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"Gopalan, Deepa"
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Diagnostic Evaluation of Chronic Thromboembolic Pulmonary Hypertension
2016
Pulmonary hypertension is defined by a mean pulmonary artery pressure greater than 25 mm Hg. Chronic thromboembolic pulmonary hypertension (CTEPH) is defined as pulmonary hypertension in the presence of an organized thrombus within the pulmonary vascular bed that persists at least 3 months after the onset of anticoagulant therapy. Because CTEPH is potentially curable by surgical endarterectomy, correct identification of patients with this form of pulmonary hypertension and an accurate assessment of surgical candidacy are essential to provide optimal care. Patients most commonly present with symptoms of exertional dyspnea and otherwise unexplained decline in exercise capacity. Atypical chest pain, a nonproductive cough, and episodic hemoptysis are observed less frequently. With more advanced disease, patients often develop symptoms suggestive of right ventricular compromise. Physical examination findings are minimal early in the course of this disease, but as pulmonary hypertension progresses, may include nonspecific finding of right ventricular failure, such as a tricuspid regurgitation murmur, pedal edema, and jugular venous distention. Chest radiographs may suggest pulmonary hypertension, but are neither sensitive nor specific for the diagnosis. Radioisotopic ventilation–perfusion scanning is sensitive for detecting CTEPH, making it a valuable screening study. Conventional catheter-based pulmonary angiography retains an important role in establishing the presence and extent of chronic thromboembolic disease. However, computed tomographic and magnetic resonance imaging are playing a growing diagnostic role. Innovative technologies such as dual-energy computed tomography, dynamic contrast–enhanced magnetic resonance imaging, and optical coherence tomography show promise for contributing diagnostic information and assisting in the preoperative characterization of patients with CTEPH.
Journal Article
Selenoprotein deficiency disorder predisposes to aortic aneurysm formation
2023
Aortic aneurysms, which may dissect or rupture acutely and be lethal, can be a part of multisystem disorders that have a heritable basis. We report four patients with deficiency of selenocysteine-containing proteins due to selenocysteine Insertion Sequence Binding Protein 2 (
SECISBP2)
mutations who show early-onset, progressive, aneurysmal dilatation of the ascending aorta due to cystic medial necrosis. Zebrafish and male mice with global or vascular smooth muscle cell (VSMC)-targeted disruption of
Secisbp2
respectively show similar aortopathy. Aortas from patients and animal models exhibit raised cellular reactive oxygen species, oxidative DNA damage and VSMC apoptosis. Antioxidant exposure or chelation of iron prevents oxidative damage in patient’s cells and aortopathy in the zebrafish model. Our observations suggest a key role for oxidative stress and cell death, including via ferroptosis, in mediating aortic degeneration.
Aortic aneurysms have a heritable basis. Here, the authors report that a selenoprotein deficiency disorder due to mutations in SECISBP2, causes oxidative stress-mediated aortic cell death, predisposing to thoracic aortic aneurysm formation.
Journal Article
Resource efficient aortic distensibility calculation by end to end spatiotemporal learning of aortic lumen from multicentre multivendor multidisease CMR images
2023
Aortic distensibility (AD) is important for the prognosis of multiple cardiovascular diseases. We propose a novel resource-efficient deep learning (DL) model, inspired by the bi-directional ConvLSTM U-Net with densely connected convolutions, to perform end-to-end hierarchical learning of the aorta from cine cardiovascular MRI towards streamlining AD quantification. Unlike current DL aortic segmentation approaches, our pipeline: (i) performs simultaneous spatio-temporal learning of the video input, (ii) combines the feature maps from the encoder and decoder using non-linear functions, and (iii) takes into account the high class imbalance. By using multi-centre multi-vendor data from a highly heterogeneous patient cohort, we demonstrate that the proposed method outperforms the state-of-the-art method in terms of accuracy and at the same time it consumes
∼
3.9 times less fuel and generates
∼
2.8 less carbon emissions. Our model could provide a valuable tool for exploring genome-wide associations of the AD with the cognitive performance in large-scale biomedical databases. By making energy usage and carbon emissions explicit, the presented work aligns with efforts to keep DL’s energy requirements and carbon cost in check. The improved resource efficiency of our pipeline might open up the more systematic DL-powered evaluation of the MRI-derived aortic stiffness.
Journal Article
From Early Morphometrics to Machine Learning—What Future for Cardiovascular Imaging of the Pulmonary Circulation?
2020
Imaging plays a cardinal role in the diagnosis and management of diseases of the pulmonary circulation. Behind the picture itself, every digital image contains a wealth of quantitative data, which are hardly analysed in current routine clinical practice and this is now being transformed by radiomics. Mathematical analyses of these data using novel techniques, such as vascular morphometry (including vascular tortuosity and vascular volumes), blood flow imaging (including quantitative lung perfusion and computational flow dynamics), and artificial intelligence, are opening a window on the complex pathophysiology and structure–function relationships of pulmonary vascular diseases. They have the potential to make dramatic alterations to how clinicians investigate the pulmonary circulation, with the consequences of more rapid diagnosis and a reduction in the need for invasive procedures in the future. Applied to multimodality imaging, they can provide new information to improve disease characterization and increase diagnostic accuracy. These new technologies may be used as sophisticated biomarkers for risk prediction modelling of prognosis and for optimising the long-term management of pulmonary circulatory diseases. These innovative techniques will require evaluation in clinical trials and may in themselves serve as successful surrogate end points in trials in the years to come.
Journal Article
How to Reliably Measure Stroke Volume Index in Pulmonary Arterial Hypertension: A Comparison of Thermodilution, Direct and Indirect Fick, and Cardiac MRI
by
Gin-Sing, Wendy
,
Davies, Rachel J
,
Howard, Luke S
in
Bias
,
Cardiac catheterization
,
cardiac magnetic resonance
2025
Stroke volume index (SVI) is an important prognostic parameter in pulmonary arterial hypertension (PAH). The direct Fick (DF) method represents the gold standard for measuring it. Indirect Fick (IF) and thermodilution (TD) are simpler and widely used alternatives. However, data on the accuracy of these methods in estimating SVI in PAH are scant. We aimed to compare these different invasive methods, and in a subgroup of patients, to a non-invasive method using MRI.
We enrolled 103 PAH patients undergoing a diagnostic or follow-up right heart catheterization at our centre (mean age 56 years, 56% female). The Bland-Altman analysis was used to assess agreement between methods. Potential demographic, clinical, and hemodynamic biases were explored. The accuracy of cardiac magnetic resonance (CMR)-derived SVI was assessed in a subset of patients.
The mean bias for IF-SVI vs. DF-SVI was -5.53 mL/min/m
with a median percentage error (PE) of 15%. The mean bias was lower, 0.09 mL/min/m
, for TD-SVI vs. DF-SVI with a median PE of 10%. Low cardiac index and severe tricuspid regurgitation (TR) were associated with a greater bias between TD and DF. CMR-SVI showed good accuracy and precision even in patients with severe TR, compared to DF.
The indirect Fick is the less reliable method to assess SVI also in PAH patients. Thermodilution is a valid alternative to direct Fick, but it should be used with caution in patients with severe TR or low cardiac index. SVI measured by cardiac MRI is a promising non-invasive alternative, especially in patients with severe TR. Our observation needs to be confirmed by other series and larger studies.
Journal Article
Utility of cardiac magnetic resonance feature tracking strain assessment in chronic thromboembolic pulmonary hypertension for prediction of REVEAL 2.0 high risk status
by
Gibbs, Simon
,
Howard, Luke
,
Davies, Rachel
in
Cross-sectional studies
,
feature tracking (CMR‐FT)
,
Pulmonary arteries
2023
Chronic thromboembolic pulmonary hypertension may be cured by pulmonary endarterectomy (PEA). Thromboembolic disease distribution/PEA success primarily determines prognosis but risk scoring criteria may be adjunctive. Right ventriculoarterial (RV‐PA) and ventriculoatrial (RV‐right atrium [RA]) coupling may be evaluated by cardiac MRI (CMR) feature tracking deformation/strain assessment. We characterized biatrial and biventricular CMR feature tracking (FT) strain parameters following PEA and tested the ability of CMR FT to identify REVEAL 2.0 high‐risk status. We undertook a retrospective single‐center cross‐sectional study of patients (n = 57) who underwent PEA (2015–2020). All underwent pre and postoperative catheterization and CMR. Pulmonary arterial hypertension validated risk scores were calculated. Significant postoperative improvements were observed in mean pulmonary artery pressure (mPAP) (pre‐op 45 ± 11 mmHg vs. post‐op 26 ± 11 mmHg; p < 0.001) and PVR however a large proportion had residual pulmonary hypertension (45%; mPAP ≥25 mmHg). PEA augmented left heart filling with left ventricular end diastolic volume index and left atrial volume index increment. Left ventricular ejection fraction was unchanged postoperatively but LV global longitudinal strain improved (pre‐op median −14.2% vs. post‐op −16.0%; p < 0.001). Right ventricular (RV) geometry and function also improved with reduction in RV mass. Most had uncoupled RV‐PA relationships which recovered (pre‐op right ventricular free wall longitudinal strain −13.2 ± 4.8%, RV stroke volume/right ventricular end systolic volume ratio 0.78 ± 0.53 vs. post‐op −16.8 ± 4.2%, 1.32 ± 0.55; both p < 0.001). Postoperatively, there were six REVEAL 2.0 high‐risk patients, best predicted by impaired RA strain which was superior to traditional volumetric parameters (area under the curve [AUC] 0.99 vs. RVEF AUC 0.88). CMR deformation/strain evaluation can offer insights into coupling recovery; RA strain may be an expeditious surrogate for the more laborious REVEAL 2.0 score.
Journal Article
Imaging in pulmonary hypertension, part 1: clinical perspectives, classification, imaging techniques and imaging algorithm
by
Gopalan, Deepa
,
Sheares, Karen
,
McCann, Caroline
in
Algorithms
,
allergy
,
Angiography - methods
2012
Pulmonary arterial hypertension (PAH) is an uncommon condition associated with significant morbidity and mortality. It has diverse aetiology with differing clinical presentations, imaging features and treatments that range from surgical treatment of proximal chronic thromboembolic disease to targeted medical therapies in small vessel disease. Current classification of pulmonary hypertension (PH) is clinically based and groups diseases with similar pathophysiological mechanisms and therapeutic approaches. Groupings include conditions characterised by diffuse small vessel diseases such as idiopathic PAH, PH secondary to chronic hypoxic lung disease, left sided cardiac disease, chronic large vessel obstruction such as chronic thromboembolic disease and a miscellaneous group of diseases. The physiological manifestation of all of these diseases is increased pulmonary vascular resistance and PAH and while clinical features may provide a clue to diagnosis imaging plays a fundamental role in establishing a precise diagnosis and therefore guides therapy. A broad range of imaging modalities is available for the patient with suspected PH including chest radiograph, echocardiography, ventilation/perfusion scintigraphy, catheter pulmonary angiography as well as cross-sectional CT and MRI. Each modality has its strengths and limitations and different techniques may be used at different stages of diagnostic investigation and frequently complement each other. For example, while MRI and echocardiography permit cardiac structural and functional assessment, CT pulmonary angiography provides exquisite morphological information about the proximal pulmonary vasculature and lung parenchyma but little functional information. Modern cross-sectional imaging techniques (CT and MRI) hold the promise of a comprehensive evaluation of the heart, circulation and lung parenchyma in PH. The authors present a multimodality-imaging algorithm for the investigation of patients with suspected PH though it is acknowledged that there is some variation in practice depending on availability of resources and expertise.
Journal Article
Access to MRI for patients with cardiac pacemakers and implantable cardioverter defibrillators
by
Abiodun, Aderonke
,
Moon, James C
,
Manisty, Charlotte
in
artificial
,
Cardiology
,
Clinical outcomes
2021
ObjectiveTo determine provision of MRI for patients with cardiac implantable electronic devices (CIEDs; pacemakers and defibrillators) in England, to understand regional variation and assess the impact of guideline changes.MethodsRetrospective data related to MRI scans performed in patients with CIED over the preceding 12 months was collected using a structured survey tool distributed to every National Health Service Trust MRI unit in England. Data were compared with similar data from 2014/2015 and with demand (estimated from local CIED implantation rates and regional population data by sustainability and transformation partnerships (STPs)).ResultsResponses were received from 212 of 223 (95%) hospitals in England. 112 (53%) MRI units’ scan patients with MR-conditional CIEDs (10% also scan non-MR conditional devices), compared with 46% of sites in 2014/2015. Total annual scan volume increased over fourfold between 2014 and 2019 (1090 to 4896 scans). There was widespread geographical variation, with five STPs (total population >3·5 million representing approximately 25 000 patients with CIED) with no local provision. There was no correlation between local demand (CIED implantation rates) and MRI provision (scan volume). Complication rates were extremely low with three events nationally in 12 months (0·06% CIED–MRI scans).ConclusionsProvision of MRI for patients with CIEDs in England increased over fourfold in 4 years, but an estimated 10-fold care gap remains. Almost half of hospitals and 1 in 10 STPs have no service, with no relationship between local supply and demand. Availability of MRI for patients with non-MR conditional devices, although demonstrably safe, remains limited.
Journal Article
A zero coronary artery calcium score in patients with stable chest pain is associated with a good prognosis, despite risk of non-calcified plaques
by
Wang, Xue
,
Williams, Michelle Claire
,
Hudson-Peacock, NJ
in
chest pain clinic
,
Coronary Artery Disease
,
CT scanning
2019
ObjectivesTo estimate the prevalence of non-calcified coronary artery disease (CAD) in patients with suspected stable angina and a zero coronary artery calcification (CAC) score, and to assess the prognostic significance of a zero CAC in these symptomatic patients.MethodsIn this prospective cohort study, consecutive patients with stable chest pain underwent CAC scoring ± CT coronary angiography (CTCA) as part of routine clinical care at a single tertiary centre over 7 years. Major adverse cardiac event (MACE) was defined as cardiac death, non-fatal myocardial infarction and/or non-elective revascularisation.ResultsA total of 915 of 1753 (52.2%) patients (mean age 56.8 ± 12.0 years; 46.2% male) had a zero CAC score. Of the 751 (82.1%) patients with a zero CAC in whom CTCA was performed, 674 (89.7%) had normal coronary arteries, 63 (8.4%) had non-calcified CAD with < 50% stenosis and 14 (1.9%) had ≥ 50% stenosis in at least one coronary artery. The negative predictive value of a zero CAC for excluding a ≥ 50% CTCA stenosis was 98.1%. Over a median follow-up period of 2.2 years (range 1.0–7.0 years), the absolute annualised rates of MACE were as follows: zero CAC 1.9 per 1000 person-years and non-zero CAC 7.4 per 1000 person-years (HR 3.8, p = 0.009). However, after adjusting for age, gender and cardiovascular risk factors using a multivariable Cox proportional hazards model, there was no statistically significant difference in the risk of MACE between the two patient cohorts (p = 0.19). After adjusting for age, gender and cardiovascular risk factors, the HR for all-cause mortality among the zero CAC cohort vers non-zero CAC was 2.1 (p = 0.27).ConclusionA zero CAC score in patients undergoing CT scanning for suspected stable angina has a high negative predictive value for the exclusion of obstructive CAD and is associated with a good medium-term prognosis.
Journal Article
Right ventricular reverse remodeling after pulmonary endarterectomy: magnetic resonance imaging and clinical and right heart catheterization assessment
by
Screaton, Nick
,
Dunning, John
,
Maccan, Caroline
in
Cardiac output determination
,
chronic thromboembolic pulmonary hypertension (CTEPH)
,
Correlation coefficients
2014
The objective of this study was to assess the effect of pulmonary endarterectomy (PEA) on right ventricular (RV) reverse remodeling using magnetic resonance imaging (MRI) and to correlate MRI findings with clinical and hemodynamic outcomes postsurgery. We performed a retrospective analysis in 72 patients undergoing PEA surgery in whom MRI and right heart catheterization (RHC) were performed preoperation and 3 months postoperation. RV volumes and mass were assessed by MRI. Continuous variables were expressed as means, changes were compared with a paired t test, and associations between the variables were explored using Pearson correlation coefficients. The mean age was 57 years, and 51% were male. Both RV end-diastolic volume (EDV; 176–117 mL; P < 0.001) and RV end-systolic volume (ESV; 129–64 mL; P < 0.001) reduced significantly following PEA. Preoperative pulmonary artery pressure (PAP) correlated moderately with ESV (r = 0.46, P < 0.001). Postoperatively, PAP correlated with EDV (r = 0.45, P < 0.001) and ESV (r = 0.44, P < 0.001). Moderate correlation was present between hemodynamic parameters: PAP, pulmonary vascular resistance, and right atrial pressure with pre- and postoperation end-systolic and end-diastolic RV mass (P < 0.001). RHC and MRI measurements of cardiac output and RV volumes were significantly different (P < 0.001). In conclusion, RV reverse remodeling, as measured by improvement in RV volumes and mass by MRI, was observed for 3 months in patients who underwent PEA surgery. This is the largest series of patients with pre- and post-PEA MRI assessment so far reported. MRI detects changes in parameters reflecting cardiac remodeling and pulmonary clearance, but measurements are significantly different from those of RHC.
Journal Article