bluuebunny/crossref_metadata_2025 huggingface dataset:
Arterial hypertension, chronic kidney and severe valvular heart disease predict worse outcome after postponing non-emergency cardiac interventions during the COVID-19-pandemic
Authors: Andress S , Felbel D , Mack A , Rattka M , D`Almeida S , Buckert D , Rottbauer W , Imhof A , Stephan T
Published: November 2023

Background

Deferral of non-emergency cardiac procedures is associated with increased early emergency cardiovascular hospitalizations. Criteria to identify patients at risk for adverse events when postponing their scheduled intervention are needed.

Aim

The aim of this study was to identify predictors associated with worse clinical outcome in cardiac patients whose non-emergency cardiovascular intervention has been deferred during the COVID-19 pandemic.

Methods

This monocentric retrospective study included patients whose non-emergency cardiac intervention has been postponed during COVID-19-related lockdown between March 19th and April 30th 2020. Cox regression was performed to identify predictors of the combined endpoint emergency cardiovascular hospitalization and death. Patients’ outcome after 12 months was compared to a seasonal control group undergoing non-emergency interventions in 2019 as scheduled.

Results

The combined endpoint of death and emergency cardiovascular hospitalization occurred in 70 (36.5%) of 193 patients with a postponed cardiovascular intervention. The planned intervention was deferred by a median of 23 [19 – 36] days. Arterial hypertension (Hazard ratio [HR] 2.27; 95%-Confidence interval [CI] 1.00-5.12; P=0.049), chronic kidney disease (HR 1.89; 95%-CI 1.03 – 3.49, P=0.041) as well as severe valvular heart disease (HR 3.08; 95%-CI 1.68-5.64; P<0.001) were independent predictors of death or emergency hospitalization. Kaplan-Maier estimators of the combined endpoint were 31% in patients with arterial hypertension, 56% in patients with severe valvular heart disease and 77% with both risk factors (HR 12.4, 95%-CI 3.8-40.7; P<0.001) and only 9% in patients without these risk factors (log rank P<0.001). Separate analyses of patients with arterial hypertension, chronic kidney disease and severe valvular heart disease revealed that deferred patients showed significantly poorer clinical outcomes when compared to the control group 2019 (log rank P<0.001, P=0.006 and P<0.001, respectively). NT-proBNP cut-off ≥ 1,109 pg/ml best predicts the occurrence of primary endpoint event in deferred patients (AUC 0.71; P<0.001; sensitivity 64%, specificity 69%).

Conclusion

Our results suggest that patients with either arterial hypertension, chronic kidney or severe valvular heart disease are at very high risk for emergency hospitalization and increased mortality in case of postponed cardiac interventions even in supposed stable clinical status. Risk is even higher in patients suffering from a combination of these conditions. In addition, measuring NT-proBNP levels might help to identify those at high or very high risk.
Sex-based analysis of NSTEMI processes of care and outcomes by hospital: a nationwide cohort study
Authors: Moledina S , Nicholas Weight N W , Mohammed Dafaalla M D , Dennis Chen D C , Muhammad Rashid M R , Mohamed Mohamed M M , Harriette Vanspall H V S , Mario Iannaccone M I , Alaide Chieffo A C , Mamas Mamas M M
Published: November 2023

Background

Contemporary studies have demonstrated that in non-ST-segment elevation myocardial infarction (NSTEMI), processes of care vary significantly according to biological sex. Little is known regarding variation in practice between geographical areas and individual centers.

Methods & Results

We identified 305,014 admissions with NSTEMI in the United Kingdom (UK) Myocardial Infarction National Audit Project (MINAP), 2010-2017, including female sex (n = 110,209). Females presented significantly older (77y vs. 69y, P<0.001), were more likely to be Caucasian (93% vs. 91%, P<0.001) and less likely to be current smokers (18% vs. 24%, P<0.001). Females were less frequently treated with GDMT after NSTEMI, less frequently managed with an invasive coronary angiogram (ICA) (58% vs. 75%, P<0.001) during index admission and less frequently underwent PCI (35% vs. 49%, P<0.001) or CABG surgery (5% vs. 9%, P<0.001) compared to males. Structural process of care differed between the sexes, with a lower proportion of females being treated on a dedicated cardiology ward (48% vs. 56%, P<0.001) or admitted under a attending cardiologist (44% vs. 52%, P<0.001). In our hospital-clustered analysis, we show a positive correlation between the risk-standardized mortality rates (RSMR) and increasing proportion of women treated for NSTEMI (R2=0.17, P<0.001). There was a clear negative correlation between the proportion of females who had an optimum opportunity-based quality indicator score (surrogate for optimum process of care) during their admission and RSMR (R2 =0.22, P<0.001), with a far weaker correlation in males (R2 =0.08, P<0.001).

Conclusion

There was a significant in variation of the management of patients with NSTEMI according to sex, with widespread geographical variation. Structural changes are likely required to enable successful change for female patients.
Societal and economic burden of dilated cardiomyopathy
Authors: Wiethoff I , Sikking M A , Evers S M A A , Henkens M T H M , Heymans S R B , Michels M , Verdonschot J A J , Hiligsmann M
Published: November 2023

Background/Introduction

Dilated cardiomyopathy (DCM) is a major cause of heart failure and can be associated with events like arrhythmias, syncope or sudden cardiac death. Next to the physical disease burden and the mental strain for patients, DCM also poses a substantial economic burden on society; however, respective data is missing.

Purpose

This study aims to measure the quality of life (QoL) and societal costs of DCM patients.

Methods

A cross-sectional evaluation of QoL and societal costs of DCM patients was performed through the 5-level EuroQol (EQ-5D-5L) and the Medical Consumption Questionnaire (iMCQ) and Productivity Cost Questionnaire (iPCQ), respectively. QoL was translated into numerical values (i.e. utilities) for statistical analysis. Costs were measured from a Dutch societal perspective including medical costs, patient and family costs, productivity losses and costs in other sectors. Final costs were extrapolated to one year, reported in 2022 Euros, and compared between DCM severity according to NYHA classes.

Results

A total of 550 DCM patients were included. Mean age was 61 years, and 34% were women. Among EQ-5D dimensions, DCM patients scored lowest in usual activities, pain/discomfort and mobility (Figure 1). Overall utility was lower than the Dutch population mean (0.840 vs. 0.869, p = .225). Total societal DCM costs were €14,843 per patient per year (Figure 2). Cost drivers were productivity losses (€7,037) and medical costs (€4,621) due to inpatient care (€2,231), outpatient care (€863) and medication (€805). Patients with more symptomatic DCM (i.e. NYHA class III or IV) had significantly higher average DCM costs per year compared to less symptomatic DCM (€31,099 vs. €11,446, p < .001) and significantly lower utilities (0.631 vs. 0.883, p < .001).

Conclusion

DCM is associated with reduced QoL and high societal costs, especially in more advanced disease stages. To our knowledge, this is the first study describing the economic burden of DCM in the Netherlands. More studies in DCM are needed to confirm these results.Quality of life of DCM patientsTotal DCM costs per patient per year
Incidence of cardiovascular diseases over the past 20 years - a population-based study in 22 million individuals
Authors: Conrad N , Jhund P S , Sattar N , Rahimi K , Mcmurray J J V
Published: November 2023

Background

The incidence of atherosclerotic diseases has declined considerably since the early 2000s but the extent to which these reductions have occurred in different subgroups of patients is unknown. Whether there have been similar changes in the incidence of other cardiovascular diseases is also uncertain.

Methods

We used linked primary and secondary electronic health records of 22 million individuals from the Clinical Practice Research Datalink (CPRD), a cohort that is representative of the UK population in terms of age and sex. We calculated the incidence of 10 cardiovascular diseases from 2000 to 2019 and used Poisson regression models to investigate temporal trends and variation by age, sex, and socioeconomic status.

Findings: Among the 22 009 375 individuals included in the study, we identified a total of 2 015 280 patients with a new diagnosis of at least one cardiovascular disease between 2000 and 2019 (mean (SD) age: 68.7 (16.8) years, 49% women). Collectively, the incidence of all 10 cardiovascular disorders (standardised by age and sex) decreased by 8% over the study period (incidence rate ratio (IRR) comparing 2017-2019 vs 2000-2002: 0.92 [0.92, 0.93]). The incidence of ischaemic heart disease and stroke decreased by about 30% over the study period (IRR comparing 2017-2019 vs 2000-2002: 0.72 [0.72, 0.73] and 0.73 [0.72, 0.74] for ischaemic heart disease and stroke, respectively), yet these improvements were largely restricted to older age groups and no improvements were observed in the incidence of atherosclerotic disease before the age of 60 years. The reductions in atherosclerotic diseases were also paralleled by a rising number of diagnoses of cardiac arrhythmias, valve disease, and thromboembolic diseases, which increased considerably over the 20 years studied (Figure 1). Most cardiovascular disorders were more common in men than in women of the same age. However, the overall crude incidence of cardiovascular diseases was similar in men and women, due to the higher number of women in older age groups. A socioeconomic gradient was evident across all cardiovascular diseases, did not decrease over time, and was most important for peripheral arterial disease (IRR most deprived compared to least deprived: 1.56 [1.55, 1.58]), heart failure (1.50 [1.49, 1.51]) and ischaemic heart disease (1.48 [1.48, 1.49]) (Figure 2).

Interpretation: Despite important improvements in the prevention of atherosclerotic diseases, the overall burden of cardiovascular diseases remains very high. Further improvements in cardiovascular disease prevention may need to consider the broader spectrum of cardiovascular diseases, such as arrhythmia, valve diseases, and thromboembolic diseases, and examine the specific needs of younger age groups and socioeconomically deprived populations.Figure 1Figure 2
Full cardiac regeneration by MicroRNA and G-actin monomer binding protein
Authors: Liu Y H , Hsieh H T , Lin J L
Published: November 2023

Myocardial infarction causes massive loss of cardiomyocytes, leading to high mortality rate and heart failure. Cardiac regeneration is thought to have therapeutic potential for myocardial infarction and heart failure.

We recently found that Nkx2.5+ cardiac myoblasts exist in declining number in the hearts of postnatal mice. The Nkx2.5+ cardiac myoblasts reactivate after myocardial infarction. They reside mostly in the subepicardium. Using inducible Nkx2.5 enhancer-Cre/ROSA26 reporter double transgenic mice to lineage trace the fate of activated Nkx2.5+ cardiac myoblasts, we documented that the activated Nkx2.5+ cardiac myoblasts proliferate and differentiate into mature cardiomyocyte in vivo. We also documented that Nkx2.5+ cardiac myoblasts originate from the embryonic epicardial cells.

Thymosin ß4 is a G-actin monomer binding protein, involved in cell proliferation, migration, and differentiation. We hypothesized that Thymosin ß4 would promote Nkx2.5+ cardiac myoblasts, an embryonic epicardial-derived cells, mobilization and cardiomyogenesis, after myocardial injury.

Various microRNAs (miR) have been reported to control cardiac development and promote cardiac regeneration. We have transfected neonatal Nkx2.5 cardiac myoblasts with various microRNAs and found miR-590 markedly promotes cardiomyogenesis capacity of cardiac progenitor cells.

We have proved that miR-590 plus Thymosin ß4 (intraperitoneal injection) markedly improved murine cardiac function after myocardial infarction. In the treatment group with miR-590 plus Thymosin ß4 (n=9), LVEF improved from 45% (Day 0) to 77% (Day 7), to 83% (Day 28), to 85% (Day 56) with no LV regional wall motion abnormality and minimal aneurysm formation. In comparison, the control group with miR-mimic plus PBS (n=7), LVEF was 50% (Day 0) to 51% (Day 7), to 56% (Day 28), to 51% (Day 56) with persistent hypokinesia at apex and anterior wall with impaired LV contractility and larger aneurysm was revealed (p<0.001). Heart section of the post-MI mouse receiving miR-590 plus Thymosin ß4 showed minimal fibrosis in the outer layer of myocardium. In contrast, large fibrotic area was noted in the no treatment group. The mice receiving miR-590 plus Thymosin ß4 had a 2-fold increase in survival rate than the control group. Enhanced cardiomyocytes proliferation was documented by phosphorylated histone H3 stain at treated 1-week post-MI heart section.

The study applies the results of our recent studies and successfully demonstrated systemic administration of miR-590 plus Thymosin ß4 markedly enhance cardiac repair/ regeneration. We anticipate the result would promote cardiac regeneration in clinical use.
Large-scale genetic and multi-omics analyses identify molecular pathways underlying dilated cardiomyopathy
Authors: Jurgens S J , Gaziano L , Garnier S , Krijger Juarez C , Kany S , Zheng S , Biddinger K , Tadros R , Ware J S , Schmidt A F , Amin A S , Ellinor P T , Charron P , Aragam K G , Bezzina C R
Published: November 2023

Background

Dilated cardiomyopathy (DCM) is a heart muscle disease that represents a major public health burden. While both common and rare genetic variants are known to affect DCM risk, previous genome-wide association studies (GWAS) have yielded only few loci and the molecular pathways underlying DCM remain largely unknown.

Purpose

We aimed to discover novel genetic loci for DCM by combining data from biobank and case-control studies, and by combining GWAS with multi-trait analyses. We also pursued multi-omics Mendelian randomization to nominate novel molecular pathways underlying DCM.

Methods and results

We first performed a GWAS of ICD-code defined DCM (N=1472 cases) from two large biobank datasets (UK Biobank and Mass General Brigham Biobank), and found good genetic correlation (rg=0.82, SE=0.22) and similar heritability estimates (h2=0.12, SE=0.03 vs. h2=0.14, SE=0.03) when compared with a previously published GWAS of recruited DCM cases. In a large meta-analysis across case-control and biobank datasets (N=4191 cases), we identified 10 loci significantly associated with DCM. We then integrated this novel meta-analysis into a multi-trait GWAS (MTAG) with MRI-derived left ventricular traits from the UK Biobank (LVEF and LVESV; N=36083), which yielded 44 lead variants at 36 significant loci. Novel loci overlap reported Mendelian cardiomyopathy genes (ACTN2, OBSCN, MYH7B), support previous mechanistic findings (HSPB8; heat shock protein family), and include genomic regions also arising from a recent GWAS of hypertrophic cardiomyopathy (notably, SVIL). We then performed Mendelian randomization analyses on the MTAG GWAS, using genetic instruments from published multi-omics datasets. Mendelian randomisation of the blood metabolome suggests potential causal roles for metabolites, notably those involved in the pentose phosphate pathway (ribitol; β=0.25, SE=0.04) and glycemic excursion (1,5-anhydroglucitol; β=0.08, SE=0.02). Analyses of the blood proteome suggest potential causal roles for several serum proteins, including proteins involved in redox balance (glutathione synthetase; β=-0.34, SE=0.05), mTORC1 signalling (LAMTOR3; β=0.08, SE=0.01), and the pentose phosphate pathway (G6PE; β=0.09, SE=0.02).

Conclusion

Our analyses link several new genomic regions with DCM, and implicate redox disbalance and alternative usage of (gluco)metabolic pathways as putative causal mechanisms of disease. Future functional studies could determine whether these represent actionable findings.
Targeting microtubule dynamics improves cardiac sodium channel function in arrhythmogenic cardiomyopathy
Authors: Nasilli G , Lin X , Perez-Hernandez M , Zhang M , Rothenberg E , Delmar M , Casini S , Remme C A
Published: November 2023

Background

Pathophysiological conditions such as heart failure and cardiomyopathy are associated with alterations in microtubule (MT) dynamics (in particular increased MT detyrosination), which have detrimental effects on cardiac function. Since the MT network is also involved in trafficking of ion channels to the cell membrane, its remodeling may also affect sodium channel (Nav1.5) function. Indeed, sodium current (INa) is typically decreased in the setting of heart failure and (arrhythmogenic) cardiomyopathy.

Purpose

To investigate the impact of MT detyrosination on Nav1.5 and INa in a mouse model of arrhythmogenic cardiomyopathy (tamoxifen-activated cardiac-specific knockout of plakophilin-2 (PKP2cKO)).

Methods and Results

Freshly isolated cardiomyocytes (CMs) from PKP2cKO mice were incubated for 2-4 hours with either 10 µM parthenolide (PTL; a compound that decreases the fraction of detyrosinated MTs) or vehicle only (DMSO). Vehicle-treated CMs from PKP2cKO mice displayed significantly increased levels of detyrosinated tubulin as compared to wild type (WT), which was attenuated by PTL treatment. PTL significantly increased whole-cell INa without affecting gating properties in PKP2cKO CMs, while it did not affect INa in WT CMs. Macropatch measurements demonstrated that PTL increased INa at both the cell end (Intercalated disc, ID) and lateral membrane (LM) of PKP2cKO CMs. Accordingly, stochastic optical reconstruction microscopy (STORM), a super-resolution approach, revealed that PTL increased Nav1.5 cluster density at both ID and LM of PKP2cKO CMs.

Conclusions

Reducing MT detyrosination by PTL increases Nav1.5 cluster density and sodium current magnitude in a mouse model of arrhythmogenic cardiomyopathy. These findings identify restoration of MT dynamics as a potential novel anti-arrhythmic therapeutic in the setting of cardiac pathology.
Validation of mitochondrial function measurements in permeabilized myocardial tissue from porcine left ventricular specimens with ischemia/reperfusion
Authors: Eickelmann C , Lieder H R , Heusch G , Kleinbongard P
Published: November 2023

Background

Mitochondrial function is critical to myocardial ischemia/reperfusion injury and cardioprotection. The measurement of mitochondrial function in isolated mitochondria requires cardiac specimens of about 300 mg and is therefore only possible at the end of an animal experiment or during cardiosurgical interventions in humans. As an alternative, permeabilized myocardial tissue can be used for quantification of mitochondrial respiration in small myocardial specimens of about only 2-5 mg, which can be retrieved by sequential biopsies in animal experiments and during cardiac catheterization in humans. Whether or not mitochondrial dysfunction during ischemia/reperfusion is reflected to the same extent in saponin-permeabilized myocardial tissue specimens (PMT) and in isolated mitochondria is still unclear.

Purpose

We attempted to validate measurements of mitochondrial respiration from PMT by comparison to those from isolated mitochondria in left ventricular myocardium from anesthetized pigs undergoing coronary occlusion/reperfusion.

Methods

Göttingen open-chest, anesthetized minipigs (n=10) were subjected to 60 min distal left anterior descending artery occlusion and 180 min reperfusion. At the end of reperfusion, PMT and isolated mitochondria were prepared from remote and ischemic/reperfused myocardium. Baseline, adenosine diphosphate-stimulated complex I (without/with cytochrome c, to account for absence or presence of the outer mitochondrial membrane integrity) and complex IV respiration was measured at 37°C during magnetic stirring using a high-resolution respirometer. Mitochondrial respiration in PMT and isolated mitochondria was normalized to protein content and the content of the mitochondrial marker protein cytochrome c oxidase 4.

Results

Mitochondrial respiration measurements in PMT and isolated mitochondria correlated well (Figure 1A) and agreed well in Bland-Altman plot (Figure 1B). While baseline respiration in PMT was somewhat higher than that in isolated mitochondria (Figure 2A), mitochondrial dysfunction during ischemia/reperfusion was equally reflected in PMT and isolated mitochondria (Figure 2B & 2C). Complex IV respiration was not different between remote myocardium and ischemic/reperfused myocardium, independently of the preparation, indicating a comparable amount of viable mitochondria (Figure 2D).

Conclusion

Mitochondrial function measurements in PMT can substitute for that in isolated mitochondria to reflect their dysfunction in ischemia/reperfusion. Thus, mitoprotective strategies targeting ischemia/reperfusion injury in small tissue samples and also in human myocardial biopsies can be followed in PMT.Figure 1Figure 2
Melatonin attenuates an impairment of metabolic reprogramming in doxorubicin-induced cardiotoxicity: insights from metabolomics study in rats
Authors: Thonusin C , Nawara W , Arinno A , Khuanjing T , Prathumsup N , Ongnok B , Chattipakorn S C , Chattipakorn N
Published: November 2023

Background

Doxorubicin is an effective chemotherapeutic agent. Unfortunately, the clinical utilization of doxorubicin is limited due to cardiotoxicity. It was previously shown that doxorubicin caused the changes in glycolysis metabolome levels, fatty acid levels, and genes involving lipid metabolism in the heart. However, the pattern of metabolic reprogramming in doxorubicin-induced heart failure remains unknown. Moreover, the benefit of melatonin in attenuating doxorubicin-induced heart failure was previously revealed. Nonetheless, the potential benefits of melatonin on metabolic reprogramming in doxorubicin-induced heart failure has never been determined.

Purposes

Using liquid chromatography coupled with mass spectrometry-based targeted metabolomics, we identified the pattern of metabolic reprogramming in rats with doxorubicin-induced heart failure. In addition, the effects of melatonin on metabolic reprogramming in doxorubicin-induced heart failure were investigated.

Methods

Male Wistar rats (n=18) were divided into 3 groups (n=6/group) to receive either 1) normal saline solution as a vehicle, 2) 3 mg/kg/day of doxorubicin at days 0, 4, 8, 15, 22, and 29, and 3) 3 mg/kg/day of doxorubicin at days 0, 4, 8, 15, 22, and 29 plus 10 mg/kg/day of melatonin at days 0-29. At day 30, echocardiography and heart rate variability were done for an evaluation of cardiac function. The rats were then euthanized to collect ventricular cardiac tissues for metabolomics study.

Results

Comparing to vehicle-treated rats, the heart of rats treated with doxorubicin alone exhibited cardiac dysfunction, increased glucose and ketone body utilization, decreased fat utilization, decreased succinate oxidation, and decreased adenosine triphosphate (ATP) production. The co-treatment with melatonin effectively restored cardiac function, glucose and ketone body utilization, and ATP production in the heart. Interestingly, the co-treatment with melatonin also increased cardiac fatty acid oxidation, branched-chain amino acid catabolism, and anaplerosis (Figure).

Conclusions

Our findings highlighted the potential benefits of melatonin on cardiac metabolic reprogramming impaired by doxorubicin. These findings also suggested that melatonin could be considered as an adjunctive treatment for doxorubicin-induced heart failure in clinical settings.
Macrophage expressed CD36 promotes plaque vulnerability in atherosclerosis
Authors: Gissler M C , Mwinyella T , Morguet C , Heitlinger S , Li X , Horstmann H , Willecke F , Marchini T , Westermann D , Wolf D
Published: November 2023

Background

Atherosclerosis is characterised by a chronic lipid-driven inflammation that accounts for the majority of deaths worldwide. CD36 is an immunoregulatory scavenger receptor at the interface of lipid metabolism and inflammation that is critically involved in atherogenesis. However, due to the lack of cell-specific in vivo models the exact role of CD36 on macrophages in atherosclerosis remains unknown to date.

Purpose

Here we aimed to evaluate the role of macrophage expressed CD36 in atherogenesis.

Approach & Results: To screen for a potential role of macrophage expressed CD36 in atherosclerosis we assessed CD36 gene expression across different leukocyte populations in single-cell-RNA Sequencing (scRNAseq) data from atherosclerotic LDLR-/- mice. Here, we identified macrophages as the main CD36 expressing cell type. In line, CD36 protein expression in aortic cell suspensions from LDLR-/- mice was significantly higher in macrophages compared to B and T cells as assessed by flow cytometry. To assess the role of macrophage expressed CD36 in atherogenesis, we generated macrophage specific CD36 deficient mice on an atherosclerotic prone LDLR deficient (LDLR-/-) background. CD36fl/fl-CXC3R1Cre LDLR-/- mice (termed iMΦ-CD36) and CD36fl/fl-CXC3R1Wt LDLR-/- controls (termed CD36fl/fl) were injected with tamoxifen for 5 consecutive days and placed on a high cholesterol diet for 16 weeks to induce atherogenesis. At harvest the aortic root was obtained from whole heart, embedded in OCT, cut and stained with Oil Red O staining for histological analyses of atherosclerotic lesions. Macrophages were differentiated from isolated bone marrow cells for in vitro assessment of ROS production and oxLDL uptake. Notably, Macrophage-specific CD36 deficiency did not affect atherosclerotic lesion size but substantially reduced the necrotic core area indicating ameliorated plaque vulnerability. In vitro, macrophage CD36 deficiency ameliorated ROS production and facilitated oxLDL uptake. Further, macrophage-specific CD36 deficiency reduced circulating MCP-1 levels. To interrogate a potential role of CD36 in human atherosclerosis, human atherosclerotic plaques were studies by scRNAseq. Similar to our observations in mice, cellular CD36 expression was highest in human macrophages/monocytes. Further pathway analysis revealed that CD36-expressing macrophages exhibited a significantly more pro-inflammatory gene signature than CD36-negative macrophages. Down this line, CD36 expression was significantly higher in unstable carotid plaques compared to stable lesions indicating that CD36 expression correlates with plaque vulnerability in humans.

Conclusion

All in all, our data indicates a pro-inflammatory role of macrophage expressed CD36 in murine and human atherosclerosis. These findings suggest that targeting CD36 on macrophages may represent a potential target for anti-atherosclerotic therapy.
Inhibition of ADAM10-mediated CX3CL1 shedding promotes survival and cardiac function early after myocardial infarction
Authors: Klapproth E , Witt A , Klose P , Guan K , Lorenz K , Saftig P , Wagner M , El-Armouche A
Published: November 2023

Background and Purpose

The metalloprotease ADAM10 has been implicated in immune regulatory processes, is upregulated in response to specific heart pathologies e.g. ischemic heart failure, and elevated serum levels of the ADAM10 substrates CX3CL1 and CXCL16 have been reported following infarction. The causal role of ADAM10 in cardiovascular diseases, however, is not known yet. By using human tissue biopsies, a cardiomyocyte-specific ADAM10 knockout mouse model (ADAM10 KO), and pharmacological ADAM10 inhibition we here comprehensively characterize the role of ADAM10 in the heart and in cardiac disease.

Methods and Results

We show that ADAM10 protein levels are upregulated in patients with ischemic cardiomyopathy (2.5-fold) and ADAM10 mRNA expression correlates with expression of atrial (NPPA) and brain natriuretic peptide (NPPB) mRNA. Upon infarction, ADAM10 expression is specifically induced in cardiomyocytes, and cardiomyocyte-specific ADAM10 KO as well as pharmacological inhibition (GI254023X) for only three days significantly improves overall survival, reduces scar size, and preserves cardiac function. Mechanistically, flow cytometry and bulk RNA sequencing identify a ADAM10/CX3CL1 axis to control neutrophil bone marrow egress and heart tissue infiltration after infarction. Diminished neutrophil migration results in long-term reduction of IL-1β-driven inflammation. Using cell culture experiments with ADAM10/CX3CL1 knockdown cardiomyocytes, we show that ADAM10-mediated ectodomain shedding of CX3CL1 specifically regulates neutrophil but not macrophage chemotaxis revealing a novel conceptual insight into how acute infarction triggers chemotactic signaling via ectodomain shedding.

Conclusion

Pharmacological and genetic targeting of the membrane sheddase ADAM10 is highly efficient for improving post-infarction cardiac function and survival via abolished post-translational CX3CL1 processing, neutrophil infiltration and IL-1β-dependent inflammation. Thus, our data reveal a novel therapeutic concept, which may close a clinically relevant therapeutic gap early after myocardial infarction.
Cryo-X-ray phase contrast imaging enables whole biopsy imaging prior to multi-omic analysis
Authors: Li K Y C , Dejea H , Bonnin A , Treibel T , Budhram-Mahadeo V , Garcia-Canadilla P , Cook A C
Published: November 2023

Background

Analysis of myocardial biopsies using conventional two-dimensional (2D) histological techniques is limited in the detection of important three-dimensional (3D) structural features, such as disarray, due to sectioning and artefacts from dehydration or chemical processing. More advanced techniques such as light-sheet microscopy, micro-computed tomography or synchrotron radiation-based X-ray phase contrast imaging can provide non-destructive, 3D histological information at high resolution for formalin-fixed and/or paraffin-embedded (FFPE) biopsies. However, formalin fixation induces crosslinking of proteins which can impact quality and their subsequent analysis, for example, fragmentation of nucleic acids. A method for imaging 3D structure of myocardial biopsies in near-native state is needed which can then be followed by downstream multi-omic applications.

Purpose

To develop a technique called cryogenic X-ray phase contrast imaging (Cryo-X-PCI) to image snap-frozen myocardial biopsies at controlled low temperatures, followed by multi-omic analysis starting with analysis of DNA and RNA.

Methods

Myocardial biopsies (n=46) were obtained from C57BL/6 mice and snap-frozen in liquid nitrogen fresh or after 4% paraformaldehyde (PFA);10% formalin fixation. Pilot human aortic stenosis biopsies were also included (n=3, fresh). X-PCI was performed at -70°C using a cryojet, 20 keV beam energy and 0.65 µm detector pixel size (Figure 1). Datasets were reconstructed using Gridrec algorithm and Paganin phase retrieval. Morphologic analysis (myocardial disarray index, fractional anisotropy, helical angle, and intrusion angle) of biopsies was performed using a structure tensor-based approach via in-house MATLAB script. After imaging, DNA and RNA were extracted from murine biopsies followed by assessment of quantity and quality.

Results

Increased intercellular space between aggregates of myocytes was observed in all samples. This is consistent with reported findings in skeletal muscle using cryogenic conditions. Nonetheless, morphologic analysis of the biopsies proved possible (Figure 2). Optimal recovery of DNA and RNA was obtained from fresh frozen samples as compared to 4% PFA-fixed or 10% formalin-fixed samples.

Conclusions

This study demonstrates Cryo-X-PCI as a potential tool for analysing myocardial biopsies of heart muscle disease including morphologic analyses. Levels of DNA and RNA were not significantly affected indicating that downstream genomics, proteomics and transcriptomics analyses should be feasible.Setup for Cryo-X-PCI of frozen biopsiesMorphologic analysis of a biopsy
Mitochondrial heteroplasmy as a marker for premature coronary artery disease: analysis of the poly-C tract of the control region sequence
Authors: Gonzalez Urbistondo F , Aparicio-Gavilanes A , Gomez J , Alvarez-Velasco R , Pascual I , Avanzas P , Alen A , Vazquez-Coto M , Gonzalez-Fernandez M , Garcia-Largo C , Cuesta-Llavona E , Moris De La Tassa C , Eliecer C , Lorca R
Published: November 2023

Mitochondrial DNA (mtDNA) differs from the nuclear genome in many aspects: a maternal inheritance pattern, being more prone to acquire somatic novo mutations, accumulative with age; and the possible coexistence of different mtDNA alleles (heteroplasmy). Mitochondria are key cellular organelles responsible for energy production, involved in complex mechanisms, including atherosclerosis. In this scenario, we aimed to evaluate mtDNA variants that could be associated with premature cardiovascular disease. We evaluated 188 consecutive patients presenting with premature myocardial infarction with ST elevation (STEMI) confirmed by coronary angiogram. mtDNA polymorphisms and clinical data were evaluated and compared with 271 individuals from the same population (control group). Tobacco consumption (80.85% vs 21.21%, p<0.01) and dyslipidemia (38.83% vs 28.41%, p=0.02) were significant more frequent among STEMI patients. Besides, C16223T mtDNA mutation and poly-C heteroplasmy were significantly more frequent among premature STEMI cases than in controls. The OR associated C16223T mtDNA mutation with an increased presence of cardiovascular risk factors. Our data suggest that mtDNA C16223T mutation and poly-C heteroplasmy may be associated with unstable atherosclerosis disease. Moreover, the presence of cardiovascular risk factors (CVRFs) was associated to C16223T mtDNA mutation, with a cumulative effect. Protective mitochondrial pathways are potential therapeutic targets. Thus, preventing exposure to the damaging mechanisms associated to CVRFs is of the utmost importancemtDNA sanger analysisBaseline characteristics.
Selective cardiac myosin inhibitors protect the heart following ischemia-reperfusion injury
Authors: Yusof L , Yellon D M , Davidson S M
Published: November 2023

Background/Introduction

Following an acute myocardial infarction, reperfusion of an occluded coronary artery is often accompanied by cardiomyocyte injury, leading to a worse long-term prognosis. Cardiomyocyte hypercontracture in the first few minutes of post-ischemic reperfusion (IR) is a critical determinant of reperfusion-induced cell death. Inhibition of hypercontracture is highly cardioprotective, but the therapies available are non-specific and unsuitable for clinical translation. Recently, cardiac myosin-targeted inhibitors (CMIs) of contraction, Mavacamten and Aficamten, have been developed to treat patients with hypertrophic cardiomyopathy. These CMIs are well tolerated and safe in clinical trials, however they have not been investigated in the setting of IR injury.

Purpose

To investigate whether these CMIs could be repurposed to reduce reperfusion-induced hypercontracture following IR, which in turn would limit infarct size.

Methods

Male Sprague Dawley rats underwent in-vivo myocardial infarction with 30 min ischemia followed by 120 min reperfusion. 15 min prior to reperfusion, Mavacamten or vehicle (10 % DMSO with 90 % corn oil) were administered intraperitoneally. In addition, in vitro experiments using primary adult rat cardiomyocytes (ARVC) were undertaken to confirm the ability of both CMIs to inhibit hypercontracture. Isolated ARVC were pre-treated with either Mavacamten or Aficamten for 30 min before incubating with carbonyl cyanide m-chlorophenylhydrazone (cCCP) to induce cell contracture.

Results

Mavacamten (2mg/kg) vs control significantly reduced regional infarct size (38.4 ± 4.6 % vs 60.3 ± 5 %, p < 0.05, n= 7-8). Notably, treatment with both Mavacamten (10mM) and Aficamten (1mM) were also inhibited the ability of cCCP to induce ARVC contracture in vitro, with significant reduction in cell contracture (59.7 ± 10.1 % and 49.8 ± 18.5 %, respectively vs control, 99.1 ± 0.6 %, p < 0.05, n= 7).

Conclusion

These findings provide additional information for further studies into the potential of these CMIs to reduce reperfusion-induced hypercontracture clinically.
A large, real-world cohort analysis of arrhythmia detections with insertable cardiac monitors
Authors: Saha S , Zhou J , Rosemas S C , Ramos V , Radtke A P , Majumder S , Sims J J , Sarkar S
Published: November 2023

Background

Insertable cardiac monitors (ICMs) provide long-term continuous monitoring for arrhythmia diagnosis and management for various clinical indications. However, little data exists on the real-world diagnostic yield of ICMs across indicated patient populations, including both expected and incidental arrhythmic findings. Validated artificial intelligence (AI) algorithms have been developed to identify true arrhythmia episodes while significantly reducing false positives, enabling the adjudication of ICM episodes for larger cohorts of patients.

Purpose

To characterize comprehensive true arrhythmia detection rates in a large real-world population with long-term ICM monitoring.

Methods

De-identified patients ≥18 years receiving a Reveal LINQ ICM between Oct 1, 2016 – Sept 30, 2020 with no prior cardiac implantable electronic devices and ≥1 year of follow-up in the CareLink monitoring database were identified (N=12,013). Patients were stratified by reason for ICM placement: N=9,841 who received ICM for diagnosis of suspected arrhythmias (40.8% unexplained syncope, 38.3% cryptogenic stroke, 9.7% palpitations, 9.7% suspected atrial fibrillation (AF), 1.6% ventricular tachycardia), and N=2,172 who received ICM for management of known AF. Device-detected ECGs during long-term follow-up were identified and processed through previously validated arrhythmia-specific AI algorithms designed to reduce false positive arrhythmia detections (each trained using ICM data from ≥25,000 adjudicated ECG episodes and validated on an independent set of ≥5,000 adjudicated ECGs).

Results

Mean (SD) and median follow-up were 24.6(12.7) and 24.5 months, respectively. In patients receiving ICM for Suspected Arrhythmia, 5,492 patients (55.8%) had ≥1 AI-adjudicated arrhythmia detected during follow-up, with 2,472 (45.0%) of these patients having ≥2 arrhythmia types detected (Table). Mean (SD) time to 1st arrhythmia detection was 7.7(9.1) months; time to 2nd arrhythmia type detected was 12.3(10.4) months. Among the 6,958 patients with longer-term ICM follow-up ≥2 years, 2,931 (42.1%) had no arrhythmias detected (i.e., arrhythmia rule-out occurred). In patients receiving ICM for AF Management, 1,737 patients (80.0%) had ≥1 arrhythmia detected, and notably 1,074 (61.8%) of these patients had ≥1 arrhythmia detected during follow-up that was not AF. Mean (SD) time to 1st arrhythmia detection was 5.3 (7.7) months; time to 2nd arrhythmia type detected was 10.4(9.9) months.

Conclusions

In a large real-world ICM population, >50% of patients had AI-adjudicated arrhythmia detections during long-term follow-up, with a significant proportion receiving additional arrhythmia diagnoses beyond the initial type diagnosed or suspected. These results suggest that in indicated patients, long-term continuous monitoring with ICMs can enable diagnosis of a variety of cardiac arrhythmias that may have otherwise remained undetected.
Electrical auricular tragus stimulation induces release of circulating cardioprotective factors in healthy human volunteers
Authors: Lieder H R , Paket U , Skyschally A , Kleinbongard P , Heusch G
Published: November 2023

Background

Vagal activation during remote ischemic conditioning (RIC) with subsequent release of cardioprotective factors from the spleen into the circulation reduces infarct size. These humoral cardioprotective factors can be transferred with plasma-dialysate from human donors undergoing RIC to isolated recipient hearts where they reduce infarct size. Electrical auricular tragus stimulation (ATS) has been demonstrated to reduce the release of cardiac injury biomarkers and ventricular arrhythmias and to improve contractile function in patients with acute myocardial infarction.

Purpose

To determine whether ATS, as RIC, induces release of cardioprotective factors into the circulation.

Methods

Healthy volunteers (3 females, 7 males, 26±5 years) were randomized to receive ATS or RIC, respectively, with an interval of at least two weeks between protocols. ATS was induced by bipolar electrical rectangular pulses of 200 µs width and a frequency of 30 Hz. The amplitude (5.5 ± 0.81 mA) was set for each volunteer to not be perceived as uncomfortable. A microprocessor-controlled circuit periodically interrupted the stimulation signal after 5 s of stimulation for 5 s. ATS was continued over 30 min. RIC served as a reference to induce the release of cardioprotective factors by 3 x 5 min blood pressure cuff inflation at 200 mmHg on the left upper arm/ 5 min deflation. Venous blood samples were taken before and 60 min after ATS or RIC, respectively, and used to prepare plasma-dialysates (1:10 dialysis against buffer for 24 h, cut-off 12-14 kDa). Male Lewis rats were sacrificed and their hearts isolated and perfused at constant pressure with buffer. Plasma-dialysates from samples taken before and 60 min after ATS or RIC, respectively, were infused for 8 min into rat hearts followed by 2 min washout before global 30 min ischemia/ 120 min reperfusion. Infarct size was demarcated by triphenyl tetrazolium chloride staining and calculated as percent of ventricular mass.

Results

With infusion of plasma-dialysate before ATS, infarct size was 30.9 ± 4.5% of ventricular mass and not different from that with infusion of plasma-dialysate before RIC (35.8 ± 5.8 %). Infusion of plasma-dialysate after ATS reduced infarct size to 18.3 ± 3.9 %. This cardioprotective effect was similar to that seen with infusion of plasma-dialysate after RIC (20.1 ± 3.5 %).

Conclusion

ATS induces the release of cardioprotective factors into the circulation of healthy volunteers. Plasma-dialysates after ATS or RIC, respectively, reduce myocardial infarct size by the same magnitude in ex vivo isolated perfused rat hearts with global ischemia/ reperfusion.
Enhancing autophagic flux via FYCO1 confers protection against adverse cardiac remodeling in response to myocardial ischemia
Authors: Senger F , Remes A , Tannert C , Schmiedel N , Mueller O , Kuhn C , Frey N
Published: November 2023

Background

Dysregulation of autophagy is known to have detrimental effects on cardiac function. Yet, the autophagy-lysosome pathway in the context of ischemia is still widely unexplored. Fyco1 is highly expressed in the heart and facilitates transport of autophagosomes in cardiomyocytes, thereby enhancing global autophagic flux.

Purpose

The purpose of our study was to study the potentially beneficial effects of activation of autophagy via FYCO1 on cardiac remodeling post myocardial infarction.

Methods

FYCO1-Tg mice were crossbred with RFP-EGFP-LC3-Tg reporter mice (FYCO1-TGxRGFP) to enable analysis of autophagic flux in vivo using confocal microscopy. Myocardial ischemia was induced by permanent ligation of left anterior descending artery (LAD). Mice were analyzed 3 and 30 days post LAD ligation. Cardiac function (ejection fraction, EF) was measured by echocardiography. Fibrosis and Infarct size (%) were assessed in Masson’s Trichrome staining. Autophagy activity was analysed by Western blot for p62 and LC3 II. Furthermore, Evans blue/TTC staining was performed to assess the area at risk and to define perfused, ischemic and necrotic area post LAD ligation.

Results

Under conditions of FYCO1 overexpression isolated cardiomyocytes were capable to remain a status of activated autophagy in hypoxia; presented with significantly increased protein levels of p62 (ctrl: 1±0,02; OE: 3,1±0,4) and LC3 II (ctrl: 1±0,05; OE: 5,5±0,4). In FYCO1-TGxRGFP mice we observed an overall increased autophagic flux demonstrated by significantly increased p62 expression (WT LAD: 2,9±0,4; TG LAD:4,0±0,5) and LC3 II protein levels (WT LAD: 1,6±0,2; TG LAD:14,0±1,4) post LAD ligation. While WT mice revealed accumulation of autolysosomes 30 days post LAD ligation as assessed by confocal microscopy (WT autophagosomes: 1±0,4; WT autolysosomes: 38,6±3,8), in FYCO1-TGxRGFP mice the ratio between autophagosomes and autolysosomes remained even (TG autophagosomes:43,3±5,1; TG autolysosomes: 73,5±12,4), suggesting preservation of adequate autophagic flux. In Evans blue/TTC staining, FYCO1-TGxRGFP mice demonstrated comparable ischemic but a markedly decreased necrotic area (ischemic: 1,9±1,8%; necrotic: 37,1±11,5%) of the LV as compared to WT (ischemic: 2,1±1,9%; necrotic: 53,4±31,4%). Fibrosis (WT: 19,6±1,8%; TG: 10,6±1,6%) and infarct size (WT: 34,5 ±3,9%; TG: 5,5±2%) was found significantly decreased in FYCO1-TGxRGFP-mice. Importantly, global heart function of FYCO1-TGxRGFP-mice was significantly improved post LAD compared to WT (EF WT: 36,7±6,3%; TG: 46,3±18,3%).

Conclusion

Our study demonstrates that activation of autophagy via FYCO1 protects against accumulation of autolysosomes and therefore protects against adverse cardiac remodeling and improves cardiac function post myocardial ischemia. These findings may offer translational potential in enhancing autophagic flux in the context of myocardial ischemia.
Treatment with empagliflozin improves cardiac function in infarcted animals associated with increased baroreflex sensitivity
Authors: Da Silva B , Nascimento-Carvalho B , De Souza L I , Da Silva M B , Marques J R , Dourado P M M , Consolim-Colombo F , Irigoyen M C C
Published: November 2023

Background

Several clinical and experimental studies have shown an improvement in cardiac function in infarcted patients and animals (diabetic or not) when treated with empagliflozin, as well as an improvement in outcomes in patients with heart failure with reduced ejection fraction or with preserved ejection fraction.

Hypothesis: Treatment with empagliflozin for 14 days (10 mg/kg) improves cardiac function in infarcted rats, secondary to increased baroreflex sensitivity.

Methods

Wistar rats were divided into 2 groups: AMI - acute myocardial infarction (n=8) and AMI+EMPA - acute myocardial infarction + Empagliflozin (n=8). The animals in both groups were anesthetized and submitted to thoracotomy and ligature of the left coronary artery. The animals in the AMI+EMPA group received daily, through oral gavage, 10 mg/kg of empagliflozin, for 14 days. After this period, an echocardiographic examination was performed, followed by cannulation of the femoral vein and artery, to assess hemodynamic parameters and baroreflex activity. The results were evaluated for normality. Data were compared by Student's t tests. And the relationship between the parameters was tested by Pearson's correlation. Results are presented as mean and standard deviation.

Results

In the echocardiographic evaluation, an improvement in diastolic function indexes was observed in the AMI+EMPA group in relation to the AMI group: E'/A' ratio (1.584 ± 0.437 vs 0.589 ± 0.129), E/E' ratio (14.11 ± 3.946 vs 29.92 ± 6.878) and systolic function: SF (29.30% ± 7.974 vs 19.20% ± 2.445), EF (53.86% ± 11.78 vs 37.91% ± 4.212), FAC (39.31% ± 7.135 vs 23.51 ± 3.940).

There was a reduction in mean blood pressure in the AMI+EMPA group (102.4 mmHg ± 6,408) compared to the AMI group (110.7 mmHg ± 8,514) and in diastolic blood pressure (84.4 mmHg ± 3.889 vs 92.8 mmHg ± 7.664).

In the assessment of baroreflex sensitivity, an improvement in tachy and bradycardic indexes was observed in the treated animals: tachycardic index (5.021 bpm/mmHg ± 0.346 vs 3.214 bpm/mmHg ± 0.418) and bradycardic index (1.569 bpm/mmHg ± 0.148 vs 0.73 bpm/ mmHg ± 0.046). In addition, the systolic function expressed by the FAC was positively associated with the reflex tachycardic index (p: 0.008; r: 0.616) and to the E'/A' ratio (p: 0.025; r: 0.576) and negatively with PAD (p: 0.040; r: -0.503).

Conclusion

Treatment with Empagliflozin in infarcted rats was able to improve left ventricular systolic and diastolic function associated with improved performance of arterial baroreceptors.