The RNA editor ADAR2 promotes immune cell trafficking by enhancing endothelial responses to interleukin-6 during sterile inflammation.

Immune cell trafficking constitutes a fundamental component of immunological response to tissue injury, but the contribution of intrinsic RNA nucleotide modifications to this response remains elusive. We report that RNA editor ADAR2 exerts a tissue- and stress-specific regulation of endothelial responses to interleukin-6 (IL-6), which tightly controls leukocyte trafficking in IL-6-inflamed and ischemic tissues. Genetic ablation of ADAR2 from vascular endothelial cells diminished myeloid cell rolling and adhesion on vascular walls and reduced immune cell infiltration within ischemic tissues. ADAR2 was required in the endothelium for the expression of the IL-6 receptor subunit, IL-6 signal transducer (IL6ST; gp130), and subsequently, for IL-6 trans-signaling responses. ADAR2-induced adenosine-to-inosine RNA editing suppressed the Drosha-dependent primary microRNA processing, thereby overwriting the default endothelial transcriptional program to safeguard gp130 expression. This work demonstrates a role for ADAR2 epitranscriptional activity as a checkpoint in IL-6 trans-signaling and immune cell trafficking to sites of tissue injury.

Clonal Hematopoiesis-Driver DNMT3A Mutations Alter Immune Cells in Heart Failure.

RATIONALE: Clonal hematopoiesis driven by mutations of DNMT3A (DNA methyltransferase 3a) is associated with increased incidence of cardiovascular disease and poor prognosis of patients with chronic heart failure (HF) and aortic stenosis. Although experimental studies suggest that DNMT3A clonal hematopoiesis-driver mutations may enhance inflammation, specific signatures of inflammatory cells in humans are missing. OBJECTIVE: To define subsets of immune cells mediating inflammation in humans using single-cell RNA sequencing. METHODS AND RESULTS: Transcriptomic profiles of peripheral blood mononuclear cells were analyzed in n=6 patients with HF harboring DNMT3A clonal hematopoiesis-driver mutations and n=4 patients with HF and no DNMT3A mutations by single-cell RNA sequencing. Monocytes of patients with HF carrying DNMT3A mutations demonstrated a significantly increased expression of inflammatory genes compared with monocytes derived from patients with HF without DNMT3A mutations. Among the specific upregulated genes were the prototypic inflammatory IL (interleukin) IL1B (interleukin 1B), IL6, IL8, the inflammasome NLRP3, and the macrophage inflammatory proteins CCL3 and CCL4 as well as resistin, which augments monocyte-endothelial adhesion. Silencing of DNMT3A in monocytes induced a paracrine proinflammatory activation and increased adhesion to endothelial cells. Furthermore, the classical monocyte subset of DNMT3A mutation carriers showed increased expression of T-cell stimulating immunoglobulin superfamily members CD300LB, CD83, SIGLEC12, as well as the CD2 ligand and cell adhesion molecule CD58, all of which may be involved in monocyte-T-cell interactions. DNMT3A mutation carriers were further characterized by increased expression of the T-cell alpha receptor constant chain and changes in T helper cell 1, T helper cell 2, T helper cell 17, CD8+ effector, CD4+ memory, and regulatory T-cell-specific signatures. CONCLUSIONS: This study demonstrates that circulating monocytes and T cells of patients with HF harboring clonal hematopoiesis-driver mutations in DNMT3A exhibit a highly inflamed transcriptome, which may contribute to the aggravation of chronic HF.

Single Nuclei Sequencing Reveals Novel Insights Into the Regulation of Cellular Signatures in Children With Dilated Cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is a leading cause of death in children with heart failure. The outcome of pediatric heart failure treatment is inconsistent, and large cohort studies are lacking. Progress may be achieved through personalized therapy that takes age- and disease-related pathophysiology, pathology, and molecular fingerprints into account. We present single nuclei RNA sequencing from pediatric patients with DCM as the next step in identifying cellular signatures. METHODS: We performed single nuclei RNA sequencing with heart tissues from 6 children with DCM with an age of 0.5, 0.75, 5, 6, 12, and 13 years. Unsupervised clustering of 18 211 nuclei led to the identification of 14 distinct clusters with 6 major cell types. RESULTS: The number of nuclei in fibroblast clusters increased with age in patients with DCM, a finding that was confirmed by histological analysis and was consistent with an age-related increase in cardiac fibrosis quantified by cardiac magnetic resonance imaging. Fibroblasts of patients with DCM >6 years of age showed a profoundly altered gene expression pattern with enrichment of genes encoding fibrillary collagens, modulation of proteoglycans, switch in thrombospondin isoforms, and signatures of fibroblast activation. In addition, a population of cardiomyocytes with a high proregenerative profile was identified in infant patients with DCM but was absent in children >6 years of age. This cluster showed high expression of cell cycle activators such as cyclin D family members, increased glycolytic metabolism and antioxidative genes, and alterations in ß-adrenergic signaling genes. CONCLUSIONS: Novel insights into the cellular transcriptomes of hearts from pediatric patients with DCM provide remarkable age-dependent changes in the expression patterns of fibroblast and cardiomyocyte genes with less fibrotic but enriched proregenerative signatures in infants.

Telomerase as a Therapeutic Target in Cardiovascular Disease.

Shortened telomeres have been linked to numerous chronic diseases, most importantly coronary artery disease, but the underlying mechanisms remain ill defined. Loss-of-function mutations and deletions in telomerase both accelerate telomere shortening but do not necessarily lead to a clinical phenotype associated with atherosclerosis, questioning the causal role of telomere length in cardiac pathology. The differential extranuclear functions of the 2 main components of telomerase, telomerase reverse transcriptase and telomerase RNA component, offer important clues about the complex relationship between telomere length and cardiovascular pathology. In this review, we critically discuss relevant preclinical models, genetic disorders, and clinical studies to elucidate the impact of telomerase in cardiovascular disease and its potential role as a therapeutic target. We suggest that the antioxidative function of mitochondrial telomerase reverse transcriptase might be atheroprotective, making it a potential target for clinical trials. Graphic Abstract: A graphic abstract is available for this article.

Clonal haematopoiesis in chronic ischaemic heart failure: prognostic role of clone size for DNMT3A- and TET2-driver gene mutations.

AIMS: Somatic mutations of the epigenetic regulators DNMT3A and TET2 causing clonal expansion of haematopoietic cells (clonal haematopoiesis; CH) were shown to be associated with poor prognosis in chronic ischaemic heart failure (CHF). The aim of our analysis was to define a threshold of variant allele frequency (VAF) for the prognostic significance of CH in CHF. METHODS AND RESULTS: We analysed bone marrow and peripheral blood-derived cells from 419 patients with CHF by error-corrected amplicon sequencing. Cut-off VAFs were optimized by maximizing sensitivity plus specificity from a time-dependent receiver operating characteristic (ROC) curve analysis from censored data. 56.2% of patients were carriers of a DNMT3A- (N = 173) or a TET2- (N = 113) mutation with a VAF >0.5%, with 59 patients harbouring mutations in both genes. Survival ROC analyses revealed an optimized cut-off value of 0.73% for TET2- and 1.15% for DNMT3A-CH-driver mutations. Five-year-mortality was 18% in patients without any detected DNMT3A- or TET2 mutation (VAF < 0.5%), 29% with only one DNMT3A- or TET2-CH-driver mutations above the respective cut-off level and 42% in patients harbouring both DNMT3A- and TET2-CH-driver mutations above the respective cut-off levels. In carriers of a DNMT3A mutation with VAF ≥ 1.15%, 5-year mortality was 31%, compared with 18% mortality in those with VAF < 1.15% (P = 0.048). Likewise, in patients with TET2 mutations, 5-year mortality was 32% with VAF ≥ 0.73%, compared with 19% mortality with VAF < 0.73% (P = 0.029). CONCLUSION: The present study defines novel threshold levels for clone size caused by acquired somatic mutations in the CH-driver genes DNMT3A and TET2 that are associated with worse outcome in patients with CHF.

Clonal haematopoiesis in patients with degenerative aortic valve stenosis undergoing transcatheter aortic valve implantation.

AIMS: Clonal haematopoiesis of indeterminate potential (CHIP), defined as the presence of an expanded somatic blood cell clone without other haematological abnormalities, was recently shown to increase with age and is associated with coronary artery disease and calcification. The most commonly mutated CHIP genes, DNMT3A and TET2, were shown to regulate inflammatory potential of circulating leucocytes. The incidence of degenerative calcified aortic valve (AV) stenosis increases with age and correlates with chronic inflammation. We assessed the incidence of CHIP and its association with inflammatory blood cell phenotypes in patients with AV stenosis undergoing transfemoral aortic valve implantation (TAVI). METHODS AND RESULTS: Targeted amplicon sequencing for DNMT3A and TET2 was performed in 279 patients with severe AV stenosis undergoing TAVI. Somatic DNMT3A- or TET2-CHIP-driver mutations with a VAF ≥ 2% were detected in 93 out of 279 patients (33.3%), with an age-dependent increase in the incidence from 25% (55-69 years) to 52.9% (90-100 years). Patients with DNMT3A- or TET2-CHIP-driver mutations did not differ from patients without such mutations in clinical parameters, concomitant atherosclerotic disease, blood cell counts, inflammatory markers, or procedural characteristics. However, patients with DNMT3A- or TET2-CHIP-driver mutations had a profoundly increased medium-term all-cause mortality following successful TAVI. Differential myeloid and T-cell distributions revealed pro-inflammatory T-cell polarization in DNMT3A-mutation carriers and increased pro-inflammatory non-classical monocytes in TET2-mutation carriers. CONCLUSION: This is the first study to show that acquired somatic mutations in the most commonly mutated CHIP-driver genes occur frequently in patients with severe degenerative AV stenosis, are associated with increased pro-inflammatory leucocyte subsets, and confer a profound increase in mortality following successful TAVI.

Release kinetics of inflammatory biomarkers in a clinical model of acute myocardial infarction.

RATIONALE: Inflammation in the setting of acute myocardial infarction (MI) has been linked to risk stratification; however, the release kinetics of inflammatory biomarkers in patients with acute MI has been difficult to establish. OBJECTIVE: The aim of this study was to determine the kinetics of changes in the levels of several biomarkers specifically linked to inflammation after transcoronary ablation of septal hypertrophy, a procedure that mimics acute MI. METHODS AND RESULTS: We analyzed release kinetics of C-reactive protein, high-sensitivity C-reactive protein, interleukin-6, soluble CD40 ligand, and peripheral blood leukocyte subsets in patients (n=21) undergoing transcoronary ablation of septal hypertrophy. Blood samples were collected before transcoronary ablation of septal hypertrophy and at various times after transcoronary ablation of septal hypertrophy. Serum levels of C-reactive protein were increased at 24 hours (1.0 mg/dL [interquartile range [IQR], 0.7-1.75] versus 0.2 mg/dL [IQR, 0.1-1.05] at baseline [BL]; P<0.001), whereas high-sensitivity C-reactive protein increased as early as 8 hours (2.68 mg/L [IQR, 1.23-11.80] versus 2.17 mg/L [IQR, 1.15-5.06] at BL; P=0.002). Interleukin-6 was significantly increased at 45 minutes (2.59 pg/mL [IQR, 1.69-5.0] versus 1.5 pg/mL [IQR, 1.5-2.21] at BL; P=0.002), and soluble CD40 ligand was significantly decreased at 60 minutes (801.6 pg/mL [IQR, 675.0-1653.5] versus 1750.0 pg/mL [IQR, 1151.0-2783.0] at BL; P=0.016). Elevated counts of polymorphonuclear neutrophils were detectable at 15 minutes, with a significant increase at 2 hours (6415 cells/µL [IQR, 5288-7827] versus 4697 cells/µL [IQR, 2892-5620] at BL; P=0.004). Significant monocytosis was observed at 24 hours (729 cells/µL [IQR, 584-1344] versus 523 cells/µL [IQR, 369-701] at BL; P=0.015). CONCLUSIONS: Interleukin-6 and neutrophil granulocytes showed a continuous rise at all prespecified time points after induction of MI. Our results provide valuable additional evidence of the diagnostic value of inflammatory biomarkers in the setting of early acute MI.

Myocardial ischemia and reperfusion leads to transient CD8 immune deficiency and accelerated immunosenescence in CMV-seropositive patients.

RATIONALE: There is mounting evidence of a higher incidence of coronary heart disease in cytomegalovirus-seropositive individuals. OBJECTIVE: The aim of this study was to investigate whether acute myocardial infarction triggers an inflammatory T-cell response that might lead to accelerated immunosenescence in cytomegalovirus-seropositive patients. METHODS AND RESULTS: Thirty-four patients with acute myocardial infarction undergoing primary percutaneous coronary intervention were longitudinally studied within 3 months after reperfusion (Cohort A). In addition, 54 patients with acute myocardial infarction and chronic myocardial infarction were analyzed in a cross-sectional study (Cohort B). Cytomegalovirus-seropositive patients demonstrated a greater fall in the concentration of terminally differentiated CD8 effector memory T cells (TEMRA) in peripheral blood during the first 30 minutes of reperfusion compared with cytomegalovirus-seronegative patients (-192 versus -63 cells/µL; P=0.008), correlating with the expression of programmed cell death-1 before primary percutaneous coronary intervention (r=0.8; P=0.0002). A significant proportion of TEMRA cells remained depleted for ≥3 months in cytomegalovirus-seropositive patients. Using high-throughput 13-parameter flow cytometry and human leukocyte antigen class I cytomegalovirus-specific dextramers, we confirmed an acute and persistent depletion of terminally differentiated TEMRA and cytomegalovirus-specific CD8(+) cells in cytomegalovirus-seropositive patients. Long-term reconstitution of the TEMRA pool in chronic cytomegalovirus-seropositive postmyocardial infarction patients was associated with signs of terminal differentiation including an increase in killer cell lectin-like receptor subfamily G member 1 and shorter telomere length in CD8(+) T cells (2225 versus 3397 bp; P<0.001). CONCLUSIONS: Myocardial ischemia and reperfusion in cytomegalovirus-seropositive patients undergoing primary percutaneous coronary intervention leads to acute loss of antigen-specific, terminally differentiated CD8 T cells, possibly through programmed cell death-1-dependent programmed cell death. Our results suggest that acute myocardial infarction and reperfusion accelerate immunosenescence in cytomegalovirus-seropositive patients.

Reference Values and Release Kinetics of B-Type Natriuretic Peptide Signal Peptide in Patients with Acute Myocardial Infarction.

BACKGROUND: The signal peptide for human B-type natriuretic peptide preprohormone (BNPsp), which is released from cardiomyocytes, is increased in plasma of patients with acute myocardial infarction (AMI); however, its exact release kinetics have not been defined. METHODS: We measured BNPsp and high-sensitivity cardiac troponin T (hs-cTnT) in a reference group of individuals without structural heart disease (n = 285) and determined the release kinetics of these biomarkers in patients (n = 29) with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy (TASH), a procedure allowing exact timing of onset of iatrogenic AMI. Blood samples were collected before TASH and at numerous preselected time points after TASH. RESULTS: The reference median BNPsp concentration was 53.4 pmol/L [interquartile range (IQR) 47.0-61.0; 95th percentile 85.9 pmol/L; 99th percentile 116.3 pmol/L]. Baseline concentrations in patients undergoing TASH were higher than in the reference group [91.9 pmol/L (IQR 62.9-116.4); P < 0.0001]. BNPsp increased significantly, peaking at 15 min after induction of AMI [149.6 pmol/L (109.5-204.9) vs baseline; P = 0.004] and declining slowly thereafter, falling below the preprocedural value after 8 h (P = 0.014). hs-cTnT increased significantly 15 min after induction of AMI [26 ng/L (19-39) vs 18 ng/L (11-29); P = 0.001] and remained high at all later time points. CONCLUSIONS: BNPsp concentrations increased immediately after AMI induction, providing early evidence of myocardial injury. The release kinetics of BNPsp differed from those of hs-cTnT. These findings provide information that should help in establishing the diagnostic value of BNPsp in the setting of early AMI.

DNMT3A clonal hematopoiesis-driver mutations induce cardiac fibrosis by paracrine activation of fibroblasts.

Hematopoietic mutations in epigenetic regulators like DNA methyltransferase 3 alpha (DNMT3A), play a pivotal role in driving clonal hematopoiesis of indeterminate potential (CHIP), and are associated with unfavorable outcomes in patients suffering from heart failure (HF). However, the precise interactions between CHIP-mutated cells and other cardiac cell types remain unknown. Here, we identify fibroblasts as potential partners in interactions with CHIP-mutated monocytes. We used combined transcriptomic data derived from peripheral blood mononuclear cells of HF patients, both with and without CHIP, and cardiac tissue. We demonstrate that inactivation of DNMT3A in macrophages intensifies interactions with cardiac fibroblasts and increases cardiac fibrosis. DNMT3A inactivation amplifies the release of heparin-binding epidermal growth factor-like growth factor, thereby facilitating activation of cardiac fibroblasts. These findings identify a potential pathway of DNMT3A CHIP-driver mutations to the initiation and progression of HF and may also provide a compelling basis for the development of innovative anti-fibrotic strategies.

Release kinetics of copeptin in patients undergoing transcoronary ablation of septal hypertrophy.

BACKGROUND: The release kinetics of copeptin in patients with acute myocardial infarction (AMI) have been difficult to establish. METHODS: We analyzed the release kinetics of copeptin in patients with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy (TASH) as a model of AMI. We included 21 consecutive patients who underwent TASH. Blood samples were collected before and at 15, 30, 45, 60, 75, 90, and 105 min, and at 2, 4, 8, and 24 h after TASH. Serum copeptin was quantified by a sandwich immunoluminometric assay. RESULTS: All patients had copeptin concentrations below the 99th percentile at baseline. The median copeptin concentration was significantly increased at 30 min [16.0 pmol/L; interquartile range (IQR), 13.4-20.2 pmol/L], compared with the median baseline concentration (6.6 pmol/L; IQR, 5.3-8.3 pmol/L; P = 0.002). The copeptin concentration peaked 90 min after induction of myocardial infarction and returned to baseline concentrations (median, 8.2 pmol/L; IQR, 6.3-10.1) after 24 h, compared with the above baseline values (P = 0.06). Serum creatine kinase (CK) activities were significantly increased above baseline values by 1 day after TASH [median maximal postprocedural CK activity, 935.0 U/L (IQR, 545.5-1115.0 U/L); median baseline CK activity, 80.0 U/L (IQR, 63.5-109.0 U/L); P < 0.001]. CONCLUSIONS: Our results provide additional evidence that early rule-out of suspected AMI is possible by using the copeptin concentration in combination with cardiac troponin T.

Regression of cardiac hypertrophy by granulocyte colony-stimulating factor-stimulated interleukin-1ß synthesis.

AIMS: Aortic stenosis causes cardiac hypertrophy and fibrosis, which often persists despite pressure unloading after aortic valve replacement. The persistence of myocardial fibrosis in particular leads to impaired cardiac function and increased mortality. We investigated whether granulocyte colony-stimulating factor (G-CSF) beneficially influences cardiac remodelling after pressure unloading. METHODS AND RESULTS: Left ventricular hypertrophy was induced by transverse aortic constriction in C57bl6 mice followed by debanding after 8 weeks. This model closely mimics aortic stenosis and subsequent aortic valve replacement. After debanding, mice were treated with either G-CSF or saline injection. Granulocyte colony-stimulating factor treatment significantly improved systolic (ejection fraction 70.48 ± 1.17 vs. 58.41 ± 1.56%, P < 0.001) and diastolic (E/E' 26.0 ± 1.0 vs. 32.6 ± 0.8, P < 0.05) function. Furthermore, cardiac fibrosis was significantly reduced in G-CSF-treated mice (collagen-I area fraction 7.96 ± 0.47 vs. 11.64 ± 1.22%, P < 0.05; collagen-III area fraction 10.73 ± 0.99 vs. 18.46 ± 0.71%, P < 0.001). Direct effects of G-CSF on cardiac fibroblasts or a relevant transdifferentiation of mobilized bone marrow cells could be excluded. However, a considerable infiltration of neutrophils was observed in G-CSF-treated mice. This sterile inflammation was accompanied by a selective release of interleukin-1 ß (IL-1ß) in the absence of other proinflammatory cytokines. In vitro experiments confirmed an increased expression of IL-1ß in neutrophils after G-CSF treatment. Interleukin-1ß directly induced the expression of the gelatinases matrix metalloproteinase-2 (MMP-2) and MMP-9 in cardiac fibroblasts thereby providing the regression of cardiac fibrosis. CONCLUSION: Granulocyte colony-stimulating factor treatment improves the cardiac function and leads to the regression of myocardial fibrosis after pressure unloading. These findings reveal a previously unknown mechanism of fibrosis regression. Granulocyte colony-stimulating factor might be a potential pharmacological treatment approach for patients suffering from congestive heart failure after aortic valve replacement, although further basic research and clinical trials are required in order to prove beneficial effects of G-CSF in the human organism.

Single-nuclear transcriptome profiling identifies persistent fibroblast activation in hypertrophic and failing human hearts of patients with longstanding disease.

AIMS: Cardiac fibrosis drives the progression of heart failure in ischaemic and hypertrophic cardiomyopathy. Therefore, the development of specific anti-fibrotic treatment regimens to counteract cardiac fibrosis is of high clinical relevance. Hence, this study examined the presence of persistent fibroblast activation during longstanding human heart disease at a single-cell resolution to identify putative therapeutic targets to counteract pathological cardiac fibrosis in patients. METHODS AND RESULTS: We used single-nuclei RNA sequencing with human tissues from two samples of one healthy donor, and five hypertrophic and two failing hearts. Unsupervised sub-clustering of 7110 nuclei led to the identification of 7 distinct fibroblast clusters. De-convolution of cardiac fibroblast heterogeneity revealed a distinct population of human cardiac fibroblasts with a molecular signature of persistent fibroblast activation and a transcriptional switch towards a pro-fibrotic extra-cellular matrix composition in patients with established cardiac hypertrophy and heart failure. This sub-cluster was characterized by high expression of POSTN, RUNX1, CILP, and a target gene adipocyte enhancer-binding protein 1 (AEBP1) (all P < 0.001). Strikingly, elevated circulating AEBP1 blood level were also detected in a validation cohort of patients with confirmed cardiac fibrosis and hypertrophic cardiomyopathy by cardiac magnetic resonance imaging (P < 0.01). Since endogenous AEBP1 expression was increased in patients with established cardiac hypertrophy and heart failure, we assessed the functional consequence of siRNA-mediated AEBP1 silencing in human cardiac fibroblasts. Indeed, AEBP1 silencing reduced proliferation, migration, and fibroblast contractile capacity and α-SMA gene expression, which is a hallmark of fibroblast activation (all P < 0.05). Mechanistically, the anti-fibrotic effects of AEBP1 silencing were linked to transforming growth factor-beta pathway modulation. CONCLUSION: Together, this study identifies persistent fibroblast activation in patients with longstanding heart disease, which might be detected by circulating AEBP1 and therapeutically modulated by its targeted silencing in human cardiac fibroblasts.

Release kinetics of cardiac biomarkers in patients undergoing transcoronary ablation of septal hypertrophy.

BACKGROUND: The release kinetics of cardiac troponin T measured with conventional vs high-sensitivity cardiac troponin T (hs-cTnT) assays in patients with acute myocardial infarction (AMI) is difficult to establish. METHODS: We analyzed the release kinetics of cTnT measured by fourth generation and high-sensitivity assays, creatine kinase-MB (CK-MB), and myoglobin in patients with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy (TASH), a model of AMI. Consecutive patients (n = 21) undergoing TASH were included. Serum and EDTA-plasma samples were collected before and at 15, 30, 45, 60, 75, 90, and 105 min, and 2, 4, 8, and 24 h after TASH. RESULTS: cTnT concentrations measured by the hs assay were significantly increased at 15 min [21.4 ng/L, interquartile range (IQR) 13.3-39.7 ng/L vs 11.3 ng/L, IQR 6.0-18.8 ng/L at baseline; P = 0.031]. In comparison, cTnT concentrations measured by the conventional fourth generation assay increased significantly at 60 min (30.0 ng/L, IQR 20.0-30.0 ng/L vs <10.0 ng/L, IQR <10.0-10.0 ng/L; P < 0.01), CK-MB at 90 min (8.4 µg/L, IQR 6.9-14.4 µg/L vs 0.9 µg/L, IQR 0.4-1.1 µg/L; P < 0.01), and myoglobin at 30 min (188.0 µg/L, IQR 154.0-233.0 µg/L vs 38.0 µg/L, IQR 28.0-56.0; P < 0.01). CONCLUSIONS: cTnT concentrations measured by the hs assay were significantly increased after TASH at all of the time points, with a doubling at 15 min after induction of AMI, confirming earlier evidence of myocardial injury compared to the fourth generation cTnT assay and CK-MB and myoglobin.

Longer leukocyte telomere length is associated with myeloid inflammation and increased mortality after transcatheter aortic valve replacement.

Aims: Inflammatory activation of leukocytes may limit prognosis of patients (pts) with severe aortic valve stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). Leukocyte telomere length (LTL) is a marker of proliferative capacity and inflammatory responsiveness but the impact of LTL on the prognosis in AS remains elusive. The aim of this study was to analyse the association of LTL with inflammatory markers and prognosis of pts undergoing TAVR. Methods and results: LTL was analysed using quantitative real-time PCR in 285 consecutive pts (median age 82 years) undergoing TAVR and correlated with 18-month all-cause mortality. C-reactive protein was significantly elevated in pts with the longest LTL (P = 0.017), paralleled by increased procalcitonin (PCT) serum levels (P = 0.0006). This inflammatory reaction was accompanied by increased myeloid cells in the highest LTL tertile, mainly a rise in circulating neutrophils (P = 0.0025) and monocytes (P = 0.01). Multivariate analysis revealed LTL (HR 2.6, 95%CI 1.4-5.1, P= 0.004) and PCT levels (HR 4.3, 95%CI 1.7-11.0, P = 0.003) as independent predictors of mortality. Conclusions: Longer LTL is associated with increased mortality after TAVR. This might be explained by enhanced proliferative capacity of cells resulting in myeloid and systemic inflammation. Our findings suggest that targeting the specific inflammation pathways could present a novel strategy to augment survival in selected patients with degenerative aortic stenosis.

Long-term cardiac pathology in individuals with mild initial COVID-19 illness.

Cardiac symptoms are increasingly recognized as late complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in previously well individuals with mild initial illness, but the underlying pathophysiology leading to long-term cardiac symptoms remains unclear. In this study, we conducted serial cardiac assessments in a selected population of individuals with Coronavirus Disease 2019 (COVID-19) with no previous cardiac disease or notable comorbidities by measuring blood biomarkers of heart injury or dysfunction and by performing magnetic resonance imaging. Baseline measurements from 346 individuals with COVID-19 (52% females) were obtained at a median of 109 days (interquartile range (IQR), 77-177 days) after infection, when 73% of participants reported cardiac symptoms, such as exertional dyspnea (62%), palpitations (28%), atypical chest pain (27%) and syncope (3%). Symptomatic individuals had higher heart rates and higher imaging values or contrast agent accumulation, denoting inflammatory cardiac involvement, compared to asymptomatic individuals. Structural heart disease or high levels of biomarkers of cardiac injury or dysfunction were rare in symptomatic individuals. At follow-up (329 days (IQR, 274-383 days) after infection), 57% of participants had persistent cardiac symptoms. Diffuse myocardial edema was more pronounced in participants who remained symptomatic at follow-up as compared to those who improved. Female gender and diffuse myocardial involvement on baseline imaging independently predicted the presence of cardiac symptoms at follow-up. Ongoing inflammatory cardiac involvement may, at least in part, explain the lingering cardiac symptoms in previously well individuals with mild initial COVID-19 illness.

Post-myocardial infarction heart failure dysregulates the bone vascular niche.

The regulation of bone vasculature by chronic diseases, such as heart failure is unknown. Here, we describe the effects of myocardial infarction and post-infarction heart failure on the bone vascular cell composition. We demonstrate an age-independent loss of type H endothelium in heart failure after myocardial infarction in both mice and humans. Using single-cell RNA sequencing, we delineate the transcriptional heterogeneity of human bone marrow endothelium, showing increased expression of inflammatory genes, including IL1B and MYC, in ischemic heart failure. Endothelial-specific overexpression of MYC was sufficient to induce type H bone endothelial cells, whereas inhibition of NLRP3-dependent IL-1ß production partially prevented the post-myocardial infarction loss of type H vasculature in mice. These results provide a rationale for using anti-inflammatory therapies to prevent or reverse the deterioration of bone vascular function in ischemic heart disease.