Myocardial fibrosis in Type 2 Diabetes is associated with functional and metabolomic parameters.

AIMS: To identify biomarkers of cardiomyopathy in patients with type 2 diabetes mellitus (T2DM) using cardiovascular magnetic resonance (CMR) and to identify associations between functional status, metabolomic profile and myocardial fibrosis. METHODS: In this prospective case control study, patients (n = 49) with T2DM without significant coronary artery disease, and matched controls (n = 18) underwent CMR, cardiopulmonary exercise testing, and plasma metabolomic analyses. RESULTS: Patients with T2DM (n = 49, median [interquartile range] age 61 [56-63] years, 61% male, diabetes duration 11 [7-20] years), historical HbA1c 7.6% (60 mmol/mol) (6.9-8.6) and matched controls (n = 18) were examined. Study patients had increased myocardial extracellular volume (ECV) (26.9 [23.8-30.0] vs 23.4 [22.4-25.5) %, p < 0.001). Increased ECV was associated with male sex (p = 0.04), time with T2DM (p = 0.02), reduced peak VO2 (R2 = 0.48, p = 0.01), increased circulating choline (p = 0.002) and cysteamine (p = 0.002) both of which were also associated with reduced peak VO2 (p < 0.025 and 0.014 respectively). CONCLUSIONS: Patients with well-controlled T2DM without significant coronary disease exhibit focal and diffuse myocardial fibrosis and diffuse myocardial fibrosis is associated with reduced exercise tolerance and metabolites. Plasma metabolites may provide mechanistic insights into diffuse myocardial fibrosis, and cardiopulmonary fitness.

Models of cardiovascular surgery biobanking to facilitate translational research and precision medicine.

Biobanking in health care has evolved over the last few decades from simple biological sample repositories to complex and dynamic units with multi-organizational infrastructure networks and has become an essential tool for modern medical research. Cardiovascular tissue biobanking provides a unique opportunity to utilize cardiac and vascular samples for translational research into heart failure and other related pathologies. Current techniques for diagnosis, classification, and treatment monitoring of cardiac disease relies primarily on interpretation of clinical signs, imaging, and blood biomarkers. Further research at the disease source (i.e. myocardium and blood vessels) has been limited by a relative lack of access to quality human cardiac tissue and the inherent shortcomings of most animal models of heart disease. In this review, we describe a model for cardiovascular tissue biobanking and databasing, and its potential to facilitate basic and translational research. We share techniques to procure endocardial samples from patients with hypertrophic cardiomyopathy, heart failure with reduced ejection fraction, and heart failure with preserved ejection fraction, in addition to aortic disease samples. We discuss some of the issues with respect to data collection, privacy, biobank consent, and the governance of tissue biobanking. The development of tissue biobanks as described here has significant scope to improve and facilitate translational research in multi-omic fields such as genomics, transcriptomics, proteomics, and metabolomics. This research heralds an era of precision medicine, in which patients with cardiovascular pathology can be provided with optimized and personalized medical care for the treatment of their individual phenotype.

The Anatomical Relationships in the Space of Retzius for Penile Implants: An MRI Analysis.

BACKGROUND: The 3-piece inflatable penile prosthesis includes an easy-to-use pump and fluid filled reservoir which is placed in either the space of Retzius (SOR) or in an alternative ectopic location. Reservoir placement in the SOR is a blind procedure despite the SOR being surrounded by many critical structures. To date only a handful of cadaveric studies have described the relevant anatomy. AIM: To use magnetic resonance imaging (MRI) as an in-vivo model to study relevant retropubic anatomy critical for SOR reservoir placement. METHODS: The study population included men with elevated prostate specific antigen or biopsy proven prostate cancer who (i) underwent pelvic MRI, (ii) without prior pelvic or inguinal surgery, and (iii) without pelvic radiation therapy. All MRIs were completed with a 3-Tesla scanner and endorectal coil. Both T1 and T2 weighted images were captured in both axial and sagittal planes. All images were reviewed by 2 independent reviewers under the supervision of a dedicated body MRI radiologist. Bladder volume was calculated using an ellipsoid formula. OUTCOMES: Relevant measurements included (i) the distance between the external inguinal ring (EIR) at the level of the pubic tubercle to the external iliac vein (EIV), (ii) the distance from the EIR at the pubic tubercle to the bladder (accounting for bladder volume) and (iii) the distance from the midline pubic symphysis to the bladder (accounting for bladder volume). Pearson correlation was used to determine correlated measurements. RESULTS: A total of 24 patients were included. Median participant age was 63 years (interquartile range, 59-66). The mean EIR-EIV distance was 3.0 ± 0.4 cm, the mean EIR-bladder distance was 1.8 ± 1.0 cm and the mean distance from the superior pubic symphysis to bladder was 0.9 ± 0.3 cm. There was a weak correlation between bladder volume and distance between the EIR and bladder (r = -0.30, P = .16). CLINICAL IMPLICATIONS: The use of MRI as an in-vivo model is a high-fidelity tool to study real time unaltered anatomy and allows for surgical preparation, diagnosis of anatomic variants and acts as a valuable teaching tool. STRENGTHS & LIMITATIONS: This is the first in-vivo model to report relevant retropubic anatomy in penile implant surgery. Our study is limited by sample size and inclusion of participants with no history of prior pelvic intervention. CONCLUSION: We demonstrate the utility of MRI as an in-vivo model, as opposed to cadaveric models, for the understanding of relevant retropubic anatomy for implant surgeons. Punjani N, Monteiro L, Sullivan J F et al. The Anatomical Relationships in the Space of Retzius for Penile Implants: An MRI Analysis. J Sex Med 2021;18:1830-1834.

Optimizing the discovery and assessment of therapeutic targets in heart failure with preserved ejection fraction.

There is an urgent need for models that faithfully replicate heart failure with preserved ejection fraction (HFpEF), now recognized as the most common form of heart failure in the world. In vitro approaches have several shortcomings, most notably the immature nature of stem cell-derived human cardiomyocytes [induced pluripotent stem cells (iPSC)] and the relatively short lifespan of primary cardiomyocytes. Three-dimensional 'organoids' incorporating mature iPSCs with other cell types such as endothelial cells and fibroblasts are a significant advance, but lack the complexity of true myocardium. Animal models can replicate many features of human HFpEF, and rodent models are the most common, and recent attempts to incorporate haemodynamic, metabolic, and ageing contributions are encouraging. Differences relating to species, physiology, heart rate, and heart size are major limitations for rodent models. Porcine models mitigate many of these shortcomings and approximate human physiology more closely, but cost and time considerations limit their potential for widespread use. Ex vivo analysis of failing hearts from animal models offer intriguing possibilities regarding cardiac substrate utilisation, but are ultimately subject to the same constrains as the animal models from which the hearts are obtained. Ex vivo approaches using human myocardial biopsies can uncover new insights into pathobiology leveraging myocardial energetics, substrate turnover, molecular changes, and systolic/diastolic function. In collaboration with a skilled cardiothoracic surgeon, left ventricular endomyocardial biopsies can be obtained at the time of valvular surgery in HFpEF patients. Critically, these tissues maintain their disease phenotype, preserving inter-relationship of myocardial cells and extracellular matrix. This review highlights a novel approach, where ultra-thin myocardial tissue slices from human HFpEF hearts can be used to assess changes in myocardial structure and function. We discuss current approaches to modelling HFpEF, describe in detail the novel tissue slice model, expand on exciting opportunities this model provides, and outline ways to improve this model further.

Nicotinamide riboside supplementation does not alter whole-body or skeletal muscle metabolic responses to a single bout of endurance exercise.

KEY POINTS: Acute nicotinamide riboside (NR) supplementation does not alter substrate metabolism at rest, during or in recovery from endurance exercise. NR does not alter NAD+ -sensitive signalling pathways in human skeletal muscle. NR supplementation and acute exercise influence the NAD+ metabolome. ABSTRACT: Oral supplementation of the NAD+ precursor nicotinamide riboside (NR) has been reported to alter metabolism alongside increasing sirtuin (SIRT) signalling and mitochondrial biogenesis in rodent skeletal muscle. However, whether NR supplementation can elicit a similar response in human skeletal muscle is unclear. This study assessed the effect of 7-day NR supplementation on whole-body metabolism and exercise-induced mitochondrial biogenic signalling in skeletal muscle. Eight male participants (age: 23 ± 4 years, V̇O2peak 46.5 ± 4.4 ml kg-1  min-1 ) received 1 week of NR or cellulose placebo (PLA) supplementation (1000 mg day-1 ). Muscle biopsies were collected from the medial vastus lateralis prior to supplementation and pre-, immediately post- and 3 h post-exercise (1 h of 60% Wmax cycling) performed following the supplementation period. There was no effect of NR supplementation on substrate utilisation at rest or during exercise or on skeletal muscle mitochondrial respiration. Global acetylation, auto-PARylation of poly ADP-ribose polymerase 1 (PARP1), acetylation of Tumour protein 53 (p53)Lys382 and Manganese superoxide dismutase (MnSOD)Lys122 were also unaffected by NR supplementation or exercise. NR supplementation did not increase skeletal muscle NAD+ concentration, but it did increase the concentration of deaminated NAD+ precursors nicotinic acid riboside (NAR) and nicotinic acid mononucleotide (NAM) and methylated nicotinamide breakdown products (Me2PY and Me4PY), demonstrating the skeletal muscle bioavailability of NR supplementation. In summary, 1 week of NR supplementation does not alter whole-body metabolism or skeletal muscle signal transduction pathways implicated in the mitochondrial adaptation to endurance exercise.

Climacturia After Radical Prostatectomy: MRI-Based Predictors.

BACKGROUND: After radical prostatectomy (RP), climacturia is a prevalent and distressing problem. To date, no specific predictors have been identified. AIM: In this analysis, we sought to find associated pelvic magnetic resonance imaging (MRI) parameters. METHODS: We identified all men in our departmental database who (i) had climacturia post-RP, ≥3 episodes; (ii) underwent a pre-RP endorectal MRI; (iii) had no radiation or androgen deprivation therapy (ADT). Soft tissue and bony dimensions were measured by 2 raters blinded to clinical and pathological data. OUTCOMES: MRI parameters included the following: maximum height, width, and depth of prostate, prostate volume, urethral width and length, lower conjugate of pelvis, bony femoral width, outer and inner levator distances and thickness. Point-biserial correlations were run on univariate associations. Logistic regression was used for the multivariable model. RESULTS: 194 consecutive pre-RP MRI studies were reviewed (56 men with and 138 without climacturia). Mean age was 60 ± 7 years, average time post-RP at assessment, 7 ± 7 months. Of MRI parameters, urethral width (r = 0.13, P = .03) and lower conjugate (r = 0.12, P = .05) were associated with presence of persistent climacturia. 2 others met criteria for multivariable analysis, prostate depth and outer levator distance. Of the non-MRI parameters, none were significantly related to climacturia and only body mass index (BMI) met criteria for multivariable analysis. On multivariable analysis, only urethral width was associated with climacturia (OR = 1.23, 95% CI: 1.01-1.49, P = .04); the wider the urethra, greater the chance of climacturia. CLINICAL IMPLICATIONS: Improved ability to predict the occurrence of orgasm-associated incontinence in the preoperative setting. STRENGTHS AND LIMITATIONS: Limitations include the fact that the MRI endorectal probe may have distorted pelvic tissues during imaging and that our study population size was small. However, prospective data collection, blinded measurements by 2 trained readers, and rigorous statistical analysis should be considered strengths. CONCLUSION: By identifying preoperative risk factors, such as urethral width on MRI, we may be able to better understand the pathophysiology of this condition and furthermore may permit us to better counsel men regarding this postoperative outcome. Sullivan JF, Ortega Y, Matsushita K, et al. Climacturia After Radical Prostatectomy: MRI-Based Predictors. J Sex Med 2020;17:1723-1728.

Metabolites downstream of predicted loss-of-function variants inform relationship to disease.

A small minority (< 3%) of protein-coding genetic variants are predicted to lead to loss of protein function. However, these predicted loss-of-function (pLOF) variants can provide insight into mode of transcriptional effect. To examine how these changes are propagated to phenotype, we determined associations with downstream metabolites. We performed association analyses of 37 pLOF variants - previously reported to be significantly associated with disease in >400,000 subjects in UK Biobank - with metabolites. We conducted these analyses in three community-based cohorts: the Framingham Heart Study (FHS) Offspring Cohort, FHS Generation 3, and the KORA F4 cohort. We identified 19 new low-frequency or rare (minor allele frequency (MAF) <5%) pLOF variant-metabolite associations, and 12 new common (MAF > 5%) pLOF variant-metabolite associations. Rare pLOF variants in the genes BTN3A2, ENPEP, and GEM that have been associated with blood pressure in UK Biobank, were associated with vasoactive metabolites indoxyl sulfate, asymmetric dimethylarginine (ADMA), and with niacinamide, respectively. A common pLOF variant in gene CCHCR1, associated with asthma in UK Biobank, was associated with histamine and niacinamide in FHS Generation 3, both reported to play a role in this disease. Common variants in olfactory receptor gene OX4C11 that associated with blood pressure in UK Biobank were associated with the nicotine metabolite cotinine, suggesting an interaction between altered olfaction, smoking behaviour, and blood pressure. These findings provide biological validity for pLOF variant-disease associations, and point to the effector roles of common metabolites. Such an approach may provide novel disease markers and therapeutic targets.

Primary care for the declining cancer survivor.

Asking yourself 1 question can help you to estimate an advanced cancer patient's prognosis and determine how best to help in setting end-of-life priorities.

TRAIL-Expressing Monocyte/Macrophages Are Critical for Reducing Inflammation and Atherosclerosis.

Circulating tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) levels are reduced in patients with cardiovascular disease, and TRAIL gene deletion in mice exacerbates atherosclerosis and inflammation. How TRAIL protects against atherosclerosis and why levels are reduced in disease is unknown. Here, multiple strategies were used to identify the protective source of TRAIL and its mechanism(s) of action. Samples from patients with coronary artery disease and bone-marrow transplantation experiments in mice lacking TRAIL revealed monocytes/macrophages as the main protective source. Accordingly, deletion of TRAIL caused a more inflammatory macrophage with reduced migration, displaying impaired reverse cholesterol efflux and efferocytosis. Furthermore, interleukin (IL)-18, commonly increased in plasma of patients with cardiovascular disease, negatively regulated TRAIL transcription and gene expression, revealing an IL-18-TRAIL axis. These findings demonstrate that TRAIL is protective of atherosclerosis by modulating monocyte/macrophage phenotype and function. Manipulating TRAIL levels in these cells highlights a different therapeutic avenue in the treatment of cardiovascular disease.

Utilizing state-of-the-art "omics" technology and bioinformatics to identify new biological mechanisms and biomarkers for coronary artery disease.

Identification of the four standard modifiable cardiovascular risk factors (SMuRFs)-diabetes mellitus, hyperlipidaemia, hypertension, and cigarette smoking-has allowed the development of risk scores. These have been used in conjunction with primary and secondary prevention strategies targeting SMuRFs to reduce the burden of CAD. Recent studies show that up to 25% of ACS patients do not have any SMuRFs. Thus, SMuRFs do not explain the entire burden of CAD. There appears to be variation at the individual level rendering some individuals relatively susceptible or resilient to developing atherosclerosis. Important disease pathways remain to be discovered, and there is renewed enthusiasm to discover novel biomarkers, biological mechanisms, and therapeutic targets for atherosclerosis. Two broad approaches are being taken: traditional approaches investigating known candidate pathways and unbiased omics approaches. We review recent progress in the field and discuss opportunities made possible by technological and data science advances. Developments in network analytics and machine learning algorithms used in conjunction with large-scale multi-omic platforms have the potential to uncover biological networks that may not have been identifiable using traditional approaches. These approaches are useful for both biomedical research and precision medicine strategies.

The transobturator suburethral sling: a safe and effective option for all degrees of post prostatectomy urinary incontinence.

INTRODUCTION: Male stress urinary incontinence (SUI) after radical prostatectomy (RP) is common. The surgical standard of care traditionally has been placement of an artificial urinary sphincter (AUS) but since its introduction the transobturator male sling has been shown to have particular unique advantages. Our aim was to assess outcomes of a consecutive series of suburethral sling insertions in men presenting with all degrees of post RP SUI. MATERIALS AND METHODS: A consecutive cohort of men undergoing AdVance sling insertion following RP were studied. Parameters assessed included pre and postoperative urinary function, 24 hour pad use, quality of life (QoL) outcomes, complications and further treatments. Degree of incontinence was categorized as mild (1-2), moderate (3-5) or severe (≥ 6) depending on daily pad use. Patients were reviewed at 1, 4 and 6 months. The International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) was used to assess symptom severity and QoL outcomes. RESULTS: Seventy-seven patients were included, mean age 68 and mean time to sling post RP 34 (8-113) months. Preoperative degree of incontinence: mild 22%, moderate 58%, severe 20%. Fourteen percent had undergone post RP radiation therapy (RT). In total 73% experienced complete resolution of symptoms post sling, 12% significant improvement, 15% no reduction in pad use. Sixty percent with severe incontinence were classified as cured (no pad or 1 dry pad for security reasons). When patients with preoperative RT were excluded, cure rate rose to 82%. On follow up survey at 30 months (mean), the ICIQ-SF score decreased from baseline 17.7 (9-21.0) to 8.0 (0-20) (p < 0.0001), CI 95% (8-12). CONCLUSIONS: Suburethral slings are effective and safe for all degrees of post RP incontinence, are associated with improved QoL parameters and with appropriate selection and counseling are a viable option for more severe degrees of post RP SUI.

Maximizing the Effectiveness of Colonoscopy in the Prevention of Colorectal Cancer.

Colonoscopy is a proven screening test for colorectal cancer; maximizing its effectiveness is the best way to decrease interval colorectal cancer. The adenoma detection rate can be improved by monitoring physician detection rates. Assistive devices and innovative endoscopic equipment may also decrease adenoma miss rates. Complete polypectomy of adenomatous lesions and recommending the proper date for the next examination are important considerations. Advanced polypectomy techniques including endoscopic mucosal resection and endoscopic mucosal dissection have a clear role in the nonsurgical management of large laterally spreading adenomatous polyps that previously would have required surgical resection.

Dimethylguanidino valeric acid is a marker of liver fat and predicts diabetes.

Unbiased, "nontargeted" metabolite profiling techniques hold considerable promise for biomarker and pathway discovery, in spite of the lack of successful applications to human disease. By integrating nontargeted metabolomics, genetics, and detailed human phenotyping, we identified dimethylguanidino valeric acid (DMGV) as an independent biomarker of CT-defined nonalcoholic fatty liver disease (NAFLD) in the offspring cohort of the Framingham Heart Study (FHS) participants. We verified the relationship between DMGV and early hepatic pathology. Specifically, plasma DMGV levels were correlated with biopsy-proven nonalcoholic steatohepatitis (NASH) in a hospital cohort of individuals undergoing gastric bypass surgery, and DMGV levels fell in parallel with improvements in post-procedure cardiometabolic parameters. Further, baseline DMGV levels independently predicted future diabetes up to 12 years before disease onset in 3 distinct human cohorts. Finally, we provide all metabolite peak data consisting of known and unidentified peaks, genetics, and key metabolic parameters as a publicly available resource for investigations in cardiometabolic diseases.

Increasing proportion of ST elevation myocardial infarction patients with coronary atherosclerosis poorly explained by standard modifiable risk factors.

Aims Identification and management of the Standard Modifiable Cardiovascular Risk Factors (SMuRFs; hypercholesterolaemia, hypertension, diabetes and smoking) has substantially improved cardiovascular disease outcomes. However, cardiovascular disease remains the leading cause of death worldwide. Suspecting an evolving pattern of risk factor profiles in the ST elevation myocardial infarction (STEMI) population with the improvements in primary care, we hypothesized that the proportion of 'SMuRFless' STEMI patients may have increased. Methods/results We performed a single centre retrospective study of consecutive STEMI patients presenting from January 2006 to December 2014. Over the study period 132/695 (25%) STEMI patients had 0 SMuRFs, a proportion that did not significantly change with age, gender or family history. The proportion of STEMI patients who were SMuRFless in 2006 was 11%, which increased to 27% by 2014 (odds ratio 1.12 per year, 95% confidence interval: 1.04-1.22). The proportion of patients with hypercholesterolaemia decreased (odds ratio 0.92, 95% confidence interval 0.86-0.98), as did the proportion of current smokers (odds ratio 0.93, 95% confidence interval 0.86-0.99), with no significant change in the proportion of patients with diabetes and hypertension. SMuRF status was not associated with extent of coronary disease; in-hospital outcomes, or discharge prescribing patterns. Conclusion The proportion of STEMI patients with STEMI poorly explained by SMuRFs is high, and is significantly increasing. This highlights the need for bold approaches to discover new mechanisms and markers for early identification of these patients, as well as to understand the outcomes and develop new targeted therapies.

High Grade Mucinous Urothelial Carcinoma of the Renal Collecting System: A Case Report.

High grade mucinous urothelial carcinoma is a rare pathological variant. There is still controversy as to its nomenclature and classification. We report the case of a 64 year old female with history of pelvic pain who was incidentally discovered to have a left upper pole renal mass. Left nephroureterectomy was performed and histopathological examination revealed high grade mucinous urothelial carcinoma. Accurate diagnosis of this distinct pathological entity will allow for better understanding of phenotypic behavior and inform best treatment strategies.

A Germline Variant on Chromosome 4q31.1 Associates with Susceptibility to Developing Colon Cancer Metastasis.

We tested for germline variants showing association to colon cancer metastasis using a genome-wide association study that compared Ashkenazi Jewish individuals with stage IV metastatic colon cancers versus those with stage I or II non-metastatic colon cancers. In a two-stage study design, we demonstrated significant association to developing metastatic disease for rs60745952, that in Ashkenazi discovery and validation cohorts, respectively, showed an odds ratio (OR) = 2.3 (P = 2.73E-06) and OR = 1.89 (P = 8.05E-04) (exceeding validation threshold of 0.0044). Significant association to metastatic colon cancer was further confirmed by a meta-analysis of rs60745952 in these datasets plus an additional Ashkenazi validation cohort (OR = 1.92; 95% CI: 1.28-2.87), and by a permutation test that demonstrated a significantly longer haplotype surrounding rs60745952 in the stage IV samples. rs60745952, located in an intergenic region on chromosome 4q31.1, and not previously associated with cancer, is, thus, a germline genetic marker for susceptibility to developing colon cancer metastases among Ashkenazi Jews.

Generation of vascular endothelial and smooth muscle cells from human pluripotent stem cells.

The use of human pluripotent stem cells for in vitro disease modelling and clinical applications requires protocols that convert these cells into relevant adult cell types. Here, we report the rapid and efficient differentiation of human pluripotent stem cells into vascular endothelial and smooth muscle cells. We found that GSK3 inhibition and BMP4 treatment rapidly committed pluripotent cells to a mesodermal fate and subsequent exposure to VEGF-A or PDGF-BB resulted in the differentiation of either endothelial or vascular smooth muscle cells, respectively. Both protocols produced mature cells with efficiencies exceeding 80% within six days. On purification to 99% via surface markers, endothelial cells maintained their identity, as assessed by marker gene expression, and showed relevant in vitro and in vivo functionality. Global transcriptional and metabolomic analyses confirmed that the cells closely resembled their in vivo counterparts. Our results suggest that these cells could be used to faithfully model human disease.

Bone Marrow-Derived Mesenchymal Stem Cells Have Innate Procoagulant Activity and Cause Microvascular Obstruction Following Intracoronary Delivery: Amelioration by Antithrombin Therapy.

Mesenchymal stem cells (MSCs) are currently under investigation as tools to preserve cardiac structure and function following acute myocardial infarction (AMI). However, concerns have emerged regarding safety of acute intracoronary (IC) MSC delivery. This study aimed to characterize innate prothrombotic activity of MSC and identify means of its mitigation toward safe and efficacious therapeutic IC MSC delivery post-AMI. Expression of the initiator of the coagulation cascade tissue factor (TF) on MSC was detected and quantified by immunofluorescence, FACS, and immunoblotting. MSC-derived TF antigen was catalytically active and capable of supporting thrombin generation in vitro. Addition of MSCs to whole citrated blood enhanced platelet thrombus deposition on collagen at arterial shear, an effect abolished by heparin coadministration. In a porcine AMI model, IC infusion of 25 × 10(6) MSC during reperfusion was associated with a decrease in coronary flow reserve but not when coadministered with an antithrombin agent (heparin). Heparin reduced MSC-associated thrombosis incorporating platelets and VWF within the microvasculature. Heparin-assisted therapeutic MSC delivery also reduced apoptosis in the infarct border zone at 24 hours, significantly improved infarct size, left ventricular (LV) ejection fraction, LV volumes, wall motion, and attenuated histologic evidence of scar formation at 6 weeks post-AMI. Heparin alone or heparin-assisted fibroblast control cell delivery had no such effect. Procoagulant TF activity of therapeutic MSCs is associated with reductions in myocardial perfusion when delivered IC may be successfully managed by heparin coadministration. This study highlights an important mechanistic insight into safety concerns associated with therapeutic IC MSC delivery for AMI.

Increases in myocardial workload induced by rapid atrial pacing trigger alterations in global metabolism.

OBJECTIVE: To determine whether increases in cardiac work lead to alterations in the plasma metabolome and whether such changes arise from the heart or peripheral organs. BACKGROUND: There is growing evidence that the heart influences systemic metabolism through endocrine effects and affecting pathways involved in energy homeostasis. METHODS: Nineteen patients referred for cardiac catheterization were enrolled. Peripheral and selective coronary sinus (CS) blood sampling was performed at serial timepoints following the initiation of pacing, and metabolite profiling was performed by liquid chromatography-mass spectrometry (LC-MS). RESULTS: Pacing-stress resulted in a 225% increase in the median rate·pressure product from baseline. Increased myocardial work induced significant changes in the peripheral concentration of 43 of 125 metabolites assayed, including large changes in purine [adenosine (+99%, p = 0.006), ADP (+42%, p = 0.01), AMP (+79%, p = 0.004), GDP (+69%, p = 0.003), GMP (+58%, p = 0.01), IMP (+50%, p = 0.03), xanthine (+61%, p = 0.0006)], and several bile acid metabolites. The CS changes in metabolites qualitatively mirrored those in the peripheral blood in both timing and magnitude, suggesting the heart was not the major source of the metabolite release. CONCLUSIONS: Isolated increases in myocardial work can induce changes in the plasma metabolome, but these changes do not appear to be directly cardiac in origin. A number of these dynamic metabolites have known signaling functions. Our study provides additional evidence to a growing body of literature on metabolic 'cross-talk' between the heart and other organs.