Publications by authors named "John P Greenwood"

The pathophysiology of myocardial injury following COVID-19 remains uncertain. COVID-HEART was a prospective, multicentre study utilising cardiovascular magnetic resonance (CMR) to characterise COVID-related myocardial injury. In this pre-specified analysis, the objectives were to examine (1) the frequency of myocardial ischaemia following COVID-19, and (2) the association between ischaemia and myocardial injury.

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Cardiology training in the UK is facing significant challenges due to a range of factors. Recent curriculum changes have further compounded this issue and significantly risk the ability to produce adequately trained consultants capable of managing patients with increasingly complex cardiovascular disease. The introduction of mandatory dual accreditation in general internal medicine (GIM) alongside cardiology, by design, results in significantly reduced training opportunities, including procedural and subspecialty exposure.

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Background: GDM and preeclampsia are common complications of pregnancy, for which overweight/obesity is a common risk factor. Both conditions are associated with a two-to-four-fold increase in future incident heart failure, which may be linked to early maladaptive myocardial changes.

Objectives: To determine maternal myocardial structural, functional, and energetic responses to pregnancies complicated by gestational diabetes mellitus (GDM) or preeclampsia compared to healthy pregnancies (HP) at third-trimester of pregnancy and twelve-months postpartum.

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Metformin is an antihyperglycemic used to treat type 2 diabetes mellitus (T2DM). Patients with T2DM are at increased risk of cardiovascular disease. We explored the association between metformin use and cardiovascular magnetic resonance (CMR) derived stress myocardial blood flow (MBF), myocardial perfusion reserve (MPR) and major adverse cardiovascular events (MACE; all cause death, MI, stroke, heart failure hospitalisation and coronary revascularisation) in patients with T2DM.

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Importance: Development of myocardial fibrosis in patients with aortic stenosis precedes left ventricular decompensation and is associated with an adverse long-term prognosis.

Objective: To investigate whether early valve intervention reduced the incidence of all-cause death or unplanned aortic stenosis-related hospitalization in asymptomatic patients with severe aortic stenosis and myocardial fibrosis.

Design, Setting, And Participants: This prospective, randomized, open-label, masked end point trial was conducted between August 2017 and October 2022 at 24 cardiac centers across the UK and Australia.

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Aims: Coronary Computed Tomography Angiography (CCTA) is a first line investigation for chest pain in patients with suspected obstructive coronary artery disease (CAD). However, many acute cardiac events occur in the absence of obstructive CAD. We assessed the lifetime cost-effectiveness of integrating a novel artificial intelligence-enhanced image analysis algorithm (AI-Risk) that stratifies the risk of cardiac events by quantifying coronary inflammation, combined with the extent of coronary artery plaque and clinical risk factors, by analysing images from routine CCTA.

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Background: Microvascular angina is associated with dysregulation of the endothelin system and impairments in myocardial blood flow, exercise capacity, and health-related quality of life. The G allele of the noncoding single nucleotide polymorphism enhances expression of the endothelin-1 gene () in human vascular cells, potentially increasing circulating concentrations of Endothelin-1 (ET-1). Whether zibotentan, an oral receptor selective antagonist, is efficacious and safe for the treatment of microvascular angina is unknown.

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Article Synopsis
  • The study examined the effects of myocardial injury in hospitalized COVID-19 survivors who had elevated troponin levels, using cardiac imaging and tracking health-related quality of life over 12 months.* -
  • Conducted in 25 UK centers, the research involved 342 participants, finding that while some cardiovascular events occurred, overall major adverse outcomes were low after 12 months.* -
  • Results showed slight improvements in heart function and quality of life after 6 months, with no evidence of ongoing myocardial inflammation or progression of heart injury.*
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Background: Patients with diabetes mellitus (DM) and heart failure (HF) have worse outcomes than normoglycemic HF patients. Cardiovascular magnetic resonance (CMR) can identify ischemic heart disease (IHD) and quantify coronary microvascular dysfunction (CMD) using myocardial perfusion reserve (MPR). We aimed to quantify the extent of silent IHD and CMD in patients with DM presenting with HF.

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  • Type 2 diabetes (T2D) involves insulin resistance and abnormal insulin secretion, and this study compares the effects of two treatments: liraglutide (which boosts insulin secretion) and pioglitazone (which reduces insulin resistance) on heart health.
  • The study involved 41 T2D patients and used various methods, including advanced imaging, to assess heart performance and function over two treatment periods with an 8-week washout in between.
  • Results showed that pioglitazone significantly improved left ventricular (LV) mass and function, while liraglutide enhanced myocardial blood flow and perfusion reserve, indicating different benefits of each treatment approach for heart health in T2D patients.
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Background: Cardiac angiosarcoma is a very rare and aggressive primary cardiac tumor associated with poor prognosis. Diagnosis is often delayed due to non-specific symptoms, with most cases involving metastases at the time of diagnosis. We describe a unique case of apparent tumor regression of cardiac angiosarcoma post percutaneous biopsy.

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Background: Cardiac magnetic resonance (CMR) in the four-chamber plane offers comprehensive insight into the volumetrics of the heart. We aimed to develop an artificial intelligence (AI) model of time-resolved segmentation using the four-chamber cine.

Methods: A fully automated deep learning algorithm was trained using retrospective multicentre and multivendor data of 814 subjects.

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Background: Pulmonary transit time (PTT) can be measured automatically from arterial input function (AIF) images of dual sequence first-pass perfusion imaging. PTT has been validated against invasive cardiac catheterisation correlating with both cardiac output and left ventricular filling pressure (both important prognostic markers in heart failure). We hypothesized that prolonged PTT is associated with clinical outcomes in patients with heart failure.

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Introduction: There are sex differences in the extent, severity, and outcomes of coronary artery disease. We aimed to assess the influence of sex on coronary atherosclerotic plaque activity measured using coronary F-sodium fluoride (F-NaF) positron emission tomography (PET), and to determine whether F-NaF PET has prognostic value in both women and men.

Methods: In a post-hoc analysis of observational cohort studies of patients with coronary atherosclerosis who had undergone F-NaF PET CT angiography, we compared the coronary microcalcification activity (CMA) in women and men.

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Aims: We aimed to identify the distinctive cardiovascular magnetic resonance (CMR) features of patients with left bundle branch block (LBBB) and heart failure with reduced ejection fraction (HFrEF) of presumed non-ischaemic aetiology. The secondary aim was to determine whether these individuals exhibit characteristics that could potentially serve as predictors of left ventricular ejection fraction (LVEF) recovery as compared with patients without LBBB.

Methods And Results: We prospectively recruited patients with HFrEF (LVEF ≤ 40%) on echocardiography who were referred for early CMR examination.

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Background: Coronary computed tomography angiography (CCTA) is the first line investigation for chest pain, and it is used to guide revascularisation. However, the widespread adoption of CCTA has revealed a large group of individuals without obstructive coronary artery disease (CAD), with unclear prognosis and management. Measurement of coronary inflammation from CCTA using the perivascular fat attenuation index (FAI) Score could enable cardiovascular risk prediction and guide the management of individuals without obstructive CAD.

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Background: Total coronary atherosclerotic plaque activity across the entire coronary arterial tree is associated with patient-level clinical outcomes.

Objectives: We aimed to investigate whether vessel-level coronary atherosclerotic plaque activity is associated with vessel-level myocardial infarction.

Methods: In this secondary analysis of an international multicenter study of patients with recent myocardial infarction and multivessel coronary artery disease, we assessed vessel-level coronary atherosclerotic plaque activity using coronary F-sodium fluoride positron emission tomography to identify vessel-level myocardial infarction.

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Purpose: Exercise imaging using current modalities can be challenging. This was patient focused study to establish the feasibility and reproducibility of exercise-cardiovascular magnetic resonance imaging (EX-CMR) acquired during continuous in-scanner exercise in asymptomatic patients with primary mitral regurgitation (MR).

Methods: This was a prospective, feasibility study.

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Background: Use of electronic methods to support informed consent ('eConsent') is increasingly popular in clinical research. This commentary reports the approach taken to implement electronic consent methods and subsequent experiences from a range of studies at the Leeds Clinical Trials Research Unit (CTRU), a large clinical trials unit in the UK.

Main Text: We implemented a remote eConsent process using the REDCap platform.

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Background: Primary percutaneous coronary intervention (pPCI) has improved clinical outcomes in patients with ST-segment-elevation myocardial infarction. However, as many as 50% of patients still have suboptimal myocardial reperfusion and experience extensive myocardial necrosis. The PiCSO-AMI-I trial (Pressure-Controlled Intermittent Coronary Sinus Occlusion-Acute Myocardial Infarction-I) evaluated whether PiCSO therapy can further reduce myocardial infarct size (IS) in patients undergoing pPCI.

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Article Synopsis
  • Recent research indicates that excess fat around the organs (visceral adiposity) is linked to heart diseases in people with type 2 diabetes.
  • Epicardial adipose tissue (EAT) surrounds the heart and influences heart health by releasing various substances (adipokines).
  • This review explored recent studies using MRI to measure EAT and its connection to heart function, suggesting that more EAT can lead to heart problems, especially in diabetic patients.
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Background: Four-dimensional-flow cardiac MR (4DF-MR) offers advantages in primary mitral regurgitation. The relationship between 4DF-MR-derived mitral regurgitant volume (MR-Rvol) and the post-operative left ventricular (LV) reverse remodeling has not yet been established.

Purpose: To ascertain if the 4DF-MR-derived MR-Rvol correlates with the LV reverse remodeling in primary mitral regurgitation.

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