Domestic Parasitic Infections in Patients with Asthma and Eosinophilia in Germany - Three Cases with Learnings in the Era of Anti- IL5 Treatments

Eosinophilic inflammation is a hallmark of asthma, and blood eosinophilia has been established as a biomarker for phenotyping asthma and predicting the response to anti-IL5 treatments. Although parasitic infections are rare in European adults, they remain an important differential diagnosis for blood eosinophilia. We present three patients with both domestic parasitic infections and asthma to raise awareness of the potential challenge of eosinophilia and to provide experience in the management of parasitic infections in the setting of planned or ongoing anti-IL5 treatment. One, a patient from Croatia with moderate asthma but severe blood eosinophilia had an underlying Strongyloides stercoralis infection, with positive stool cultures. Second, a patient with severe allergic asthma and gastrointestinal symptoms had a positive S. stercoralis titer in serology with a clinical response to treatment with ivermectin. Third, a patient with severe nonallergic eosinophilic asthma and eosinophilic granulomatosis with polyangiitis (EGPA) showed an increasing hepatic tumour under anti-IL5-receptor therapy. Positive serology confirmed the diagnosis of Echinococcus multilocularis, and albendazole therapy was initiated. Anti-IL5 therapies were safely started (Patient 2) or resumed (Patient 3) after the initiation of antiparasitic treatment. Screening for parasitic infections is useful in cases of hypereosinophilia, extrapulmonary symptoms or stay in endemic regions.

Association of Complement and MAPK Activation With SARS-CoV-2-Associated Myocardial Inflammation

Question

What is the cardiac phenotype of patients with SARS-CoV-2 infection compared with viral and immune-mediated myocarditis and noninflammatory cardiomyopathy?

Findings

In this case series of 19 patients undergoing endomyocardial biopsies, cardiac specimens of patients with SARS-CoV-2 infection had a higher abundance of complement-associated factors and serine/threonine protein kinases, with mitogen-activated protein kinase–associated pathways having the highest abundance. Similarities in the cardiac immune signature were found among those with SARS-CoV-2 infection and viral myocarditis.

Meaning

In this study, the exploratory data, which characterized myocardial inflammation by deep phenotyping, have implications for the development of treatment strategies to reduce SARS-CoV-2–mediated tissue injury; these findings require confirmation in a prospective and extended cohort of patients.

Importance

Myocardial injury is a common feature of patients with SARS-CoV-2 infection. However, the cardiac inflammatory processes associated with SARS-CoV-2 infection are not completely understood.

Objective

To investigate the inflammatory cardiac phenotype associated with SARS-CoV-2 infection compared with viral myocarditis, immune-mediated myocarditis, and noninflammatory cardiomyopathy by integrating histologic, transcriptomic, and proteomic profiling.

Design, Setting, and Participants

This case series was a cooperative study between the Ludwig Maximilian University Hospital Munich and the Cardiopathology Referral Center at the University of Tübingen in Germany. A cohort of 19 patients with suspected myocarditis was examined; of those, 5 patients were hospitalized with SARS-CoV-2 infection between March and May 2020. Cardiac tissue specimens from those 5 patients were compared with specimens from 5 patients with immune-mediated myocarditis, 4 patients with non–SARS-CoV-2 viral myocarditis, and 5 patients with noninflammatory cardiomyopathy, collected from January to August 2019.

Exposures

Endomyocardial biopsy.

Main Outcomes and Measures

The inflammatory cardiac phenotypes were measured by immunohistologic analysis, RNA exome capture sequencing, and mass spectrometry–based proteomic analysis of endomyocardial biopsy specimens.

Results

Among 19 participants, the median age was 58 years (range, 37-76 years), and 15 individuals (79%) were male. Data on race and ethnicity were not collected. The abundance of CD163+ macrophages was generally higher in the cardiac tissue of patients with myocarditis, whereas lymphocyte counts were lower in the tissue of patients with SARS-CoV-2 infection vs patients with non–SARS-CoV-2 virus-associated and immune-mediated myocarditis. Among those with SARS-CoV-2 infection, components of the complement cascade, including C1q subunits (transcriptomic analysis: 2.5-fold to 3.6-fold increase; proteomic analysis: 2.0-fold to 3.4-fold increase) and serine/cysteine proteinase inhibitor clade G member 1 (transcriptomic analysis: 1.7-fold increase; proteomic analysis: 2.6-fold increase), belonged to the most commonly upregulated transcripts and differentially abundant proteins. In cardiac macrophages, the abundance of C1q was highest in SARS-CoV-2 infection. Assessment of important signaling cascades identified an upregulation of the serine/threonine mitogen-activated protein kinase pathways.

Conclusions and Relevance

This case series found that the cardiac immune signature varied in inflammatory conditions with different etiologic characteristics. Future studies are needed to examine the role of these immune pathways in myocardial inflammation.

Differences in Cardiac Magnetic Resonance Imaging Markers Between Patients With COVID-19-associated Myocardial Injury and Patients With Clinically Suspected Myocarditis

PURPOSE

Coronavirus 2019 disease (COVID-19) has been shown to affect the myocardium, resulting in a worse clinical outcome. In this registry study, we aimed to identify differences in cardiac magnetic resonance imaging (CMRI) between COVID-19 and all-cause myocarditis.

MATERIALS AND METHODS

We examined CMRI of patients with COVID-19 and elevated high-sensitivity serum troponin levels performed between March 31st and May 5th and compared them to CMRI of patients without SARS-CoV-2 infection with suspected myocarditis in the same time period. For this purpose, we evaluated Lake-Louise Criteria for myocarditis by determining nonischemic myocardial injury via T1-mapping, extracellular volume, late gadolinium enhancement, and myocardial edema (ME) by T2-mapping and fat-saturated T2w imaging (T2Q).

RESULTS

A total of 15 of 18 (89%) patients with COVID-19 had abnormal findings. The control group consisted of 18 individuals. There were significantly fewer individuals with COVID-19 who had increased T2 (5 vs. 10; P=0.038) and all-cause ME (7 vs. 15; P=0.015); thus, significantly fewer patients with COVID-19 fulfilled Lake-Louise Criteria (6 vs. 17; P<0.001). In contrast, nonischemic myocardial injury was not significantly different. In the COVID-19 group, indexed end-diastolic volume of the left ventricle showed a significant correlation to the extent of abnormal T1 (R2=0.571; P=0.017) and extracellular volume (R2=0.605; P=0.013) and absolute T1, T2, and T2Q (R2=0.644; P=0.005, R2=0.513; P=0.035 and R2=0.629; P=0.038, respectively); in the control group, only extracellular volume showed a weak correlation (R2=0.490; P=0.046).

CONCLUSIONS

Cardiac involvement in COVID-19 seems to show less ME than all-cause myocarditis. Abnormal CMRI markers correlated to left ventricle dilation only in the COVID-19 group. Larger comparative studies are needed to verify our findings.

Cardiac manifestation is evident in chorea-acanthocytosis but different from McLeod syndrome

INTRODUCTION

We aimed to study the various cardiac manifestations of the two core neuroacanthocytosis (NA) syndromes, namely chorea-acanthocytosis (ChAc) and McLeod syndrome (MLS). So far, cardiac involvement has been described as specific feature only for MLS.

METHODS

We studied six patients with ChAc (mean age 44.5 years, five men, one woman) and six patients with MLS (mean age 57.1 years, all men). Cardiac evaluation included echocardiography and/or cardiac magnetic resonance imaging (cardiac MRI), 24-h ECG-recording and examination of cardiac biomarkers.

RESULTS

Cardiac involvement of ChAc was found in four of six patients. Two patients showed mildly reduced left ventricular ejection fraction (LVEF), two other patients mild to moderate left ventricular (LV) dilatation. Neither an increase in ventricular ectopic beats nor ventricular tachycardia were evident in ChAc. Four of five MLS patients showed left ventricle dilatation and reduced left ventricular ejection fraction (LVEF). Two of these, in addition, had critical ventricular tachycardia. High sensitive troponin T was elevated in all patients, for whom data were available (n = 10). In contrast, elevation of high sensitive troponin I was found in one of six ChAc and one of two MLS patients.

CONCLUSION

For the first time, we reveal cardiac involvement in a cohort of six ChAc patients, while the risk to develop heart failure seems lower than in MLS. Our study confirms the malignant nature of MLS in terms of ventricular arrhythmias and progression to advanced heart failure. Herein, we define disease-specific recommendations for cardiac assessment in both conditions.

s-VCAM-1 is an independent predictor of all-cause mortality in patients with dilated cardiomyopathy and hypokinetic non-dilated cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): University Medicine Munich University Medicine Greifswald

Introduction

The vascular cell adhesion molecule-1 (VCAM-1) is overexpressed in a number of different inflammatory processes on activated endothelium. This could be shown in both a mouse model for autoimmune myocarditis and in human heart tissue from patients with lymphocytic myocarditis.

In addition to the tissue-bound one, a soluble isoform of VCAM-1 (s-VCAM-1) can also be detected in the blood. Higher levels have been associated with worse clinical outcome in chronic heart failure patients of different etiology and other patient groups.

Purpose

Since both inflammation and fibrosis are key processes involved in the pathogenesis of dilated cardiomyopathy (DCM) and hypokinetic non-dilated cardiomyopathy (HNDC), we aimed to investigate the prognostic value of s-VCAM-1 plasma levels for survival in a large cohort of DCM and HNDC patients.

Methods

The cohort comprised of patients with a primary diagnosis of DCM, defined as reduced left ventricular ejection fraction (LVEF &lt;45%), increased left ventricular enddiastolic diameter according to HENRY score (LVEDD &gt;117%) at time of diagnosis as well as HNDC, defined as a reduced left ventricular ejection fraction (LVEF &lt;45%) but no increased LVEDD according to HENRY score (LVEDD &lt; =117%). Exclusion criteria were primary valvular diseases (≥ second degree), acute myocarditis, cancer, chronic alcoholism, coronary artery disease with epicardial stenosis &gt;50%, peripheral artery occlusive disease, known auto-immune disease and heart failure of other origins. Levels of s-VCAM-1 were measured in human plasma using an enzyme-linked immunosorbent assay (R&D Systems, USA). A Cox proportional hazard model for the association between s-VCAM-1 and all-cause mortality was adjusted for age, sex, time since symptom-onset, LVEF, kidney function (eGFR-CKDEPI), CRP and NT-proBNP.

Results

A total of 334 DCM patients were included in this single-center cohort (78.4 % males) with a mean age of 54.0 years [interquartile range [IQR] 47.0, 63.2). On average time since symptom onset was 1.5 years (IQR 0.1, 1.1), LVEF 30.7 % (IQR 25, 37), LVEDD 67.1 mm (IQR 62, 72). During a median follow-up of 12.4 years (IQR 10.1, 13.9), a total of 118 (35.3 %) patients died. Multivariable-adjusted cox regression model revealed a significantly increased all-cause mortality risk with increasing levels of s-VCAM-1 (p for trend =0.039), (hazard ratio [HR] 1.00045 (Conf. Interval 1.00002, 1.00087) for VCAM increase of 1 ng/mL, for increase of 100 ng/ml HR 1.046 (Conf- interval 1.002, 1.091), for increase of 1000ng/ml HR 1.57 (Conf_interval 1.02-2.41) (Kaplan Meier survival estimates see Figure 1, median s-VCAM-1 = 664 ng/ml, IQR 515,874).

Conclusions

s-VCAM-1 predicts long-term survival in DCM patients independent of NT-pro-BNP and other risk determinants. Further research needs to evaluate whether this biomarker proves useful in monitoring and planning management of DCM and HNDC patients (e.g. more intensive management in high-risk patients).

Abstract Figure. Kaplan-Meier survival estimates

Pembrolizumab-induced myocarditis in a patient with malignant mesothelioma: plasma exchange as a successful emerging therapy-case report

Malignant mesothelioma is an aggressive cancer associated with prior exposure to asbestos and dismal prognosis. Immune checkpoint inhibitor therapy is currently approved by the Food and Drug Administration for pre-treated malignant pleural mesothelioma. We describe a 75-year-old patient with disseminated, progressive malignant mesothelioma receiving 2 cycles of pembrolizumab who presented with generalized muscle weakness, shortness of breath, double vision and ptosis. There was no previous history of cardiovascular disease. The clinical picture, supported by the detection of anti-titin autoantibodies suggested myasthenia gravis (MG). Also, cardiac biomarkers were elevated. Echocardiography showed new severely reduced ejection fraction. A 12-lead resting electrocardiogram (ECG) revealed ST segment elevation in the posterior leads with polymorphic ventricular extrasystoles. Because cardiac catheterization revealed no relevant coronary lesions, immune checkpoint inhibitor-associated myocarditis and MG were suspected. Management and Outcome: The patient was started on steroids. Within a few days of presentation respiratory failure set in and the patient was intubated. Recurrent arrhythmias followed, which were treated by repeated emergency electrical cardioversion. In order to relieve myasthenic symptoms, plasma exchange was initiated and 10 cycles were carried out. This consequently also led to an improvement of myocarditis. Upon discharge, the ejection fraction recovered. The patient recovered and was alive at 1-year follow-up, without relevant limitations to his quality of life. Discussion and Conclusion: The article further discusses the use of plasma exchange for immune checkpoint inhibitor-associated myocarditis based on a review of literature. We conclude that patients showing no improvement after steroid therapy for immune checkpoint inhibitor-related myocarditis should be evaluated for plasma exchange, which appears to be an effective treatment option.

Left and right ventricular dysfunction in patients with COVID-19-associated myocardial injury

Purpose

SARS-COV-2 infection can develop into a multi-organ disease. Although pathophysiological mechanisms of COVID-19-associated myocardial injury have been studied throughout the pandemic course in 2019, its morphological characterisation is still unclear. With this study, we aimed to characterise echocardiographic patterns of ventricular function in patients with COVID-19-associated myocardial injury.

Methods

We prospectively assessed 32 patients hospitalised with COVID-19 and presence or absence of elevated high sensitive troponin T (hsTNT+ vs. hsTNT-) by comprehensive three-dimensional (3D) and strain echocardiography.

Results

A minority (34.3%) of patients had normal ventricular function, whereas 65.7% had left and/or right ventricular dysfunction defined by impaired left and/or right ventricular ejection fraction and strain measurements. Concomitant biventricular dysfunction was common in hsTNT+ patients. We observed impaired left ventricular (LV) global longitudinal strain (GLS) in patients with myocardial injury (-13.9% vs. -17.7% for hsTNT+ vs. hsTNT-, p = 0.005) but preserved LV ejection fraction (52% vs. 59%, p = 0.074). Further, in these patients, right ventricular (RV) systolic function was impaired with lower RV ejection fraction (40% vs. 49%, p = 0.001) and reduced RV free wall strain (-18.5% vs. -28.3%, p = 0.003). Myocardial dysfunction partially recovered in hsTNT + patients after 52 days of follow-up. In particular, LV-GLS and RV-FWS significantly improved from baseline to follow-up (LV-GLS: -13.9% to -16.5%, p = 0.013; RV-FWS: -18.5% to -22.3%, p = 0.037).

Conclusion

In patients with COVID-19-associated myocardial injury, comprehensive 3D and strain echocardiography revealed LV dysfunction by GLS and RV dysfunction, which partially resolved at 2-month follow-up.

Trial registration

COVID-19 Registry of the LMU University Hospital Munich (CORKUM), WHO trial ID DRKS00021225.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-020-01572-8.

Myocardial Inflammation and Dysfunction in COVID-19-Associated Myocardial Injury

BACKGROUND

Myocardial injury, defined by elevated troponin levels, is associated with adverse outcome in patients with coronavirus disease 2019 (COVID-19). The frequency of cardiac injury remains highly uncertain and confounded in current publications; myocarditis is one of several mechanisms that have been proposed.

METHODS

We prospectively assessed patients with myocardial injury hospitalized for COVID-19 using transthoracic echocardiography, cardiac magnetic resonance imaging, and endomyocardial biopsy.

RESULTS

Eighteen patients with COVID-19 and myocardial injury were included in this study. Echocardiography revealed normal to mildly reduced left ventricular ejection fraction of 52.5% (46.5%-60.5%) but moderately to severely reduced left ventricular global longitudinal strain of -11.2% (-7.6% to -15.1%). Cardiac magnetic resonance showed any myocardial tissue injury defined by elevated T1, extracellular volume, or late gadolinium enhancement with a nonischemic pattern in 16 patients (83.3%). Seven patients (38.9%) demonstrated myocardial edema in addition to tissue injury fulfilling the Lake-Louise criteria for myocarditis. Combining cardiac magnetic resonance with speckle tracking echocardiography demonstrated functional or morphological cardiac changes in 100% of investigated patients. Endomyocardial biopsy was conducted in 5 patients and revealed enhanced macrophage numbers in all 5 patients in addition to lymphocytic myocarditis in 1 patient. SARS-CoV-2 RNA was not detected in any biopsy by quantitative real-time polymerase chain reaction. Finally, follow-up measurements of left ventricular global longitudinal strain revealed significant improvement after a median of 52.0 days (-11.2% [-9.2% to -14.7%] versus -15.6% [-12.5% to -19.6%] at follow-up; P=0.041).

CONCLUSIONS

In this small cohort of COVID-19 patients with elevated troponin levels, myocardial injury was evidenced by reduced echocardiographic left ventricular strain, myocarditis patterns on cardiac magnetic resonance, and enhanced macrophage numbers but not predominantly lymphocytic myocarditis in endomyocardial biopsies.

Cardioprotective Potential of Human Endothelial-Colony Forming Cells from Diabetic and Nondiabetic Donors

Objective: The potential therapeutic role of endothelial progenitor cells (EPCs) in ischemic heart disease for myocardial repair and regeneration is subject to intense investigation. The aim of the study was to investigate the proregenerative potential of human endothelial colony-forming cells (huECFCs), a very homogenous and highly proliferative endothelial progenitor cell subpopulation, in a myocardial infarction (MI) model of severe combined immunodeficiency (SCID) mice. Methods: CD34⁺ peripheral blood mononuclear cells were isolated from patient blood samples using immunomagnetic beads. For generating ECFCs, CD34⁺ cells were plated on fibronectin-coated dishes and were expanded by culture in endothelial-specific cell medium. Either huECFCs (5 × 10⁵) or control medium were injected into the peri-infarct region after surgical MI induction in SCID/beige mice. Hemodynamic function was assessed invasively by conductance micromanometry 30 days post-MI. Hearts of sacrificed animals were analyzed by immunohistochemistry to assess cell fate, infarct size, and neovascularization (huECFCs n = 15 vs. control n = 10). Flow-cytometric analysis of enzymatically digested whole heart tissue was used to analyze different subsets of migrated CD34⁺/CD45⁺ peripheral mononuclear cells as well as CD34⁻/CD45⁻ cardiac-resident stem cells two days post-MI (huECFCs n = 10 vs. control n = 6). Results: Transplantation of human ECFCs after MI improved left ventricular (LV) function at day 30 post-MI (LVEF: 30.43 ± 1.20% vs. 22.61 ± 1.73%, p < 0.001; ΔP/ΔT_max 5202.28 ± 316.68 mmHg/s vs. 3896.24 ± 534.95 mmHg/s, p < 0.05) when compared to controls. In addition, a significantly reduced infarct size (50.3 ± 4.5% vs. 66.1 ± 4.3%, p < 0.05) was seen in huECFC treated animals compared to controls. Immunohistochemistry failed to show integration and survival of transplanted cells. However, anti-CD31 immunohistochemistry demonstrated an increased vascular density within the infarct border zone (8.6 ± 0.4 CD31⁺ capillaries per HPF vs. 6.2 ± 0.5 CD31⁺ capillaries per HPF, p < 0.001). Flow cytometry at day two post-MI showed a trend towards increased myocardial homing of CD45⁺/CD34⁺ mononuclear cells (1.1 ± 0.3% vs. 0.7 ± 0.1%, p = 0.2). Interestingly, we detected a significant increase in the population of CD34⁻/CD45⁻/Sca1⁺ cardiac resident stem cells (11.7 ± 1.7% vs. 4.7 ± 1.7%, p < 0.01). In a subgroup analysis no significant differences were seen in the cardioprotective effects of huECFCs derived from diabetic or nondiabetic patients. Conclusions: In a murine model of myocardial infarction in SCID mice, transplantation of huECFCs ameliorated myocardial function by attenuation of adverse post-MI remodeling, presumably through paracrine effects. Cardiac repair is enhanced by increasing myocardial neovascularization and the pool of Sca1⁺ cardiac resident stem cells. The use of huECFCs for treating ischemic heart disease warrants further investigation.

P6385Association of prehospital acetylsalicylic acid and heparin administration with favourable neurological outcome after out-of-hospital cardiac arrest: a matched-pair analysis

Background/Introduction

To date, no prehospital administered drug has shown to influence favourable neurological outcome in patients with out-of-hospital cardiac arrest (OHCA). Early administration of antiplatelet and anticoagulant medication might affect organ microcirculation and therefore favourable neurological outcome in the setting of OHCA.

Purpose

To evaluate the effect of prehospital acetylsalicylic acid and heparin (AH) administration on favourable neurological outcome and overall survival after OHCA in a large multicentre registry.

Methods

We examined patients with cardiac causes of OHCA that were prospectively included in the German Resuscitation Registry. Patients that were administered AH in the prehospital setting were matched in a 1:4 ratio with patients that were not administered AH. Pairs were matched for age >80 years, public place of collapse, initial ECG rhythm, witnessed by lay people and by emergency medical services (EMS), bystander CPR, usage of vasopressors, ECG signs of ACS or diagnosed ACS, coronary angiography conducted and hypothermia conducted. Analyses in the patients were stratified by treatment arm. Data was collected from 2011 to 2017 and analysed from January 2019 to March 2019. The primary endpoint was favourable neurological outcome at hospital discharge defined as cerebral performance category (CPC) 1 or 2. Secondary endpoints were return of spontaneous circulation (ROSC) as well as survival to hospital discharge. Logistic regression analysis and chi square analysis were used to evaluate the primary and secondary endpoints, respectively.

Results

Within the German Resuscitation Registry, 17,139 patients included between 2011 and 2017 had a presumably cardiac cause of OHCA with completed follow-up data. 205 patients were administered AH in the prehospital setting, whereas 16,934 were not. After matching in a 1:4 ratio, 174 patients in the AH group and 696 in the noAH group were suitable for analysis of the primary and the secondary endpoints. Prehospital AH administration was associated with favourable neurological outcome (OR for CPC 1 or 2 at hospital discharge 1.489 [1.026–2.162], p=0.036). Patients with AH were more likely to have ROSC (73.6% vs. 65.7% in the noAH group, p=0.047). Survival to hospital discharge was not statistically different between groups (32.8% vs. 28.5% in the noAH group).

Consort flow-diagram

Conclusion(s)

In this matched-pair analysis, prehospital administration of AH was associated with an enhanced ROSC rate and with favorable neurological outcome. Randomized controlled trials are needed to confirm these results.

Midkine drives cardiac inflammation by promoting neutrophil trafficking and NETosis in myocarditis

Heart failure due to dilated cardiomyopathy is frequently caused by myocarditis. However, the pathogenesis of myocarditis remains incompletely understood. Here, we report the presence of neutrophil extracellular traps (NETs) in cardiac tissue of patients and mice with myocarditis. Inhibition of NET formation in experimental autoimmune myocarditis (EAM) of mice substantially reduces inflammation in the acute phase of the disease. Targeting the cytokine midkine (MK), which mediates NET formation in vitro, not only attenuates NET formation in vivo and the infiltration of polymorphonuclear neutrophils (PMNs) but also reduces fibrosis and preserves systolic function during EAM. Low-density lipoprotein receptor-related protein 1 (LRP1) acts as the functionally relevant receptor for MK-induced PMN recruitment as well as NET formation. In summary, NETosis substantially contributes to the pathogenesis of myocarditis and drives cardiac inflammation, probably via MK, which promotes PMN trafficking and NETosis. Thus, MK as well as NETs may represent novel therapeutic targets for the treatment of cardiac inflammation.

Monitoring of Cardiac Remodeling in a Mouse Model of Pressure-Overload Left Ventricular Hypertrophy with [18F]FDG MicroPET

PURPOSE

This study aims to analyze the left ventricular function parameters, scar load, and hypertrophy in a mouse model of pressure-overload left ventricular (LV) hypertrophy over the course of 8 weeks using 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) micro-positron emission tomography (microPET) imaging.

PROCEDURES

LV hypertrophy was induced in C57BL/6 mice by transverse aortic constriction (TAC). Myocardial hypertrophy developed after 2-4 weeks. ECG-gated microPET scans with [¹⁸F]FDG were performed 4 and 8 weeks after surgery. The extent of fibrosis was measured by histopathologic analysis. LV function parameters and scar load were calculated using QGS®/QPS®. LV metabolic volume (LVMV) and percentage injected dose per gram were estimated by threshold-based analysis.

RESULTS

The fibrotic tissue volume increased significantly from 4 to 8 weeks after TAC (​1.67 vs. 3.91  mm³; P = 0.044). There was a significant increase of the EDV (4 weeks: 54 ± 15 μl, 8 weeks: 79 ± 32 μl, P < 0.01) and LVMV (4 weeks: 222 ± 24 μl, 8 weeks: 276 ± 52 μl, P < 0.01) as well as a significant decrease of the LVEF (4 weeks: 56 ± 17 %, 8 weeks: 44 ± 20 %, P < 0.01). The increase of LVMV had a high predictive value regarding the amount of ex vivo measured fibrotic tissue (R = 0.905, P < 0.001). The myocardial metabolic defects increased within 4 weeks (P = 0.055) but only moderately correlated with the fibrosis volume (R = 0.502, P = 0.021). The increase in end-diastolic volume showed a positive correlation with the fibrosis at 8 weeks (R = 0.763, P = 0.017).

CONCLUSIONS

[¹⁸F]FDG-PET is applicable for serial in vivo monitoring of the TAC mouse model. Myocardial hypertrophy, the dilation of the left ventricle, and the decrease in LVEF could be reliably quantified over time, as well as the developing localized scar. The increase in volume over time is predictive of a high fibrosis load.

Diagnostic and prognostic value of miR-1 and miR-29b on adverse ventricular remodeling after acute myocardial infarction - The SITAGRAMI-miR analysis

BACKGROUND

MicroRNAs (miRs) have shown to exert fibrotic and anti-fibrotic effects in preclinical models of acute myocardial infarction (AMI). The aim of this study was to evaluate miR-1, miR-21, miR-29b and miR-92a as circulating biomarkers for adverse ventricular remodeling (AVR) in post-AMI patients.

METHODS

Plasma levels of miR-1, miR-21, miR-29b and miR-92a were measured in 44 patients of the SITAGRAMI trial population at day 4, day 9 and 6month after AMI and in 18 matched controls (CTL). MiR expression patterns were correlated with magnetic resonance imaging (MRI) parameters for AVR (absolute change (Δ) in infarct volume (IV), left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume (LVEDV) between day 4 and 6months after AMI) and a combined cardiovascular endpoint.

RESULTS

Expression of miR-1, miR-21 and miR-29b but not miR-92a was increased in AMI vs. CTL cohort showing highest miR levels at d9. However, only miR-1 and miR-29b levels significantly correlated with ΔIV and showed a trend for correlation with ΔLVEF. Only miR-29b levels at day 9 correlated with ΔLVEDV at 6-month follow-up. There was no correlation of miR levels with an adverse outcome.

CONCLUSION

Mir-1 and miR-29b plasma levels post-AMI correlate with IV changes. In addition, miR-29b levels are associated with changes of LVEDV over time. These results provide insights into the role of miRs as diagnostic AVR surrogate markers. Further large scale clinical trials will be needed to evaluate the real prognostic relevance of these miRs with respect to a clinical implication in the future.

Soluble Vascular Cell Adhesion Molecule-1 (VCAM-1) as a Biomarker in the Mouse Model of Experimental Autoimmune Myocarditis (EAM)

Vascular cell adhesion molecule-1 (VCAM-1) is strongly upregulated in hearts of mice with coxsackie virus-induced as well as in patients with viral infection-triggered dilated cardiomyopathy. Nevertheless, the role of its soluble form as a biomarker in inflammatory heart diseases remains unclear. Therefore, we investigated whether plasma levels of soluble VCAM-1 (sVCAM-1) directly correlated with disease activity and progression of cardiac dysfunction in the mouse model of experimental autoimmune myocarditis (EAM). EAM was induced by immunization of BALB/c mice with heart-specific myosin-alpha heavy chain peptide together with complete Freund`s adjuvant. ELISA revealed strong expression of cardiac VCAM-1 (cVCAM-1) throughout the course of EAM in immunized mice compared to control animals. Furthermore, sVCAM-1 was elevated in the plasma of immunized compared to control mice at acute and chronic stages of the disease. sVCAM-1 did not correlate with the degree of acute cardiac inflammation analyzed by histology or cardiac cytokine expression investigated by ELISA. Nevertheless, heart to body weight ratio correlated significantly with sVCAM-1 at chronic stages of EAM. Cardiac systolic dysfunction studied with positron emission tomography indicated a weak relationship with sVCAM-1 at the chronic stage of the disease. Our data provide evidence that plasma levels of sVCAM-1 are elevated throughout all stages of the disease but showed no strong correlation with the severity of EAM.

MicroRNAs as a diagnostic tool for heart failure and atrial fibrillation

MicroRNAs (miRNAs) are small non-coding RNAs, which are directly involved in the regulation of post-transcriptional gene expression. Their biological function represents a repression of protein expression of the targeted messenger-RNA(s). Expression of several miRNAs is somehow tissue-specific or cell-specific and their expression pattern can reflect an underlying pathophysiological condition. Beyond this biological function their role as potential biomarkers has been emerged in the past years. This was based on the fact that miRNAs can be detected in blood samples (serum or plasma) in a surprisingly stable form, by contrast to mRNAs. This fact made miRNAs interesting candidates for biomarkers providing information with respect to a potentially ongoing pathophysiological condition and could thereby have an impact on specific treatment strategies in patients. In this review we try to provide an overview of the potential role of miRNAs as a diagnostic tool in atrial fibrillation and heart failure patients taken different methodological aspects and distinct type of patients into account.

Sitagliptin plus granulocyte colony-stimulating factor in patients suffering from acute myocardial infarction: A double-blind, randomized placebo-controlled trial of efficacy and safety (SITAGRAMI trial)

OBJECTIVE

In animal models, G-CSF based progenitor cell mobilization combined with a DPP4 inhibitor leads to increased homing of bone marrow derived progenitor cells to the injured myocardium via the SDF1/CXCR4 axis resulting in improved ejection fraction and survival after acute myocardial infarction (AMI).

RESEARCH DESIGN AND METHODS

After successful revascularization in AMI, 174 patients were randomized 1:1 in a multi-centre, prospective, placebo-controlled, parallel group, double blind, phase III efficacy and safety trial to treatment with G-CSF and Sitagliptin (GS) or placebo. Diabetic and non-diabetic patients were included in our trial. The primary efficacy endpoint hierarchically combined global left and right ventricular ejection fraction changes from baseline to 6 months of follow-up (ΔLVEF, ΔRVEF), as determined by cardiac MRI.

RESULTS

At follow-up ΔLVEF as well as ΔRVEF did not differ between the GS and placebo group. Patients in the placebo group had a similar risk for a major adverse cardiac event within 12 months of follow-up as compared to patients under GS.

CONCLUSION

Progenitor cell therapy comprising the use of G-CSF and Sitagliptin after successfully revascularized acute myocardial infarction fails to show a beneficial effect on cardiac function and clinical events after 12 months. (EudraCT: 2007-003,941-34; ClinicalTrials.gov: NCT00650143, funding: Heinz-Nixdorf foundation).

FDG-PET reveals improved cardiac regeneration and attenuated adverse remodelling following Sitagliptin + G-CSF therapy after acute myocardial infarction

AIMS

Dual therapy comprising G-CSF for mobilization of bone marrow-derived progenitor cells (BMPCs), with simultaneous pharmacological inhibition of dipeptidylpeptidase-IV for enhanced myocardial recruitment of circulating BMPC via the SDF-1α/CXCR4-axis, has been shown to improve survival after acute myocardial infarction (AMI). Using an innovative method to provide non-invasive serial in vivo measurements and information on metabolic processes, we aimed to substantiate the possible effects of this therapeutic concept on cardiac remodelling after AMI using 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography (FDG-PET).

METHODS AND RESULTS

AMI was induced in C57BL/6 mice by performing surgical ligation of the left anterior descending artery in these mice. Animals were then treated with granulocyte-colony stimulating factor + Sitagliptin (GS) or placebo for a duration of 5 days following AMI. From serial PET scans, we verified that the infarct size in GS-treated mice (n = 13) was significantly reduced at Day 30 after AMI when compared with the mice receiving placebo (n = 10). Analyses showed a normalized FDG uptake on Day 6 in GS-treated mice, indicating an attenuation of the cardiac inflammatory response to AMI in treated animals. Furthermore, flow cytometry showed a significant increase in the anti-inflammatory M2-macrophages subpopulation in GS-treated animals. In comparing GS treated with placebo animals, those receiving GS-therapy showed a reduction in myocardial hypertrophy and left ventricular dilatation, which indicates the beneficial effect of GS treatment on cardiac remodelling. Remarkably, flow cytometry and immunohistochemistry showed an increase of myocardial c-kit positive cells in treated mice (n = 12 in both groups).

CONCLUSION

Using the innovative method of micro-PET for non-invasive serial in vivo measurements of metabolic myocardial processes in mice, we were able to provide mechanistic evidence that GS therapy improves cardiac regeneration and reduces adverse remodelling after AMI.

Isolation and expansion of cytokeratin positive progenitor cells from adult murine pancreatic ducts expressing Pdx-1, Nestin, Sox9, MafA and hepatic nuclear factors

BACKGROUND

Recent studies suggest that stem cells may represent a putative source for the generation of beta cells. However, the identity and characteristics of stem cells from adult pancreas and conditions for their large scale expansion are still poorly defined.

METHODS

DPC were isolated from adult pancreatic ducts of C57Bl/6 mice. Expression profile was investigated by PCR, FACS and immunohistochemistry.

RESULTS

DPC express a panel of stem cell associated markers such as Pdx-1, cytokeratin-19 (CK19), nestin, Sox9 together with the transcription factor MafA and hepatic nuclear factors HNF1β, HNF3β, HNF4α und HNF6. This gene expression profile is suggesting that DPC might be a promising tool for endocrine differentiation. After stimulation with picolinic acid and hypoxia, DPC expressed the endocrine differentiation marker Ngn3. Nevertheless, insulin production was not observed.

CONCLUSIONS

We here describe a protocol for the isolation end expansion of murine pancreatic ductal progenitor cells (DPC) displaying high self-renewal, spheroid- and colony-forming capacity. Further studies are required to elucidate the conditions for differentiation into mature pancreatic endocrine cell lineages.

Mobilisation of haemopoietic stem cells in teriparatide-treated patients

Parathyroid hormone (PTH) is the predominant regulator of calcium/phosphate homeostasis in the human body. Beside this classical function, preclinical and clinical studies indicated a relevant role for PTH in mobilisation of bone marrow-derived cells into peripheral blood. In addition, recombinant PTH (teriparatide) was recently approved for the treatment of severe osteoporosis. Therefore, it was the aim of the present study to investigate the dynamics of haemopoietic stem cells and corresponding in peripheral blood of 13 patients with osteoporosis during treatment with teriparatide. We were able to show that administration of teriparatide is sufficient to mobilise haemopoietic stem cells into the bloodstream accompanied by an alteration of mobilising cytokines. In conclusion, teriparatide might be a useful tool in the context of stem cell mobilisation.

Attenuation of cardiac hypertrophy by G-CSF is associated with enhanced migration of bone marrow-derived cells

Granulocyte-colony stimulating factor (G-CSF) has been shown to promote mobilization of bone marrow-derived stem cells (BMCs) into the bloodstream associated with improved survival and cardiac function after myocardial infarction. Therefore, the aim of the present study was to investigate whether G-CSF is able to attenuate cardiac remodelling in a mouse model of pressure-induced LV hypertrophy focusing on mobilization and migration of BMCs. LV hypertrophy was induced by transverse aortic constriction (TAC) in C57BL/6J mice. Four weeks after TAC procedure. Mice were treated with G-CSF (100 μg/kg/day; Amgen Biologicals) for 2 weeks. The number of migrated BMCs in the heart was analysed by flow cytometry. mRNA expression and protein level of different growth factors in the myocardium were investigated by RT-PCR and ELISA. Functional analyses assessed by echocardiography and immunohistochemical analysis were performed 8 weeks after TAC procedure. G-CSF-treated animals revealed enhanced homing of VLA-4⁺ and c-kit⁺ BMCs associated with increased mRNA expression and protein level of the corresponding homing factors Vascular cell adhesion protein 1 and Stem cell factor in the hypertrophic myocardium. Functionally, G-CSF significantly preserved LV function after TAC procedure, which was associated with a significantly reduced area of fibrosis compared to control animals. Furthermore, G-CSF-treated animals revealed a significant improvement of survival after TAC procedure. In summary, G-CSF treatment preserves cardiac function and is able to diminish cardiac fibrosis after induction of LV hypertrophy associated with increased homing of VLA-4⁺ and c-kit⁺ BMCs and enhanced expression of their respective homing factors VCAM-1 and SCF.

Impact of parathyroid hormone on bone marrow-derived stem cell mobilization and migration

Parathyroid hormone (PTH) is well-known as the principal regulator of calcium homeostasis in the human body and controls bone metabolism via actions on the survival and activation of osteoblasts. The intermittent administration of PTH has been shown to stimulate bone production in mice and men and therefore PTH administration has been recently approved for the treatment of osteoporosis. Besides to its physiological role in bone remodelling PTH has been demonstrated to influence and expand the bone marrow stem cell niche where hematopoietic stem cells, capable of both self-renewal and differentiation, reside. Moreover, intermittent PTH treatment is capable to induce mobilization of progenitor cells from the bone marrow into the bloodstream. This novel function of PTH on modulating the activity of the stem cell niche in the bone marrow as well as on mobilization and regeneration of bone marrow-derived stem cells offers new therapeutic options in bone marrow and stem cell transplantation as well as in the field of ischemic disorders.

Short-term inhibition of DPP-4 enhances endothelial regeneration after acute arterial injury via enhanced recruitment of circulating progenitor cells

BACKGROUND

Endothelial injuries regularly occur in atherosclerosis and during interventional therapies of the arterial occlusive disease. Disturbances in the endothelial integrity can lead to insufficient blood supply and bear the risk of thrombus formation and acute vascular occlusion. At present, effective therapeutics to restore endothelial integrity are barely available. We analyzed the effect of pharmacological DPP-4-inhibition by Sitagliptin on endogenous progenitor cell-based endothelial regeneration via the SDF-1α/CXCR4-axis after acute endothelial damage in a mouse model of carotid injury.

METHODS AND RESULTS

Induction of a defined endothelial injury was performed in the carotid artery of C57Bl/6 mice which led to a local upregulation of SDF-1α expression. Animals were treated with placebo, Sitagliptin or Sitagliptin+AMD3100. Using mass spectrometry we could prove that Sitagliptin prevented cleavage of the chemokine SDF-1α. Accordingly, increased SDF-1α concentrations enhanced recruitment of systemically applied and endogenous circulating CXCR4+ progenitor cells to the site of vascular injury followed by a significantly accelerated reendothelialization as compared to placebo-treated animals. Improved endothelial recovery, as well as recruitment of circulating CXCR4+ progenitor cells (CD133+, Flk1+), was reversed by CXCR4-antagonization through AMD3100. In addition, short-term Sitagliptin treatment did not significantly promote neointimal or medial hyperplasia.

CONCLUSION

Sitagliptin can accelerate endothelial regeneration after acute endothelial injury. DPP-4 inhibitors prevent degradation of the chemokine SDF-1α and thus improve the recruitment of regenerative circulating CXCR4+ progenitor cells which mediate local endothelial cell proliferation without adversely affecting vessel wall architecture.

Increased numbers of bone marrow-derived cells in parathyroid adenoma

BACKGROUND

In primary hyperparathyroidism (PHPT), the increased levels of parathyroid hormone (PTH) result in mobilisation of bone-marrow-derived cells (BMCs) into peripheral blood. However, the fate of these cells is still unknown.

MATERIALS AND METHODS

In this study, we sought to investigate cells with typical surface markers of BMCs within parathyroid adenomas (PA) of patients with primary hyperparathyroidism. We therefore investigated PA and normal parathyroid glands (NPG) of 15 patients with PHPT by immunohistochemistry and PCR.

RESULTS

mRNA levels for CD31, CD34 and CD45 were significantly increased in PA compared to NPG. Immunohistochemical staining for CD31 and CD34 revealed a significantly higher vessel density in PA. Furthermore, scattered single cells expressing CD31, CD34 or CD45 were significantly augmented compared to normal parathyroid glands and directly correlated with vessel density. mRNA levels of SDF-1 was increased whereas its major inhibitor dipeptidylpeptidase IV (DPP IV) is decreased in PA, suggesting that the SDF-1 axis plays a role in the migration of BMCs into PA.

CONCLUSION

These data indicate a possible role of BMCs in the pathophysiology of PA of patients with PHPT.

The role of 1.5 tesla MRI and anesthetic regimen concerning cardiac analysis in mice with cardiomyopathy

Accurate assessment of left ventricular function in rodent models is essential for the evaluation of new therapeutic approaches for cardiac diseases. In our study, we provide new insights regarding the role of a 1.5 Tesla (T) magnetic resonance imaging (MRI) device and different anesthetic regimens on data validity. As dedicated small animal MRI and echocardiographic devices are not broadly available, we evaluated whether monitoring cardiac function in small rodents with a clinical 1.5 T MRI device is feasible. On a clinical electrocardiogram (ECG) synchronized 1.5 T MRI scanner we therefore studied cardiac function parameters of mice with chronic virus-induced cardiomyopathy. Thus, reduced left ventricular ejection fraction (LVEF) could be verified compared to healthy controls. However, our results showed a high variability. First, anesthesia with medetomidine, midazolam and fentanyl (MMF) led to depressed cardiac function parameters and more variability than isoflurane gas inhalation anesthesia, especially at high concentrations. Furthermore, calculation of an average ejection fraction value from sequenced scans significantly reduced the variance of the results. To sum up, we introduce the clinical 1.5 T MRI device as a new tool for effective analysis of left ventricular function in mice with cardiomyopathy. Besides, we suggest isoflurane gas inhalation anesthesia at high concentrations for variance reduction and recommend calculation of an average ejection fraction value from multiple sequenced MRI scans to provide valid data and a solid basis for further clinical testing.

Preconditioning with levosimendan before implantation of left ventricular assist devices

In this retrospective study, we investigated the impact of preconditioning of the right ventricle with the calcium sensitizer levosimendan immediately before left ventricular assist device (LVAD) implantation on outcome and survival. Nine consecutive LVAD patients (seven suffering from dilative cardiomyopathy and two from ischemic cardiomyopathy) with echocardiographic and invasive evidence of right heart insufficiency received levosimendan with 0.1 μg/kg body weight/min for 24 h before implantation of the assist device (seven HeartWare and two Jarvik 2000). Administration of levosimendan was safe and had not to be discontinued in any patient. We observed no relevant side effects. Twelve-month survival after implantation of the LVAD was 89% representing a superior outcome compared with the fifth INTERMACS registry data with 75% survival. Two temporary extracorporeal membrane-oxygenation implantations were necessary due to intraoperative right ventricular dysfunction. Only one patient died 5 weeks after LVAD implantation of multiorgan failure, five patients were successfully transplanted, and three patients underwent LVAD implantation for destination therapy. Levosimendan might improve clinical outcome and survival when used as pretreatment in patients with right heart insufficiency prior to LVAD implantation. However, we recommend a larger controlled trial in the future to confirm our preliminary results.

Enhanced stem cell migration mediated by VCAM-1/VLA-4 interaction improves cardiac function in virus-induced dilated cardiomyopathy

Endogenous circulation of bone marrow-derived cells (BMCs) was observed in patients with dilated cardiomyopathy (DCM) who showed cardiac upregulation of Vascular Cell Adhesion Protein-1 (VCAM-1). However, the underlying pathophysiology is currently unknown. Thus, we aimed to analyze circulation, migration and G-CSF-based mobilization of BMCs in a murine model of virus-induced DCM. Mice with coxsackievirus B3 (CVB3) induced DCM and healthy controls were analyzed regarding their myocardial homing factors by PCR. To determine cardiac VCAM-1 expression ELISA and immunohistochemistry were applied. Flow cytometry was performed to analyze BMCs. Cardiac diameters and function were evaluated by echocardiography before and 4 weeks after G-CSF treatment. In murine CVB3-induced DCM an increase of BMCs in peripheral blood and a decrease of BMCs in bone marrow was observed. We found an enhanced migration of Very Late Antigen-4 (VLA-4⁺) BMCs to the diseased heart overexpressing VCAM-1 and higher numbers of CD45⁻CD34⁻Sca-1⁺ and CD45⁻CD34⁻c-kit⁺ cells. Mobilization of BMCs by G-CSF boosted migration along the VCAM-1/VLA-4 axis and reduced apoptosis of cardiomyocytes. Significant improvement of cardiac function was detected by echocardiography in G-CSF-treated mice. Blocking VCAM-1 by a neutralizing antibody reduced the G-CSF-dependent effects on stem cell migration and cardiac function. This is the first study showing that in virus-induced DCM VCAM-1/VLA-4 interaction is crucial for recruitment of circulating BMCs leading to beneficial anti-apoptotic effects resulting in improved cardiac function after G-CSF-induced mobilization.