Publications by authors named "Peter M Schofield"

Background: Coronary computed tomography angiography (CCTA) can identify high-risk coronary plaque types. However, the inter-observer variability for high-risk plaque features, including low attenuation plaque (LAP), positive remodelling (PR), and the Napkin-Ring sign (NRS), may reduce their utility, especially amongst less experienced readers.

Methodology: In a prospective study, we compared the prevalence, location and inter-observer variability of both conventional CT-defined high-risk plaques with a novel index based on quantifying the ratio of necrotic core to fibrous plaque using individualised X-ray attenuation cut-offs (the CT-defined thin-cap fibroatheroma - CT-TCFA) in 100 patients followed-up for 7 years.

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Objective: To assess the utility of left bundle branch block (LBBB) as an activation criterion for primary percutaneous coronary intervention (PPCI).

Design: Retrospective observational cohort study.

Setting: Single UK heart attack centre.

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Objectives: The purpose of this study was to determine whether thin-capped fibroatheromata (TCFA) identified by virtual histology intravascular ultrasound (VH-IVUS) are associated with major adverse cardiac events (MACE) on individual plaque or whole patient analysis.

Background: Post-mortem studies have identified TCFA as the substrate for most myocardial infarctions. However, little is known about the natural history of individual TCFA and their link with MACE.

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Objective: Leukocyte telomere length (LTL), a marker of cellular senescence, is inversely associated with cardiovascular events. However, whether LTL reflects plaque extent or unstable plaques, and the mechanisms underlying any association are unknown.

Methods And Results: One hundred seventy patients with stable angina or acute coronary syndrome referred for percutaneous coronary intervention underwent 3-vessel virtual histology intravascular ultrasound; 30 372 mm of intravascular ultrasound pullback and 1096 plaques were analyzed.

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Background: The EuroQoL 5D (EQ-5D) has been widely used in studies of cardiac disease, but its measurement properties in this group are not well established. The study aimed to quantify the relationship between measures commonly used in studies of cardiac disease and the EQ-5D index across different levels of disease severity.

Methods: Patient-level data from 7 studies of cardiac interventions were used, which included randomised trials and observational studies.

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Background: An elevation in cardiac troponin-I (cTnI) after elective percutaneous coronary intervention (PCI) is because of cardiac necrosis and has prognostic implications. Primary microvascular dysfunction, evident before PCI, and paucity of coronary collaterals at baseline may influence cTnI.

Methods: We selected 22 patients awaiting elective PCI for a single-vessel, type-A coronary stenosis, with normal left ventricular function and a normal preprocedure cTnI.

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Aims: Remote ischaemic pre-conditioning (RIPC) reduces distant tissue ischaemia reperfusion injury. We tested the hypothesis that RIPC would protect the left ventricle (LV) from ischaemic dysfunction and stunning.

Methods And Results: Forty-two patients with single vessel coronary disease and normal LV function were prospectively recruited.

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Article Synopsis
  • - The study investigated the effects of remote ischemic preconditioning (IPC) on reducing cardiac troponin I (cTnI) release after elective percutaneous coronary intervention (PCI), a procedure linked to myocyte necrosis and adverse cardiovascular events in about one-third of cases.
  • - Researchers randomized 242 patients to either receive remote IPC before PCI, which involved inflating a blood pressure cuff to induce temporary ischemia, or a control group with an uninflated cuff.
  • - Results showed that the remote IPC group had significantly lower cTnI levels 24 hours post-PCI and experienced less chest discomfort and fewer major cardiovascular events over six months compared to the control group.
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Background: Spinal cord stimulation (SCS) and percutaneous myocardial laser revascularisation (PMR) are treatment modalities used to treat refractory angina pectoris, with the major aim of such treatment being the relief of disabling symptoms. This study compared the change in myocardial perfusion following SCS and PMR treatment.

Methods: Subjects with Canadian Cardiovascular Society class 3/4 angina and reversible perfusion defects as assessed by single-photon emission computed tomographic myocardial perfusion scintigraphy were randomised to SCS (34) or PMR (34).

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Multivariate analysis of 1H-NMR spectra of blood sera was reported previously to predict angiographically defined advanced coronary artery disease (CAD) with >90% accuracy and specificity. The analysis depended mainly on the major lipid regions of the spectra, but many variables, including gender and drug treatment, affect lipid composition and are potential confounders. We have determined the predictive power of the same methodology for angiographically defined CAD using plasma samples from groups of male patients, classified by statin treatment, who had normal coronary arteries (NCAs) or CAD.

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Aims: Refractory angina pectoris leads to significant morbidity. Treatment options include percutaneous myocardial laser revascularization (PMR) and spinal cord stimulation (SCS). This study was designed to compare these two treatments.

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We have previously shown that an antibody pool present in normal human serum binds cytokine receptors in vitro and may therefore interfere with assays that capture cytokines using their receptors. Here we show that this antibody pool is the same as the natural antibody termed anti-gal, that binds to the alpha-galactosyl carbohydrate epitope (alpha-gal) and which is the predominant obstacle to xenotransplantation. We report that there are high levels of IgD anti alpha-gal in most volunteers, in addition to the IgG2, IgA and IgM immunoglobulin isotypes against alpha-gal previously described.

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This study examined from a health service perspective whether percutaneous myocardial laser revascularisation (PMR) plus standard medical management is cost-effective when compared with standard medical management alone in the treatment of refractory angina. This involved a cost-utility analysis using patient-specific data from a single-centre, randomised, controlled trial carried out in the United Kingdom. Of 73 patients diagnosed as having refractory angina and not suitable for conventional forms of revascularisation, 36 were randomised to PMR plus medical management and 37 to medical management alone.

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The chemokines are a family of signalling proteins that participate in regulation of the immune system and have been implicated in the pathogenesis of vascular diseases. Deleting the gene encoding the chemokine MCP-1 in mouse models of atherosclerosis reduces lipid lesion formation and circulating chemokines are upregulated in man immediately following myocardial infarction (MI) or coronary angioplasty. We have therefore investigated whether circulating levels of two chemokines (MCP-1 and eotaxin) differ between subjects with and without atherosclerosis.

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Superior vena cava (SVC) obstruction most commonly results from malignant disease of the superior mediastinum, which is amenable to percutaneous stenting. Superior vena cava syndrome can also be caused by transvenous pacemaker electrodes and indwelling venous catheters, when it may be refractory to minimally invasive treatment. We report 2 patients with superior vena cava obstruction treated successfully by a surgical bypass approach using cryopreserved aortic arch homografts.

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This study aimed to determine the safety and efficacy of percutaneous myocardial laser revascularization (PMLR). Seventy-three patients with stable angina pectoris (class III or IV) who were unsuitable for conventional revascularization and had evidence of reversible ischemia by thallium-201 scintigraphy, ejection fraction of > or =25%, and myocardial wall thickness > or =8 mm were randomized to optimal medical therapy alone (n = 37) or PMLR with optimal medical therapy (n = 36). Patients were followed up at 3, 6, and 12 months.

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The application of chemometric methods to 1H NMR spectroscopic data has been documented for pathophysiological processes. In this study we show the application of 1H NMR-based metabonomics to investigate a relationship between serum metabolic profiles and hypertension. Although hypertension can be defined using blood pressure measurements, the underlying aetiology and metabolic effects are not so readily identified.

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Although a wide range of risk factors for coronary heart disease have been identified from population studies, these measures, singly or in combination, are insufficiently powerful to provide a reliable, noninvasive diagnosis of the presence of coronary heart disease. Here we show that pattern-recognition techniques applied to proton nuclear magnetic resonance (1H-NMR) spectra of human serum can correctly diagnose not only the presence, but also the severity, of coronary heart disease. Application of supervised partial least squares-discriminant analysis to orthogonal signal-corrected data sets allows >90% of subjects with stenosis of all three major coronary vessels to be distinguished from subjects with angiographically normal coronary arteries, with a specificity of >90%.

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