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Abstract Monocytes directly contribute to atherosclerosis development by their recruitment to plaques in which they differentiate into macrophages. In the present study, we ask how modulating monocyte glucose metabolism could affect their homeostasis and their impact on atherosclerosis. Here we investigate how circulating metabolites control monocyte behavior in blood, bone marrow and peripheral tissues of mice. We find that serum glucose concentrations correlate with monocyte numbers. In diet-restricted mice, monocytes fail to metabolically reprogram from glycolysis to fatty acid oxidation, leading to reduced monocyte numbers in the blood. Mechanistically, Glut1-dependent glucose metabolism helps maintain CD115 membrane expression on monocytes and their progenitors, and regulates monocyte migratory capacity by modulating CCR2 expression. Results from genetic models and pharmacological inhibitors further depict the relative contribution of different metabolic pathways to the regulation of CD115 and CCR2 expression. Meanwhile, Glut1 inhibition does not impact atherosclerotic plaque development in mouse models despite dramatically reducing blood monocyte numbers, potentially due to the remaining monocytes having increased migratory capacity. Together, these data emphasize the role of glucose uptake and intracellular glucose metabolism in controlling monocyte homeostasis and functions.

Background Detailed visualization and precise measurements of aortic valve dimensions are critical for the success of transcatheter aortic valve implantation and for the prevention of complications. Currently, multislice computed tomography is the gold standard for assessment of the aortic annulus and surrounding structures to determine the prosthesis size. New technologies such as virtual reality (VR) not only enable 3‐dimensional (3D) visualization with the potential to improve understanding of anatomy and pathology but also allow measurements in 3D. This study aims to investigate the feasibility, accuracy, and reproducibility of VR for the visualization of the aortic valve, the surrounding structures, and its role in preprocedural sizing for transcatheter aortic valve implantation. Methods and Results Based on the preprocedural multislice computed tomography data, 3mensio measurements and 3D visualizations and measurements using VR software were performed retrospectively on 60 consecutive patients who underwent transcatheter aortic valve implantation at our heart center. There were no significant differences but strong correlations between the VR measurements compared with those performed with the 3mensio software. Furthermore, excellent or good intra‐ and interobserver reliability could be demonstrated for all values. In a structured questionnaire, users reported that VR simplified anatomical understanding, improved 3D comprehension of adjacent structures, and was associated with very good self‐perceived depth perception. Conclusions The use of VR for preprocedural transcatheter aortic valve implantation sizing is feasible and has precise and reproducible measurements. In addition, 3D visualization improves anatomical understanding and orientation. To evaluate the potential benefits of 3D visualization for planning further cardiovascular interventions, research in this field is needed.

Abstract Aims We aimed to conduct a clinical process cost analysis to evaluate all upcoming costs of mitral valve transcatheter edge-to-edge repair (M-TEER) treatment using the MitraClip and the PASCAL repair system. Methods First, we prospectively enrolled 107 M-TEER patients treated with either the PASCAL or MitraClip system and compared all upcoming costs during the M-TEER procedure and the associated in-hospital stay. Second, we retrospectively analysed 716 M-TEER procedures with regard to the occurrence of complications and their associated costs. All materials used in the catheterization laboratory for the procedures were evaluated. The cost analysis considered various expenses, such as general in-hospital costs, device costs, catheter laboratory and material costs. Results In the prospective study, 51 patients were treated using the PASCAL system, and 56 were treated using the MitraClip system. The two groups had comparable baseline characteristics and comorbidities. The total in-hospital costs were 25 414 (Interquartile range (IQR) 24 631, 27 697) € in the PASCAL group and 25 633 (IQR 24 752, 28 256) € in the MitraClip group (p = 0.515). The major cost driver was initial material expenditure, mostly triggered by device costs, which were similar to the PASCAL and MitraClip systems. Overall intensive care unit and general ward costs did not differ between the PASCAL and MitraClip groups. In the retrospective analysis, M-TEER-related complications were rare but were associated with higher costs, mainly due to prolonged hospitalisation. Conclusion The major cost driver of M-TEER was the material expenditure, which was mostly triggered by high device costs. The costs of treating patients were similar for the PASCAL and MitraClip systems. M-TEER-related complications are associated with higher costs, mainly due to prolonged hospitalisation. This analysis provides valuable insights into reducing expenses by modifying the process of M-TEER.

Summary: Studies indicate that the radiotracer 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG) can be metabolized beyond 2-[18F]FDG-6-phosphate (2-[18F]FDG-6-P), but its metabolism is incompletely understood. Most importantly, it remains unclear whether downstream metabolism affects tracer accumulation in vivo. Here we present a fingerprint of 2-[18F]FDG radiometabolites over time in cancer cells, corresponding tumor xenografts and murine organs. Strikingly, radiometabolites representing glycogen metabolism or the oxPPP correlated inversely with tracer accumulation across all examined tissues. Recent studies suggest that not only hexokinase, but also hexose-6-phosphate dehydrogenase (H6PD), an enzyme of the oxidative pentose phosphate pathway (oxPPP), determines 2-[18F]FDG accumulation. However, little is known about the corresponding enzyme glucose-6-phosphate dehydrogenase (G6PD). Our mechanistic in vitro experiments on the role of the oxPPP propose that 2-[18F]FDG can be metabolized via both G6PD and H6PD, but data from separate enzyme knockdown suggest diverging roles in downstream tracer metabolism. Overall, we propose that tissue-specific metabolism beyond 2-[18F]FDG-6-P could matter for imaging.

Background Neurologic events during primary stay in heart transplant (HTx) recipients may be associated with reduced outcome and survival, which we aim to explore with the current study. Methods and Results We screened and included all patients undergoing HTx in our center between September 2010 and December 2022 (n=268) and checked for the occurrence of neurologic events within their index stay. Neurologic events were defined as ischemic stroke, hemorrhage, hypoxic ischemic injury, or acute symptomatic neurologic dysfunction without central nervous system injury. The cohort was then divided into recipients with (n=33) and without (n=235) neurologic events after HTx. Using a multivariable Cox regression model, the association of neurologic events after HTx and survival was assessed. Recipients with neurologic events displayed a longer intensive care unit stay (30 versus 16 days; P=0.009), longer mechanical ventilation (192 versus 48 hours; P

Buspirone is commonly used to treat generalized anxiety disorder and demonstrates a limited side-effect profile compared to other anxiolytics. Buspirone is considered generally safe, and neuropsychiatric adverse reactions are uncommon. There are rare clinical case reports that suggest buspirone-induced psychosis. We present a case of buspirone worsening psychosis for a patient psychiatrically hospitalized for an episode of decompensated schizoaffective disorder. The patient had a primary diagnosis of schizoaffective disorder and was treated with antipsychotics during this hospitalization, but his symptoms worsened when buspirone was administered on two separate occasions. During the first trial of buspirone, the patient exhibited traits of increased aggression, odd behaviors, and paranoia. The buspirone was discontinued after the patient admitted to hiding his pills to later consume through nasal ingestion. The second trial resulted in repeated exacerbated symptoms of paranoia related to food and substantially decreased oral intake. Considering its complex mechanism of action, buspirone is suggested to derive its neuropharmacological effects through 5-HT1A receptors. However, the drug also has been found to mediate dopamine neurotransmission. Buspirone acts as an antagonist at presynaptic dopamine D2, D3, and D4 receptors. Yet, contrary to expected outcomes, it was unable to produce antipsychotic effects and instead resulted in a substantial increase in dopaminergic metabolites. The route of administration may also play a role in the enhancement of the buspirone’s effects, particularly considering that after first-pass metabolism, buspirone has approximately 4% oral bioavailability. Intranasal administration of buspirone leads to faster drug absorption by direct transport from the nasal mucosa to the brain and increased bioavailability.

Abstract In-hospital cardiac arrest (IHCA) is associated with poor outcomes. There are currently no standards for cardiac arrest teams in terms of member composition and task allocation. Here we aimed to compare two different cardiac arrest team concepts to cover IHCA management in terms of survival and neurological outcomes. This prospective study enrolled 412 patients with IHCA from general medical wards. From May 2014 to April 2016, 228 patients were directly transferred to the intensive care unit (ICU) for ongoing resuscitation. In the ICU, resuscitation was extended to advanced cardiac life support (ACLS) (Load-and-Go [LaG] group). By May 2016, a dedicated cardiac arrest team provided by the ICU provided ACLS in the ward. After return of spontaneous circulation (ROSC), the patients (n = 184) were transferred to the ICU (Stay-and-Treat [SaT] group). Overall, baseline characteristics, aetiologies, and characteristics of cardiac arrest were similar between groups. The time to endotracheal intubation was longer in the LaG group than in the SaT group (6 [5, 8] min versus 4 [2, 5] min, p = 0.001). In the LaG group, 96% of the patients were transferred to the ICU regardless of ROSC achievement. In the SaT group, 83% of patients were transferred to the ICU (p = 0.001). Survival to discharge did not differ between the LaG (33%) and the SaT (35%) groups (p = 0.758). Ultimately, 22% of patients in the LaG group versus 21% in the SaT group were discharged with good neurological outcomes (p = 0.857). In conclusion, we demonstrated that the cardiac arrest team concepts for the management of IHCA did not differ in terms of survival and neurological outcomes. However, a dedicated (intensive care) cardiac arrest team could take some load off the ICU.

Abstract Aims Percutaneous left ventricular assist devices (pVADs) are used to haemodynamically stabilize patients with cardiogenic shock (CS) caused by acute myocardial infarction (AMI). One out of every two patients has a non‐ischaemic cause of CS, and these patients differ profoundly from patients with AMI‐related CS. We assessed the usefulness of pVAD support for patients with non‐ischaemic CS. Methods and results We analysed 106 patients with CS and Impella® support between 2015 and 2018. CS was non‐ischaemic in 36 patients and AMI‐related in 70 patients. Compared with the AMI group, those in the non‐ischaemic group were significantly younger [median age 62 (50.8, 70.8) years vs. 68 (58.0, 75.5) years, P = 0.007] and had more patients with severely reduced left ventricular function (94% vs. 79%, P = 0.035) and worse glomerular filtration rate [45 (27, 57) mL/min vs. 60 (44, 78) mL/min]. Propensity score matching yielded 31 patients with non‐ischaemic CS and 31 patients with AMI‐related CS, without a difference in baseline laboratory values or comorbidities. In both groups, pVAD support was performed along with haemodynamic stabilization, reduction of catecholamines and normalization of lactate levels. In 7 days, systolic blood pressure increased from 91 (80, 101) mmHg at baseline to 100 (100, 120) mmHg in the non‐ischaemic CS group (P = 0.001) and 89 (80, 100) mmHg at baseline to 112 (100, 128) mmHg in the AMI‐related CS group (P = 0.001). Moreover, in 7 days, the need of catecholamines (calculated as vasoactive‐inotropic score) decreased from 32.0 (11.1, 47.0) at baseline to 5.3 (0, 16.1) in the non‐ischaemic group (P = 0.001) and from 35.2 (18.11, 67.0) to zero (0, 0) in the AMI‐related CS group (P = 0.001). Lactate level decreased from 3.8 (2.8, 5.9) mmol/L at baseline to 1.0 (0.8, 2.1) mmol/L (P = 0.001) in the non‐ischaemic CS group and from 3.8 (2.6, 6.5) mmol/L to 1.2 (1.0, 2.0) mmol/L in the AMI‐related group (P = 0.001). In the non‐ischaemic CS group, eight patients (25.8%) were upgraded to veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) or long‐term mechanical circulatory support. Two of these upgraded patients received heart transplantation. In the AMI group, eight patients (25.8%) were upgraded to VA‐ECMO or long‐term mechanical circulatory support. Ninety‐day survival did not significantly differ between the groups (non‐ischaemic CS group 48.4%, AMI‐related CS group 45.2%, P = 0.799). Conclusions pVAD support is useful for haemodynamic stabilization of patients with non‐ischaemic CS and is valuable as a bridge to patients' recovery or long‐term left ventricular support and heart transplantation.

Residual and recurrent tricuspid regurgitation may occur frequently after surgical tricuspid valve repair. However, reoperation for tricuspid regurgitation is rare, although many patients are again highly symptomatic. Tricuspid transcatheter edge-to-edge repair (TEER) is a promising therapy for severe tricuspid regurgitation. Herein, we report a 77-year-old woman with recurrent symptomatic massive tricuspid regurgitation 2 years after sutured annuloplasty of the tricuspid valve. TEER was successfully performed using the TriClip® device and tricuspid regurgitation was reduced to a mild degree. In conclusion, tricuspid TEER is feasible following surgical suture annuloplasty. TEER is an alternative option for patients with a failed previous annuloplasty repair for tricuspid regurgitation to undergo a less invasive treatment rather than a potentially higher-risk reoperation.

Myat Soe Thet et al. published a letter [...]

Abstract Aims Percutaneous mitral valve repair (PMVR) has emerged as standard treatment in selected patients with clinically relevant mitral regurgitation (MR) and increased surgical risk. We aimed to evaluate the safety and clinical outcomes in nonagenarians undergoing PMVR. Methods and results Altogether, 493 patients with severe MR who were treated with PMVR were included in this open‐label prospective study and followed up for 2 years. We treated 25 patients with PMVR aged 90 years or above, 185 patients aged 80–89 years, and 283 patients aged

Introduction: Mesenchymal stromal/stem cells (MSCs) derived from fat tissue are an encouraging tool for regenerative medicine. They share properties similar to the bone marrow-derived MSCs, but the amount of MSCs per gram of fat tissue is 500x higher. The fat tissue can easily be digested by collagenase, releasing a heterogeneous cell fraction called stromal vascular fraction (SVF) which contains a variable amount of stromal/stem cells. In Europe, cell products like the SVF derived from fat tissue are considered advanced therapy medicinal product (ATMPs). As a consequence, the manufacturing process has to be approved via GMP-compliant process validation. The problem of the process validation for SVF is the heterogeneity of this fraction. Methods: Here, we modified existing purification strategies by adding an additional plastic adherence incubation of maximal 20 hours after SVF isolation. The resulting cell fraction was characterized and compared to SVF as well as cultivated adipose-derived stromal/stem cells (ASCs) with respect to viability and cell yield, the expression of surface markers, differentiation potential and cytokine expression. Results: Short-term incubation significantly reduced the heterogeneity of the resulting cell fraction compared to SVF. The cells were able to differentiate into adipocytes, chondrocytes, and osteoblasts. More importantly, they expressed trophic proteins which have been previously associated with the beneficial effects of MSCs. Furthermore, GMP compliance of the production process described herein was acknowledged by the national regulatory agencies (DE_BB_01_GMP_2017_1018). Conclusion: Addition of a short purification-step after the SVF isolation is a cheap and fast strategy to isolate a homogeneous uncultivated GMP-compliant cell fraction of ASCs.

Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 (n = 241). Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days (≤50th percentile, n = 92), 4 to 7 days (50th–75th percentile, n = 80), and ≥8 days (≥75th percentile, n = 69). Donor LOS in the ICU ranged between 0 and 155 days (median 4, IQR 3–8 days). No association between the LOS in the ICU and survival after HTx was observed (AUC for overall survival 0.514). Neither the Kaplan–Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients’ peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.

The epidermis is a multi-layered epithelium that consists mainly of keratinocytes which proliferate in its basal layer and then differentiate to form the stratum corneum, the skin's ultimate barrier to the environment. During differentiation keratinocyte function, chemical composition, physical properties, metabolism and secretion are profoundly changed. Extrinsic or intrinsic stressors, like ultraviolet (UV) radiation thus may differently affect the epidermal keratinocytes, depending on differentiation stage. Exposure to UV elicits the DNA damage responses, activation of pathways which detoxify or repair damage or induction of programmed cell death when the damage was irreparable. Recently, rapid diversion of glucose flux into the pentose phosphate pathway (PPP) was discovered as additional mechanism by which cells rapidly generate reduction equivalents and precursors for nucleotides – both being in demand after UV damage. There is however little known about the correlation of such metabolic activity with differentiation state, cell damage and tissue localization of epidermal cells. We developed a method to correlate the activity of G6PD, the first and rate-limiting enzyme of this metabolic UV response, at cellular resolution to cell type, differentiation state, and cell damage in human skin and in organotypic reconstructed epidermis. We thereby could verify rapid activation of G6PD as an immediate UVB response not only in basal but also in differentiating epidermal keratinocytes and found increased activity in cells which initiated DNA damage responses. When keratinocytes had been UVB irradiated before organotypic culture, their distribution within the skin equivalent was abnormal and the G6PD activity was reduced compared to neighboring cells. Finally, we found that the anti-diabetic and potential anti-aging drug metformin strongly induced G6PD activity throughout reconstructed epidermis. Activation of the protective pentose phosphate pathway may be useful to enhance the skin's antioxidant defense systems and DNA damage repair capacity on demand.

Summary: Mechanistic or mammalian target of rapamycin complex 1 (mTORC1) is an important regulator of effector functions, proliferation, and cellular metabolism in macrophages. The biochemical processes that are controlled by mTORC1 are still being defined. Here, we demonstrate that integrative multiomics in conjunction with a data-driven inverse modeling approach, termed COVRECON, identifies a biochemical node that influences overall metabolic profiles and reactions of mTORC1-dependent macrophage metabolism. Using a combined approach of metabolomics, proteomics, mRNA expression analysis, and enzymatic activity measurements, we demonstrate that Tsc2, a negative regulator of mTORC1 signaling, critically influences the cellular activity of macrophages by regulating the enzyme phosphoglycerate dehydrogenase (Phgdh) in an mTORC1-dependent manner. More generally, while lipopolysaccharide (LPS)-stimulated macrophages repress Phgdh activity, IL-4-stimulated macrophages increase the activity of the enzyme required for the expression of key anti-inflammatory molecules and macrophage proliferation. Thus, we identify Phgdh as a metabolic checkpoint of M2 macrophages. : Wilson et al. show that Tsc2, a negative regulator of mTORC1 signaling, critically influences the metabolome of macrophages. Inverse data-driven modeling and multiomics data reveal that Phgdh is an mTORC1-dependent metabolic checkpoint of macrophage proliferation and polarization. Phgdh is required for the expression of key anti-inflammatory molecules and M2 proliferation. Keywords: Tsc2, mTOR, serine/glycine pathway, Phgdh, macrophage polarization, macrophage proliferation, metabolomics, metabolic modeling, biochemical Jacobian, cancer, tumor-associated macrophages

Tumor cell crosstalk with platelets and, subsequently, their activation are key steps in hematogenous tumor metastasis. MACC1 is an oncogene involved in molecular pathogenesis of colorectal cancer (CRC) and other solid tumor entities, mediating motility and metastasis, making MACC1 an accepted prognostic biomarker. However, the impact of MACC1 on platelet activation has not yet been addressed. Here, we investigated the activation of platelets by human CRC cells upon MACC1 modulation, indicated by platelet aggregation and granule release. These approaches led to the identification of insulin-like growth factor binding protein-2 (IGFBP2) as a functional downstream molecule of MACC1, affecting communication with platelets. This was confirmed by an shRNA-mediated IGFBP2 knockdown, while maintaining MACC1 activity. Although IGFBP2 displayed an attenuated platelet activation potential, obviously by scavenging IGF-I as a platelet costimulatory mediator, the MACC1/IGFBP2 axis did not affect the thrombin formation potential of the cells. Furthermore, the IGFBP2/MACC1-driven cell migration and invasiveness was further accelerated by platelets. The key role of IGFBP2 for the metastatic spread in vivo was confirmed in a xenograft mouse model. Data provide evidence for IGFBP2 as a downstream functional component of MACC1-driven metastasis, linking these two accepted oncogenic biomarkers for the first time in a platelet context.

The glucose derivative 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG) is still the most used radiotracer for positron emission tomography, as it visualizes glucose utilization and energy demand. In general, 2-[18F]FDG is said to be trapped intracellularly as 2-[18F]FDG-6-phosphate, which cannot be further metabolized. However, increasingly, this dogma is being questioned because of publications showing metabolism beyond 2-[18F]FDG-6-phosphate and even postulating 2-[18F]FDG imaging to depend on the enzyme hexose-6-phosphate dehydrogenase in the endoplasmic reticulum. Therefore, we aimed to study 2-[18F]FDG metabolism in the human cancer cell lines HT1080, HT29 and Huh7 applying HPLC. We then compared 2-[18F]FDG metabolism with intracellular tracer accumulation, efflux and the cells’ metabolic state and used a graphical Gaussian model to visualize metabolic patterns. The extent of 2-[18F]FDG metabolism varied considerably, dependent on the cell line, and was significantly enhanced by glucose withdrawal. However, the metabolic pattern was quite conserved. The most important radiometabolites beyond 2-[18F]FDG-6-phosphate were 2-[18F]FDMannose-6-phosphate, 2-[18F]FDG-1,6-bisphosphate and 2-[18F]FD-phosphogluconolactone. Enhanced radiometabolite formation under glucose reduction was accompanied by reduced efflux and mirrored the cells’ metabolic switch as assessed via extracellular lactate levels. We conclude that there can be considerable metabolism beyond 2-[18F]FDG-6-phosphate in cancer cell lines and a comprehensive understanding of 2-[18F]FDG metabolism might help to improve cancer research and tumor diagnosis.

Pancreatic cancer patients have an elevated risk of suffering from venous thrombosis. Among several risk factors that contribute to hypercoagulability of this malignancy, platelets possess a key role in the initiation of clot formation. Although single mechanisms of platelet activation are well-known in principle, combinations thereof and their potential synergy to mediate platelet activation is, in the case of pancreatic cancer, far from being clear. Applying an inhibitor screening approach using light transmission aggregometry, dense granule release, and thrombin formation assays, we provide evidence that a combination of tissue factor-induced thrombin formation by cancer cells and their platelet P-selectin binding is responsible for AsPC-1 and Capan-2 pancreatic cancer cell-mediated platelet activation. While the blockade of one of these pathways leads to a pronounced inhibition of platelet aggregation and dense granule release, the simultaneous blockade of both pathways is inevitable to prevent platelet aggregation completely and minimize ATP release. In contrast, MIA PaCa-2 pancreatic cancer cells express reduced levels of tissue factor and P-selectin ligands and thus turn out to be poor platelet activators. Consequently, a simultaneous blockade of thrombin and P-selectin binding seems to be a powerful approach, as mediated by heparin to crucially reduce the hypercoagulable state of pancreatic cancer patients.

Metastasis is responsible for the majority of cancer associated fatalities. Tumor cells leaving the primary tumor and entering the blood flow immediately interact with platelets. Activated platelets contribute in different ways to cancer cell survival and proliferation, e.g. in formation of the early metastatic niche by release of different growth factors and chemokines. Here we show that a direct interaction between platelets and MV3 melanoma or MCF7 breast cancer cells induces platelet activation and a VEGF release in citrated plasma that cannot be further elevated by the coagulation cascade and generated thrombin. In contrast, the release of platelet-derived chemokines CXCL5 and CXCL7 depends on both, a thrombin-mediated platelet activation and a direct interaction between tumor cells and platelets. Preincubation of platelets with therapeutic concentrations of unfractionated heparin reduces the tumor cell initiated VEGF release from platelets. In contrast, tumor cell induced CXCL5 and CXCL7 release from platelets was not impacted by heparin pretreatment in citrated plasma. In defibrinated, recalcified plasma, on the contrary, heparin is able to reduce CXCL5 and CXCL7 release from platelets by thrombin inhibition. Our data indicate that different chemokines and growth factors in diverse platelet granules are released in tightly regulated processes by various trigger mechanisms. We show for the first time that heparin is able to reduce the mediator release induced by different tumor cells both in a contact and coagulation dependent manner.