteristics, and the incidence of early PCD were evaluated via meta-analysis and meta-regression models. We identified 39 relevant studies encapsulating 2408 patients. Out of 2171 patients who underwent post-procedural DW-MRI, 1601 were found to have at least one new SBI (pooled effect size 0.76, 95% CI: 0.72-0.81). The incidence of reported stroke with focal neurological deficits was 3%. Meta-regression noted that diabetes, chronic renal disease, 3-Tesla MRI, and pre-dilation were associated with increased SBI risk. The prevalence of early PCD increased during follow-up, from 16% at 10.0 ± 6.3 days to 26% at 6.1 ± 1.7 months and meta-regression suggested an association between the mean number of new SBI and incidence of PCD. The use of cerebral embolic protection devices (CEPDs) appeared to decrease the volume of SBI, but not their overall incidence. CONCLUSIONS: Silent brain infarcts are common after TAVI; and diabetes, kidney disease, and pre-dilation increase overall SBI risk. While higher numbers of new SBIs appear to adversely affect early neurocognitive outcomes, long-term follow-up studies remain necessary as TAVI expands to low-risk patient populations. The use of CEPD did not result in a significant decrease in the occurrence of SBI.


Assuntos
Estenose da Valva Aórtica , Isquemia Encefálica , Substituição da Valva Aórtica Transcateter , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/epidemiologia , Infarto Encefálico/etiologia , Cognição , Imagem de Difusão por Ressonância Magnética , Humanos , Fatores de Risco , Substituição da Valva Aórtica Transcateter/efeitos adversos
11.
Otol Neurotol ; 42(2): e177-e185, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33443358

RESUMO

INTRODUCTION: Long term results of ossiculoplasty surgery are considered poor with displacement and extrusion amongst the common reasons for failure. Application of 3Dimensional (3D) printing may help overcome some of these barriers, however digital methods to attain accurate 3D morphological studies of ossicular anatomy are lacking, exacerbated by the limitation of resolution of clinical imaging. METHODS: 20 human cadaveric temporal bones were assessed using micro computed tomography (CT) imaging to demonstrate the lowest resolution required for accurate 3D reconstruction. The bones were then scanned using conebeam CT (125 µm) and helical CT (0.6 mm). 3D reconstruction using clinical imaging techniques with microCT imaging (40 µm resolution) as a reference was assessed. The incus was chosen as the focus of study. Two different methods of 3D printing techniques were assessed. RESULTS: A minimum resolution of 100 µm was needed for adequate 3D reconstruction of the ossicular chain. Conebeam CT gave the most accurate data on 3D analysis, producing the smallest mean variation in surface topography data relative to microCT (mean difference 0.037 mm, p < 0.001). Though the incus varied in shape in between people, paired matches were identical. Thus, the contralateral side can be used for 3D printing source data if the ipsilateral incus is missing. Laser based 3D printing was superior to extrusion based printing to achieve the resolution demands for 3D printed ossicles. CONCLUSION: Resolution of modern imaging allows 3D reconstructions and 3D printing of human ossicles with good accuracy, though it is important to pay attention to thresholding during this process.


Assuntos
Medicina de Precisão , Impressão Tridimensional , Ossículos da Orelha/diagnóstico por imagem , Ossículos da Orelha/cirurgia , Humanos , Bigorna , Microtomografia por Raio-X
12.
Circulation ; 143(9): 878-891, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33231097

RESUMO

BACKGROUND: Neurocognitive outcomes beyond childhood in people with a Fontan circulation are not well defined. This study aimed to investigate neurocognitive functioning in adolescents and adults with a Fontan circulation and associations with structural brain injury, brain volumetry, and postnatal clinical factors. METHODS: In a binational study, participants with a Fontan circulation without a preexisting major neurological disability were prospectively recruited from the Australia and New Zealand Fontan Registry. Neurocognitive function was assessed by using Cogstate software in 107 participants with a Fontan circulation and compared with control groups with transposition of the great arteries (n=50) and a normal circulation (n=41). Brain MRI with volumetric analysis was performed in the participants with a Fontan circulation and compared with healthy control data from the ABIDE I and II (Autism Brain Imaging Data Exchange) and PING (Pediatric Imaging, Neurocognition, and Genetics) data repositories. Clinical data were retrospectively collected. RESULTS: Of the participants with a Fontan circulation who had a neurocognitive assessment, 55% were male and the mean age was 22.6 years (SD 7.8). Participants with a Fontan circulation performed worse in several areas of neurocognitive function compared with those with transposition of the great arteries and healthy controls (P<0.05). Clinical factors associated with worse neurocognitive outcomes included more inpatient days during childhood, younger age at Fontan surgery, and longer time since Fontan procedure (P<0.05). Adults with a Fontan circulation had more marked neurocognitive dysfunction than adolescents with a Fontan circulation in 2 domains (psychomotor function, P=0.01 and working memory, P=0.02). Structural brain injury was present in the entire Fontan cohort; the presence of white matter injury was associated with worse paired associate learning (P<0.001), but neither the presence nor severity of infarct, subcortical gray matter injury, and microhemorrhage was associated with neurocognitive outcomes. Compared with healthy controls, people with a Fontan circulation had smaller global brain volumes (P<0.001 in all regions) and smaller regional brain volumes in most cerebral cortical regions (P<0.05). Smaller global brain volumes were associated with worse neurocognitive functioning in several domains (P<0.05). A significant positive association was also identified between global brain volumes and resting oxygen saturations (P≤0.04). CONCLUSIONS: Neurocognitive impairment is common in adolescents and adults with a Fontan circulation and is associated with smaller gray and white matter brain volume. Understanding modifiable factors that contribute to brain injury to optimize neurocognitive function is paramount.

14.
Brain Imaging Behav ; 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32720180

RESUMO

Sports-related concussion (SRC) is a complex and heterogeneous injury with psychological, cognitive and functional consequences. Advances in diffusion magnetic resonance imaging (dMRI) allow sensitive measurement of white matter pathology post-SRC and may provide insight into injury and recovery. We systematically reviewed and meta-analyzed the literature examining dMRI alongside cognitive, emotional or motor assessments to determine relationships between these analyses. Sixteen studies examining young athletes (n = 6) or retired professionals (n = 10) met the inclusion criteria, with 12 emotional, 10 cognitive and four motor assessments. Studies had heterogeneous methodology, moderate quality and modest sample sizes. Fractional anisotropy (FA) was the most frequent dMRI metric, with SRC-induced changes described most commonly in the frontal lobe and least in the cerebellum and brainstem. There is an emerging complementary role for dMRI as part of a comprehensive assessment battery for SRC. However, larger-scale studies with broader subject populations (specifically, in females and in the 30-45 year age range) are needed to corroborate findings and determine the true diagnostic utility of dMRI post-SRC.

15.
Heliyon ; 6(6): e04007, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32613096

RESUMO

We have previously shown that a severely energy-restricted diet leads to greater loss of weight, fat, lean mass and bone mineral density (BMD) at 12 months in postmenopausal women with obesity than a moderately energy-restricted diet. We now aim to evaluate whether these effects are sustained longer term (ie, at 36 months). 101 postmenopausal women were randomized to either 12 months of moderate (25 to 35%) energy restriction with a food-based diet (moderate intervention), or 4 months of severe (65 to 75%) energy restriction with a total meal replacement diet followed by moderate energy restriction for 8 months (severe intervention). Body weight and composition were measured at 0, 24 and 36 months. Participants in the severe intervention lost ~1.5 to 1.7 times as much weight, waist circumference, whole-body fat mass and visceral adipose tissue compared to those in the moderate intervention, and were 2.6 times more likely (42% versus 16%) to have lost 10% or more of their initial body weight at 36 months (P < 0.01 for all). However, those in the severe versus moderate intervention lost ~1.4 times as much whole-body lean mass (P < 0.01), albeit this was proportional to total weight lost and there was no greater loss of handgrip strength, and they also lost ~2 times as much total hip BMD between 0 and 36 months (P < 0.05), with this bone loss occurring in the first 12 months. Thus, severe energy restriction is more effective than moderate energy restriction for reducing weight and adiposity in postmenopausal women in the long term (3 years), but attention to BMD loss in the first year is required. Trial registration: Australian New Zealand Clinical Trials Registry Reference Number: 12612000651886, anzctr.org.au.

16.
Neuroreport ; 31(10): 746-753, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32501890

RESUMO

Correcting for eddy currents, movement-induced distortion and gradient inhomogeneities is imperative when processing diffusion MRI (dMRI) data, but is highly computing resource-intensive. Recently, Compute Unified Device Architecture (CUDA) was implemented for the widely-used eddy-correction software, 'eddy', which reduces processing time and allows more comprehensive correction. We investigated processing speed, performance and compatibility of CUDA-enabled eddy-current correction processing compared to commonly-used non-CUDA implementations. Four representative dMRI datasets from the Human Connectome Project, Alzheimer's Disease Neuroimaging Initiative and Chronic Diseases Connectome Project were processed on high-specification and regular workstations through three different configurations of 'eddy'. Processing times and graphics processing unit (GPU) resources used were monitored and compared. Using CUDA reduced the 'eddy' processing time by a factor of up to five. The CUDA slice-to-volume correction method was also faster than non-CUDA eddy except when datasets were large. We make a series of recommendations for eddy configuration and hardware. We suggest that users of eddy-correction software for dMRI processing utilise CUDA and take advantage of the slice-to-volume correction option. We recommend that users run eddy on computers with at least 32GB motherboard random access memory (RAM), and a graphics card with at least 4.5GB RAM and 3750 cores to optimise processing time.

17.
Front Neurol ; 11: 350, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508733

RESUMO

Objective: Mild traumatic brain injury (mTBI) is associated with depressed mood acutely post-injury, but there is little evidence regarding long-term depression. The aim of this study was to determine the odds ratio (OR) of depression chronically following mTBI. Methods: We searched Medline (PubMed), ProQuest, and Web of Science from date of database creation to January 23, 2019, for eligible studies examining depression at least 6 months post-injury in adult subjects with mTBI of any etiology, including civilians and military. Three authors independently reviewed titles and abstracts for study eligibility. Data were extracted and collated by two investigators. Risk of bias was assessed with the SIGN methodology. Study data were pooled using random-effects meta-analysis. The primary exposure was mTBI, and the primary outcome was depression. Secondary exploratory variables were time of assessment, age at injury, age at assessment, sex, and etiology. Results: We included 47 cross-sectional studies (n = 25,103 mTBI and 29,982 control), 26 cohort studies (n = 70,119 mTBI, 262,034 control), four prospective observational studies (n = 1,058 mTBI and 733 control), two prospective longitudinal studies (n = 119 mTBI, 81 control), two case-control studies (n = 56 mTBI, 56 control), and one randomized controlled trial (n = 252 mTBI, 3,214 control). mTBI was associated with a 3.29-fold increased risk of depression (OR 3.29, 95% CI 2.68-4.03, I 2 = 96%). The OR for depression did not change when subjects were assessed at 6-12 months (OR 2.43, 1.45-4.07), years 1-2 (OR 4.12, 2.10-8.07); 2-10 (OR 3.28, 2.42-4.46), or 10+ (OR 3.42, 1.51-7.77). Similar risk of depression was sustained across different age at injury (<25: OR 2.26, 1.82-2.81; 25-35: OR 4.67, 3.06-7.14; >35: OR 2.69, 1.42-5.10) and different age at assessment (<40 years: OR 3.14, 2.48-3.99; >40 years: OR 4.57, 2.54-8.24). Female sex had a non-significant increase in OR (OR 19.97, 2.39-166.93) compared to male (OR 3.0, 2.33-3.86). mTBI etiology had no impact on depression. Conclusions: Those experiencing mTBI are more than three times more likely to experience depression compared to those without a history of mTBI, and this risk remains decades beyond the mTBI event. Future longitudinal studies are needed to identify and mitigate this risk.

18.
J Cardiovasc Magn Reson ; 22(1): 45, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32536342

RESUMO

BACKGROUND: As the average age of patients with severe aortic stenosis (AS) who receive procedural intervention continue to age, the need for non-invasive modalities that provide accurate diagnosis and operative planning is increasingly important. Advances in cardiovascular magnetic resonance (CMR) over the past two decades mean it is able to provide haemodynamic data at the aortic valve, along with high fidelity anatomical imaging. METHODS: Electronic databases were searched for studies comparing CMR to transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE) in the diagnosis of AS. Studies were included only if direct comparison was made on matched patients, and if diagnosis was primarily through measurement of aortic valve area (AVA). RESULTS: Twenty-three relevant, prospective articles were included in the meta-analysis, totalling 1040 individual patients. There was no significant difference in AVA measured as by CMR compared to TEE. CMR measurements of AVA size were larger compared to TTE by an average of 10.7% (absolute difference: + 0.14cm2, 95% CI 0.07-0.21, p < 0.001). Reliability was high for both inter- and intra-observer measurements (0.03cm2 +/- 0.04 and 0.02cm2 +/- 0.01, respectively). CONCLUSIONS: Our analysis demonstrates the equivalence of AVA measurements using CMR compared to those obtained using TEE. CMR demonstrated a small but significantly larger AVA than TTE. However, this can be attributed to known errors in derivation of left ventricular outflow tract size as measured by TTE. By offering additional anatomical assessment, CMR is warranted as a primary tool in the assessment and workup of patients with severe AS who are candidates for surgical or transcatheter intervention.


Assuntos
Insuficiência da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/diagnóstico por imagem , Valva Aórtica/diagnóstico por imagem , Hemodinâmica , Imageamento por Ressonância Magnética , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/fisiopatologia , Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/cirurgia , Tomada de Decisão Clínica , Ecocardiografia Transesofagiana , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
19.
J Cardiovasc Magn Reson ; 22(1): 31, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32375896

RESUMO

BACKGROUND: The T1 Mapping and Extracellular volume (ECV) Standardization (T1MES) program explored T1 mapping quality assurance using a purpose-developed phantom with Food and Drug Administration (FDA) and Conformité Européenne (CE) regulatory clearance. We report T1 measurement repeatability across centers describing sequence, magnet, and vendor performance. METHODS: Phantoms batch-manufactured in August 2015 underwent 2 years of structural imaging, B0 and B1, and "reference" slow T1 testing. Temperature dependency was evaluated by the United States National Institute of Standards and Technology and by the German Physikalisch-Technische Bundesanstalt. Center-specific T1 mapping repeatability (maximum one scan per week to minimum one per quarter year) was assessed over mean 358 (maximum 1161) days on 34 1.5 T and 22 3 T magnets using multiple T1 mapping sequences. Image and temperature data were analyzed semi-automatically. Repeatability of serial T1 was evaluated in terms of coefficient of variation (CoV), and linear mixed models were constructed to study the interplay of some of the known sources of T1 variation. RESULTS: Over 2 years, phantom gel integrity remained intact (no rips/tears), B0 and B1 homogenous, and "reference" T1 stable compared to baseline (% change at 1.5 T, 1.95 ± 1.39%; 3 T, 2.22 ± 1.44%). Per degrees Celsius, 1.5 T, T1 (MOLLI 5s(3s)3s) increased by 11.4 ms in long native blood tubes and decreased by 1.2 ms in short post-contrast myocardium tubes. Agreement of estimated T1 times with "reference" T1 was similar across Siemens and Philips CMR systems at both field strengths (adjusted R2 ranges for both field strengths, 0.99-1.00). Over 1 year, many 1.5 T and 3 T sequences/magnets were repeatable with mean CoVs < 1 and 2% respectively. Repeatability was narrower for 1.5 T over 3 T. Within T1MES repeatability for native T1 was narrow for several sequences, for example, at 1.5 T, Siemens MOLLI 5s(3s)3s prototype number 448B (mean CoV = 0.27%) and Philips modified Look-Locker inversion recovery (MOLLI) 3s(3s)5s (CoV 0.54%), and at 3 T, Philips MOLLI 3b(3s)5b (CoV 0.33%) and Siemens shortened MOLLI (ShMOLLI) prototype 780C (CoV 0.69%). After adjusting for temperature and field strength, it was found that the T1 mapping sequence and scanner software version (both P < 0.001 at 1.5 T and 3 T), and to a lesser extent the scanner model (P = 0.011, 1.5 T only), had the greatest influence on T1 across multiple centers. CONCLUSION: The T1MES CE/FDA approved phantom is a robust quality assurance device. In a multi-center setting, T1 mapping had performance differences between field strengths, sequences, scanner software versions, and manufacturers. However, several specific combinations of field strength, sequence, and scanner are highly repeatable, and thus, have potential to provide standardized assessment of T1 times for clinical use, although temperature correction is required for native T1 tubes at least.


Assuntos
Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/normas , Imagens de Fantasmas/normas , Consenso , Humanos , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes
20.
Heart Lung Circ ; 29(10): 1542-1553, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32327310

RESUMO

BACKGROUND: New-onset atrial fibrillation (NOAF) is a well-recognised, although variably reported complication following surgical aortic valve replacement (SAVR). Rates of NOAF following transcatheter aortic valve implantation (TAVI) seem to be notably less than SAVR, even though this population is typically older and of higher risk. The aim of this study was to determine the prevalence of NOAF in both these populations and associated postoperative outcomes. METHODS: We conducted a systematic review and meta-analysis of studies reporting rates of NOAF post SAVR or TAVI, along with early postoperative outcomes. Twenty-five (25) studies with a total of 13,010 patients were included in the final analysis. RESULTS: The prevalence of NOAF post SAVR was 0.4 (95% CI 0.36-0.44) and post TAVI 0.15 (95% CI 0.11-0.18). NOAF was associated with an increased risk of postoperative cerebrovascular accident (CVA) for SAVR and TAVI (RR 1.44 95% CI 1.01-2.06 and RR 2.24 95% CI 1.46-3.45 respectively). NOAF was associated with increased mortality in the TAVI group (RR 3.02 95% CI 1.55-5.9) but not the SAVR group (RR 1.00, 95% CI 0.54-1.84). Hospital length of stay was increased for both TAVI and SAVR patients with NOAF (MD 2.54 days, 95% CI 2.0-3.00) and (MD 1.64 days, 95% CI 0.04-3.24 respectively). CONCLUSIONS: The prevalence of NOAF is significantly less following TAVI, as compared to SAVR. While NOAF is associated with increased risk of postoperative stroke for both groups, for TAVI alone NOAF confers increased risk of early mortality.


Assuntos
Estenose da Valva Aórtica/cirurgia , Fibrilação Atrial/epidemiologia , Próteses Valvulares Cardíacas/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Substituição da Valva Aórtica Transcateter/efeitos adversos , Fibrilação Atrial/etiologia , Saúde Global , Humanos , Complicações Pós-Operatórias/etiologia , Prevalência , Fatores de Risco
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