Kelly Parke - Academia.edu (original) (raw)

Papers by Kelly Parke

Research paper thumbnail of Does nocturnal haemodialysis improve heart disease for patients on dialysis?

Research paper thumbnail of A comparison of liver fat fraction measurement on MRI at 3T and 1.5T

PLOS ONE

Purpose Volumetric liver fat fraction (VLFF) measurements were made using the HepaFat-Scan® techn... more Purpose Volumetric liver fat fraction (VLFF) measurements were made using the HepaFat-Scan® technique at 1.5T and 3T to determine the agreement between the measurements obtained at the two fields. Methods Sixty patients with type 2 diabetes (67% male, mean age 50.92 ± 6.56yrs) and thirty healthy volunteers (50% male, mean age 48.63 ± 6.32yrs) were scanned on 1.5T Aera and 3T Skyra (Siemens, Erlangen, Germany) MRI scanners on the same day using the HepaFat-Scan® gradient echo protocol with modification of echo times for 3T (TEs 2.38, 4.76, 7.14 ms at 1.5T and 1.2, 2.4, 3.6 ms at 3T). The 3T analyses were performed independently of the 1.5T analyses by a different analyst, blinded from the 1.5T results. Data were analysed for agreement and bias using Bland-Altman methods and intraclass correlation coefficients (ICC). A second cohort of 17 participants underwent interstudy repeatability assessment of VLFF measured by HepaFat-Scan® at 3T. Results A small, but statistically significant m...

Research paper thumbnail of The Interfield Strength Agreement of Left Ventricular Strain Measurements at 1. 5 T and 3 T Using Cardiac MRI Feature Tracking

Journal of Magnetic Resonance Imaging

Research paper thumbnail of Fibro‐inflammatory recovery and type 2 diabetes remission following a low calorie diet but not exercise training: A secondary analysis of the DIASTOLIC randomised controlled trial

Diabetic Medicine

Aims: To investigate the relationship between fibro-inflammatory biomarkers and cardiovascular st... more Aims: To investigate the relationship between fibro-inflammatory biomarkers and cardiovascular structure/function in people with Type 2 Diabetes (T2D) compared to healthy controls and the effect of two lifestyle interventions in T2D. Methods: Data were derived from the DIASTOLIC randomised controlled trial (RCT) and includes a comparison between those with T2D and the matched healthy volunteers recruited at baseline. Adults with T2D without cardiovascular disease (CVD) were randomized to a 12-week intervention either: (1) exercise training, (2) a low-energy (∼810 kcal/day) meal-replacement plan (MRP) or (3) standard care. Principal Component and Fisher's linear discriminant analysis were used to investigate the relationships between MRI acquired cardiovascular outcomes and fibro-inflammatory biomarkers in cases versus controls and preand post-intervention in T2D. Results: At baseline, 83 people with T2D (mean age 50.5 ± 6.4; 58% male) and 36 healthy controls (mean age 48.6 ± 6.2; 53% male) were compared and 76 people with T2D completed the RCT for pre-post-analysis. Compared to healthy controls, subjects with T2D had adverse cardiovascular remodelling and a fibroinflammatory profile (20 differentially expressed biomarkers). The 3D data visualisations showed almost complete separation between healthy controls and those with T2D, and a marked shift towards healthy controls following the MRP (15 biomarkers significantly changed) but not exercise training. Conclusions: Fibro-inflammatory pathways and cardiovascular structure/function are adversely altered before the onset of symptomatic CVD in middle-aged adults with T2D. The MRP improved the fibro-inflammatory profile of people with T2D This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Research paper thumbnail of 156 Effects of a low-energy meal replacement programme on reverse cardiac remodelling in asymptomatic people with type 2 diabetes: a comparison between south asians and white europeans

Imaging

Results. Figure 1 (left panel) shows PV loops from one representative patient. The non-invasive m... more Results. Figure 1 (left panel) shows PV loops from one representative patient. The non-invasive method demonstrated strong correlations and low bias compared to invasive data (Fig. 1, right panel) for stroke work, potential energy, end-systolic pressure-volume relationship, energy per ejected volume, ventricular efficiency, arterial elastance, and mean external power (Table 1). Conclusions Pressure-volume loops can be precisely and accurately computed from cardiovascular magnetic resonance imaging and brachial cuff blood pressure in humans, and is ready for use in research applications.

Research paper thumbnail of 4 Inter-modality agreement and test-retest reproducibility of CMR and Echocardiography for assessing myocardial deformation in type 2 diabetes mellitus

Abstracts, 2021

hyperaemic coronary flow reserve. Thus, we hypothesised that patients in AF would achieve splenic... more hyperaemic coronary flow reserve. Thus, we hypothesised that patients in AF would achieve splenic switch-off less frequently than those in sinus rhythm (SR). Methods 1100 adenosine stress CMR studies were retrospectively identified from a prospectively maintained clinical CMR database over a 5-year period (2016-2021). 71 patients in AF on ECG at the time of CMR were identified. The SR cohort was drawn by propensity score matching to the AF group for age, sex, and body mass index. The adenosine dose administered, symptoms, and heart-rate change observed during infusion and scan result were recorded. Splenic switch-off was evaluated subjectively through visual assessment and semiquantitatively via changes in splenic and myocardial signal intensity from rest to stress. Multivariate logistic regression analysis assessed for predictors of splenic switch-off. Results 70 AF patients were matched to 70 in SR (mean age: 72±8 years vs 72±9 years, p=0.96;%male: 86% vs 84%, p=0.81). Subjective splenic switch-off occurred significantly less frequently in AF than in SR (34/70 [49%] vs 53/70 [76%], p=0.003). Objective assessment supported this, with a smaller splenic signal intensity difference between stress and rest in AF vs SR (median splenic stress:rest peak signal intensity ratio 0.92 [IQR, 0.61-1.11] vs 0.56 [IQR, 0.45-0.75], p<0.001). A heart-rate increase over 10bpm in response to adenosine was a significant predictor of visual splenic switchoff in SR patients but not in AF patients. Fewer AF patients had inducible ischaemia than SR patients (9/70 [13%] vs 17/ 69 [25%], p=0.058). However, this difference was not driven by inducible ischaemia rates between AF and SR patients who did not achieve splenic switch-off (6/36 [17%] vs 4/17 [24%], p=0.403). Conclusions In this retrospective propensity matched study, splenic switch-off occurred significantly less frequently in patients with AF. This may risk the under-diagnosis of inducible ischaemia, but requires further assessment.

Research paper thumbnail of The impact of lifestyle intervention on left atrial function in type 2 diabetes: results from the DIASTOLIC study

The International Journal of Cardiovascular Imaging, 2022

Aerobic exercise training and low energy diets have been shown to improve left ventricular remode... more Aerobic exercise training and low energy diets have been shown to improve left ventricular remodelling and diastolic function in adults with type 2 diabetes (T2D), albeit with differential effects. The impact of these lifestyle interventions on left atrial (LA) function, however, has not previously been reported. The DIASTOLIC study was a prospective, randomised, open-label, blind endpoint trial, in which 90 people with obesity and T2D and no prevalent cardiovascular disease were randomised to a 12-week intervention of: (i) routine care, (ii) aerobic exercise training, or (iii) low energy (≈ 810 kcal/day) meal replacement plan (MRP). Cardiac magnetic resonance (CMR) imaging was performed pre- and post-intervention. Image analysis included LA volumes (LAV), emptying fraction (LAEF), and LA strain (LAS) corresponding to LA reservoir (LAS-r), conduit (LAS-cd), and booster pump (LAS-bp) function. 73 participants with T2D (mean age 50 ± 6 years, 62% male, body mass index (BMI) 36.1 ± 5.3...

Research paper thumbnail of 22 Inter-field strength agreement of left ventricular strain and strain rate using Tissue Tracking and AI derived global longitudinal shortening

BSCMR annual meeting 2021 – abstract submission, 2021

Methods The core cohort (502,655) was derived from the UK Biobank prospective study. Data from th... more Methods The core cohort (502,655) was derived from the UK Biobank prospective study. Data from the CMR sub-study (39,703) were used which utilised a 1.5 Tesla scanner and an automated scan analyser. Participants with a history of CVD and loop diuretic use were excluded. Baseline characteristics, including demographics, comorbidities, and biomarkers, were compared. LV volumes and CO were compared, and linearly regressed for an association with SA ethnicity. HF incidence rates were calculated from new HF hospitalisations (ICD10 codes: I50.0, I50.1, I50.9, I11.0, I13.0 and I13.2). Cox-proportional hazards analysis determined comparative risk of developing HF. Results Ninety-four (1.3%) of SA had HF and 4,218 (1.0%) of WE had HF. Higher proportions of WE with HF had elevated levels of cholesterol and smoking history (e.g.: 41.2% vs. 11.7% of SA with HF, p<0.0001). Higher proportions of SA with HF had hypertension and type 2 diabetes (33.0% vs. 9.0%, p<0.0001) and duration of diabetes (13 years vs. 7 years, p=0.0018). All indexed LV parameters were smaller after adjustment for prevalent risk factors (e.g.: LV end diastolic volume reduced by 20.7 ml, p<0.0001). A trend for a higher risk of HF was present in SA, which was attenuated by cholesterol (HR: 1.25, p=0.072 and HR: 1.11, p=0.450). Conclusion A trend for a higher risk of HF is present in SA, potentially due to cholesterol and smaller cardiac structures promoting myocardial strain in maintaining ejection fraction. Future research should determine causes of new HF events and confirm subtypes. Abstract 22 Figure 1 Scatterplots (showing the unity line) and Bland-Altman plots for left ventricular global systolic strain and global longitudinal shortening measurements. GCS, global circumferential strain; GLS, global longitudinal strain; GRS, global radial strain; LV, left ventricular

Research paper thumbnail of 125 Cardiac metabolic flexibility and myocardial substrate utilisation in response to pharmacological stress in type 2 diabetes

Heart failure, 2021

significantly smaller on OCT: mean intimal thickness (IT) by OCT was 0.21±0.1mm vs 0.44±0.24 mm b... more significantly smaller on OCT: mean intimal thickness (IT) by OCT was 0.21±0.1mm vs 0.44±0.24 mm by IVUS, p <0.001. A mean ITOCT >0.25mm had a sensitivity of 86.7% and specificity of 74.3% at detecting Stanford grade 4 CAV. Those with CAV evident on ICA had significant reduction in graft ejection fraction (EF) over median follow up of 7.3 years (mean DEF-3.6% with CAV vs +3.8% without CAV, p=0.04). Patients with mean ITOCT >0.25mm in at least one vessel had a lower EF at time of surveillance (55.9% vs 61.1%, p=0.0007) (figure 2). Only two MACEs were noted. Conclusion Coronary imaging with OCT correlates well with IVUS for detection of CAV. Mean IT of >0.25mm on OCT detects Stanford grade 4 CAV with reasonable accuracy and may be a useful cut-point for clinical use.Combined angiography and OCT to screen for CAV within 12-24 months of transplant predicts concurrent and future deterioration in left ventricular function, thus may trigger early alterations to clinical management to prevent clinical worsening.

Research paper thumbnail of Differences in native T1 and native T2 mapping between patients on hemodialysis and control subjects

European Journal of Radiology, 2021

PURPOSE Myocardial native T1 is a potential measure of myocardial fibrosis, but concerns remain o... more PURPOSE Myocardial native T1 is a potential measure of myocardial fibrosis, but concerns remain over the potential influence of myocardial edema to increased native T1 signal in subjects prone to fluid overload. This study describes differences in native T2 (typically raised in states of myocardial edema) and native T1 times in patients on hemodialysis by comparing native T1 and native T2 times between subjects on hemodialysis to an asymptomatic control group. Reproducibility of these sequences was tested. METHODS Subjects were recruited prospectively and underwent 3 T-cardiac MRI with acquisition of native T1 and native T2 maps. Between group differences in native T1 and T2 maps were assessed using one-way ANOVAs. 30 subjects underwent test-retest scans within a week of their original scan to define sequence reproducibility. RESULTS 261 subjects completed the study (hemodialysis n = 124, control n = 137). Native T1 times were significantly increased in subjects on hemodialysis compared to control subjects (1259 ms ± 51 vs 1212 ms ± 37, p < 0.01). There was no difference in native T2 times between subjects on hemodialysis and control subjects (39.5 ms ± 2.5 vs 39.5 ms ± 2.3, p = 0.9). These differences were unchanged after adjustment for relevant baseline differences (age, sex and hemoglobin). Inter-study reproducibility for native T1 and T2 mapping was excellent (coefficient of variability 0.9 % and 2.6 % respectively). CONCLUSIONS The increased native T1 signal demonstrated in subjects on hemodialysis occurs independently of differences in native T2 and the two parameters are not orthogonal. Elevated native T1 in patients on hemodialysis may be driven by water related to myocardial fibrosis rather than edema from volume overload.

Research paper thumbnail of 10 Inter-field strength agreement of myocardial strain measurements using tissue tracking cardiovascular magnetic resonance imaging

Abstracts, 2019

myocardial segments for detecting artefacts, but with indicating distractions leading to suboptim... more myocardial segments for detecting artefacts, but with indicating distractions leading to suboptimal accuracy (figure 1c). A CNN trained with additional guidance on attention is shown to pay the desired attention to the right structures and avoids distractions (figure 1d). Conclusion CNN designed with support of attention visualisation, and trained with guidance on attention can lead to significantly more transparent and accountable AI use in clinical practice.

Research paper thumbnail of P424CMR assessment of left atrial quantitation in aortic stenosis: reproducibility and comparison of different techniques

European Heart Journal - Cardiovascular Imaging, 2019

Background: Short axis (SAX) method is the gold standard for measuring left atrial (LA) volume, h... more Background: Short axis (SAX) method is the gold standard for measuring left atrial (LA) volume, however, Biplane area length method (ALM) has been used widely in clinical practice. This is for practical reasons, since 4-and 2-chamber cines are routinely acquired. However, their test-retest reproducibility has not been well studied. Methods: 11 patients with moderate-severe aortic stenosis (AS) had two CMR's a week apart at 3T. LA minimum and maximum volumes and LA ejection fraction (EF) were quantified by SAX and ALM (including and excluding the LA appendage) by two observers. The interobserver and test-retest reproducibility were assessed. Results: There was excellent correlation between volumes with and without LAA inclusion on ALM, with no difference in LAEF. There was good correlation in the volumes using ALM and SAX methods, with slightly higher volumes and lower LAEF using SAX (p < 0.01 and p = 0.03 respectively excluding LAA). The test-retest repeatability was excellent for SAX (CoV ∼10%, ICC 0.96) and moderate for ALM (CoV 18-23% excluding LAA and 20-30% including LAA, ICC ∼0.8 for volumes only). Conclusion: SAX stack is the most reproducible method for assessing LA volumes and LAEF by CMR in AS patients. However, LA volumes correlate well with biplane method, but with poorer reproducibility for LAEF.

Research paper thumbnail of P599Relationship between coronary artery calcium and hyperaemic myocardial blood flow in asymptomatic adults with type 2 diabetes

European Heart Journal - Cardiovascular Imaging, 2019

Background: The relationship between coronary artery calcium score (CAC) and hyperaemic myocardia... more Background: The relationship between coronary artery calcium score (CAC) and hyperaemic myocardial blood flow (MBF) in asymptomatic people with type 2 diabetes (T2D) and no history of cardiovascular disease is unknown. Purpose: To determine whether CAC is independently associated with stress MBF in asymptomatic people with T2D. Methods: We recruited adults with T2D and no history of cardiovascular disease. Subjects underwent anthropometry, CT CAC and adenosine stress 3T CMR. Perfusion imaging used a dual sequence and inline automated reconstruction and post-processing for quantification. Subjects with reversible perfusion defects on visual analyses of perfusion images were excluded. Results: 29 people with T2D were included. Anthropometric, CAC and CMR data are presented in Table 1. CAC was the only univariable predictor of hyperaemic global MBF, with which it showed an inverse correlation (Table 1). In a multivariable model containing age, gender and CAC, CAC was the only independent predictor of global MBF (β=-0.409, p = 0.032). Conclusions: In asymptomatic people with T2D and no perfusion defects, CAC is an independent determinant of stress MBF. Non-obstructive coronary disease should therefore be accounted for when assessing potential causes of microvascular dysfunction. Baseline anthropometric, CAC and CMR data, with univariate predictors of global stress MBF.

Research paper thumbnail of P598Correlation between arterial stiffness using oscillometry and cardiovascular magnetic resonance in a population with heart failure with preserved ejection fraction (HFpEF)

European Heart Journal - Cardiovascular Imaging, 2019

Research paper thumbnail of A comparison of the reproducibility of two cine-derived strain software programmes in disease states

European Journal of Radiology, 2019

A comparison of the reproducibility of two cine-derived strain software programmes in disease sta... more A comparison of the reproducibility of two cine-derived strain software programmes in disease states.

Research paper thumbnail of P421Comparison of left ventricular volumetric assessment by standard steady-state free precession and real time cine imaging

European Heart Journal - Cardiovascular Imaging, 2019

Background: Cardiovascular magnetic resonance (CMR) has become the gold standard for the assessme... more Background: Cardiovascular magnetic resonance (CMR) has become the gold standard for the assessment of cardiac volumetry and function. Currently, the technique of choice is cine imaging with steady-state free precession (SSFP), involving the acquisition of a multi-breathhold stack of short-axis images (acquisition time up to 10 minutes). Hence, accelerated image acquisition may be desirable in order to improve the time efficiency of the CMR examination and also to reduce the occurrence of motion artefact in subjects experiencing difficulty breath-holding. Purpose: To compare a novel non-breath-hold SSFP multi-slice real-time Cine sequence with the standard multi-breath-hold SSFP technique for the assessment of left ventricular (LV) volumes and systolic function. Methods: We prospectively studied 20 patients with known or suspected cardiac disease referred for routine clinical CMR assessment. Functional assessment was performed with a standard SSFP sequence (approximate acquisition matrix 256 X 166, acquisition voxel size 1.66 X 1.33 X 8mm, 30 phases, TR 48.16, IPAT 3, retrospective or prospective triggering depending on R-R regularity). Functional assessment was also carried out using a novel real time Cine sequence (approximate acquisition matrix 160 x 92, acquisition voxel size 3.26 X 2.5 X 8mm, number of phases determined according to R-R interval, TR 42.84, IPAT 4). Quantification of end-diastolic volume index [EDVi], endsystolic volume index [ESVi] and ejection fraction [EF] was performed by single observer in a blinded fashion. Image quality for both scans was graded on a 4-point scale. Results: Scans from 20 patients (age 63.0 ± 11.7 years, 13 male) were analysed. All images for both techniques were analysable and image quality was rated as excellent/good in 85% of real-time images and 90% of standard cine images. The duration of imaging was 15 ± 7 seconds for the real-time sequence and 383 ± 139 seconds for the standard sequence (p < 0.0001). LVEF was quantified as similar for both methods (49.6 ± 9.1% for real-time vs. 48.6 ± 8.5% for standard, p = 0.27, intraclass correlation (ICC) 0.90, 95% confidence interval [CI] 0.77-0.96). There was also excellent agreement for EDVi (ICC 0.96, 95% CI 0.89-0.98, p = 0.47 for difference) and for ESVi (ICC 0.95, 95% CI 0.88-0.98, p = 0.22 for difference). Conclusion: For assessment of LV volumes and function, a non-breath-hold multi-slice real-time cine sequence is feasible in the clinical setting and achieves similar values to segmented breath-held cine acquisitions. This technique may prove useful in patients with breath-holding difficulty, in patients with arrhythmias, or to accelerate exam times to enhance patient flow. Figure: Bland-Altman plots of ejection fraction (EF), end-diastolic volume index (EDVi) and end-systolic volume index (ESVi)

Research paper thumbnail of Interrelationship between micronutrients and cardiovascular structure and function in type 2 diabetes

Journal of Nutritional Science

Micronutrients are important for normal cardiovascular function. They may play a role in the incr... more Micronutrients are important for normal cardiovascular function. They may play a role in the increased risk of cardiovascular disease observed in people with type 2 diabetes (T2D) and T2D-related heart failure. The aims of this study were to (1) examine micronutrient status in people with T2D v. healthy controls; (2) assess any changes following a nutritionally complete meal replacement plan (MRP) compared with routine care; (3) determine if any changes were associated with changes in cardiovascular structure/function. This was a secondary analysis of data from a prospective, randomised, open-label, blinded end-point trial of people with T2D, with a nested case–control [NCT02590822]. Anthropometrics, cardiac resonance imaging and fasting blood samples (to quantify vitamins B1, B6, B12, D and C; and iron and ferritin) were collected at baseline and 12 weeks following the MRP or routine care. Comparative data in healthy controls were collected at baseline. A total of eighty-three peop...

Research paper thumbnail of 56-OR: Fibro-inflammatory Plasma Biomarkers and Relation to Cardiovascular Remodeling in Type 2 Diabetes (T2D)

Research paper thumbnail of 160 The impact of exercise and diet intervention on left atrial function in type 2 diabetes: results from a randomised study

Research paper thumbnail of Male sex adversely affects the phenotypic expression of diabetic heart disease

Therapeutic Advances in Endocrinology and Metabolism

Background: Type 2 diabetes (T2D) is associated with an increased risk of heart failure (HF) and ... more Background: Type 2 diabetes (T2D) is associated with an increased risk of heart failure (HF) and cardiovascular mortality. A large-scale meta-analysis on HF found that diabetes was more frequent in women than men, and diabetes appeared to have attenuated the otherwise protective effect of female sex on progression of cardiomyopathy. The exact underlying mechanisms for this remain unclear. Here, we aimed to determine the effect of sex on the phenotypic expression of diabetic heart disease in patients with T2D. Methods: A total of 62 male [mean age 44 ± 8 years, body mass index (BMI) 33 ± 5 kg/m2, mean HBA1c of 7.8 ± 1.8%] and 67 female (44 ± 10 years, BMI 35 ± 6 kg/m2, HBA1c 7.6 ± 1.2%) T2D patients on oral glucose-lowering treatment, and 16 male (48 ± 17 years, BMI 25 ± 3 kg/m2) and 14 female (50 ± 10 years, BMI 25 ± 4 kg/m2) controls were recruited. Left ventricular (LV) volumes, mass, function and deformation, and left atrial (LA) volumes and function were assessed using cardiac m...

Research paper thumbnail of Does nocturnal haemodialysis improve heart disease for patients on dialysis?

Research paper thumbnail of A comparison of liver fat fraction measurement on MRI at 3T and 1.5T

PLOS ONE

Purpose Volumetric liver fat fraction (VLFF) measurements were made using the HepaFat-Scan® techn... more Purpose Volumetric liver fat fraction (VLFF) measurements were made using the HepaFat-Scan® technique at 1.5T and 3T to determine the agreement between the measurements obtained at the two fields. Methods Sixty patients with type 2 diabetes (67% male, mean age 50.92 ± 6.56yrs) and thirty healthy volunteers (50% male, mean age 48.63 ± 6.32yrs) were scanned on 1.5T Aera and 3T Skyra (Siemens, Erlangen, Germany) MRI scanners on the same day using the HepaFat-Scan® gradient echo protocol with modification of echo times for 3T (TEs 2.38, 4.76, 7.14 ms at 1.5T and 1.2, 2.4, 3.6 ms at 3T). The 3T analyses were performed independently of the 1.5T analyses by a different analyst, blinded from the 1.5T results. Data were analysed for agreement and bias using Bland-Altman methods and intraclass correlation coefficients (ICC). A second cohort of 17 participants underwent interstudy repeatability assessment of VLFF measured by HepaFat-Scan® at 3T. Results A small, but statistically significant m...

Research paper thumbnail of The Interfield Strength Agreement of Left Ventricular Strain Measurements at 1. 5 T and 3 T Using Cardiac MRI Feature Tracking

Journal of Magnetic Resonance Imaging

Research paper thumbnail of Fibro‐inflammatory recovery and type 2 diabetes remission following a low calorie diet but not exercise training: A secondary analysis of the DIASTOLIC randomised controlled trial

Diabetic Medicine

Aims: To investigate the relationship between fibro-inflammatory biomarkers and cardiovascular st... more Aims: To investigate the relationship between fibro-inflammatory biomarkers and cardiovascular structure/function in people with Type 2 Diabetes (T2D) compared to healthy controls and the effect of two lifestyle interventions in T2D. Methods: Data were derived from the DIASTOLIC randomised controlled trial (RCT) and includes a comparison between those with T2D and the matched healthy volunteers recruited at baseline. Adults with T2D without cardiovascular disease (CVD) were randomized to a 12-week intervention either: (1) exercise training, (2) a low-energy (∼810 kcal/day) meal-replacement plan (MRP) or (3) standard care. Principal Component and Fisher's linear discriminant analysis were used to investigate the relationships between MRI acquired cardiovascular outcomes and fibro-inflammatory biomarkers in cases versus controls and preand post-intervention in T2D. Results: At baseline, 83 people with T2D (mean age 50.5 ± 6.4; 58% male) and 36 healthy controls (mean age 48.6 ± 6.2; 53% male) were compared and 76 people with T2D completed the RCT for pre-post-analysis. Compared to healthy controls, subjects with T2D had adverse cardiovascular remodelling and a fibroinflammatory profile (20 differentially expressed biomarkers). The 3D data visualisations showed almost complete separation between healthy controls and those with T2D, and a marked shift towards healthy controls following the MRP (15 biomarkers significantly changed) but not exercise training. Conclusions: Fibro-inflammatory pathways and cardiovascular structure/function are adversely altered before the onset of symptomatic CVD in middle-aged adults with T2D. The MRP improved the fibro-inflammatory profile of people with T2D This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Research paper thumbnail of 156 Effects of a low-energy meal replacement programme on reverse cardiac remodelling in asymptomatic people with type 2 diabetes: a comparison between south asians and white europeans

Imaging

Results. Figure 1 (left panel) shows PV loops from one representative patient. The non-invasive m... more Results. Figure 1 (left panel) shows PV loops from one representative patient. The non-invasive method demonstrated strong correlations and low bias compared to invasive data (Fig. 1, right panel) for stroke work, potential energy, end-systolic pressure-volume relationship, energy per ejected volume, ventricular efficiency, arterial elastance, and mean external power (Table 1). Conclusions Pressure-volume loops can be precisely and accurately computed from cardiovascular magnetic resonance imaging and brachial cuff blood pressure in humans, and is ready for use in research applications.

Research paper thumbnail of 4 Inter-modality agreement and test-retest reproducibility of CMR and Echocardiography for assessing myocardial deformation in type 2 diabetes mellitus

Abstracts, 2021

hyperaemic coronary flow reserve. Thus, we hypothesised that patients in AF would achieve splenic... more hyperaemic coronary flow reserve. Thus, we hypothesised that patients in AF would achieve splenic switch-off less frequently than those in sinus rhythm (SR). Methods 1100 adenosine stress CMR studies were retrospectively identified from a prospectively maintained clinical CMR database over a 5-year period (2016-2021). 71 patients in AF on ECG at the time of CMR were identified. The SR cohort was drawn by propensity score matching to the AF group for age, sex, and body mass index. The adenosine dose administered, symptoms, and heart-rate change observed during infusion and scan result were recorded. Splenic switch-off was evaluated subjectively through visual assessment and semiquantitatively via changes in splenic and myocardial signal intensity from rest to stress. Multivariate logistic regression analysis assessed for predictors of splenic switch-off. Results 70 AF patients were matched to 70 in SR (mean age: 72±8 years vs 72±9 years, p=0.96;%male: 86% vs 84%, p=0.81). Subjective splenic switch-off occurred significantly less frequently in AF than in SR (34/70 [49%] vs 53/70 [76%], p=0.003). Objective assessment supported this, with a smaller splenic signal intensity difference between stress and rest in AF vs SR (median splenic stress:rest peak signal intensity ratio 0.92 [IQR, 0.61-1.11] vs 0.56 [IQR, 0.45-0.75], p<0.001). A heart-rate increase over 10bpm in response to adenosine was a significant predictor of visual splenic switchoff in SR patients but not in AF patients. Fewer AF patients had inducible ischaemia than SR patients (9/70 [13%] vs 17/ 69 [25%], p=0.058). However, this difference was not driven by inducible ischaemia rates between AF and SR patients who did not achieve splenic switch-off (6/36 [17%] vs 4/17 [24%], p=0.403). Conclusions In this retrospective propensity matched study, splenic switch-off occurred significantly less frequently in patients with AF. This may risk the under-diagnosis of inducible ischaemia, but requires further assessment.

Research paper thumbnail of The impact of lifestyle intervention on left atrial function in type 2 diabetes: results from the DIASTOLIC study

The International Journal of Cardiovascular Imaging, 2022

Aerobic exercise training and low energy diets have been shown to improve left ventricular remode... more Aerobic exercise training and low energy diets have been shown to improve left ventricular remodelling and diastolic function in adults with type 2 diabetes (T2D), albeit with differential effects. The impact of these lifestyle interventions on left atrial (LA) function, however, has not previously been reported. The DIASTOLIC study was a prospective, randomised, open-label, blind endpoint trial, in which 90 people with obesity and T2D and no prevalent cardiovascular disease were randomised to a 12-week intervention of: (i) routine care, (ii) aerobic exercise training, or (iii) low energy (≈ 810 kcal/day) meal replacement plan (MRP). Cardiac magnetic resonance (CMR) imaging was performed pre- and post-intervention. Image analysis included LA volumes (LAV), emptying fraction (LAEF), and LA strain (LAS) corresponding to LA reservoir (LAS-r), conduit (LAS-cd), and booster pump (LAS-bp) function. 73 participants with T2D (mean age 50 ± 6 years, 62% male, body mass index (BMI) 36.1 ± 5.3...

Research paper thumbnail of 22 Inter-field strength agreement of left ventricular strain and strain rate using Tissue Tracking and AI derived global longitudinal shortening

BSCMR annual meeting 2021 – abstract submission, 2021

Methods The core cohort (502,655) was derived from the UK Biobank prospective study. Data from th... more Methods The core cohort (502,655) was derived from the UK Biobank prospective study. Data from the CMR sub-study (39,703) were used which utilised a 1.5 Tesla scanner and an automated scan analyser. Participants with a history of CVD and loop diuretic use were excluded. Baseline characteristics, including demographics, comorbidities, and biomarkers, were compared. LV volumes and CO were compared, and linearly regressed for an association with SA ethnicity. HF incidence rates were calculated from new HF hospitalisations (ICD10 codes: I50.0, I50.1, I50.9, I11.0, I13.0 and I13.2). Cox-proportional hazards analysis determined comparative risk of developing HF. Results Ninety-four (1.3%) of SA had HF and 4,218 (1.0%) of WE had HF. Higher proportions of WE with HF had elevated levels of cholesterol and smoking history (e.g.: 41.2% vs. 11.7% of SA with HF, p<0.0001). Higher proportions of SA with HF had hypertension and type 2 diabetes (33.0% vs. 9.0%, p<0.0001) and duration of diabetes (13 years vs. 7 years, p=0.0018). All indexed LV parameters were smaller after adjustment for prevalent risk factors (e.g.: LV end diastolic volume reduced by 20.7 ml, p<0.0001). A trend for a higher risk of HF was present in SA, which was attenuated by cholesterol (HR: 1.25, p=0.072 and HR: 1.11, p=0.450). Conclusion A trend for a higher risk of HF is present in SA, potentially due to cholesterol and smaller cardiac structures promoting myocardial strain in maintaining ejection fraction. Future research should determine causes of new HF events and confirm subtypes. Abstract 22 Figure 1 Scatterplots (showing the unity line) and Bland-Altman plots for left ventricular global systolic strain and global longitudinal shortening measurements. GCS, global circumferential strain; GLS, global longitudinal strain; GRS, global radial strain; LV, left ventricular

Research paper thumbnail of 125 Cardiac metabolic flexibility and myocardial substrate utilisation in response to pharmacological stress in type 2 diabetes

Heart failure, 2021

significantly smaller on OCT: mean intimal thickness (IT) by OCT was 0.21±0.1mm vs 0.44±0.24 mm b... more significantly smaller on OCT: mean intimal thickness (IT) by OCT was 0.21±0.1mm vs 0.44±0.24 mm by IVUS, p <0.001. A mean ITOCT >0.25mm had a sensitivity of 86.7% and specificity of 74.3% at detecting Stanford grade 4 CAV. Those with CAV evident on ICA had significant reduction in graft ejection fraction (EF) over median follow up of 7.3 years (mean DEF-3.6% with CAV vs +3.8% without CAV, p=0.04). Patients with mean ITOCT >0.25mm in at least one vessel had a lower EF at time of surveillance (55.9% vs 61.1%, p=0.0007) (figure 2). Only two MACEs were noted. Conclusion Coronary imaging with OCT correlates well with IVUS for detection of CAV. Mean IT of >0.25mm on OCT detects Stanford grade 4 CAV with reasonable accuracy and may be a useful cut-point for clinical use.Combined angiography and OCT to screen for CAV within 12-24 months of transplant predicts concurrent and future deterioration in left ventricular function, thus may trigger early alterations to clinical management to prevent clinical worsening.

Research paper thumbnail of Differences in native T1 and native T2 mapping between patients on hemodialysis and control subjects

European Journal of Radiology, 2021

PURPOSE Myocardial native T1 is a potential measure of myocardial fibrosis, but concerns remain o... more PURPOSE Myocardial native T1 is a potential measure of myocardial fibrosis, but concerns remain over the potential influence of myocardial edema to increased native T1 signal in subjects prone to fluid overload. This study describes differences in native T2 (typically raised in states of myocardial edema) and native T1 times in patients on hemodialysis by comparing native T1 and native T2 times between subjects on hemodialysis to an asymptomatic control group. Reproducibility of these sequences was tested. METHODS Subjects were recruited prospectively and underwent 3 T-cardiac MRI with acquisition of native T1 and native T2 maps. Between group differences in native T1 and T2 maps were assessed using one-way ANOVAs. 30 subjects underwent test-retest scans within a week of their original scan to define sequence reproducibility. RESULTS 261 subjects completed the study (hemodialysis n = 124, control n = 137). Native T1 times were significantly increased in subjects on hemodialysis compared to control subjects (1259 ms ± 51 vs 1212 ms ± 37, p < 0.01). There was no difference in native T2 times between subjects on hemodialysis and control subjects (39.5 ms ± 2.5 vs 39.5 ms ± 2.3, p = 0.9). These differences were unchanged after adjustment for relevant baseline differences (age, sex and hemoglobin). Inter-study reproducibility for native T1 and T2 mapping was excellent (coefficient of variability 0.9 % and 2.6 % respectively). CONCLUSIONS The increased native T1 signal demonstrated in subjects on hemodialysis occurs independently of differences in native T2 and the two parameters are not orthogonal. Elevated native T1 in patients on hemodialysis may be driven by water related to myocardial fibrosis rather than edema from volume overload.

Research paper thumbnail of 10 Inter-field strength agreement of myocardial strain measurements using tissue tracking cardiovascular magnetic resonance imaging

Abstracts, 2019

myocardial segments for detecting artefacts, but with indicating distractions leading to suboptim... more myocardial segments for detecting artefacts, but with indicating distractions leading to suboptimal accuracy (figure 1c). A CNN trained with additional guidance on attention is shown to pay the desired attention to the right structures and avoids distractions (figure 1d). Conclusion CNN designed with support of attention visualisation, and trained with guidance on attention can lead to significantly more transparent and accountable AI use in clinical practice.

Research paper thumbnail of P424CMR assessment of left atrial quantitation in aortic stenosis: reproducibility and comparison of different techniques

European Heart Journal - Cardiovascular Imaging, 2019

Background: Short axis (SAX) method is the gold standard for measuring left atrial (LA) volume, h... more Background: Short axis (SAX) method is the gold standard for measuring left atrial (LA) volume, however, Biplane area length method (ALM) has been used widely in clinical practice. This is for practical reasons, since 4-and 2-chamber cines are routinely acquired. However, their test-retest reproducibility has not been well studied. Methods: 11 patients with moderate-severe aortic stenosis (AS) had two CMR's a week apart at 3T. LA minimum and maximum volumes and LA ejection fraction (EF) were quantified by SAX and ALM (including and excluding the LA appendage) by two observers. The interobserver and test-retest reproducibility were assessed. Results: There was excellent correlation between volumes with and without LAA inclusion on ALM, with no difference in LAEF. There was good correlation in the volumes using ALM and SAX methods, with slightly higher volumes and lower LAEF using SAX (p < 0.01 and p = 0.03 respectively excluding LAA). The test-retest repeatability was excellent for SAX (CoV ∼10%, ICC 0.96) and moderate for ALM (CoV 18-23% excluding LAA and 20-30% including LAA, ICC ∼0.8 for volumes only). Conclusion: SAX stack is the most reproducible method for assessing LA volumes and LAEF by CMR in AS patients. However, LA volumes correlate well with biplane method, but with poorer reproducibility for LAEF.

Research paper thumbnail of P599Relationship between coronary artery calcium and hyperaemic myocardial blood flow in asymptomatic adults with type 2 diabetes

European Heart Journal - Cardiovascular Imaging, 2019

Background: The relationship between coronary artery calcium score (CAC) and hyperaemic myocardia... more Background: The relationship between coronary artery calcium score (CAC) and hyperaemic myocardial blood flow (MBF) in asymptomatic people with type 2 diabetes (T2D) and no history of cardiovascular disease is unknown. Purpose: To determine whether CAC is independently associated with stress MBF in asymptomatic people with T2D. Methods: We recruited adults with T2D and no history of cardiovascular disease. Subjects underwent anthropometry, CT CAC and adenosine stress 3T CMR. Perfusion imaging used a dual sequence and inline automated reconstruction and post-processing for quantification. Subjects with reversible perfusion defects on visual analyses of perfusion images were excluded. Results: 29 people with T2D were included. Anthropometric, CAC and CMR data are presented in Table 1. CAC was the only univariable predictor of hyperaemic global MBF, with which it showed an inverse correlation (Table 1). In a multivariable model containing age, gender and CAC, CAC was the only independent predictor of global MBF (β=-0.409, p = 0.032). Conclusions: In asymptomatic people with T2D and no perfusion defects, CAC is an independent determinant of stress MBF. Non-obstructive coronary disease should therefore be accounted for when assessing potential causes of microvascular dysfunction. Baseline anthropometric, CAC and CMR data, with univariate predictors of global stress MBF.

Research paper thumbnail of P598Correlation between arterial stiffness using oscillometry and cardiovascular magnetic resonance in a population with heart failure with preserved ejection fraction (HFpEF)

European Heart Journal - Cardiovascular Imaging, 2019

Research paper thumbnail of A comparison of the reproducibility of two cine-derived strain software programmes in disease states

European Journal of Radiology, 2019

A comparison of the reproducibility of two cine-derived strain software programmes in disease sta... more A comparison of the reproducibility of two cine-derived strain software programmes in disease states.

Research paper thumbnail of P421Comparison of left ventricular volumetric assessment by standard steady-state free precession and real time cine imaging

European Heart Journal - Cardiovascular Imaging, 2019

Background: Cardiovascular magnetic resonance (CMR) has become the gold standard for the assessme... more Background: Cardiovascular magnetic resonance (CMR) has become the gold standard for the assessment of cardiac volumetry and function. Currently, the technique of choice is cine imaging with steady-state free precession (SSFP), involving the acquisition of a multi-breathhold stack of short-axis images (acquisition time up to 10 minutes). Hence, accelerated image acquisition may be desirable in order to improve the time efficiency of the CMR examination and also to reduce the occurrence of motion artefact in subjects experiencing difficulty breath-holding. Purpose: To compare a novel non-breath-hold SSFP multi-slice real-time Cine sequence with the standard multi-breath-hold SSFP technique for the assessment of left ventricular (LV) volumes and systolic function. Methods: We prospectively studied 20 patients with known or suspected cardiac disease referred for routine clinical CMR assessment. Functional assessment was performed with a standard SSFP sequence (approximate acquisition matrix 256 X 166, acquisition voxel size 1.66 X 1.33 X 8mm, 30 phases, TR 48.16, IPAT 3, retrospective or prospective triggering depending on R-R regularity). Functional assessment was also carried out using a novel real time Cine sequence (approximate acquisition matrix 160 x 92, acquisition voxel size 3.26 X 2.5 X 8mm, number of phases determined according to R-R interval, TR 42.84, IPAT 4). Quantification of end-diastolic volume index [EDVi], endsystolic volume index [ESVi] and ejection fraction [EF] was performed by single observer in a blinded fashion. Image quality for both scans was graded on a 4-point scale. Results: Scans from 20 patients (age 63.0 ± 11.7 years, 13 male) were analysed. All images for both techniques were analysable and image quality was rated as excellent/good in 85% of real-time images and 90% of standard cine images. The duration of imaging was 15 ± 7 seconds for the real-time sequence and 383 ± 139 seconds for the standard sequence (p < 0.0001). LVEF was quantified as similar for both methods (49.6 ± 9.1% for real-time vs. 48.6 ± 8.5% for standard, p = 0.27, intraclass correlation (ICC) 0.90, 95% confidence interval [CI] 0.77-0.96). There was also excellent agreement for EDVi (ICC 0.96, 95% CI 0.89-0.98, p = 0.47 for difference) and for ESVi (ICC 0.95, 95% CI 0.88-0.98, p = 0.22 for difference). Conclusion: For assessment of LV volumes and function, a non-breath-hold multi-slice real-time cine sequence is feasible in the clinical setting and achieves similar values to segmented breath-held cine acquisitions. This technique may prove useful in patients with breath-holding difficulty, in patients with arrhythmias, or to accelerate exam times to enhance patient flow. Figure: Bland-Altman plots of ejection fraction (EF), end-diastolic volume index (EDVi) and end-systolic volume index (ESVi)

Research paper thumbnail of Interrelationship between micronutrients and cardiovascular structure and function in type 2 diabetes

Journal of Nutritional Science

Micronutrients are important for normal cardiovascular function. They may play a role in the incr... more Micronutrients are important for normal cardiovascular function. They may play a role in the increased risk of cardiovascular disease observed in people with type 2 diabetes (T2D) and T2D-related heart failure. The aims of this study were to (1) examine micronutrient status in people with T2D v. healthy controls; (2) assess any changes following a nutritionally complete meal replacement plan (MRP) compared with routine care; (3) determine if any changes were associated with changes in cardiovascular structure/function. This was a secondary analysis of data from a prospective, randomised, open-label, blinded end-point trial of people with T2D, with a nested case–control [NCT02590822]. Anthropometrics, cardiac resonance imaging and fasting blood samples (to quantify vitamins B1, B6, B12, D and C; and iron and ferritin) were collected at baseline and 12 weeks following the MRP or routine care. Comparative data in healthy controls were collected at baseline. A total of eighty-three peop...

Research paper thumbnail of 56-OR: Fibro-inflammatory Plasma Biomarkers and Relation to Cardiovascular Remodeling in Type 2 Diabetes (T2D)

Research paper thumbnail of 160 The impact of exercise and diet intervention on left atrial function in type 2 diabetes: results from a randomised study

Research paper thumbnail of Male sex adversely affects the phenotypic expression of diabetic heart disease

Therapeutic Advances in Endocrinology and Metabolism

Background: Type 2 diabetes (T2D) is associated with an increased risk of heart failure (HF) and ... more Background: Type 2 diabetes (T2D) is associated with an increased risk of heart failure (HF) and cardiovascular mortality. A large-scale meta-analysis on HF found that diabetes was more frequent in women than men, and diabetes appeared to have attenuated the otherwise protective effect of female sex on progression of cardiomyopathy. The exact underlying mechanisms for this remain unclear. Here, we aimed to determine the effect of sex on the phenotypic expression of diabetic heart disease in patients with T2D. Methods: A total of 62 male [mean age 44 ± 8 years, body mass index (BMI) 33 ± 5 kg/m2, mean HBA1c of 7.8 ± 1.8%] and 67 female (44 ± 10 years, BMI 35 ± 6 kg/m2, HBA1c 7.6 ± 1.2%) T2D patients on oral glucose-lowering treatment, and 16 male (48 ± 17 years, BMI 25 ± 3 kg/m2) and 14 female (50 ± 10 years, BMI 25 ± 4 kg/m2) controls were recruited. Left ventricular (LV) volumes, mass, function and deformation, and left atrial (LA) volumes and function were assessed using cardiac m...