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.

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.

The novel coronavirus designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which initially manifests by fever and pneumonia and leads to acute respiratory distress syndrome in the most severe cases. Previous epidemics with members of the coronavirus family demonstrated cytokine release syndrome (CRS) to be the major cause of mortality and morbidity in patients infected with SARS-CoV and Middle Eastern respiratory syndrome virus.¹ Elevated serum concentrations of the cytokine interleukin 6 (IL-6) and other proinflammatory cytokines are hallmarks of CRS.² Indeed, CRS is also common in patients with COVID-19, and most importantly, serum levels of the prototypical marker IL-6 correlate with acute respiratory distress syndrome and are associated with adverse clinical outcomes in patients infected with SARS-CoV-2.^3,4 Clinically, by far the most important risk indicators for adverse outcomes in COVID-19 are advanced age and the presence of cardiovascular comorbidities.⁵

Mosaic loss of Y chromosome (LOY) in blood cells is the most common acquired mutation, increases with age, and is related to cardiovascular disease. Loss of Y chromosome induces cardiac fibrosis in murine experiments mimicking the consequences of aortic valve stenosis, the prototypical age-related disease. Cardiac fibrosis is the major determinant of mortality even after transcatheter aortic valve replacement (TAVR). It was hypothesized that LOY affects long-term outcome in men undergoing TAVR. Using digital PCR in DNA of peripheral blood cells, LOY (Y/X ratio) was assessed by targeting a 6 bp sequence difference between AMELX and AMELY genes using TaqMan. The genetic signature of monocytes lacking the Y chromosome was deciphered by scRNAseq. In 362 men with advanced aortic valve stenosis undergoing successful TAVR, LOY ranged from −4% to 83.4%, and was >10% in 48% of patients. Three-year mortality increased with LOY. Receiver operating characteristic (ROC) curve analysis revealed an optimal cut-off of LOY >17% to predict mortality. In multivariate analysis, LOY remained a significant (P < 0.001) independent predictor of death during follow-up. scRNAseq disclosed a pro-fibrotic gene signature with LOY monocytes displaying increased expression of transforming growth factor (TGF) β-associated signaling, while expression of TGFβ-inhibiting pathways was down-regulated. This is the first study to demonstrate that LOY in blood cells is associated with profoundly impaired long-term survival even after successful TAVR. Mechanistically, the pro-fibrotic gene signature sensitizing the patient-derived circulating LOY monocytes for the TGFβ signaling pathways supports a prominent role of cardiac fibrosis in contributing to the effects of LOY observed in men undergoing TAVR. Mosaic loss of Y chromosome and mortality post TAVR.

Aims Systemic inflammatory response, identified by increased total leucocyte counts, was shown to be a strong predictor of mortality after transcatheter aortic valve implantation (TAVI). Yet the mechanisms of inflammation‐associated poor outcome after TAVI are unclear. Therefore, the present study aimed at investigating individual inflammatory signatures and functional heterogeneity of circulating myeloid and T‐lymphocyte subsets and their impact on 1 year survival in a single‐centre cohort of patients with severe aortic stenosis undergoing TAVI. Methods and results One hundred twenty‐nine consecutive patients with severe symptomatic aortic stenosis admitted for transfemoral TAVI were included. Blood samples were obtained at baseline, immediately after, and 24 h and 3 days after TAVI, and these were analysed for inflammatory and cardiac biomarkers. Myeloid and T‐lymphocyte subsets were measured using flow cytometry. The inflammatory parameters were first analysed as continuous variables; and in case of association with outcome and area under receiver operating characteristic (ROC) curve (AUC) ≥ 0.6, the values were dichotomized using optimal cut‐off points. Several baseline inflammatory parameters, including high‐sensitivity C‐reactive protein (hsCRP; HR = 1.37, 95% CI: 1.15–1.63; P < 0.0001) and IL‐6 (HR = 1.02, 95% CI: 1.01–1.03; P = 0.003), lower counts of Th2 (HR = 0.95, 95% CI: 0.91–0.99; P = 0.009), and increased percentages of Th17 cells (HR = 1.19, 95% CI: 1.02–1.38; P = 0.024) were associated with 12 month all‐cause mortality. Among postprocedural parameters, only increased post‐TAVI counts of non‐classical monocytes immediately after TAVI were predictive of outcome (HR = 1.03, 95% CI: 1.01–1.05; P = 0.003). The occurrence of SIRS criteria within 48 h post‐TAVI showed no significant association with 12 month mortality (HR = 0.57, 95% CI: 0.13–2.43, P = 0.45). In multivariate analysis of discrete or dichotomized clinical and inflammatory variables, the presence of diabetes mellitus (HR = 3.50; 95% CI: 1.42–8.62; P = 0.006), low left ventricular (LV) ejection fraction (HR = 3.16; 95% CI: 1.35–7.39; P = 0.008), increased baseline hsCRP (HR = 5.22; 95% CI: 2.09–13.01; P < 0.0001), and low baseline Th2 cell counts (HR = 8.83; 95% CI: 3.02–25.80) were significant predictors of death. The prognostic value of the linear prediction score calculated of these parameters was superior to the Society of Thoracic Surgeons score (AUC: 0.88; 95% CI: 0.78–0.99 vs. 0.75; 95% CI: 0.64–0.86, respectively; P = 0.036). Finally, when analysing LV remodelling outcomes, ROC curve analysis revealed that low numbers of Tregs (P = 0.017; AUC: 0.69) and increased Th17/Treg ratio (P = 0.012; AUC: 0.70) were predictive of adverse remodelling after TAVI. Conclusions Our findings demonstrate an association of specific pre‐existing inflammatory phenotypes with increased mortality and adverse LV remodelling after TAVI. Distinct monocyte and T‐cell signatures might provide additive biomarkers to improve pre‐procedural risk stratification in patients referred to TAVI for severe aortic stenosis.

Background: Spontaneous pneumomediastinum (SPM) is an uncommon disorder. It is rarely reported in paediatric patients and may be accompanied by subcutaneous emphysema. It is usually benign and self-limiting, with only supportive therapy being needed, but severe cases may require invasive measures. Asthma exacerbations have classically been described as a cause of SPM. However, detailed descriptions in asthmatic children are scarce. We aimed at improving the current understanding of the features of SPM and subcutaneous emphysema, and outcomes, by means of a case report and a systematic review. Methods: For the systematic review a literature search was performed in PubMed to identify reported cases of SPM in asthmatic children. Results: The case a 10-year-old asthmatic girl with SPM is reported. The patient received an inhaled corticosteroid and long-acting beta2 agonist, in addition to sublingual immunotherapy (SLIT) with eventual control of asthma symptoms. Review: A total of 114 published cases were found since 1995, most of them in teenagers; no sex differences were observed. Clinical presentation was associated with an asthma exacerbation in a number of cases. Other presenting features were chest pain, dyspnoea, cough, and particularly acute swelling of the face, neck, and upper chest. Subcutaneous emphysema was present in most patients. Overall, three cases of pneumothorax and two cases of pneumorrhachis were reported. Therapy was mainly based on supportive care, rest, oxygen therapy, analgesics, steroids, and bronchodilators. All patients recovered spontaneously, in spite of a small initial increase in SPM in a few cases. Conclusions: Early identification of patients at risk of SPM would avoid the high number of under-diagnosed cases. Patients should be treated not only with supportive therapy but also with measures to achieve control of the underlying cause (such as poorly controlled asthma).