Key Points Question What are the cardiovascular effects in unselected patients with recent coronavirus disease 2019 (COVID-19)? Findings In this cohort study including 100 patients recently recovered from COVID-19 identified from a COVID-19 test center, cardiac magnetic resonance imaging revealed cardiac involvement in 78 patients (78%) and ongoing myocardial inflammation in 60 patients (60%), which was independent of preexisting conditions, severity and overall course of the acute illness, and the time from the original diagnosis. Meaning These findings indicate the need for ongoing investigation of the long-term cardiovascular consequences of COVID-19.

Key Points Question What is the clinical significance of clonal hematopoiesis of indeterminate potential (CHIP) for chronic heart failure (CHF) owing to ischemic origin? Findings In this cohort study, CHIP had a high prevalence in 200 investigated patients with CHF. While no clinical baseline characteristics associated with CHF were different between CHIP carriers and non-CHIP carriers, except for the mean age, harboring mutations in the most prevalent driver genes associated with CHIP, namely DNMT3A and TET2 , was associated with a significant and profound increase in death and rehospitalization for heart failure. Meaning Clonal hematopoiesis of indeterminate potential is presented as a newly identified risk factor for impaired long-term survival and increased disease progression in patients with CHF that may be well targetable as a valuable approach to precision medicine in patients with CHF carrying specific mutations encoding for clonal hematopoiesis.

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.

Rationale: Clonal hematopoiesis (CH) driven by mutations of DNA methyltransferase 3a (DNMT3A) 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 CH-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 analysed in N=6 HF patients harboring DNMT3A CH-driver mutations and N=4 patients with HF and no DNMT3A mutations by single-cell RNA-sequencing. Monocytes of HF patients carrying DNMT3A mutations demonstrated a significantly increased expression of inflammatory genes compared to monocytes derived from HF patients without DNMT3A mutations. Among the specific up-regulated genes were the prototypic inflammatory interleukin (IL) IL1B, 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 pro-inflammatory 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 Th1, Th2, Th17, CD8+ effector, CD4+ memory and Treg specific signatures. Conclusions: This study demonstrates that circulating monocytes and T-cells of HF patients harboring CH-driver mutations in DNMT3A exhibit a highly inflamed transcriptome, which may contribute to the aggravation of chronic heart failure.

Background-Shortening of mean telomere length (TL) in white blood cells is correlated with the development of coronary heart disease (CHD) and with increased mortality due to infectious disease. The goal of the present study was to investigate whether telomere shortening in CHD is restricted to specific peripheral blood lymphocyte and/or myeloid cell subpopulations. Results were correlated to TL in CD34 ϩ hematopoietic peripheral blood stem cells and progenitor cells obtained from the same individual patients. Methods and Results-TL was measured by multicolor flow cytometry-fluorescent in situ hybridization in 12 leukocyte subpopulations after immunomagnetic bead sorting. We investigated TL in 14 young (mean age 25 years) and 13 older (mean age 65 years) healthy male volunteers and in 25 age-matched patients with CHD (mean age 65 years). We show that TL in granulocytes and monocytes mirrors TL of CD34 ϩ peripheral blood stem cells and progenitor cells extremely well (rϭ0.95, PϽ0.0001) in patients and in healthy adults. TL was Ϸ0.5 kilobases (kb) shorter in leukocytes from patients with CHD than in their age-matched control subjects. This difference was identical for CD34ϩ peripheral blood stem cells and progenitor cells, monocytes, granulocytes, B lymphocytes, and CD4 ϩ T cells, including their memory and naïve subpopulations. Surprisingly, only in cytotoxic CD8ϩ T lymphocytes, we found a substantially increased TL deficit of 1.0 kb in CHD patients as opposed to control subjects. Further analysis revealed that TL shortening was particularly pronounced in CD8 ϩ CD28 Ϫ T cells obtained from cytomegalovirus-seropositive CHD patients, whereas such a difference was not observed in healthy cytomegalovirus-positive as opposed to cytomegalovirus-negative control subjects. Finally, TL shortening of CD8 ϩ CD45 RAϩ T cells was correlated with the decrease in left ventricular function in CHD patients (rϭ0.629, Pϭ0.001). Conclusions-Telomere shortening in patients with CHD could potentially be attributed to either inherited TL shortening or acquired accelerated telomere shortening restricted to the hematopoietic system, which affects the baseline TL of all peripheral blood cell populations, including peripheral blood stem cells and progenitor cells. In addition, cytomegalovirus-seropositive patients but not healthy control subjects exhibited further shortening of their cytotoxic T lymphocytes. Surprisingly, TL shortening of CD8 ϩ T lymphocytes in CHD patients demonstrated a very strong correlation with cardiac dysfunction, which suggests a mechanistic link between CHD and immunosenescence. (Circulation. 2009;120: 1364-1372.) Key Words: telomere Ⅲ coronary disease Ⅲ cytomegalovirus Ⅲ aging Ⅲ immunology Ⅲ stem cells Ⅲ T cells I ndividuals with shorter telomeres of their peripheral blood leukocytes carry a higher risk for dying of infectious and cardiovascular disease. 1 Naturally, both disease entities appear to represent different mechanisms in which telomere biology is involved. On closer examination, inflammation plays a cr...

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.

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.

Chronic arterial occlusion leads to growth of collaterals - a process termed arteriogenesis, in which macrophages play a prominent role in remodelling and growth. However, a detailed analysis which of distinct macrophage subpopulations involved in arteriogenesis has never been performed. In the present study the temporal and spatial distribution of macrophage subtypes during arteriogenesis in a rat model with chronically elevated fluid shear stress (FSS) is investigated. Local macrophage subpopulations were histologically immuno-phenotyped using CD68 (a ubiquitous macrophage marker) and CD163, a specific M2 macrophage marker. Without occlusion few M2-macrophages reside in the perivascular space. Early after occlusion (12h) the number of M2 macrophages increases strongly and M1 macrophages begin emerging into the collateral. After 3 days they appear in the perivascular space. Both macrophage subtypes increase until 28d after treatment, whereas M2 macrophages dominate at the site of collateral growth. The local distribution of the subpopulations changes during the arteriogenic process. Whereas M1 macrophages are detected directly adjacent to the media, M2 macrophages are present in the most outer perivascular region of the growing collateral vessel. Systemic alterations of blood leucocytes in mice after femoral artery ligature (FAL) were investigated by FACS analysis of serial blood samples. During collateral remodelling histological changes were not reflected in circulating monocytes in the peripheral blood. The activation state of macrophages in mice with FAL was modulated by injections of either dexamethasone or the interleukins IL10 or IL3/IL14. The arteriogenic response was assessed by hind limb perfusion with laser Doppler measurements after 3, 7 and 14d. Suppressing inflammatory monocyte subtypes (M1) with dexamethasone led to impaired perfusion recovery after FAL in mice, whereas IL10 or IL4/IL13 application significantly increased perfusion recovery. This investigation demonstrates that a forced shift towards M2 macrophages improves the arteriogenic response. The distinct early increase and spatial distribution of M2 macrophages support the idea that this subtype plays a predominant role during collateral remodelling.