Early Detection of Cardiotoxicity Using [64Cu]Cu-NODAGA-E[(cRGDyK)]2 PET Imaging in a Rat Model of Doxorubicin-Induced Heart Failure.

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 [64Cu]Cu-NODAGA-E[(cRGDyK)]2 positron emission tomography-computed tomography ([64Cu]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. [64Cu]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 [64Cu]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 [64Cu]Cu-RGD PET/CT at early time points. [64Cu]Cu-RGD uptake in the myocardial septum and thymus predicted a low left ventricular ejection fraction in week 8.

Increased Subclinical Coronary Artery Pathology in Type 2 Diabetes With Albuminuria.

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.

Ceramides are decreased after liraglutide treatment in people with type 2 diabetes: a post hoc analysis of two randomized clinical trials.

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.

[68Ga]Ga-NODAGA-E[(cRGDyK)]2 angiogenesis PET following myocardial infarction in an experimental rat model predicts cardiac functional parameters and development of heart failure.

BACKGROUND: Angiogenesis has increasingly been a target for imaging and treatment over the last decade. The integrin αvß3 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 [68Ga]Ga-RGD as a marker of angiogenesis following MI and its ability to predict cardiac functional parameters. METHODS: First, the real-time interaction between [68Ga]Ga-RGD and integrin αvß3 was investigated using surface plasmon resonance (SPR). Second, an animal study was performed to investigate the [68Ga]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 [68Ga]Ga-RGD tracer was evaluated ex vivo using histology, autoradiography, gamma counting and flow cytometry. RESULTS: SPR showed that [68Ga]Ga-RGD has a high affinity for integrin αvß3, forming a strong and stable binding. PET/CT showed a significantly higher uptake of [68Ga]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 [68Ga]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 [68Ga]Ga-RGD has a high affinity for integrin αvß3, which enables the evaluation of angiogenesis and remodeling. The [68Ga]Ga-RGD uptake after one week indicates that [68Ga]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.

[68Ga]Ga-NODAGA-E[(cRGDyK)]2 and [64Cu]Cu-DOTATATE PET Predict Improvement in Ischemic Cardiomyopathy.

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 [18F]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 [68Ga]Ga-RGD and [64Cu]Cu-DOTATATE. There was no overall effect of the treatment. Rats that improved left ventricular ejection fraction (LVEF) had higher uptake of both [68Ga]Ga-RGD and [64Cu]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 [68Ga]Ga-RGD and p = 0.045 for [64Cu]Cu-DOTATATE). High uptake of [68Ga]Ga-RGD and [64Cu]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.

[64Cu]Cu-DOTATATE PET metrics in the investigation of atherosclerotic inflammation in humans.

PURPOSE: The aim of this study was to assess and compare the arterial uptake of the inflammatory macrophage targeting PET tracer [64Cu]Cu-DOTATATE in patients with no or known cardiovascular disease (CVD) to investigate potential differences in uptake. METHODS: Seventy-nine patients who had undergone [64Cu]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, SUVmax (P = .03), SUVmds (0.05), TBRmax (P < .01), TBRmds (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 TBRmds (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 [64Cu]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.

In vivo molecular imaging of cardiac angiogenesis in persons with and without type 2 diabetes: A cross-sectional 68 Ga-RGD-PET study.

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 [TBRmean ]) 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 TBRmean 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 TBRmean 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.

Feasibility of positron range correction in 82-Rubidium cardiac PET/CT.

BACKGROUND: Myocardial perfusion imaging (MPI) using positron emission tomography (PET) tracers is an essential tool in investigating diseases and treatment responses in cardiology. 82Rubidium (82Rb)-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 82Rb-PET in rats. METHODS: The effect of positron range correction (PRC) on 82Rb-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 82Rb-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.

In vivo detection of urokinase-type plasminogen activator receptor (uPAR) expression in arterial atherogenesis using [64Cu]Cu-DOTA-AE105 positron emission tomography (PET).

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 [64Cu]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 [64Cu]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 (TBRmax) in five large arteries showed a higher [64Cu]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 [64Cu]Cu-DOTA-AE105 that may non-invasively detect extracellular matrix remodeling during atherogenesis.

Semaglutide reduces vascular inflammation investigated by PET in a rabbit model of advanced atherosclerosis.

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: [64Cu]Cu-DOTATATE for imaging of activated macrophages, [18F]FDG imaging cellular metabolism and [18F]NaF PET visualizing micro-calcifications. Tracer uptake was quantified by maximum standardized uptake value (SUVmax) and target-to-background-ratio (TBRmax). Animals were euthanized for autoradiographic imaging and histological analyses. RESULTS: A reduction in activated macrophage tracer-uptake was observed in the semaglutide group (SUVmax: p = 0.001 and TBRmax: p = 0.029). When imaging cellular metabolism, an attenuation of SUVmax and TBRmax 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 (SUVmax: p = 0.62 and TBRmax: p = 0.36). Values of macrophage density in the vessel wall were significantly correlated with SUVmax 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.

Liraglutide Lowers Palmitoleate Levels in Type 2 Diabetes. A Post Hoc Analysis of the LIRAFLAME Randomized Placebo-Controlled Trial.

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.

Amiodarone attenuates cardiac Rubidium-82 in consecutive PET/CT scans in a rodent model.

BACKGROUND: Risk stratification and diagnosis using Rubidium-82 (82Rb) 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 82Rb 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 82Rb in the heart in healthy rats. METHODS: Seventy-seven Sprague-Dawley rats were included in the cross-sectional study. All rats underwent baseline 82Rb 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 82Rb 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 82Rb. However, amiodarone result in a significantly lowered 82Rb 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.

Myocardial perfusion recovery induced by an α-calcitonin gene-related peptide analogue.

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, [99mTc]Tc-sestamibi was administered to determine the myocardial perfusion before treatment. Twenty minutes, 24 and 48 h after [99mTc]Tc-sestamibi injection, the rats were treated with either SAX or placebo. Final infarct size was determined three weeks later by [99mTc]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.

Effect of 26 Weeks of Liraglutide Treatment on Coronary Artery Inflammation in Type 2 Diabetes Quantified by [64Cu]Cu-DOTATATE PET/CT: Results from the LIRAFLAME Trial.

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 [64Cu]Cu-DOTATATE positron emission tomography and computed tomography scan of the heart at baseline and after 26 weeks of treatment. Coronary artery uptake of [64Cu]Cu-DOTATATE were measured as maximum standardized uptake values (SUVmax); and means of the maximum values (mSUVmax), both values were calculated at the level of each participant and each individual coronary-segment. Results: SUVmax and mSUVmax values decreased significantly in the liraglutide group both at the participant level (SUVmax: p=0.013; mSUVmax: p=0.004) and at the coronary-segment level (SUVmax: p=0.001; mSUVmax: p<0.0001). No change was observed in the placebo group neither at the participant level (SUVmax: p=0.69; mSUVmax: p=0.67) or at the coronary-segment level (SUVmax: p=0.49; mSUVmax: p=0.30). When comparing the mean change in uptake values between the two groups at both the participant level (SUVmax: p=0.076; mSUVmax: p=0.077) and the coronary segment level (SUVmax: p=0.13; mSUVmax: p=0.11) a borderline significant difference was observed. Baseline SUVmax [64Cu]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 [64Cu]Cu-DOTATATE uptake in the coronary arteries whereas this was not seen in the placebo treated group. In addition, [64Cu]Cu-DOTATATE PET/CT as a marker of coronary inflammation correlated with the systemic inflammation marker hs-CRP.

The Association Between Cardiovascular Autonomic Function and Changes in Kidney and Myocardial Function in Type 2 Diabetes and Healthy Controls.

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 82Rb 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, HbA1c, 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.

The Initial Cardiac Tissue Response to Cryopreserved Allogeneic Adipose Tissue-Derived Mesenchymal Stromal Cells in Rats with Chronic Ischemic Cardiomyopathy.

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.

Effect of liraglutide on expression of inflammatory genes in type 2 diabetes.

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-1ß (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.