Alexander Fletcher

University of Glasgow | UofG · Institute of Cardiovascular and Medical Sciences

Inherited thoracic aortopathies denote a group of congenital conditions that predispose to disease of the thoracic aorta. Aortic wall weakness and abnormal aortic hemodynamic profiles predispose these patients to dilatation of the thoracic aorta, which is generally silent but can precipitate aortic dissection or rupture with devastating and often f...

Background Standard methods for quantifying positron emission tomography (PET) uptake in the aorta are time consuming and may not reflect overall vessel activity. We describe aortic microcalcification activity (AMA), a novel method for quantifying ¹⁸ F-sodium fluoride (18F-NaF) uptake in the thoracic aorta. Methods Twenty patients underwent two hy...

Objectives The purpose of this study was to investigate whether thoracic ¹⁸F-sodium fluoride positron emission tomography (PET) could improve the identification of patients at the highest risk of ischemic stroke. Background Aortic atherosclerosis represents an important contributor to ischemic stroke risk. Identifying patients with high-risk aorti...

Aims: The influence haemodynamics have on vessel wall pathobiology in aortic disease is incomplete. This aim of this study was to develop a repeatable method for assessing the relationship between aortic wall shear stress (WSS) and disease activity by fusing 4D flow cardiovascular magnetic resonance (CMR) with hybrid positron emission tomography (...

Background: Patients with thoracic aortopathy are at increased risk of catastrophic aortic dissection, carrying with it substantial mortality and morbidity. Although granular medial calcinosis (medial microcalcification) has been associated with thoracic aortopathy, its relationship to disease severity has yet to be established. Methods: One hun...

Background Patients with osteoporosis demonstrate increased vascular calcification but the effect of osteoporosis treatments on vascular calcification remains unclear. The present study aimed to examine whether coronary or aortic calcification are influenced by denosumab and alendronic acid treatment. Methods and Results In a double‐blind randomiz...

Background: Bicuspid aortic valve is associated with thoracic aortopathy with many patients suffering aortic dissection below the aortic diameter threshold for prophylactic aortic replacement surgery. In aortopathy, the aortic wall media initially undergoes increasing microcalcification due to elastin fibre fragmentation but with disease progressio...

Introduction Non-invasive detection of pathological changes in thoracic aortic disease remains an unmet clinical need particularly for patients with congenital heart disease. Positron emission tomography combined with magnetic resonance imaging (PET-MRI) could provide a valuable low-radiation method of aortic surveillance in high-risk groups. Quant...

Purpose To assess periaortic adipose tissue attenuation at CT angiography in different abdominal aortic aneurysm disease states. Materials and Methods In a retrospective observational study from January 2018 to December 2022, periaortic adipose tissue attenuation was assessed at CT angiography in patients with asymptomatic or symptomatic (including...

Background Myocardial fibrosis following myocardial infarction (MI) is a key healing mechanism and involves widespread fibroblast activation. Once activated, fibroblasts express fibroblast activation protein (FAP) (1). Hybrid positron emission tomography (PET) imaging of radiolabelled fibroblast activation protein inhibitor (FAPI) fused with cardio...

BACKGROUND Anthracycline-induced cardiotoxicity has a variable incidence, and the development of left ventricular dysfunction is preceded by elevations in cardiac troponin concentrations. Beta-adrenergic receptor blocker and renin-angiotensin system inhibitor therapies have been associated with modest cardioprotective effects in unselected patients...

Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation - Prof Marc Dweck Senior Fellowship, and BHF Research Excellence Award 3 for Dr Anna K Barton. Background Myocardial fibrosis is a key healing response following myocardial infarction (MI). Although scar formation...

Objective In patients with abdominal aortic aneurysms, sodium [ ¹⁸ F]fluoride positron emission tomography identifies aortic microcalcification and disease activity. Increased uptake is associated with aneurysm expansion and adverse clinical events. The effect of endovascular aneurysm repair (EVAR) on aortic disease activity and sodium [ ¹⁸ F]fluor...

Background Anthracycline-induced cardiotoxicity has a variable incidence, and the development of left ventricular dysfunction is preceded by elevations in cardiac troponin concentrations. Beta-adrenergic receptor blocker and renin-angiotensin-system inhibitor therapies have been associated with modest cardioprotective effects in unselected patients...

Abstract Background Aortic microcalcification activity is a recently described method of measuring aortic sodium [18F]fluoride uptake in the thoracic aorta on positron emission tomography. In this study, we aimed to compare and to modify this method for use within the infrarenal aorta of patients with abdominal aortic aneurysms. Methods Twenty-five...

Objectives In a proof-of-concept study, this investigation aimed to establish whether ¹⁸F-sodium fluoride (¹⁸F-NaF) positron emission tomography (PET) combined with computed tomography (CT) angiography could identify aortic medial disease activity in patients with acute aortic syndrome. Background Acute aortic syndrome is associated with aortic me...

Background: Aortic microcalcification activity is a recently described method of measuring aortic ¹⁸F-sodium fluoride uptake in the thoracic aorta on positron emission tomography . In this study, we aimed to compare and to modify this method for use within the infrarenal aorta of patients with abdominal aortic aneurysms. Methods: Twenty-five patien...

Objectives The aim of this study was to describe the potential of ¹⁸F-sodium fluoride (¹⁸F-NaF) positron emission tomography (PET) to identify graft vasculopathy and to investigate the influence of coronary artery bypass graft (CABG) surgery on native coronary artery disease activity and progression. Background As well as developing graft vasculop...

Introduction Acute aortic syndromes (AAS) include aortic dissection, intramural haematoma and penetrating aortic ulcer, all of which are caused by aortic wall failure and associated with significant mortality. Although, treatment options currently include early surgical intervention or aggressive medical management, disease progression and devastat...

Background Arterial 18F-sodium fluoride (18F-NaF) activity on positron emission tomography (PET) is a marker of active microcalcification and atherosclerosis. Coronary 18F-NaF activity (CMA) predicts coronary artery disease progression and subsequent myocardial infarction. Objective To investigate whether aortic 18F-NaF activity (AMA) predicts tho...

Background: There remain major uncertainties regarding disease activity within the retained native aortic valve as well as bioprosthetic valve durability following transcatheter aortic valve implantation (TAVI). We aimed to assess native aortic valve disease activity and bioprosthetic valve durability in patients with TAVI in comparison to subjects...

Introduction Acute aortic syndromes (AAS) include aortic dissection, intramural haematoma and penetrating aortic ulcer, all of which are caused by aortic wall failure and associated with significant mortality. Although, treatment options currently include early surgical intervention or aggressive medical management, disease progression and devastat...

Background Arterial 18F-sodium fluoride (18F-NaF) activity on positron emission tomography (PET) is a marker of active microcalcification and atherosclerosis. Coronary 18F-NaF activity (CMA) predicts coronary artery disease progression and subsequent myocardial infarction. We aimed to investigate whether aortic 18F-NaF activity (AMA) predicts thora...

Background Acute aortic syndrome is a catastrophic condition characterised by medial degeneration and cellular destruction within the aortic wall. 18F-Sodium fluoride (18F-NaF) positron emission tomography (PET) detects microscopic calcification as a marker of disease activity. This proof-of-concept study aims characterise 18F-NaF PET in patients w...

Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship Background Calcification of the thoracic aorta is associated with poor vessel wall health. Early detection of this disease process may highlight those at risk of future cardio...

Objective Short stature in Turner Syndrome (TS) may be accompanied by skeletal disproportion. This retrospective study investigates growth and disproportion from early childhood to adult height. Study design Data were collected from 59 girls prior to growth hormone (rhGH) treatment and in 30 girls followed‐up longitudinally. Standard deviation sco...

Calcific aortic valve disease is the most common valvular disease and confers significant morbidity and mortality. There are currently no medical therapies that successfully halt or reverse the disease progression, making surgical replacement the only treatment currently available. The majority of patients will receive a bioprosthetic valve, which...

Background Inherited thoracic aortic diseases are at substantially increased risk of aneurysm formation, aortic dissection or rupture. Importantly, up to 70% of dissections occur in aortas with a diameter below the threshold for prophylactic surgical replacement. Increased aortic stiffness and microcalcification have previously been identified as f...

Background Acute aortic syndrome is characterised by diseases that disrupt the intima and weaken the aorta. This damaged aorta is prone to aneurysmal dilation and ultimately rupture – a catastrophic event. 18F-sodium fluoride positron emission tomography and computed tomography (PET-CT) is a promising multimodality imaging technique that informs on...

Inherited thoracic aortopathies denote a group of congenital conditions that predispose to disease of the thoracic aorta. Aortic wall weakness and abnormal aortic hemodynamic profiles predispose these patients to dilatation of the thoracic aorta, which is generally silent but can precipitate aortic dissection or rupture with devastating and often f...

The annual image competition, Reflections of Research, provides a glimpse into the cutting-edge heart and circulatory research funded by the British Heart Foundation.

Aortic stenosis is the most prevalent valvular heart disease worldwide, and rates are increasing with the growing and more elderly population. Although the precise mechanisms that underpin aortic valve stenosis are incompletely understood, pathological valvular calcification has emerged as a key instigator in mediating the biomechanical stiffening...

Atherosclerosis is a chronic immunomodulated disease that affects multiple vascular beds and results in a significant worldwide disease burden. Conventional imaging modalities focus on the morphological features of atherosclerotic disease such as the degree of stenosis caused by a lesion. Modern CT, MR and positron emission tomography scanners have...

Inflammation affects the aortic wall through complex pathways that alter its biomechanical structure and cellular composition. Inflammatory processes that predominantly affect the intima cause occlusive disease whereas medial inflammation and degeneration cause aneurysm formation. Aortic inflammatory pathways share common metabolic features that ca...

We calculated aortic root Z-scores and aortic size index in a cohort of patients with Turner’s Syndrome using six different body surface area equations. We compared the results of each calculation to that of DuBois finding a significant change in risk stratification. Our work highlights the potential inaccuracies if using multiple body surface area...

Previous studies have identified that receiving specialist care close to home can positively influence patients’ experience. Despite this, a review of cardiology outpatient appointments at the Royal Hospital for Children in Glasgow demonstrated that a large number of families are bypassing their local children’s cardiology centre to attend cardiac...