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Background:The reference standard of detecting acute rejection (AR) in adult heart transplant (HTx) patients is an endomyocardial biopsy (EMB). The majority of EMBs are performed in asymptomatic patients. However, the benefit of diagnosing and treating AR compared to the risk of EMB complications has not been compared in the contemporary era (2010-current).Objectives:This study compared treated AR and EMB complications in HTx patients.Methods:The authors retrospectively analyzed 2,769 EMB obtained in 326 consecutive HTx patients between August 2019 and August 2022. Variables included surveillance versus for cause indication, recipient and donor characteristics, EMB procedural data and pathologic grades, treatment for AR, and clinical outcomes.Results:The overall EMB complication rate was 1.6%. EMBs performed within 1 month after HTx compared to after 1 month HTx showed significantly increased complications (OR = 12.74, p < 0.001). The treated AR rate was 14.2% in the for cause EMBs and 1.2% in the surveillance EMBs. We found the benefit/risk ratio was significantly lower in the surveillance compared to the for cause EMB group (OR = 0.05, p < 0.001).Conclusions:The yield of surveillance EMBs has declined in the contemporary era, while for cause EMBs continued to demonstrate a high benefit/risk ratio. The risk of EMB complications was highest within 1 month after HTx. Surveillance EMB protocols in HTx patients may need to be re-evaluated.

Vein grafts, the most commonly used conduits in multi-vessel coronary artery bypass grafting surgery, have high intermediate- and long-term failure rates. The abrupt and marked increase in hemodynamic loads on the vein graft is a known contributor to failure. Recent computational modeling suggests that veins can more successfully adapt to an increase in mechanical load if the rate of loading is gradual. Applying an external wrap or support at the time of surgery is one way to reduce the transmural load, and this approach has improved performance relative to an unsupported vein graft in several animal studies. Yet, a clinical trial in humans has shown benefits and drawbacks, and mechanisms by which an external wrap affects vein graft adaptation remain unknown. This study aims to elucidate such mechanisms using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, hemodynamics using computational fluid dynamics, structure using histology, and transcriptional changes using bulk RNA-sequencing in an ovine carotid-jugular interposition vein graft model, without and with an external biodegradable wrap that allows loads to increase gradually. We show that a biodegradable external wrap promotes luminal uniformity, physiological wall shear stress, and a consistent vein graft phenotype, namely, it prevents over-distension, over-thickening, intimal hyperplasia, and inflammation, and it preserves mechanotransduction. These mechanobiological insights into vein graft adaptation in the presence of an external support can inform computational growth and remodeling models of external support and facilitate design and manufacturing of next-generation external wrapping devices. STATEMENT OF SIGNIFICANCE: External mechanical support is emerging as a promising technology to prevent vein graft failure following coronary bypass graft surgery. While variants of this technology are currently under investigation in clinical trials, the fundamental mechanisms of adaptation remain poorly understood. We employ an ovine carotid-jugular interposition vein graft model, with and without an external biodegradable wrap to provide mechanical support, and probe vein graft adaptation using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, fluid flow using computational fluid dynamics, vascular composition and structure using histology, and transcriptional changes using bulk RNA sequencing. We show that the wrap mitigates vein graft failure by promoting multiple adaptive mechanisms (across biological scales).

We demonstrated that joint delivery of human-derived endothelial progenitor cell (EPC) and smooth muscle cell (SMC) sheets mimics the native architecture of structurally mature blood vessels and contributes to limiting ventricular remodeling using a confluent SMC-EPC bi-level cell sheet engineered by cell-sheet technology and transplanted into an athymic rodent model of myocardial infarction. Enhanced vasculogenic potential was observed in vitro when EPCs were stimulated with SMC-conditioned culture medium, augmenting angiogenesis in vivo. Increased structurally mature vessel density, myocardial upregulation of biological adhesion, and vasculature developmental genes in the ischemic border zone myocardium showed interaction between cells and the extracellular matrix. Cell fate tracking experiments featuring xenogeneic transplantation showed transplanted EPCs and SMCs to have elements of the newly formed vasculature. Specialized magnetic resonance imaging of the cell-sheet-transplanted rodents suggested prolonged cell retention. The robust angiogenic effect of the transplanted cell sheets induced reverse ventricular remodeling of the ischemic heart. Bioinformatic analyses indicated that these cell sheets promote transcriptome-wide changes in the left ventricular response to acute ischemia, promote productive remodeling, and prevent pathological ventricular dilation. Thus, the human-derived, spatially arranged SMC-EPC bi-level cell sheet is a promising therapy for increasing myocardial viability and limiting adverse ventricular remodeling after myocardial infarction.

Newborn mammals, including piglets, exhibit natural heart regeneration after myocardial infarction (MI) on postnatal day 1 (P1), but this ability is lost by postnatal day 7 (P7). The electrophysiologic properties of this naturally regenerated myocardium have not been examined. We hypothesized that epicardial conduction is preserved after P1 MI in piglets. Yorkshire-Landrace piglets underwent left anterior descending coronary artery ligation at age P1 (n = 6) or P7 (n = 7), After 7 weeks, cardiac magnetic resonance imaging was performed with late gadolinium enhancement for analysis of fibrosis. Epicardial conduction mapping was performed using custom 3D-printed high-resolution mapping arrays. Age- and weight-matched healthy pigs served as controls (n = 6). At the study endpoint, left ventricular (LV) ejection fraction was similar for controls and P1 pigs (46.4 ± 3.0% vs. 40.3 ± 4.9%, p = 0.132), but significantly depressed for P7 pigs (30.2 ± 6.6%, p < 0.001 vs. control). The percentage of LV myocardial volume consisting of fibrotic scar was 1.0 ± 0.4% in controls, 9.9 ± 4.4% in P1 pigs (p = 0.002 vs. control), and 17.3 ± 4.6% in P7 pigs (p < 0.001 vs. control, p = 0.007 vs. P1). Isochrone activation maps and apex activation time were similar between controls and P1 pigs (9.4 ± 1.6 vs. 7.8 ± 0.9 ms, p = 0.649), but significantly prolonged in P7 pigs (21.3 ± 5.1 ms, p < 0.001 vs. control, p < 0.001 vs. P1). Conduction velocity was similar between controls and P1 pigs (1.0 ± 0.2 vs. 1.1 ± 0.4 mm/ms, p = 0.852), but slower in P7 pigs (0.7 ± 0.2 mm/ms, p = 0.129 vs. control, p = 0.052 vs. P1). Overall, our data suggest that epicardial conduction dynamics are conserved in the setting of natural heart regeneration in piglets after P1 MI.

Introduction: We designed a novel mitral annuloplasty ring based on healthy human imaging to allow for the mitral valve (MV) annular conformational changes while restricting the anteroposterior (AP) distance. The objectives were to evaluate ex vivo biomechanics of the novel ring and to validate the annular dynamics after ring implantation in vivo. Methods: Cardiac MRI exams were obtained for 3 healthy volunteers. The MV annulus was tracked (Fig. A-C). Based the imaging data, a novel ring was manufactured (Fig. D-F). An ex vivo annular dilation model of mitral regurgitation was used in a left heart simulator (Fig. G, H) to measure hemodynamics and chordal forces at dilated baseline and after repair using the novel, rigid, and flexible rings in 5 porcine MVs. Novel (n = 6) or rigid rings (n = 5) were implanted into male Dorset sheep. Pre- and post-operative cardiac MRI exams were analyzed. Results: Repair using the novel, rigid, and flexible ring reduced regurgitation fraction from 30.0 ± 5.8% at dilated baseline to 4.7 ± 2.7%, 2.4 ± 3.2%, and 17.8 ± 10.0% ( p < .0001, Fig. I-N ). Peak forces on the primary chordae decreased after ring annuloplasty repair ( p < .0001, Fig. O ). The novel ring also showed lower peak forces compared to the rigid ring (p = .03) in secondary chordae ( Fig. P ). MV annular motion was preserved in vivo using the novel ring but restricted to a planar geometry using the rigid ring ( Fig. Q-S ). Annular height to intercommissure ratio at midsystole were similar pre-repair (0.2 ± 0.1) and after novel ring repair (0.2 ± 0.0, p = .89). The variance of AP distance during the cardiac cycle was similar between the novel (0.4 ± 0.3) and rigid ring (0.5 ± 0.1, p = .58). Conclusions: This novel mitral annuloplasty ring demonstrated excellent capability in reducing AP dimension and repairing regurgitation with a superior chordal force profile while facilitating the annular flexible motion. Future studies will focus on evaluating repair durability and effect on left ventricular remodeling.

BACKGROUND: Manganese-enhanced MRI (MEMRI) detects viable cardiomyocytes based on the intracellular manganese uptake via L-type calcium-channels. This study aimed to quantify myocardial viability based on manganese uptake by viable myocardium in the infarct core (IC), peri-infarct region (PIR) and remote myocardium (RM) using T1 mapping before and after MEMRI and assess their association with cardiac function and arrhythmogenesis. METHODS: Fifteen female swine had a 60-minute balloon ischemia-reperfusion injury in the LAD. MRI (Signa 3T, GE Healthcare) and electrophysiological study (EPS) were performed 4 weeks later. MEMRI and delayed gadolinium-enhanced MRI (DEMRI) were acquired on LV short axis. The DEMRI positive total infarct area was subdivided into the regions of MEMRI-negative non-viable IC and MEMRI-positive viable PIR. T1 mapping was performed to evaluate native T1, post-MEMRI T1, and delta R1 (R1(post)-R1(pre), where R1 equals 1/T1) of each territory. Their correlation with LV function and EPS data was assessed. RESULTS: PIR was characterized by intermediate native T1 (1530.5±75.2ms) compared to IC (1634.7±88.4ms, p=0.001) and RM (1406.4±37.9ms, p

Endogenous capability of the post-mitotic human heart holds great promise to restore the injured myocardium. Recent evidence indicates that the extracellular vesicles (EVs) regulate cardiac homeostasis and regeneration. Here, we investigated the molecular mechanism of EVs for self-repair. We isolated EVs from human iPSC-derived cardiomyocytes (iCMs), which were exposed to hypoxic (hEVs) and normoxic conditions (nEVs), and examined their roles in in vitro and in vivo models of cardiac injury. hEV treatment significantly improved the viability of hypoxic iCMs in vitro and cardiac function of severely injured murine myocardium in vivo. Microarray analysis of the EVs revealed significantly enriched expression of the miR-106a-363 cluster (miR cluster) in hEVs vs. nEVs. This miR cluster preserved survival and contractility of hypoxia-injured iCMs and maintained murine left-ventricular (LV) chamber size, improved LV ejection fraction, and reduced myocardial fibrosis of the injured myocardium. RNA-Seq analysis identified Jag1-Notch3-Hes1 as a target intracellular pathway of the miR cluster. Moreover, the study found that the cell cycle activator and cytokinesis genes were significantly up-regulated in the iCMs treated with miR cluster and Notch3 siRNA. Together, these results suggested that the miR cluster in the EVs stimulated cardiomyocyte cell cycle re-entry by repressing Notch3 to induce cell proliferation and augment myocardial self-repair. The miR cluster may represent an effective therapeutic approach for ischemic cardiomyopathy.

Introduction: We investigated whether the negatively-charged sulfated dextran-coated iron oxide (SDIO) nanoparticles with higher affinity with macrophage can delineate inflammation more efficiently compared to non-sulfated dextran-coated iron oxide (DIO) nanoparticles in mice LAD ligation model. Methods: After mice were induced with LAD ligation, SDIO or DIO nanoparticles (15mg/kg) were injected intravenously at either day 1, day 3, day 5, and day 7. MRI was performed pre- and post-24 hours later. Dephasing signal loss caused by iron-oxide nanoparticles was detected by gradient echo sequence. Iron uptake was quantified by T2* mapping and calculated as delta R2* (=1/T2*(post)-1/T2*(post)) in the region of interest in the infarct, peri-infarct, and remote zones. Results: SDIO injection produced clear signal voids in the peri-infarct zone at day 3 (n=8), which extend into the infarct zone at day 5 (n=3) (figure). The signal was remarkably decreased at day 7 (n=7). Iron uptake represented by delta R2* in the peri-infarct (80.6±35.7 s -1 ) was significantly higher than that in the infarct (32.3±32.6 s -1 , p-1 , p-1 , p-1 ,p=0.04) were significantly higher than the remote (4.2±14.1 s -1 , p Conclusions: SDIO can detect inflammation in the peri-infarct region in the early phase of acute myocardial infarction.

Introduction: Coronary artery disease is a leading cause of death worldwide. Ischemic injury leads to myocardial dysfunction, resulting in heart failure. Exosomes have emerged as a promising therapeutic for restoring the failing heart. Fundamental questions such as cell of origin and molecular cargo for optimal therapeutic effect are areas of intense research. Our lab has shown that the exosomes from bone marrow derived mesenchymal stem cells (MSC-Ex) and induced pluripotent stem cell derived cardiomyocytes (iCM-Ex) both restore injured murine myocardium. These results led us to compare the therapeutic effects of MSC-Ex vs. iCM-Ex in a porcine myocardial ischemia reperfusion (IR) injury model, a step toward predicting efficacy in humans. Hypothesis: iCM-Ex is superior to MSC-Ex in restoring the injured porcine myocardium. Methods and Results: Pigs underwent ischemia reperfusion (IR) injury, consisting of 1 hour percutaneous balloon occlusion of the proximal left anterior descending artery immediately distal to the first septal artery. Following IR injury, 5 x 10 11 exosomes were delivered in ten, 500μL intramyocardial injections using a BioCardio Helix™ catheter. Biplane ventriculography was used to target the peri-infarct region. At 2- and 4-weeks post-infarct, pigs underwent cardiac MRI (cMRI) with ciné, delayed-enhanced (DEMRI) and manganese-enhanced (MEMRI) MRI. Pigs treated with iCM-Ex (n = 5) demonstrated a 41% improvement in left ventricular ejection fraction (LVEF, p = 0.004) and 35% reduction in indexed left ventricular end diastolic volume (p = 0.008) compared to controls while MSC-Ex (N = 5) did not demonstrate significant functional improvement. Furthermore, DEMRI and MEMRI showed a 21% reduction in myocardial scar (p = 0.14) in iCM-Ex treated animals compared to control while MSC-Ex group showed no difference. RNA-seq of the exosomes and transcriptomic analysis of the ex vivo myocardium will delineate the molecular mechanism of action and the putative intracellular pathway. Conclusion: iCM-Ex is superior to MSC-Ex in improving LVEF and reducing myocardial scar formation following ischemic insult. Comparative analysis between iCM-Ex and MSC-Ex is underway to identify the molecular targets that restore the failing heart.

BackgroundMitochondrial dysfunction results in an imbalance between energy supply and demand in a failing heart. An innovative therapy that targets the intracellular bioenergetics directly through mitochondria transfer may be necessary.ObjectivesThe purpose of this study was to establish a preclinical proof-of-concept that extracellular vesicle (EV)-mediated transfer of autologous mitochondria and their related energy source enhance cardiac function through restoration of myocardial bioenergetics.MethodsHuman-induced pluripotent stem cell-derived cardiomyocytes (iCMs) were employed. iCM-conditioned medium was ultracentrifuged to collect mitochondria-rich EVs (M-EVs). Therapeutic effects of M-EVs were investigated using invivo murine myocardial infarction (MI) model.ResultsElectron microscopy revealed healthy-shaped mitochondria inside M-EVs. Confocal microscopy showed that M-EV-derived mitochondria were transferred into the recipient iCMs and fused with their endogenous mitochondrial networks. Treatment with 1.0× 108/ml M-EVs significantly restored the intracellular adenosine triphosphate production and improved contractile profiles of hypoxia-injured iCMs as early as 3h after treatment. In contrast, isolated mitochondria that contained 300× more mitochondrial proteins than 1.0× 108/ml M-EVs showed no effect after 24 h. M-EVs contained mitochondrial biogenesis-related messenger ribonucleic acids, including proliferator-activated receptor γ coactivator-1α, which on transfer activated mitochondrial biogenesis in the recipient iCMs at 24h after treatment. Finally, intramyocardial injection of 1.0× 108 M-EVs demonstrated significantly improved post-MI cardiac function through restoration of bioenergetics and mitochondrial biogenesis.ConclusionsM-EVs facilitated immediate transfer of their mitochondrial and nonmitochondrial cargos, contributing to improved intracellular energetics invitro. Intramyocardial injection of M-EVs enhanced post-MI cardiac function invivo. This therapy can be developed as a novel, precision therapeutic for mitochondria-related diseases including heart failure.

Introduction: Newborn piglets reportedly exhibit natural heart regeneration after myocardial infarction (MI). However, the electrophysiologic properties of this regenerated muscle have not been examined. We hypothesized that epicardial electrical conduction is preserved after MI in newborn piglets. Methods: Yorkshire-Landrace piglets underwent left anterior descending coronary artery ligation on postnatal day 1 (P1, n=4) or postnatal day 7 (P7, n=7), infarcting the anteroseptal left ventricle through which the Purkinje conduction system passes. After 7 weeks, cardiac magnetic resonance imaging (MRI) was performed with late gadolinium enhancement for fibrosis analysis. Epicardial conduction mapping was performed using custom 3D-printed, 256-channel high-resolution mapping arrays (Fig 1A). Age- and weight-matched healthy pigs served as controls (n=7). Data are expressed as mean±SD. Results: MRI analysis revealed significant differences between the control, P1, and P7 groups in ejection fraction (47.6±3.1% vs 37.6±3.3% vs 30.2±6.6%, p Conclusion: P1 piglets exhibited incomplete natural cardiac regeneration after MI but nevertheless demonstrated electrophysiologic conservation of epicardial conduction dynamics.

Background Exosomes are small extracellular vesicles that function as intercellular messengers and effectors. Exosomal cargo contains regulatory small molecules, including mi RNA s, mRNA s, lnc RNA s, and small peptides that can be modulated by different pathological stimuli to the cells. One of the main mechanisms of action of drug therapy may be the altered production and/or content of the exosomes. Methods and Results We studied the effects on exosome production and content by neprilysin inhibitor/angiotensin receptor blockers, sacubitril/valsartan and valsartan alone, using human‐induced pluripotent stem cell‐derived cardiomyocytes under normoxic and hypoxic injury model in vitro , and assessed for physiologic correlation using an ischemic myocardial injury rodent model in vivo. We demonstrated that the treatment with sacubitril/valsartan and valsartan alone resulted in the increased production of exosomes by induced pluripotent stem cell‐derived cardiomyocytes in vitro in both conditions as well as in the rat plasma in vivo. Next‐generation sequencing of these exosomes exhibited downregulation of the expression of rno‐miR‐181a in the sacubitril/valsartan treatment group. In vivo studies employing chronic rodent myocardial injury model demonstrated that miR‐181a antagomir has a beneficial effect on cardiac function. Subsequently, immunohistochemical and molecular studies suggested that the downregulation of miR‐181a resulted in the attenuation of myocardial fibrosis and hypertrophy, restoring the injured rodent heart after myocardial infarction. Conclusions We demonstrate that an additional mechanism of action of the pleiotropic effects of sacubitril/valsartan may be mediated by the modulation of the mi RNA expression level in the exosome payload.

Background Induced pluripotent stem cells and their differentiated cardiomyocytes ( iCM s) have tremendous potential as patient‐specific therapy for ischemic cardiomyopathy following myocardial infarctions, but difficulties in viable transplantation limit clinical translation. Exosomes secreted from iCM s (iCM‐Ex) can be robustly collected in vitro and injected in lieu of live iCM s as a cell‐free therapy for myocardial infarction. Methods and Results iCM ‐Ex were precipitated from iCM supernatant and characterized by protein marker expression, nanoparticle tracking analysis, and functionalized nanogold transmission electron microscopy. iCM ‐Ex were then used in in vitro and in vivo models of ischemic injuries. Cardiac function in vivo was evaluated by left ventricular ejection fraction and myocardial viability measurements by magnetic resonance imaging. Cardioprotective mechanisms were studied by JC ‐1 (tetraethylbenzimidazolylcarbocyanine iodide) assay, immunohistochemistry, quantitative real‐time polymerase chain reaction, transmission electron microscopy, and immunoblotting. iCM ‐Ex measured ≈140 nm and expressed CD 63 and CD 9. iCM and iCM ‐Ex micro RNA profiles had significant overlap, indicating that exosomal content was reflective of the parent cell. Mice treated with iCM ‐Ex demonstrated significant cardiac improvement post–myocardial infarction, with significantly reduced apoptosis and fibrosis. In vitro iCM apoptosis was significantly reduced by hypoxia and exosome biogenesis inhibition and restored by treatment with iCM ‐Ex or rapamycin. Autophagosome production and autophagy flux was upregulated in iCM ‐Ex groups in vivo and in vitro. Conclusions iCM‐Ex improve post–myocardial infarction cardiac function by regulating autophagy in hypoxic cardiomyoytes, enabling a cell‐free, patient‐specific therapy for ischemic cardiomyopathy.

Genetic variation in the FAM13A (Family with Sequence Similarity 13 Member A) locus has been associated with several glycemic and metabolic traits in genome-wide association studies (GWAS). Here, we demonstrate that in humans, FAM13A alleles are associated with increased FAM13A expression in subcutaneous adipose tissue (SAT) and an insulin resistance-related phenotype (e.g. higher waist-to-hip ratio and fasting insulin levels, but lower body fat). In human adipocyte models, knockdown of FAM13A in preadipocytes accelerates adipocyte differentiation. In mice, Fam13a knockout (KO) have a lower visceral to subcutaneous fat (VAT/SAT) ratio after high-fat diet challenge, in comparison to their wild-type counterparts. Subcutaneous adipocytes in KO mice show a size distribution shift toward an increased number of smaller adipocytes, along with an improved adipogenic potential. Our results indicate that GWAS-associated variants within the FAM13A locus alter adipose FAM13A expression, which in turn, regulates adipocyte differentiation and contribute to changes in body fat distribution., Genetic variants in the FAM13A locus have been associated with anthropometric and glycemic traits. Here, using fine-mapping, in vitro knockdown studies in pre-adipocytes and in vivo knockout in mice, the authors show that FAM13A is involved in regulating fat distribution and metabolic traits.

Evaluation of parameters relating to serum ferritin and iron is critically important in the diagnosis of iron deficiency anemia (IDA). The recent development of automated systems for hematology analysis has made it possible to measure reticulocyte hemoglobin equivalent (RET-He), which is thought to reflect iron content in reticulocytes, in the same sample used for complete blood count tests. If RET-He is, indeed, capable of evaluating iron deficiency (ID), it would be useful for immediate diagnosis of IDA. In the present study, we examined the usefulness of RET-He for diagnosis of ID. Blood samples were obtained from 211 patients. Anemia was defined as hemoglobin (Hb) level of

The use of dipeptidyl peptidase (DPP)-4 inhibitors in patients with type 2 diabetes treated with insulin may be beneficial. However, the long-term efficacy and safety of vildagliptin add-on therapy in these patients remains unclear.A total of 73 patients with type 2 diabetes treated with insulin were randomly assigned to receive either add-on therapy of vildagliptin (n=37) or conventional therapy without DPP-4 inhibitors (n=36) for glucose control. Hemoglobin A1c (HbA1c) levels, dose and number of insulin injections, number of hypoglycemia episodes, and liver and renal function were monitored for 2years.The baseline characteristics of subjects, including age, dose of insulin injections, or HbA1c levels, did not differ between the two groups. In the vildagliptin group, HbA1c levels significantly decreased and the significance of HbA1c reduction was maintained for 24months (from 8.0±1.2% to 7.4±1.0%, p0.05, at the end of observational period). In addition, the dose and number of insulin injections significantly reduced (-5.6units, p0.01, and -0.9 times, p0.001). However, these parameters were unchanged in the control group. The number of patients who experienced three or more episodes of hypoglycemia per year was significantly lower in the vildagliptin group (n=4) than in the control group (n=11) (odds ratio, 0.28; 95% confidence interval, 0.08-0.97; p0.05).Vildagliptin as an add-on to insulin treatment for 24months was well tolerated and led to sustained reductions in HbA1c, the dose and number of insulin injections, and the risk of hypoglycemia.

Although ischemic heart disease is the leading cause of death worldwide, mainstay treatments ultimately fail because they do not adequately address disease pathophysiology. Restoring the microvascular perfusion deficit remains a significant unmet need and may be addressed via delivery of pro-angiogenic cytokines. The therapeutic effect of cytokines can be enhanced by encapsulation within hydrogels, but current hydrogels do not offer sufficient clinical translatability due to unfavorable viscoelastic mechanical behavior which directly impacts the ability for minimally-invasive catheter delivery. In this report, we examine the therapeutic implications of dual-stage cytokine release from a novel, highly shear-thinning biocompatible catheter-deliverable hydrogel. We chose to encapsulate two protein-engineered cytokines, namely dimeric fragment of hepatocyte growth factor (HGFdf) and engineered stromal cell-derived factor 1α (ESA), which target distinct disease pathways. The controlled release of HGFdf and ESA from separate phases of the hyaluronic acid-based hydrogel allows extended and pronounced beneficial effects due to the precise timing of release. We evaluated the therapeutic efficacy of this treatment strategy in a small animal model of myocardial ischemia and observed a significant benefit in biological and functional parameters. Given the encouraging results from the small animal experiment, we translated this treatment to a large animal preclinical model and observed a reduction in scar size, indicating this strategy could serve as a potential adjunct therapy for the millions of people suffering from ischemic heart disease.

Reactive oxygen species (ROS) such as superoxide anion and hydrogen peroxide are produced highly in myocarditis. ROS, which not only act as effectors for pathogen killing but also mediate signal transduction in the stress responsive pathways, are closely related with both innate and adaptive immunity. On the other hand, oxidative stress overwhelming the capacity of anti-oxidative system generated in severe inflammation has been suggested to damage tissues and exacerbate inflammation. Oxidative stress worsens the autoimmunological process of myocarditis, and suppression of the anti-oxidative system and long-lasting oxidative stress could be one of the pathological mechanisms of cardiac remodeling leading to inflammatory cardiomyopathy. Oxidative stress is considered to be one of the promising treatment targets of myocarditis. Evidences of anti-oxidative treatments in myocarditis have not been fully established. Basic strategies of anti-oxidative treatments include inhibition of ROS production, activation of anti-oxidative enzymes and elimination of generated free radicals. ROS are produced by mitochondrial respiratory chain reactions and enzymes including NADPH oxidases, cyclooxygenase, and xanthine oxidase. Other systems involved in inflammation and stress response, such as NF-κB, Nrf2/Keap1, and neurohumoral factors also influence oxidative stress in myocarditis. The efficacy of anti-oxidative treatments could also depend on the etiology and the phases of myocarditis. We review in this article the pathological significance of ROS and oxidative stress, and the potential anti-oxidative treatments in myocarditis.

Objective We herein conducted a retrospective study to evaluate the long-term efficacy and safety of sitagliptin treatment in elderly patients with type 2 diabetes mellitus. Methods We analyzed the changes in glycemic control in 112 Japanese type 2 diabetes patients over 65 years of age treated with 50 mg/day sitagliptin. Hemoglobin A1c (HbA1c) levels, liver and kidney functions, and usage of hypoglycemic agents were recorded for 24 months. Results HbA1c levels were significantly decreased, and the significance of HbA1c reduction was maintained during the observation period [from 7.7±1.1% to 7.2±0.7% (p

We investigated whether the negatively-charged sulfated dextran-coated iron oxide (SDIO) nanoparticles with higher affinity with macrophages can detect inflammation more efficiently compared to non-sulfated dextran-coated iron oxide (DIO) nanoparticles in mice LAD ligation model. After mice were

Mitochondrial dysfunction results in an imbalance between energy supply and demand in a failing heart. Extracellular vesicle (EV)-mediated transfer of autologous mitochondria and their related energy source may enhance cardiac function following myocardial injury through restoration of myocardial

Background: Induced pluripotent stem cells (iPSCs) and their differentiated cardiomyocytes (iCMs) have tremendous potential as patient-specific therapy for myocardial injury (MI). Our previous work showed that the iCMs restore the injured murine myocardium through secretion of paracrine factors, modulating apoptotic pathways to restore the murine peri-infarct region (PIR). Hypothesis: iCM-derived exosomes (iCM-Ex), a major constituent of the iCM secretome, may salvage the injured cardiomyocytes in the PIR. Methods: iCM-Ex were precipitated from iCM supernatant and characterized using various molecular analyses. Immunodeficient mice sustained MIs and received iCMs, iCM-Ex, or PBS control via direct intramyocardial injection into the PIR. Cardiac MRI assessed LV ejection fraction (LVEF) and viability at 2- and 4-week post-injection. iCMs, iCM-Ex, and PIR tissue were isolated for molecular and histological analyses. Results: iCM-Ex measured approximately 142 nm and expressed CD63 and CD9. iCM and iCM-Ex miRNA profiles had significant overlap, indicating that exosomal content was reflective of the parent cell. In vitro iCM apoptosis was increased significantly by hypoxia and exosome biogenesis inhibition while iCM-Ex or rapamycin reduced iCM apoptosis (p Conclusions: iCM-Ex demonstrated similar efficacy as the iCMs in improving post-MI cardiac function by regulating autophagy and apoptosis of hypoxia injured cardiomyocytes. This finding represents the potential of cell-free, patient-specific biologic to treat ischemic cardiomyopathy by stimulation of an endogenous repair mechanism.

Post-operative adhesions form as a result of normal wound healing processes following any type of surgery. In cardiac surgery, pericardial adhesions are particularly problematic during reoperations, as surgeons must release the adhesions from the surface of the heart before the intended procedure can begin, thereby substantially lengthening operation times and introducing risks of haemorrhage and injury to the heart and lungs during sternal re-entry and cardiac dissection. Here we show that a dynamically crosslinked supramolecular polymer-nanoparticle hydrogel, with viscoelastic and flow properties that enable spraying onto tissue as well as robust tissue adherence and local retention in vivo for two weeks, reduces the formation of pericardial adhesions. In a rat model of severe pericardial adhesions, the hydrogel markedly reduced the severity of the adhesions, whereas commercial adhesion barriers (including Seprafilm and Interceed) did not. The hydrogels also reduced the severity of cardiac adhesions (relative to untreated animals) in a clinically relevant cardiopulmonary-bypass model in sheep. This viscoelastic supramolecular polymeric hydrogel represents a promising clinical solution for the prevention of post-operative pericardial adhesions.

Although human induced pluripotent stem cells (iPSCs) and their derivatives have great potential for the treatment of heart failure. The therapeutic benefit is limited by translational challenges of stem cells such as cell engraftment. Thus, a robust in vivo imaging technology is indispensable to advance the clinical implementation of stem cell therapy. While no available imaging technology meets the requirement for in vivo stem cell tracking, MRI is a highly promising tool due to its high spatial resolution, temporal resolution, and tissue contrast; yet, this modality lacks sensitivity. Superparamagnetic iron oxide particles (SPIONs) addresses this critical imaging issue and have been used as an MRI contrast agent for stem cell tracking. However, their critical limitation is the inability to evaluate cell viability as SPIONs remain in the tissue long after the death of transplanted cells. To address this shortcoming of SPIONs, the novel magneto-endosymbiont-based (MEs) contrast agent was developed (Magnelle®, Bell Biosystems, Inc., South SF, CA). The MEs utilize the magnetosome biosynthesized by magnetotactic bacteria (MTB), a specific intracellular structure containing inorganic magnetic iron crystals (magnetite or greigite). Having superparamagnetic property like SPIONs, MEs can be detected on T2* weighted imaging. MEs have high safety profile and do not interfere with the functions of transfected cells. Unlike SPIONs, the antiginecity of the MEs are readily recognized and removed from macrophages quickly after the death of labeled cells, eliminating signals from dead cells. In the previous study from our group, iPSC derived cardiomyocytes were labeled with MEs and detected successfully on MRI after transplantation into the heart. In vivo ME signals corresponded with luciferase-based bioluminescence imaging (BLI) of the transplanted cell viability. In conclusion, ME is a novel MRI contrast agent for in vivo cellular tracking that allows accurate longitudinal visualization of the engrafted cells.

The peri-infarct region (PIR) consists of a mixed composition of salvageable injured cardiomyocytes and fibrosis and is linked to increased cardiovascular event rates in ischemic cardiomyopathy patients. Therefore, identifying and quantifying PIR volumes and composition has an important clinical value in predicting the likelihood of arrhythmogenesis and in considering revascularization or medical/defibrillator management on an individualized patient basis. In addition to the established importance of assessing the volume of gadolinium enhancement and the heterogeneous gadolinium signal intensity in the PIR, T1 mapping may provide a more reproducible and accurate method to delineate the PIR extent and variability. While the value of native T1 mapping has not been clearly established in ischemic cardiomyopathy, T1 mapping combined with the unique strengths of varying contrast agents may help to delineate the roles of the PIR in the clinical management. The ECV changes in the infarct injury region measured by the administration of gadolinium-based contrast agents can predict LV functional outcome and cardiovascular events following myocardial infarction. Alternatively, the use of manganese-based contrast agents generates a more accurate quantification of myocardial viability based on manganese uptake into live cardiomyocytes via voltage-gated calcium channels, which may possibly predict future outcomes more sensitively compared to the evaluation of cardiac fibrosis and extracellular volume (ECV) fraction. Finally, our current tools to identify, quantify, and correlate PIR characteristics with arrhythmia, functional recovery, and overall prognosis are still developing despite early data suggesting valuable predictive/prognostic information residing within the PIR.

Supplemental Digital Content is available in the text., Rationale: The impact of cardioprotective strategies and ischemia duration on postischemia/reperfusion (I/R) myocardial tissue composition (edema, myocardium at risk, infarct size, salvage, intramyocardial hemorrhage, and microvascular obstruction) is not well understood. Objective: To study the effect of ischemia duration and protective interventions on the temporal dynamics of myocardial tissue composition in a translational animal model of I/R by the use of state-of-the-art imaging technology. Methods and Results: Four 5-pig groups underwent different I/R protocols: 40-minute I/R (prolonged ischemia, controls), 20-minute I/R (short-duration ischemia), prolonged ischemia preceded by preconditioning, or prolonged ischemia followed by postconditioning. Serial cardiac magnetic resonance (CMR)-based tissue characterization was done in all pigs at baseline and at 120 minutes, day 1, day 4, and day 7 after I/R. Reference myocardium at risk was assessed by multidetector computed tomography during the index coronary occlusion. After the final CMR, hearts were excised and processed for water content quantification and histology. Five additional healthy pigs were euthanized after baseline CMR as reference. Edema formation followed a bimodal pattern in all 40-minute I/R pigs, regardless of cardioprotective strategy and the degree of intramyocardial hemorrhage or microvascular obstruction. The hyperacute edematous wave was ameliorated only in pigs showing cardioprotection (ie, those undergoing short-duration ischemia or preconditioning). In all groups, CMR-measured edema was barely detectable at 24 hours postreperfusion. The deferred healing-related edematous wave was blunted or absent in pigs undergoing preconditioning or short-duration ischemia, respectively. CMR-measured infarct size declined progressively after reperfusion in all groups. CMR-measured myocardial salvage, and the extent of intramyocardial hemorrhage and microvascular obstruction varied dramatically according to CMR timing, ischemia duration, and cardioprotective strategy. Conclusions: Cardioprotective therapies, duration of index ischemia, and the interplay between these greatly influence temporal dynamics and extent of tissue composition changes after I/R. Consequently, imaging techniques and protocols for assessing edema, myocardium at risk, infarct size, salvage, intramyocardial hemorrhage, and microvascular obstruction should be standardized accordingly.

Late gadolinium enhancement (LGE) with cardiac magnetic resonance (CMR) imaging has demonstrated the capability of stratifying hypertrophic cardiomyopathy (HCM). Stress perfusion test of CMR can quantify myocardial perfusion reserve (MPR), but its clinical role is not determined. The purpose of this study was to investigate the relationship between MPR and LGE in patients with HCM. A total of 61 consecutive cases underwent complete evaluation with electrocardiography and CMR [cine imaging, coronary MR angiography (MRA), and stress perfusion testing with LGE]. HCM cases were diagnosed by the Japanese conventional guideline prior to this CMR study. Mild LVH was defined as more than 13 mm in maximum LV wall thickness at end diastole on the cine imaging of the CMR. MPR was calculated as the ratio of stress/rest myocardial blood flow using an intensity curve on the stress perfusion test. Cases with ischemic heart disease were excluded from the study based on clinical history and coronary MRA. There were 37 HCM and 24 mild LVH cases (average age: 60.5 ± 10.9 vs. 64.8 ± 10.8; male: 62.2 vs. 75.0%, respectively, non-significant). MPR in HCM was lower than in LVH (1.5 ± 0.5 vs. 2.2 ± 0.9, p

Extracellular vesicles (EVs) are essential tools for conveying biological information and modulating functions of recipient cells. Implantation of isolated or modulated EVs can be innovative therapeutics for various diseases. Furthermore, EVs could be a biocompatible drug delivery vehicle to carry both endogenous and exogenous biologics. Tracking EVs should play essential roles in understanding the functions of EVs and advancing EV therapeutics. EVs have the characteristic structures consisting of the lipid bilayer and specific membrane proteins, through which they can be labeled efficiently. EVs can be labeled either directly using probes or indirectly by transfection of reporter genes. Optical imaging (fluorescent imaging and bioluminescent imaging), single-photon emission computed tomography (SPECT)/positron emission tomography (PET), and magnetic resonance imaging (MRI) are currently used for imaging EVs. Labeling EVs with superparamagnetic iron oxide (SPIO) nanoparticles for MRI tracking is a promising method that can be translated into clinic. SPIO can be internalized by most of the cell types and then released as SPIO containing EVs, which can be visualized on T2*-weighted imaging. However, this method has limitations in real-time imaging because of the life cycle of SPIO after EV degradation. Further studies will be needed to validate SPIO labeling by other imaging modalities in preclinical studies. The emerging technologies of labeling and imaging EVs with SPIO in comparison with other imaging modalities are reviewed in this paper.

Marfan syndrome (MFS) is a systemic connective tissue disorder caused by mutations in the extracellular matrix protein fibrillin-1. While it is known that patients with MFS are at high risk of dental disorders and cardiovascular diseases, little information has been provided to date. To clarify the prevalence of periodontitis in patients with MFS, their oral condition and cardiovascular complications were evaluated. The subjects were patients with MFS (n = 40) who attended the University of Tokyo hospital; age- and gender-matched healthy individuals (n = 14) constituted a control group. Cardiovascular complications and full-mouth clinical measurements, including number of teeth, probing of pocket depth (PD), bleeding on probing (BOP), and community periodontal index (CPI) were recorded. MFS patients had more frequent cardiovascular complications (95 %) compared with the controls (0 %). MFS patients had periodontitis (CPI 3 and 4) more frequently (87.5 %) than the age- and gender-matched control subjects (35.7 %). Furthermore, MFS patients had significantly more severe periodontitis (CPI 2.90 ± 0.12 vs 1.64 ± 0.32) and fewer remaining teeth (26.7 ± 0.4 vs 28.4 ± 0.4) compared with the controls. However, PD and BOP were comparable between MFS patients and the control group. A high incidence of periodontitis and cardiovascular complications was observed in Japanese MFS patients.

Periodontitis is one of the most common infections in humans. Recently, published reports assert that periodontitis is associated with cardiovascular disease. Although it is said that viral, bacterial infections and autoimmune diseases may be the cause of myocarditis, the pathogenesis of it remains unclear. The aim of this study was to investigate the influence of a periodontal pathogen on experimental autoimmune myocarditis (EAM). Porphyromonas gingivalis (P.g.), PBS as a control, were injected into the mice. Histopathological and immunohistochemical analyses were performed. We examined heart mRNA levels using quantitative RT-PCR. The anti-P.g. IgG antibody level in plasma samples of the P.g.-injected group significantly increased compared with the PBS-injected group. Histopathological analysis detected that the myocarditis-affected areas and the fibrotic area in the P.g.-injected EAM group significantly increased compared with the PBS-injected EAM group ( P < 0.05). Immunohistochemical analysis detected that more CD11b-positive cells were shown in the heart of the P.g.-injected EAM group compared with the PBS EAM-injected group ( P < 0.05). Hearts from the P.g.-injected EAM group showed significantly increased expression of monocyte chemoattractant protein-1, IFN-γ, and matrix metalloproteinase-9 (MMP-9) mRNA compared with the hearts from the PBS-injected EAM group ( P < 0.05). On day 7, serum levels of IL-6 were significantly enhanced in the P.g.-injected EAM group compared with the PBS-injected EAM group ( P < 0.05). These results showed that P.g. injection could deteriorate EAM in mice through CD11b-positive cells, cytokines, and MMP-9 expression.

Inflammation plays a significant role in a wide range of cardiovascular diseases (CVDs). The numerous implications of inflammation in all steps of CVDs, including initiation, progression and complications, have prompted the emergence of noninvasive imaging modalities as diagnostic, prognostic and monitoring tools. In this review, we first synthesize the existing evidence on the role of inflammation in vascular and cardiac diseases, in order to identify the main targets used in noninvasive imaging. We chose to focus on positron emission tomographic (PET) and magnetic resonance imaging (MRI) studies, which offer the greatest potential of translation and clinical application. We detail the main preclinical and clinical studies in the following CVDs: coronary and vascular atherosclerosis, abdominal aortic aneurysms, myocardial infarction, myocarditis, and acute heart transplant rejection. We highlight the potential complementary roles of these imaging modalities, which are currently being studied in the emerging technology of PET/MRI. Finally, we provide a perspective on innovations and future applications of noninvasive imaging of cardiovascular inflammation. (Circ J 2016; 80: 1269-1277).

Induced pluripotent stem cells and their differentiated cardiomyocytes (iCMs) have tremendous potential as patient-specific therapy for myocardial injury (MI). Our previous work showed that iCMs secrete paracrine factors, modulating apoptotic pathways to restore the murine peri-infarct region (PIR

Induced pluripotent stem cells (iPSCs) and iPSC-derived cardiomyocytes (iCMs) are promising therapeutic approach to salvage the injured myocardium; however, suboptimal in vivo stem cell engraftment and tumorigenicity impede clinical translation. Recent evidence indicates that the stem cells exert