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This pilot trial aimed to investigate the utilization of (111)In-labeling of mesenchymal stromal cells (MSC) for in vivo tracking after intramyocardial transplantation in a xenotransplantation model with gender mismatched cells. Human male MSC were expanded ex vivo and labeled with (111)In-tropolone. Ten female pigs were included. The labeled cells were transplanted intramyocardially using a percutaneous injection system. The (111)In activity was determined using gamma camera imaging. Excised hearts were analyzed by fluorescence in situ hybridization (FISH) and microscopy. Gamma camera imaging revealed focal cardiac (111)In accumulations up to 6 days after injection (N = 4). No MSC could be identified with FISH, and microscopy identified widespread acute inflammation. Focal (111)In accumulation, inflammation but no human MSC were similarly seen in pigs (N = 2) after immunosuppression. A comparable retention of (111)In activity was observed after intramyocardial injection of (111)In-tropolone (without cells) (N = 2), but without sign of myocardial inflammation. Injection of labeled non-viable cells (N = 1) also led to high focal (111)In activity up to 6 days after intramyocardial injection. As a positive control of the FISH method, we identified labeled cells both in culture and immediately after cell injection in one pig. This pilot trial suggests that after intramyocardial injection (111)In stays in the myocardium despite possible disappearance of labeled cells. This questions the clinical use of (111)In-labeled cells for tracking. The results further suggest that xenografting of human MSC into porcine hearts leads to inflammation contradicting previous studies implying a special immunoprivileged status for MSC. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine whether ischaemia grade (GI) on the presenting ECG and duration of symptoms can identify subgroups of patients who would derive more benefit than the general population of patients with ST segment elevation acute myocardium infarction (STEMI) from primary percutaneous coronary intervention (pPCI) over thrombolytic treatment (TT) in reducing mortality or reinfarction. METHODS: 1319 DANAMI-2 (Danish trial in Acute Myocardial Infarction-2) patients were classified as having grade 2 ischaemia (GI2; ST segment elevation without terminal QRS distortion) or grade 3 ischaemia (GI3; ST segment elevation with terminal QRS distortion in > or = 2 adjacent leads), and were divided into early and late groups split by the median time (3 h) from symptom onset to treatment. Outcomes were 30-day mortality and reinfarction. RESULTS: Mortality was significantly higher for GI3 than for GI2 (9.7% v 4.8%, p < 0.001) and doubled for patients presenting late (GI2: 6.0% v 3.3%, p = 0.01; GI3: 12.5% v 4.7%, p = 0.05). Overall mortality did not differ significantly between pPCI and TT; however, a 5.5% absolute mortality reduction was seen in GI3 treated early with pPCI (1.4% v 6.9%, p = 0.10). Reinfarction rate was particularly high among GI3 patients presenting late and treated with TT (12.2%). pPCI in such patients significantly reduced the rate of reinfarction (0%, p < 0.001). Logistic regression analysis showed that age (odds ratio (OR) 1.09, 95% confidence interval (CI) 1.06 to 1.12, p < 0.001), prior angina (OR 2.56, 95% CI 1.44 to 4.54, p = 0.001), heart rate (OR 1.03, 95% CI 1.01 to 1.04, p = 0.001) and GI3 (OR 1.91, 95% CI 1.06 to 3.44, p = 0.031) were independently associated with mortality, whereas the sum of ST segment elevation was not. CONCLUSIONS: GI3 is an independent predictor of mortality among patients with STEMI. Mortality increased significantly with symptom duration in both GI2 and GI3. pPCI may be especially beneficial for patients with GI3 presenting early, whereas patients with GI3 presenting late and treated with TT are at particular risk of reinfarction. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the spontaneous occurrence of circulating mesenchymal stem cells (MSC) and angiogenic factors in patients with ST elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). DESIGN: In 20 patients with STEMI, blood samples were obtained on days 1, 3, 7, 14, 21, and 28 after the acute PCI. Fifteen patients with a normal coronary angiography formed a control group. MSC (CD45-/CD34-), plasma stromal derived factor 1 (SDF-1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2) were measured by multiparametric flow cytometry and enzyme linked immunosorbent assay (ELISA). RESULTS: Circulating CD45-/CD34- cells were significantly decreased on day 7 compared with day 3. Cell counts normalised one month after the acute onset of STEMI. The changes were mainly seen in patients with a large infarction. Plasma SDF-1 increased significantly from day 3 to day 28, and VEGF-A and FGF-2 increased significantly from day 7 to day 28. CONCLUSIONS: Spontaneous sequential fluctuations in MSC and the increase in vascular growth factor concentrations after STEMI suggest that the optimal time for additional stem cell therapy is three weeks after a myocardial infarction to obtain the maximum effects by stimulating endogenous growth factors on the delivered stem cells. [ABSTRACT FROM AUTHOR]

A pivotal animal model for development of anticancer molecules is mice with subcutaneous tumors, grown by injection of xenografted tumor cells, where micro-Computed Tomography (µCT) of the mice is used to analyze the efficacy of the anticancer molecule. Manual delineation of the tumor region is necessary for the analysis, which is time-consuming and inconsistent, highlighting the need for automatic segmentation (AS) tools. This study introduces a preclinical µCT database, comprising 452 whole-body scans from 223 individual mice with subcutaneous tumors, spanning ten diverse µCT datasets conducted between 2014 and 2020 on a preclinical PET/CT scanner, making it the hitherto largest dataset of its kind. Each tumor is annotated manually by three expert annotators, allowing for robust model development. Inter-annotator agreement was analyzed, and we report an overall annotation agreement of 0.903 ± 0.046 (mean ± std) Fleiss' Kappa and a mean deviation in volume estimation of 0.015 ± 0.010 cm 3 (6.9% ± 4.7), which establishes a human baseline accuracy for delineation of subcutaneous tumors, while showing good inter-annotator agreement., (© 2024. The Author(s).)

Background: Infective endocarditis (IE) is a serious and fatal condition, with prosthetic valve endocarditis representing the worst prognosis. The recommended nuclear imaging modality 2-deoxy-2-[ 18 F]fluoro-D-glucose positron emission tomography/computed tomography ([ 18 F]FDG PET/CT) has limitations. In this case series, we present two patients with IE scanned with a novel PET tracer [ 64 Cu]Cu-DOTATATE ([ 64 Cu]Cu-[1,4,7,10-tetraazacyclododecane- N , N ', N ″, N ‴-tetra acetic acid]-d-Phe1, Tyr3-octreotate)., Case Summary: An 84-year-old female patient (Patient 1) with a biological mitral valve prosthesis (MVP) was admitted acutely from the outpatient clinic. Transoesophageal echocardiography showed vegetations on the MVP. The patient underwent [ 64 Cu]Cu-DOTATATE PET/CT, which showed uptake at the site of infection. The patient underwent surgical valve replacement. The post-operative period was without significant complications, and the patient was discharged home. In another case, a 72-year-old male patient (Patient 2) with a medical history of mild mitral valve stenosis, aortic valve stenosis, and gastrointestinal stromal tumour was admitted to the hospital for back and abdominal pain and subfebrile episodes. Transoesophageal echocardiography showed large vegetations in the native aortic valve. The patient underwent [ 64 Cu]Cu-DOTATATE PET/CT, which showed no uptake at the site of the suspected infection. The patient underwent surgical valve replacement. The post-operative period was characterized by Candida albicans sternitis, and after prolonged hospitalization, the patient died of respiratory failure as a complication of sepsis., Discussion: In conclusion, this is the first case series presenting two patients with definite IE (modified Duke criteria), who were scanned with the novel [ 64 Cu]Cu-DOTATATE PET/CT. Patient 1, with endocarditis in the MVP, showed an uptake of the tracer, while Patient 2, with native aortic valve endocarditis, did not show any uptake., Competing Interests: Conflict of interest: K.H.-T., M.Ø.F., P.H., and R.S.R.: none declared. A.K.: inventor/holds IPR on a patent covering [64Cu]Cu-DOTATATE for use in neuroendocrine tumours. L.K. has received lecture fees from Astra Zeneca, Bayer, Boehringer, Novartis, and Novo, unrelated to this manuscript. E.F. has received independent research grant related to valvular heart disease and endocarditis from the Novo Nordisk Foundation and the Danish Heart Association, unrelated to this manuscript., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Doxorubicin (DOX) is a common and highly effective chemotherapeutic. However, its use is limited by cardiotoxic effects and the lack of methods to detect these at early time points. In the present study, we evaluated if [ 64 Cu]Cu-NODAGA-E[(cRGDyK)]2 positron emission tomography-computed tomography ([ 64 Cu]Cu-RGD PET/CT) could detect cardiotoxicity in a rat model of DOX-induced heart failure. Male Lewis rats were divided into two groups and treated with either a cumulative dose of 15 mg/kg of DOX or left untreated. Cardiac anatomy and function were assessed using magnetic resonance imaging at baseline and in week 8. [ 64 Cu]Cu-RGD PET/CT scans were performed in week 4. DOX treatment led to a decline in pump function as well as an increase in cardiac and thymic uptake of [ 64 Cu]Cu-RGD. In addition, DOX altered cardiac gene expression, led to infiltration of immune cells, reduced endothelial content, and increased interstitial fibrosis. Furthermore, concentrations of inflammatory plasma proteins were increased in the DOX group. In conclusion, DOX treatment resulted in the development of cardiotoxicity and heart failure, which could be detected using [ 64 Cu]Cu-RGD PET/CT at early time points. [ 64 Cu]Cu-RGD uptake in the myocardial septum and thymus predicted a low left ventricular ejection fraction in week 8.

Diabetes affects the kidneys, and the presence of albuminuria reflects widespread vascular damage and is a risk factor for cardiovascular disease (CVD). Still, the pathophysiological association between albuminuria and CVD remains incompletely understood. Recent advances in noninvasive imaging enable functional assessment of coronary artery pathology and present an opportunity to explore the association between albuminuria and CVD. In this cross-sectional study, we evaluated the presence of subclinical coronary artery pathology in people with type 2 diabetes, free of overt CVD. Using multimodal imaging, we assessed the coronary microcalcification activity (18F-sodium fluoride positron emission tomography/computed tomography [PET/CT], plaque inflammation [64Cu-DOTATATE PET/CT], and myocardial flow reserve [82Rb PET/CT]). The study population consisted of 90 participants, stratified by albuminuria; 60 had historic or current albuminuria (urine albumin-to-creatinine ratio [UACR] ≥30 mg/g]), and 30 had normoalbuminuria (UACR <30 mg/g). We demonstrated that any albuminuria (historic or current) was associated with a more severe phenotype, in particular, higher levels of microcalcifications and impaired myocardial microvascular function; however, coronary inflammation activity was similar in people with and without albuminuria. Our findings establish a potential underlying mechanism connecting cardiovascular and kidney diseases and could indicate the initial stages of the cardiorenal syndrome., (© 2024 by the American Diabetes Association.)

Background: Angiogenesis has increasingly been a target for imaging and treatment over the last decade. The integrin α v β 3 is highly expressed in cells during angiogenesis and are therefore a promising target for imaging. In this study, we aimed to investigate the PET tracer [ 68 Ga]Ga-RGD as a marker of angiogenesis following MI and its ability to predict cardiac functional parameters., Methods: First, the real-time interaction between [ 68 Ga]Ga-RGD and integrin α v β 3 was investigated using surface plasmon resonance (SPR). Second, an animal study was performed to investigate the [ 68 Ga]Ga-RGD uptake in the infarcted area after one and four weeks following MI in a rat model (MI = 68, sham surgery = 36). Finally, the specificity of the [ 68 Ga]Ga-RGD tracer was evaluated ex vivo using histology, autoradiography, gamma counting and flow cytometry., Results: SPR showed that [ 68 Ga]Ga-RGD has a high affinity for integrin α v β 3 , forming a strong and stable binding. PET/CT showed a significantly higher uptake of [ 68 Ga]Ga-RGD in the infarcted area compared to sham one week (p < 0.001) and four weeks (p < 0.001) after MI. The uptake of [ 68 Ga]Ga-RGD after one week correlated to end diastolic volume (r = 0.74, p < 0.001) and ejection fraction (r = - 0.71, p < 0.001) after four weeks., Conclusion: This study demonstrates that [ 68 Ga]Ga-RGD has a high affinity for integrin α v β 3 , which enables the evaluation of angiogenesis and remodeling. The [ 68 Ga]Ga-RGD uptake after one week indicates that [ 68 Ga]Ga-RGD may be used as an early predictor of cardiac functional parameters and possible development of heart failure after MI. These encouraging data supports the clinical translation and future use in MI patients., (© 2023. The Author(s).)

Background: Specific ceramides have been identified as risk markers for cardiovascular disease (CVD) years before onset of disease. Treatment with the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide has been shown to induce beneficial changes in the lipid profile and reduce the risk of CVD. Reducing lipotoxic lipids with an antidiabetic drug therapy could be a path towards precision medicine approaches for the treatment of complications to diabetes. In this post-hoc study, an investigation was carried out on the effect of liraglutide on CVD-risk associated ceramides in two randomized clinical trials including participants with type 2 diabetes (T2D)., Methods: This study analyzed plasma samples from two independent randomized placebo-controlled clinical trials. The first trial, Antiproteinuric Effects of Liraglutide Treatment (LirAlbu12) followed a crossover design where 27 participants were treated for 12 weeks with either liraglutide (1.8 mg/d) or placebo, followed by a four-week washout period, and then another 12 weeks of the other treatment. The second clinical trial, Effect of Liraglutide on Vascular Inflammation in Type-2 Diabetes (LiraFlame26), lasted for 26 weeks and followed a parallel design, where 102 participants were randomized 1:1 to either liraglutide or placebo. Heresix prespecified plasma ceramides were measured using liquid chromatography mass spectrometry and assessed their changes using linear mixed models. Possible confounders were assessed with mediation analyses., Results: In the LiraFlame26 trial, 26-week treatment with liraglutide resulted in a significant reduction of two ceramides associated with CVD risk, C16 Cer and C24:1 Cer (p < 0.05) compared to placebo. None of the remaining ceramides showed statistically significant changes in response to liraglutide treatment compared to placebo. Significant changes in ceramides were not found after 12-weeks of liraglutide treatment in the LirAlbu12 trial. Mediation analyses showed that weight loss did not affect ceramide reduction., Conclusions: It was demonstrated that treatment with liraglutide resulted in a reduction in C16 Cer and C24:1 Cer after 26 weeks of treatment. These findings suggest the GLP-1RA can be used to modulate ceramides in addition to its other properties., Trial Registration: Clinicaltrial.gov identifier: NCT02545738 and NCT03449654., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Purpose: The aim of this study was to assess and compare the arterial uptake of the inflammatory macrophage targeting PET tracer [ 64 Cu]Cu-DOTATATE in patients with no or known cardiovascular disease (CVD) to investigate potential differences in uptake., Methods: Seventy-nine patients who had undergone [ 64 Cu]Cu-DOTATATE PET/CT imaging for neuroendocrine neoplasm disease were retrospectively allocated to three groups: controls with no known CVD risk factors (n = 22), patients with CVD risk factors (n = 24), or patients with known ischemic CVD (n = 33). Both maximum, mean of max and most-diseased segment (mds) standardized uptake value (SUV) and target-to-background ratio (TBR) uptake metrics were measured and reported for the carotid arteries and the aorta. To assess reproducibility between different reviewers, Bland-Altman plots were made., Results: For the carotid arteries, SUV max (P = .03), SUV mds (0.05), TBR max (P < .01), TBR mds (P < .01), and mean-of-max TBR (P = .01) were overall shown to provide a group-wise difference in uptake. When measuring uptake values in the aorta, a group-wise difference was only observed with TBR mds (P = .04). Overall, reproducibility of the reported uptake metrics was excellent for SUVs and good to excellent for TBRs for both the carotid arteries and the aorta., Conclusion: Using [ 64 Cu]Cu-DOTATATE PET imaging as a marker of atherosclerotic inflammation, we were able to demonstrate differences in some of the most frequently reported uptake metrics in patients with different degrees of CVD. Measurements of the carotid artery as either maximum uptake values or most-diseased segment analysis showed the best ability to discriminate between the groups., (© 2022. The Author(s).)

An increasing number of patients are living with chronic ischemic cardiomyopathy (ICM) and/or heart failure. Treatment options and prognostic tools are lacking for many of these patients. Our aim was to investigate the prognostic value of imaging angiogenesis and macrophage activation via positron emission tomography (PET) in terms of functional improvement after cell therapy. Myocardial infarction was induced in rats. Animals were scanned with [ 18 F]FDG PET and echocardiography after four weeks and randomized to allogeneic adipose tissue-derived stromal cells (ASCs, n = 18) or saline ( n = 9). Angiogenesis and macrophage activation were assessed before and after treatment by [ 68 Ga]Ga-RGD and [ 64 Cu]Cu-DOTATATE. There was no overall effect of the treatment. Rats that improved left ventricular ejection fraction (LVEF) had higher uptake of both [ 68 Ga]Ga-RGD and [ 64 Cu]Cu-DOTATATE at follow-up ( p = 0.006 and p = 0.008, respectively). The uptake of the two tracers correlated with each other (r = 0.683, p = 0.003 pre-treatment and r = 0.666, p = 0.004 post-treatment). SUVmax at follow-up could predict improvement in LVEF ( p = 0.016 for [ 68 Ga]Ga-RGD and p = 0.045 for [ 64 Cu]Cu-DOTATATE). High uptake of [ 68 Ga]Ga-RGD and [ 64 Cu]Cu-DOTATATE PET after injection of ASCs or saline preceded improvement in LVEF. The use of these tracers could improve the monitoring of heart failure patients in treatment.

Aims: To assess cardiac angiogenesis in type 2 diabetes by positron emission tomography (PET) tracer [ 68 Ga]Ga-NODAGA-E[(cRGDyK)] 2 ( 68 Ga-RGD) imaging., Methods: Cross-sectional study including 20 persons with type 2 diabetes and 10 non-diabetic controls (CONs). Primary prespecified outcome was difference in cardiac angiogenesis (cardiac 68 Ga-RGD mean target-to-background ratio [TBR mean ]) between type 2 diabetes and CONs. Secondary outcome was to investigate associations between cardiac angiogenesis and kidney function and other risk factors., Results: Participants with type 2 diabetes had a mean ± SD age of 61 ± 9 years, 30% were women, median (IQR) diabetes duration of 11 (6-19) years and 3 (15%) had a history of cardiovascular disease. The CONs had comparable age and sex distribution to the participants with type 2 diabetes, and none had a history of coronary artery disease. Myocardial flow reserve was lower in type 2 diabetes (2.7 ± 0.6) compared with CONs (3.4 ± 1.2) ( p  = 0.03) and coronary artery calcium score was higher (562 [142-905] vs. 1 [0-150] p  = 0.04). Cardiac 68 Ga-RGD TBR mean was similar in participants with type 2 diabetes (0.89 ± 0.09) and CONs (0.89 ± 0.10) ( p  = 0.92). Cardiac 68 Ga-RGD TBR mean was not associated with estimated glomerular filtration rate, urine albumin creatinine ratio, cardiovascular disease, coronary artery calcium score or baroreflex sensitivity, neither in pooled analyses nor in type 2 diabetes., Conclusions: Cardiac angiogenesis, evaluated with 68 Ga-RGD PET, was similar in type 2 diabetes and CONs. Cardiac angiogenesis was not associated with kidney function or other risk markers in pooled analyses or in analyses restricted to type 2 diabetes., (© 2022 Diabetes UK.)

Background: Risk stratification and diagnosis using Rubidium-82 ( 82 Rb) positron emission tomography (PET) is a routine clinical approach in coronary artery disease (CAD). Various drugs are used to treat CAD; however, whether any of them change the uptake of 82 Rb in the heart has not been investigated. The aim of this study is to determine whether drugs used in treatment of CAD affect the uptake of 82 Rb in the heart in healthy rats., Methods: Seventy-seven Sprague-Dawley rats were included in the cross-sectional study. All rats underwent baseline 82 Rb PET/CT and divided into eleven groups treated with different drugs. One group was control group (no treatment), eight groups were treated with monotherapy (amiodarone, acetylsalicylic acid (ASA), clopidogrel, ticagrelor, atorvastatin, enalapril, amlodipine, metoprolol succinate), and two groups were treated with polypharmacy (ASA, ticagrelor, atorvastatin, amlodipine or ASA, clopidogrel, atorvastatin, amlodipine). Once a day, they were administered pharmacological therapy through oral gavage, and on day seven, follow-up scanned with 82 Rb PET/CT., Results: In the control group without pharmacological treatment, no difference in the standard uptake value (SUV) ratio between heart and muscle from baseline to follow-up (5.8 vs 7.0, P = .3) was found. The group treated with amiodarone had a significantly reduced SUV ratio from baseline to follow-up (5.8 vs 5.1, P = .008). All other drugs investigated had no difference in SUV ratio from baseline to follow-up., Conclusion: In this study, we showed that drugs normally used to treat CAD do not affect the uptake of 82 Rb. However, amiodarone result in a significantly lowered 82 Rb uptake, compared to control. This information about amiodarone would probably not change the size assessment of a myocardial perfusion defect in a clinical setting. However, it could change the kinetic parameters when assessing absolute myocardial blood flow in patients treated with amiodarone., (© 2021. American Society of Nuclear Cardiology.)

Background: Endogenous calcitonin gene-related peptide (CGRP) induces cardioprotective effects through coronary vasodilation. However, the systemic administration of CGRP induces peripheral vasodilation and positive chronotropic and inotropic effects. This study aims to examine the net effect on coronary perfusion of the systemically administered α-calcitonin gene-related peptide analogue, SAX, in rats during myocardial infarction., Methods: Forty Sprague-Dawley rats underwent myocardial infarction. Following left anterior descending artery occlusion, [ 99m Tc]Tc-sestamibi was administered to determine the myocardial perfusion before treatment. Twenty minutes, 24 and 48 h after [ 99m Tc]Tc-sestamibi injection, the rats were treated with either SAX or placebo. Final infarct size was determined three weeks later by [ 99m Tc]Tc-sestamibi SPECT/CT scan., Results: Thirty-one rats survived the surgery and 20 completed the follow-up SPECT/CT scan (SAX n = 12; Placebo n = 8). At baseline, there was no difference in size of perfusion defect between the groups (P = .88), but at follow-up the SAX group had improved myocardial recovery compared to the placebo group (P = .04), corresponding to a relative perfusion recovery of 55% in SAX-treated rats., Conclusion: The CGRP analogue, SAX, has a cardioprotective effect in this rat model of myocardial infarction, improving myocardial perfusion recovery after chronic occlusion of the coronary artery., (© 2021. The Author(s).)

Background: Myocardial perfusion imaging (MPI) using positron emission tomography (PET) tracers is an essential tool in investigating diseases and treatment responses in cardiology. 82 Rubidium ( 82 Rb)-PET imaging is advantageous for MPI due to its short half-life, but cannot be used for small animal research due to the long positron range. We aimed to correct for this, enabling MPI with 82 Rb-PET in rats., Methods: The effect of positron range correction (PRC) on 82 Rb-PET was examined using two phantoms and in vivo on rats. A NEMA NU-4-inspired phantom was used for image quality evaluation (%standard deviation (%SD), spillover ratio (SOR) and recovery coefficient (RC)). A cardiac phantom was used for assessing spatial resolution. Two rats underwent rest 82 Rb-PET to optimize number of iterations, type of PRC and respiratory gating., Results: NEMA NU-4 metrics (no PRC vs PRC): %SD 0.087 versus 0.103; SOR (air) 0.022 versus 0.002, SOR (water) 0.059 versus 0.019; RC (3 mm) 0.219 versus 0.584, RC (4 mm) 0.300 versus 0.874, RC (5 mm) 0.357 versus 1.197. Cardiac phantom full width at half maximum (FWHM) and full width at tenth maximum (FWTM) (no PRC vs. PRC): FWTM 6.73 mm versus 3.26 mm (true: 3 mm), FWTM 9.27 mm versus 7.01 mm. The in vivo scans with respiratory gating had a homogeneous myocardium clearly distinguishable from the blood pool., Conclusion: PRC improved the spatial resolution for the phantoms and in vivo at the expense of slightly more noise. Combined with respiratory gating, the spatial resolution achieved using PRC should allow for quantitative MPI in small animals., (© 2022. The Author(s).)

Background and Aims: The objective of this study was to investigate the effects of semaglutide, a long acting glucagon-like peptide-1 receptor agonist, on atherosclerotic inflammation and calcification using a multimodality positron emission tomography and computed tomography (PET/CT) approach., Methods: Atherosclerotic New Zealand White rabbits were randomized to an intervention- (n = 12) or placebo group (n = 11) receiving either semaglutide or saline-placebo. PET/CT imaging was done before and after 16-weeks of intervention. Three different radiotracers were used: [ 64 Cu]Cu-DOTATATE for imaging of activated macrophages, [ 18 F]FDG imaging cellular metabolism and [ 18 F]NaF PET visualizing micro-calcifications. Tracer uptake was quantified by maximum standardized uptake value (SUV max ) and target-to-background-ratio (TBR max ). Animals were euthanized for autoradiographic imaging and histological analyses., Results: A reduction in activated macrophage tracer-uptake was observed in the semaglutide group (SUV max : p = 0.001 and TBR max : p = 0.029). When imaging cellular metabolism, an attenuation of SUV max and TBR max was observed in the semaglutide group (p = 0.034 and p = 0.044). We found no difference in uptake of the micro-calcification tracer between the two groups (SUV max : p = 0.62 and TBR max : p = 0.36). Values of macrophage density in the vessel wall were significantly correlated with SUV max values of the activated macrophage (r = 0.54, p = 0.0086) and cellular metabolism tracers (r = 0.51, p = 0.013)., Conclusions: Semaglutide decreased vascular uptake of tracers imaging activated macrophages and cellular metabolism but not micro-calcifications compared to a saline placebo. This supports the hypothesis that semaglutide reduces atherosclerotic inflammation by means of decreased activated macrophage activity., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Background and Aims: Urokinase-type plasminogen activator receptor (uPAR) is associated with extracellular matrix (ECM) degradation and cancer aggressiveness. Its role in arterial atherogenesis as a molecular imaging target is not well-established. The aim of this study was to non-invasively visualize uPAR expression in atherosclerosis by a novel uPAR-targeting positron emission tomography (PET) tracer [ 64 Cu]Cu-DOTA-AE105., Methods: We used molecular biology to investigate uPAR expression by analyzing human atherosclerotic plaques and cultured cells. A retrospective analysis was performed on patients, who underwent combined PET/CT (n = 10) to measure [ 64 Cu]Cu-DOTA-AE105 uptake in five large arteries, divided into a high and low-risk group based on coronary artery calcium score (CAC score)., Results: The in vitro assay for THP-1 monocytes displayed a significantly upregulated uPAR expression upon stimulation (5.2-fold upregulation, p < 0.0001 by a one-way ANOVA followed by Tukey's test) by single-cell flowcytometric analysis. Freshly excised human atherosclerotic plaques underwent flow cytometric and microarray analyses manifesting 73.9 ± 2.9% of mononuclear phagocyte system (MPS) cells expressing uPAR and had a greater than 7-fold higher gene expression of plasminogen activator urokinase receptor (PLAUR, p = 0.002), integrin subunit alpha X (ITGAX, p = 0.0008), and cluster of differentiation 163 (CD163, p < 0.0001). The tissue-to-background ratios (TBR max ) in five large arteries showed a higher [ 64 Cu]Cu-DOTA-AE105 uptake in the group with high CAC score compared to the group with low CAC score (2.4 ± 0.1 vs 1.7 ± 0.1, p = 0.057), significantly higher in the ascending aorta (2.7 ± 0.1 vs 2.0 ± 0.1, p = 0.038) and the abdominal aorta (3.2 ± 0.2 vs 2.0 ± 0.2, p = 0.038) by a non-parametric Mann-Whitney test., Conclusions: uPAR is abundantly expressed by MPS cells in atherosclerotic plaques and can be visualized by the novel PET tracer [ 64 Cu]Cu-DOTA-AE105 that may non-invasively detect extracellular matrix remodeling during atherogenesis., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Liraglutide is a glucose-lowering medication used to treat type 2 diabetes and obesity. It is a GLP-1 receptor agonist with downstream metabolic changes beyond the incretin system, such as reducing the risk of cardiovascular complications. The understanding of these changes is critical for improving treatment outcomes. Herein, we present a post hoc experimental analysis using metabolomic phenotyping to discover molecular mecphanisms in response to liraglutide., Method: Plasma samples were obtained from The LiraFlame Study (ClinicalTrials.gov identifier: NCT03449654), a randomized double-blinded placebo-controlled clinical trial, including 102 participants with type 2 diabetes randomized to either liraglutide or placebo treatment for 26 weeks. Mass spectrometry-based metabolomics analyses were carried out on samples from baseline and the end of the trial. Metabolites (n=114) were categorized into pathways and linear mixed models were constructed to evaluate the association between changes in metabolites and liraglutide treatment., Results: We found the free fatty acid palmitoleate was significantly reduced in the liraglutide group compared to placebo (adjusted for multiple testing p-value = 0.04). The activity of stearoyl-CoA desaturase-1 (SCD1), the rate limiting enzyme for converting palmitate into palmitoleate, was found significantly downregulated by liraglutide treatment compared to placebo (p-value = 0.01). These metabolic changes have demonstrated to be linked to insulin sensitivity and cardiovascular health., Competing Interests: EZ and BS are now employees of Novo Nordisk A/S, work related to this article was done when EZ was employed by Steno Diabetes Center Copenhagen. TH, RR, and PR have shares in Novo Nordisk A/S. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wretlind, Zobel, de Zawadzki, Ripa, Curovic, von Scholten, Mattila, Hansen, Kjær, Vestergaard, Rossing and Legido-Quigley.)

Background: The mechanisms linking cardiovascular autonomic neuropathy, diabetic kidney disease and cardiovascular mortality in type 2 diabetes are widely unknown. We investigated the relationship between baseline cardiovascular autonomic function and changes in kidney and myocardial function over six years in patients with type 2 diabetes and healthy controls., Methods: Post-hoc analysis of a cohort study in 24 patients with type 2 diabetes and 18 healthy controls. Baseline determinants were cardiovascular autonomic reflex tests (heart rate response to: standing (30:15); deep breathing (E:I); and the Valsalva test) and time- and frequency-domain heart rate variability indices. Outcomes were changes in estimated glomerular filtration rate (eGFR), albuminuria, myocardial flow reserve (MFR) measured by cardiac 82 Rb Positron emission tomography computed tomography (PET/CT), and coronary artery calcium score (CACS)., Results: Mean age at inclusion was 61 ± 10 years and 36% were female. Mean follow up time was 6 ± 0 years. A lower response in heart rate to the Valsalva test (corresponding to weaker autonomic function) was associated with a larger decline in eGFR (p=0.04), but not significantly after adjustment for sex, baseline age, smoking status, systolic blood pressure, heart rate, HbA 1c , body mass index and baseline eGFR (p=0.12). A higher baseline response in heart rate to standing (30:15) was associated with a larger decline in myocardial flow reserve in the unadjusted analysis (p=0.02) and after adjustment (p=0.02). A higher response in heart rate to the Valsalva maneuver was associated with a larger increase in CACS (p = 0.02), but the association became insignificant after adjustment (p = 0.16)., Conclusion: A lower response in heart rate to the Valsalva test was associated with a larger decline in kidney function, indicating that autonomic dysfunction may predict future loss of kidney function. However, we did not find any association between lower values in cardiovascular autonomic function at baseline and a worsening in albuminuria, myocardial function, or atherosclerotic burden., Competing Interests: PR reports having received research grants from Astra Zeneca and Novo Nordisk and given lectures for Astra Zeneca, Mundipharma and Boehringer Ingelheim and has served as a consultant for Astra Zeneca, Bayer, Eli Lilly, Boehringer Ingelheim, Astellas, Gilead, Sanofi Aventis Vifor, and Novo Nordisk, all fees given to Steno Diabetes Center. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Laursen, Rasmussen, Zobel, Hasbak, von Scholten, Holmvang, Ripa, Hansen, Frimodt-Moeller, Kjaer, Rossing and Hansen.)

Aim: To test the hypothesis that treatment with liraglutide can reduce cardiac adipose tissue., Materials and Methods: LIRAFLAME is a randomized placebo-controlled, double-blind, parallel clinical study. Participants with type 2 diabetes were randomized to treatment with liraglutide 1.8 mg/d or placebo for 26 weeks. Computed tomography was performed at baseline and at end of treatment to evaluate the cardiac adipose tissue volume, quantified automatically. We report the results of a secondary endpoint evaluating changes in cardiac adipose tissue., Results: A total of 102 participants were randomly assigned to liraglutide (n = 51) or placebo (n = 51). At baseline, the mean (SD) cardiac adipose tissue volume was comparable between the liraglutide and the placebo group (232.6 [112.8] vs. 227.0 [103.2] mL; P = 0.80). The mean change in body weight was -3.7 (-4.8, -2.6) kg in the liraglutide and -0.18 (-0.76, 0.40) kg in the placebo group. From baseline to end of treatment the mean cardiac adipose tissue change was -11.5 (95% confidence interval -17.6, -5.4) mL in the liraglutide (P < 0.001) and -0.01 (-5.3, 5.3) mL in the placebo (P = 1.00) groups. The reduction in cardiac adipose tissue was significantly greater in the liraglutide compared to the placebo group (mean difference -11.4 [-19.4, -3.3] mL; P = 0.006), but significance was lost after adjustment for changes in body mass index (P = 0.46)., Conclusion: Treatment with liraglutide for 26 weeks was associated with a reduction in cardiac adipose tissue compared to placebo. The reduction was not independent of weight loss, suggesting that this is not a drug-specific effect., (© 2021 John Wiley & Sons Ltd.)

Background: Quantification of coronary artery inflammation and atherosclerosis remains a challenge in high-risk individuals. In this study we sought to investigate if the glucagon like peptide-1 receptor agonist liraglutide has a direct anti-inflammatory effect in the coronary arteries using positron emission tomography (PET) with a radioactive tracer targeting activated macrophages in the vessel-wall., Methods: Thirty randomly selected participants with type 2 diabetes from the placebo-controlled trial LIRAFLAME were enrolled in this sub-study. Participants were, prior to enrollment in this sub-study, randomized to either treatment with daily liraglutide (n=15) or placebo (n=15). Both groups underwent a combined [ 64 Cu]Cu-DOTATATE positron emission tomography and computed tomography scan of the heart at baseline and after 26 weeks of treatment. Coronary artery uptake of [ 64 Cu]Cu-DOTATATE were measured as maximum standardized uptake values (SUV max ); and means of the maximum values (mSUV max ), both values were calculated at the level of each participant and each individual coronary-segment., Results: SUV max and mSUV max values decreased significantly in the liraglutide group both at the participant level (SUV max : p=0.013; mSUV max : p=0.004) and at the coronary-segment level (SUV max : p=0.001; mSUV max : p<0.0001). No change was observed in the placebo group neither at the participant level (SUV max : p=0.69; mSUV max : p=0.67) or at the coronary-segment level (SUV max : p=0.49; mSUV max : p=0.30). When comparing the mean change in uptake values between the two groups at both the participant level (SUV max : p=0.076; mSUV max : p=0.077) and the coronary segment level (SUV max : p=0.13; mSUV max : p=0.11) a borderline significant difference was observed. Baseline SUV max [ 64 Cu]Cu-DOTATATE uptake values showed a weak positive correlation with the inflammatory biomarker high-sensitivity c-reactive protein (τ =0.26, p=0.045)., Conclusion: Liraglutide treatment for 26-weeks caused a significant reduction in [ 64 Cu]Cu-DOTATATE uptake in the coronary arteries whereas this was not seen in the placebo treated group. In addition, [ 64 Cu]Cu-DOTATATE PET/CT as a marker of coronary inflammation correlated with the systemic inflammation marker hs-CRP., Competing Interests: AK has received consultancy fees from Novo Nordisk and is an inventor on a patent of [64Cu]Cu-DOTATATE. RR, BS, TH, and PR have shares in Novo Nordisk A/S. BS and EZ are now employees of Novo Nordisk A/S. PR has received the following: Consultancy and/or speaking fees (to Steno Diabetes Center Copenhagen) from AbbVie, Astellas, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lilly, MSD, Novo Nordisk and Sanofi Aventis; Research grants to institution from AbbVie, AstraZeneca and Novo Nordisk. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Jensen, Zobel, von Scholten, Rotbain Curovic, Hansen, Rossing, Kjaer and Ripa.)

Mesenchymal stromal cells have proven capable of improving cardiac pump function in patients with chronic heart failure, yet little is known about their mode of action. The aim of the study was to investigate the short-term effect of cryopreserved allogeneic rat adipose tissue-derived stromal cells (ASC) on cardiac composition, cellular subpopulations, and gene transcription in a rat model of chronic ischemic cardiomyopathy (ICM). Myocardial infarction (MI) was induced by permanent ligation of the left anterior descending coronary artery. After 6 weeks, the rats were treated with ASCs, saline, or no injection, using echo-guided trans-thoracic intramyocardial injections. The cardiac tissue was subsequently collected for analysis of cellular subpopulations and gene transcription 3 and 7 days after treatment. At day 3, an upregulation of genes associated with angiogenesis were present in the ASC group. On day 7, increases in CCR2 + and CD38 + macrophages ( p = 0.047 and p = 0.021), as well as in the CD4/CD8 lymphocyte ratio ( p = 0.021), were found in the ASC group compared to the saline group. This was supported by an upregulation of genes associated with monocytes/macrophages. In conclusion, ASC treatment initiated an immune response involving monocytes/macrophages and T-cells and induced a gene expression pattern associated with angiogenesis and monocyte/macrophage differentiation.

Anti-inflammatory effects of glucagon-like peptide 1 receptor agonist (GLP-1 RA) treatment in T2D may contribute to the cardiovascular benefits observed with GLP-1 RAs in outcome studies. We investigated if the GLP-1 RA liraglutide exerts anti-inflammatory effects through modulation of inflammatory gene expression in peripheral blood mononuclear cells (PBMCs). From 54 participants of a double-blinded trial where individuals with type 2 diabetes (T2D) were randomized to liraglutide (1.8 mg/day) or placebo for 26 weeks, a sub-study was performed in which PBMCs were extracted from fresh blood at study start and at end-of-treatment. The expression of selected inflammatory genes in PBMCs were measured by quantitative real-time polymerase chain reaction (PCR). Moreover, the expression of the GLP-1 receptor (GLP1R) was examined in a subset (n = 40) of the PBMC samples. The human monocytic cell line THP-1 was used for in vitro GLP-1 exposure experiments. The expression of tumor necrosis factor-α (TNFA) (p = 0.004) and interleukin-1β (IL1B) was downregulated (p = 0.046) in the liraglutide-treated group (n = 31), and unchanged in the placebo group (n = 21, p ≥ 0.11), with no significant differences between the two groups (p ≥ 0.67). The expression of interferon-γ (IFNG) and cluster of differentiation 163 (CD163) were upregulated in both groups (p ≤ 0.006) with no differences between groups (p ≥ 0.47). C-C Motif Chemokine Ligand 5 (CCL5) was upregulated in the liraglutide-treated group (p = 0.002) and unchanged in the placebo group (p = 0.14), with no significant difference between groups (p = 0.36). Intercellular adhesion molecule 1 (ICAM1) was unchanged in both groups (p ≥ 0.43). GLP1R expression in the PBMCs was undetectable. In vitro experiments showed no effect of GLP-1 treatment on inflammatory gene expression in THP-1 cells. GLP1R expression in THP-1 cells was not detectable. In summary, we observed a discrete modulatory effect of liraglutide on the expression of inflammatory genes in PBMCs. The lack of evidence for GLP1R expression in PBMCs and THP-1 cells suggests that possible effects of liraglutide on the PBMCs' gene expression are most likely indirect. Further investigations are needed to establish the anti-inflammatory potential of GLP-1 RAs., (© 2021. The Author(s).)

Introduction: Treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) can reduce risk of cardiovascular disease (CVD) in persons living with type 2 diabetes, however the mechanisms explaining this cardiovascular benefit are still debated. We investigated changes in the plasma lipidome following treatment with the GLP-1 RA liraglutide., Research Design and Methods: In a double-blind placebo-controlled trial, we randomized 102 persons with type 2 diabetes to liraglutide or placebo for 26 weeks. Fasting blood plasma was collected at baseline and at end-of-treatment. The lipidome was measured using liquid-chromatography-coupled mass-spectrometry as a secondary end point in the study. Treatment response of each lipid was tested with lipid-specific linear mixed-effect models comparing liraglutide with placebo. Bonferroni p<7.1e-03 was employed. The independence of the findings from clinical covariates was evaluated with adjustment for body mass index, HbA 1c , fasting status, lipid-lowering treatment and change in lipid-lowering treatment during the trial., Results: In total, 260 lipids were identified covering 11 lipid families. We observed significant decreases following liraglutide treatment compared with placebo in 21 lipids (p<7.1e-03) from the following lipid families: ceramides, hexocyl-ceramides, phosphatidylcholines, phosphatidylethanolamines and triglycerides. We confirmed these findings in adjusted models (p≤0.01). In the liraglutide-treated group, the individual lipids were reduced in the range of 14%-61% from baseline level, compared with 19% decrease to 27% increase from baseline level in the placebo group., Conclusions: Compared with placebo, liraglutide treatment led to a significant downregulation in ceramides, phospholipids and triglycerides, which all are linked to higher risk of CVD. These findings were independent of relevant clinical covariates. Our findings are hypothesis generating and shed light on the biological mechanisms underlying the cardiovascular benefits observed with GLP-1 RAs in outcome studies, and further strengthen the evidence base for recommending GLP-1 RAs to prevent CVD in type 2 diabetes., Trial Registration Number: NCT03449654., Competing Interests: Competing interests: AW, VRC, TS and CL-Q declares no competing interests. AK has received consultancy fees from Novo Nordisk. RSR, BJvS, TWH and PR have shares in Novo Nordisk and BJvS and EHZ is now an employee of Novo Nordisk, but work related to this article was conducted while EHZ was employed by Steno Diabetes Center Copenhagen. PR has received the following: consultancy and/or speaking fees (to Steno Diabetes Center Copenhagen) from AbbVie, Astellas, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lilly, MSD, Novo Nordisk and Sanofi Aventis; research grants to institution from AbbVie, AstraZeneca and Novo Nordisk., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Quantification of vascular inflammation before and after treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may help reveal mechanistic pathways underlying the cardiovascular benefits of these drugs. We assessed change in vascular inflammation in the carotid arteries over 26 weeks by copper-64-labeled [1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid]-D-Phe1, Tyr3-octreotate ([ 64 Cu]DOTATATE) PET in 30 participants included in a substudy of a double-blind trial where persons with type 2 diabetes (T2D) were randomized to liraglutide ( n = 15) or placebo ( n = 15) for 26 weeks. Mean age (SD) was 66.4 (7.2) years, HbA 1c 56.4 (9.2) mmol/mol and BMI 28.9 (4.6) kg/m 2 . Weight and HbA 1c were significantly reduced by liraglutide vs. placebo ( p ≤ 0.01). The [ 64 Cu]DOTATATE uptake (mean standardized uptake values) was significantly reduced in the liraglutide-treated group (-0.11 [95% confidence interval -0.19 to -0.03], p = 0.01) and not changed significantly in the placebo group (-0.07 [-0.14 to 0.01], p = 0.08). The mean difference between groups did not reach significance (-0.04 [-0.15 to 0.07], p = 0.44). In conclusion, [ 64 Cu]DOTATATE uptake was reduced in persons with T2D treated with liraglutide. However, the reduction compared to placebo did not reach statistical significance, perhaps due to limited power. A reduction in vascular inflammation with liraglutide could help explain the cardiovascular protection observed with GLP-1 RAs in outcome studies but warrants further and larger studies.

Background: The mechanism behind the cardiovascular protection observed with human GLP-1 RA (glucagon-like peptide-1 receptor agonists) in type 2 diabetes is unknown. We hypothesized that treatment with the GLP-1 RA liraglutide had a positive effect on vascular inflammation., Methods: LIRAFLAME (Effect of liraglutide on vascular inflammation in type-2 diabetes: A randomized, placebocontrolled, double-blind, parallel clinical PET/CT trial) was a double-blind, randomized controlled trial performed at a single university hospital clinic in Denmark. Patients with type 2 diabetes were via computer-generated randomization list assigned (1:1) liraglutide up to 1.8 mg or placebo once daily for 26 weeks. The primary end point was change in vascular inflammation over 26 weeks assessed by [ 18 F]-fluorodeoxyglucose positron emission tomography/computed tomography. Analyses were based on intention-to-treat. Key secondary outcomes included change in other indices of atherosclerosis., Results: Between October 26, 2017, and August 16, 2019, 147 patients were screened and 102 were randomly assigned to liraglutide (n=51) or placebo (n=51) and 99 (97%) completed the trial. Change in the [ 18 F]-fluorodeoxyglucose positron emission tomography measure of vascular inflammation (active-segment target-to-background ratio) did not differ between treatment groups: change from baseline to 26 weeks was -0.04 (95% CI, -0.17 to 0.08) in the liraglutide group compared with -0.09 (-0.19 to 0.01) in the placebo group (mean difference, 0.05 [95% CI, -0.11 to 0.21], P =0.53). Secondary analyses restricted to [ 18 F]-fluorodeoxyglucose positron emission tomography of the carotid arteries as well as other indices of atherosclerosis confirmed the primary result. We performed an explorative analysis of interaction between treatment group and history of cardiovascular disease ( P =0.052)., Conclusions: In this low to moderate risk population with type 2 diabetes, liraglutide did not change vascular inflammation assessed as [ 18 F]-fluorodeoxyglucose uptake compared with placebo. An explorative analysis indicated a possible effect in persons with history of cardiovascular disease, in line with current guidelines where liraglutide is recommended to patients with history of cardiovascular disease. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03449654.

Background: Cardiac Rubidium-82 ( 82 Rb) positron emission tomography/computed tomography (PET/CT) provides a measure of the myocardial blood flow and the myocardial flow reserve, which reflects the function of both large epicardial arteries and the myocardial microcirculation. Knowledge on changes in the myocardial microvascular function over time is lacking., Methods: In this cohort study, we recruited 60 persons with type 2 diabetes and 30 non-diabetic controls, in 2013; all free of overt cardiovascular disease. All underwent a cardiac 82 Rb PET/CT scan. In 2019, all survivors (n = 82) were invited for a repeated cardiac 82 Rb PET/CT scan using the same protocol, and 29 with type 2 diabetes and 19 controls participated., Results: Median duration between visits was 6.2 years (IQR: 6.1-6.3). In the total cohort, the mean age was 66.4 years (SD: 9.3) and 33% were females. The myocardial flow reserve was lower in persons with type 2 diabetes compared to controls (p = 0.002) but there was no temporal change in the myocardial flow reserve in participants with type 2 diabetes: mean change: -0.22 (95% CI: -0.47 to 0.02) nor in controls: -0.12 (-0.49 to 0.25) or when comparing type 2 diabetes to controls: mean difference: -0.10 (95% CI: -0.52 to 0.31). The temporal reduction in stress-induced myocardial blood flow did not differ within the groups but was more pronounced in type 2 diabetes compared to controls: mean difference: -0.30 (95% CI: -0.55 to -0.04)., Conclusion: The myocardial microvascular function was impaired in persons with type 2 diabetes compared to controls but did not change significantly in either of the groups when evaluated over 6 years., (© 2021 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.)

Background: Atherosclerotic plaque vulnerability is comprised by plaque composition driven by inflammatory activity and these features can be depicted with 3D ultrasound and 2-[18F]FDG-PET, respectively. The study investigated timely changes in carotid artery plaque inflammation and morphology after a thromboembolic event with PET/CT and novel ultrasound volumetric grayscale median (GSM) readings. Patients with a single hemisphere-specific neurological symptom and the presence of an ipsilateral carotid artery atherosclerotic plaque were prospectively included to both 2-[18F]FDG PET/CT and 3D ultrasound scans of the plaque immediately after their event and again three months later. On PET/CT images the maximum standardized uptake value (SUV max ) was measured and the volumetric ultrasound acquisitions were analyzed using a semiautomated software measuring GSM values., Results: Baseline scans were performed by a mean of 7 days (range 2-14) after the symptom and again after 98 days (range 91-176). For the entire group (n = 14), we found a decrease in average SUV max from baseline to follow-up of - 0.18 (95% confidence interval: - 0.34 to - 0.02, P = 0.034). GSM did not increase significantly over time (mean change: + 2.21, 95% confidence interval: - 17.02 to 21.44, P = 0.808)., Conclusion: A decrease in culprit lesion 2-[18F]FDG-uptake 3 months after an event indicates a decrease in inflammatory activity, suggesting that carotid plaque stabilization over time. 3D ultrasound morphological quantitative differences in GSM were not detectable after 3 months.

Angiogenesis is involved in regeneration of cardiac tissue following acute myocardial infarction (MI), a disease often investigated in rat models. Therefore, the ability to thoroughly evaluate the angiogenic response following experimentally induced MI in rats, and distinguish it from inflammation, is desired. This would enable evaluation of the angiogenic potential of new therapeutics and improve knowledge on MI pathophysiology. Due to the complex response to MI involving multiple cell types and the limited selection of rat-specific antibodies, careful optimization is crucial to capture this complexity. Here, we present an 8-color flow cytometry-based multicolor panel that will enable quantification of the ongoing angiogenic response as well as characterize the cells involved. A detailed description of tissue preparation, immunostaining, and gating strategy is provided. © 2021 Wiley Periodicals LLC. Basic Protocol: Cardiac tissue preparation and staining to investigate the ongoing angiogenic response in rat cardiac tissue following myocardial infarction Support Protocol: Titration of all antibodies in the presented panel., (© 2021 Wiley Periodicals LLC.)

Background: Doxorubicin is a cornerstone in lymphoma treatment, but is limited by dose-dependent cardiotoxicity. Rubidium-82 positron emission tomography ( 82 Rb PET) assesses coronary microvascular function through absolute quantification of myocardial perfusion and myocardial perfusion reserve (MPR). Doxorubicin-induced microvascular injury represents a potential early marker of cardiotoxicity., Methods and Results: We included 70 lymphoma patients scheduled for doxorubicin-based treatment. Cardiotoxicity was evaluated with 82 Rb PET myocardial perfusion imaging during rest and adenosine stress before chemotherapy and shortly after the first doxorubicin exposure. Patients with a MPR decline > 20% were defined as having a low threshold for cardiotoxicity. In the 54 patients with complete data sets, MPR was significantly lower after the initial doxorubicin exposure (2.69 vs 2.51, P = .03). We registered a non-significant decline in stress perfusion (3.18 vs 3.02 ml/g/min, P = .08), but no change in resting myocardial perfusion. There were 13 patients with a low cardiotoxic threshold. These patients had a significantly higher age, but were otherwise similar to the remaining part of the study population., Conclusion: Decreases in MPR after initial doxorubicin exposure in lymphoma patients may represent an early marker of doxorubicin-induced cardiotoxicity. The prognostic value of acute doxorubicin-induced changes in MPR remains to be investigated.

Background: Doxorubicin is the mainstay of curative lymphoma treatment but is associated with a dose-dependent cardiotoxicity that is often recognized too late to avoid substantial irreversible cardiac injury. Iodine-123 metaiodobenzylguanidine ( 123 I-MIBG) is a gamma-emitting tracer that mimics noradrenaline uptake, storage, and release mechanisms in adrenergic presynaptic neurons. 123 I-MIBG scintigraphy can be used for assessment of doxorubicin-induced injury to myocardial adrenergic neurons during treatment and could be the tool for early detection of doxorubicin cardiotoxicity, which is currently lacking., Methods and Results: A total of 37 lymphoma patients scheduled for doxorubicin treatment were included in our study. 123 I-MIBG imaging was performed prior to chemotherapy and after a median of 4 cycles of doxorubicin. Early and late heart-to-mediastinum ratios (H/M early and H/M late ) and washout rate (WOR) were used for evaluation of cardiotoxicity. The prognostic value of 123 I-MIBG results was assessed using left ventricular ejection fraction (LVEF) as measured by cardiac magnetic resonance at 1-year follow-up. We found a post-therapy increase in WOR (including nine patients with > 10% increase), which was not statistically significant (18.6 vs 23.4%, P = 0.09). The difference appeared to be driven by an increase in H/M early . LVEF decreased from baseline to 1-year follow-up (64 vs 58%, P = 0.03). LVEF change was not associated with changes in WOR (P = 0.5)., Conclusion: The present study does not provide evidence for 123 I-MIBG imaging as a clinically applicable tool for early detection of doxorubicin-induced cardiotoxicity.

Aims: We have shown that 14q32 microRNAs are highly involved in vascular remodelling and cardiovascular disease. However, the 14q32 locus also encodes 41 'orphan' small nucleolar RNAs (snoRNAs). We aimed to gather evidence for an independent role for 14q32 snoRNAs in human cardiovascular disease., Methods and Results: We performed a lookup of the 14q32 region within the dataset of a genome wide association scan in 5244 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Single nucleotide polymorphisms (SNPs) in the snoRNA-cluster were significantly associated with heart failure. These snoRNA-cluster SNPs were not linked to SNPs in the microRNA-cluster or in MEG3, indicating that snoRNAs modify the risk of cardiovascular disease independently. We looked at expression of 14q32 snoRNAs throughout the human cardio-vasculature. Expression profiles of the 14q32 snoRNAs appeared highly vessel specific. When we compared expression levels of 14q32 snoRNAs in human vena saphena magna (VSM) with those in failed VSM-coronary bypasses, we found that 14q32 snoRNAs were up-regulated. SNORD113.2, which showed a 17-fold up-regulation in failed bypasses, was also up-regulated two-fold in plasma samples drawn from patients with ST-elevation myocardial infarction directly after hospitalization compared with 30 days after start of treatment. However, fitting with the genomic associations, 14q32 snoRNA expression was highest in failing human hearts. In vitro studies show that the 14q32 snoRNAs bind predominantly to methyl-transferase Fibrillarin, indicating that they act through canonical mechanisms, but on non-canonical RNA targets. The canonical C/D-box snoRNA seed sequences were highly conserved between humans and mice., Conclusion: 14q32 snoRNAs appear to play an independent role in cardiovascular pathology. 14q32 snoRNAs are specifically regulated throughout the human vasculature and their expression is up-regulated during cardiovascular disease. Our data demonstrate that snoRNAs merit increased effort and attention in future basic and clinical cardiovascular research., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Background: Small-animal myocardial infarct models are frequently used in the assessment of new cardioprotective strategies. A validated quantification of perfusion using a non-cyclotron-dependent PET tracer would be of importance in monitoring response to therapy. We tested whether myocardial PET perfusion imaging is feasible with Rubidium-82 ( 82 Rb) in a small-animal scanner using a rat myocardial infarct model., Methods: 18 Sprague-Dawley rats underwent permanent coronary artery ligation (infarct group), and 11 rats underwent ischemia-reperfusion (reperfusion group) procedure. 82 Rb-PET and magnetic resonance imaging (MRI) were conducted before and after the intervention. Perfusion was compared to both left ventricle ejection fraction (LVEF) and infarct size assessed by MRI., Results: Follow-up global 82 Rb-uptake correlated significantly with infarct size (infarct group: r = -0.81, P < 0.001 and reperfusion group: r = -0.61, P = 0.04). Only 82 Rb-uptake in the infarct group correlated with LVEF. At follow-up, a higher segmental 82 Rb-uptake in the infarct group was associated with better wall motion (β = 0.034, CI [0.028;0.039], P < 0.001, R 2  = 0.30), and inversely associated with scar transmurality (β = -2.4 [-2.6; -2.2], P < 0.001, R 2  = 0.59). The associations were similar for the reperfusion group., Conclusion: 82 Rb-PET is feasible in small animal scanners despite the long positron range and enables fast and time-efficient myocardial perfusion imaging in rat models.

Background and Aims: The advantage of combining molecular and morphological imaging, e.g. positron emission tomography and magnetic resonance imaging (PET/MRI), is reflected in the increased use of these modalities as surrogate end-points in clinical trials. This study aimed at evaluating plaque inflammation using 18 F-fluorodeoxyglucose ( 18 F-FDG)-PET/MRI, and gene expression in a minipig model of atherosclerosis., Methods: Göttingen Minipigs were fed for 60 weeks with fat/fructose/cholesterol-rich diet (FFC), chow (Control) or FFC-diet changed to chow midway (diet normalization group; DNO). In all groups, 18 F-FDG-PET/MRI of the abdominal aorta was assessed midway and at study-end. The aorta was analyzed using histology and gene expression., Results: At study-end, FFC had significantly higher FDG-uptake compared to Control (target-to-background maximal uptake, TBR Max (95% confidence interval) CI TBRMax : 0.092; 7.32) and DNO showed significantly decreased uptake compared to FFC (CI TBRMax : -5.94;-0.07). No difference was observed between DNO and Control (CI TBRMax : -2.71; 4.11). FFC displayed increased atherosclerosis and gene expression of inflammatory markers, including vascular cell adhesion molecule 1 (VCAM-1), cluster of differentiation 68 (CD68), matrix metalloproteinase 9 (MMP9), cathepsin K (CTSK) and secreted phosphoprotein 1 (SPP1) compared to Control and DNO (all, p < 0.05). FDG-uptake correlated with gene expression of inflammatory markers, including CD68, ρ s  = 0.58; MMP9, ρ s  = 0.46; SPP1, ρ s  = 0.44 and CTSK, ρ s  = 0.49; (p ≤ 0.01 for all)., Conclusions: In a model of atherosclerosis, 18 F-FDG-PET/MRI technology allows for detection of inflammation in atherosclerotic plaques, consistent with increased inflammatory gene expression. Our findings corroborate clinical data and are important in pre-clinical drug development targeting plaque inflammation., (Copyright © 2019. Published by Elsevier B.V.)

Background: Assessment of infarct size after myocardial infarction is predictive of subsequent morphological changes and clinical outcome. This study aimed to assess subacute post-intervention Rubidium-82 ( 82 Rb)-PET imaging in predicting left ventricle ejection fraction, regional wall motion, and final infarct size by CMR at 3-months after STEMI., Methods: STEMI patients undergoing percutaneous coronary intervention were included prospectively. Rest-only 82 Rb-PET perfusion imaging was performed at median 36 hours [IQR: 22 to 50] after the treatment. The extent of hypoperfusion and absolute blood flow (mL·min·g) were estimated on a global and a 17-segment model with dedicated software. At 3-months follow-up patients completed the CMR functional and late gadolinium enhancement imaging., Results: 42 patients were included, but only 35 had follow-up CMR and constituted the study population. Absolute blood flow was significantly lower in the infarct-related territory compared to remote myocardium, P < .005. Extent of hypoperfusion correlated with final infarct size, r = 0.58, P < .001, while blood flow correlated with ejection fraction, r = 0.41, P < .05. In linear mixed models, higher subacute absolute blood flow (β = 4.6, confidence interval [3.5; 5.2], P < .001, R 2  = 0.67) was associated with greater wall motion. Segmental extent of subacute hypoperfusion (β = 0.43 [0.38; 0.49], P < .001, R 2  = 0.58) was associated with the degree of late gadolinium enhancement at 3-months., Conclusions: Subacute rest-only 82 Rb-PET is feasible following STEMI and seems predictive of myocardial function and infarct size at 3-months.

Background: People living with HIV (PLWH) appear to be at increased risk of cardiovascular disease (CVD), and this is possibly more pronounced in women living with HIV (WLWH). In the general population, men are more likely to develop obstructive coronary artery disease (CAD), and women often present with a nonobstructive pattern with cardiac microvascular dysfunction. We investigated cardiac microvascular function in men and women living with HIV and tested for association with cytomegalovirus (CMV) immunoglobulin G (IgG), as this has been associated with CVD in PLWH., Methods: In a cross-sectional study, 94 PLWH on antiretroviral therapy were scanned with 82 Rb positron emission tomography/computed tomography at rest and during adenosine-induced stress, which enables the quantification of the myocardial flow reserve (MFR). CMV IgG was measured in plasma., Results: WLWH had significantly lower MFR compared with men living with HIV (MLWH; P = .003), and >45% of the women had an MFR indicative of cardiac microvascular dysfunction, whereas this was only true for 24% of men ( P = .03). CMV IgG concentrations were inversely associated with MFR among WLWH but not MLWH ( P = .05 for interaction)., Conclusions: In this first study comparing MFR in women and men living with HIV, we found that WLWH had significantly lower MFR than MLWH and 45% of the women had cardiac microvascular dysfunction despite younger age and lower cardiovascular risk. Furthermore, CMV IgG was inversely associated with MFR among women but not men. This calls for attention to CVD among young WLWH even with low cardiovascular risk.

Background: Determining infarct size and myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) is important when assessing the efficacy of new reperfusion strategies. We investigated whether rest 82 Rb-PET myocardial perfusion imaging can estimate area at risk, final infarct size, and myocardial salvage index when compared to cardiac SPECT and magnetic resonance (CMR)., Methods: Twelve STEMI patients were injected with 99m Tc-Sestamibi intravenously immediate prior to reperfusion. SPECT, 82 Rb-PET, and CMR imaging were performed post-reperfusion and at a 3-month follow-up. An automated algorithm determined area at risk, final infarct size, and hence myocardial salvage index., Results: SPECT, CMR, and PET were performed 2.2 ± 0.5, 34 ± 8.5, and 32 ± 24.4 h after reperfusion, respectively. Mean (± SD) area at risk were 35.2 ± 16.6%, 34.7 ± 11.3%, and 28.1 ± 16.1% of the left ventricle (LV) in SPECT, CMR, and PET, respectively, P = 0.04 for difference. Mean final infarct size estimates were 12.3 ± 15.4%, 13.7 ± 10.4%, and 11.9 ± 14.6% of the LV in SPECT, CMR, and PET imaging, respectively, P = .72. Myocardial salvage indices were 0.64 ± 0.33 (SPECT), 0.65 ± 0.20 (CMR), and 0.63 ± 0.28 (PET), (P = .78)., Conclusions: 82 Rb-PET underestimates area at risk in patients with STEMI when compared to SPECT and CMR. However, our findings suggest that PET imaging seems feasible when assessing the clinical important parameters of final infarct size and myocardial salvage index, although with great variability, in a selected STEMI population with large infarcts. These findings should be confirmed in a larger population.

Background: Cell therapy for heart disease has been proven safe and efficacious, despite poor cell retention in the injected area. Improving cell retention is hypothesized to increase the treatment effect. In the present study, human adipose-derived stromal cells (ASCs) were delivered in an in situ forming alginate hydrogel following acute myocardial infarction (AMI) in rats., Methods: ASCs were transduced with luciferase and tested for ASC phenotype. AMI was inducted in nude rats, with subsequent injection of saline (controls), 1 × 10 6 ASCs in saline or 1 × 10 6 ASCs in 1% ( w / v ) alginate hydrogel. ASCs were tracked by bioluminescence and functional measurements were assessed by magnetic resonance imaging (MRI) and 82 rubidium positron emission tomography (PET)., Results: ASCs in both saline and alginate hydrogel significantly increased the ejection fraction (7.2% and 7.8% at 14 days and 7.2% and 8.0% at 28 days, resp.). After 28 days, there was a tendency for decreased infarct area and increased perfusion, compared to controls. No significant differences were observed between ASCs in saline or alginate hydrogel, in terms of retention and functional salvage., Conclusion: ASCs improved the myocardial function after AMI, but administration in the alginate hydrogel did not further improve retention of the cells or myocardial function.

Due to improvements in early detection and treatment of malignant disease, the population of cancer survivors is constantly expanding. Cancer survivors are faced with chemotherapy-related long-term side effects, including irreversible cardiac injury with risk of heart failure (HF). Numerous antineoplastic regimens are associated with risk of cardiac side effects, but anthracyclines in particular carry a severe risk of cardiotoxicity. Currently, serial echocardiographic evaluation of resting left ventricular ejection fraction (LVEF) is the gold standard for monitoring anthracycline-induced cardiac side effects from chemotherapy. LVEF measurements are, however, limited by their low sensitivity. A normal LVEF does not exclude cardiotoxicity and declines in LVEF are usually not observed before the occurrence of irreversible cardiomyopathy. Hence, a clinically applicable high-sensitivity diagnostic tool for early detection of chemotherapy-related cardiotoxicity is still lacking and alternative non-invasive imaging modalities are therefore being investigated. 123 I-MIBG is a noradrenaline (NA) analogue used for evaluation of cardiac adrenergic function, including assessment of HF prognosis and evaluation of HF treatment response. However, the role of 123 I-MIBG for monitoring chemotherapy-related cardiotoxicity is still unclear. Here, we review the value of 123 I-MIBG imaging for early detection and prevention of anthracycline-induced cardiomyopathy., (© 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.)

For imaging of atherosclerotic disease, lumenography using computed tomography, ultrasonography, or invasive angiography is still the backbone of evaluation. However, these methods are less effective to predict the likelihood of future thromboembolic events caused by vulnerability of plaques. PET and MR imaging have been used separately with success for plaque characterization. Where MR imaging has the ability to reveal plaque composition, PET has the ability to visualize plaque activity. Together this leads to a comprehensive evaluation of plaque vulnerability. In this review, the authors go through data and arguments that support increased use of PET/MR imaging in atherosclerotic imaging., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Unlabelled: The somatostatin receptor subtype 2 is expressed on macrophages, an abundant cell type in the atherosclerotic plaque. Visualization of somatostatin receptor subtype 2, for oncologic purposes, is frequently made using the DOTA-derived somatostatin analogs DOTATOC or DOTATATE for PET. We aimed to compare the uptake of the PET tracers (68)Ga-DOTATOC and (64)Cu-DOTATATE in large arteries, in the assessment of atherosclerosis by noninvasive imaging technique, combining PET and CT. Further, the correlation of uptake and cardiovascular risk factors was investigated., Methods: Sixty consecutive patients with neuroendocrine tumors underwent both (68)Ga-DOTATOC and (64)Cu-DOTATATE PET/CT scans, in random order. For each scan, the maximum and mean standardized uptake values (SUVs) were calculated in 5 arterial segments. In addition, the blood-pool-corrected target-to-background ratio was calculated. Uptake of the tracers was correlated with cardiovascular risk factors collected from medical records., Results: We found detectable uptake of both tracers in all arterial segments studied. Uptake of (64)Cu-DOTATATE was significantly higher than (68)Ga-DOTATOC in the vascular regions both when calculated as maximum and mean uptake. There was a significant association between Framingham risk score and the overall maximum uptake of (64)Cu-DOTATATE using SUV (r = 0.4; P = 0.004) as well as target-to-background ratio (r = 0.3; P = 0.04), whereas no association was found with (68)Ga-DOTATOC. The association of risk factors and maximum SUV of (64)Cu-DOTATATE was found driven by body mass index, smoking, diabetes, and coronary calcium score (P < 0.001, P = 0.01, P = 0.005, and P = 0.03, respectively)., Conclusion: In a series of oncologic patients, vascular uptake of (68)Ga-DOTATOC and (64)Cu-DOTATATE was found, with highest uptake of the latter. Uptake of (64)Cu-DOTATATE, but not of (68)Ga-DOTATOC, was correlated with cardiovascular risk factors, suggesting a potential role for (64)Cu-DOTATATE in the assessment of atherosclerosis., (© 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)