Serum Markers of Neurodegeneration Are Strongly Linked to Heart Failure Severity and Outcome.

BACKGROUND: Cognitive impairment is prevalent in patients with heart failure with reduced ejection fraction (HFrEF), affecting self-care and outcomes. Novel blood-based biomarkers have emerged as potential diagnostic tools for neurodegeneration. OBJECTIVES: This study aimed to assess neurodegeneration in HFrEF by measuring neurofilament light chain (NfL), total tau (t-tau), amyloid beta 40 (Aß40), and amyloid beta 42 (Aß42) in a large, well-characterized cohort. METHODS: The study included 470 patients with HFrEF from a biobank-linked prospective registry at the Medical University of Vienna. High-sensitivity single-molecule assays were used for measurement. Unplanned heart failure (HF) hospitalization and all-cause death were recorded as outcome parameters. RESULTS: All markers, but not the Aß42:Aß40 ratio, correlated with HF severity, ie, N-terminal pro-B-type natriuretic peptide and NYHA functional class, and comorbidity burden and were significantly associated with all-cause death and HF hospitalization (crude HR: all-cause death: NfL: 4.44 [95% CI: 3.02-6.53], t-tau: 5.04 [95% CI: 2.97-8.58], Aß40: 3.90 [95% CI: 2.27-6.72], and Aß42: 5.14 [95% CI: 2.84-9.32]; HF hospitalization: NfL: 2.48 [95% CI: 1.60-3.85], t-tau: 3.44 [95% CI: 1.95-6.04], Aß40: 3.13 [95% CI: 1.84-5.34], and Aß42: 3.48 [95% CI: 1.93-6.27]; P < 0.001 for all). These associations remained statistically significant after multivariate adjustment including N-terminal pro-B-type natriuretic peptide. The discriminatory accuracy of NfL in predicting all-cause mortality was comparable to the well-established risk marker N-terminal pro-B-type natriuretic peptide (C-index: 0.70 vs 0.72; P = 0.225), whereas the C-indices of t-tau, Aß40, Aß42, and the Aß42:Aß40 ratio were significantly lower (P < 0.05 for all). CONCLUSIONS: Neurodegeneration is directly interwoven with the progression of HF. Biomarkers of neurodegeneration, particularly NfL, may help identify patients potentially profiting from a comprehensive neurological work-up. Further research is necessary to test whether early diagnosis or optimized HFrEF treatment can preserve cognitive function.

Myocardial Oedema as a Consequence of Viral Infection and Persistence-A Narrative Review with Focus on COVID-19 and Post COVID Sequelae.

Microvascular integrity is a critical factor in myocardial fluid homeostasis. The subtle equilibrium between capillary filtration and lymphatic fluid removal is disturbed during pathological processes leading to inflammation, but also in hypoxia or due to alterations in vascular perfusion and coagulability. The degradation of the glycocalyx as the main component of the endothelial filtration barrier as well as pericyte disintegration results in the accumulation of interstitial and intracellular water. Moreover, lymphatic dysfunction evokes an increase in metabolic waste products, cytokines and inflammatory cells in the interstitial space contributing to myocardial oedema formation. This leads to myocardial stiffness and impaired contractility, eventually resulting in cardiomyocyte apoptosis, myocardial remodelling and fibrosis. The following article reviews pathophysiological inflammatory processes leading to myocardial oedema including myocarditis, ischaemia-reperfusion injury and viral infections with a special focus on the pathomechanisms evoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition, clinical implications including potential long-term effects due to viral persistence (long COVID), as well as treatment options, are discussed.

A Case of Autoimmune Small Fiber Neuropathy as Possible Post COVID Sequelae.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is reported to induce and augment autoimmune processes. Moreover, postinfectious effects of coronavirus disease 2019 (COVID-19) are still poorly understood and often resemble symptoms of the acute infection phase. A patient with swollen extremities was presented to the Department of Angiology at the Medical University of Vienna with complaints of muscle and joint pain, paresthesia, and arterial hypertension with intense headache. Prior to these complaints, she had been suffering from various symptoms since November 2020, following a SARS-CoV-2 infection in the same month. These included recurrent sore throat, heartburn, dizziness, and headache. Paresthesia and muscle and joint pain started in temporal relation to a human papillomavirus (HPV) vaccination. Since the patient was suffering from severe pain, intensive pain management was performed. Skin and nerve biopsies revealed autoimmune small fiber neuropathy. The patient's condition could be related to COVID-19, as her first symptoms began in temporal relation to the SARS-CoV-2 infection. Furthermore, in the disease course, antinuclear (ANA) and anti-Ro antibodies, as well as anti-cyclic citrullinated peptide (anti-CCP) antibodies, could be detected. Together with the symptoms of xerophthalmia and pharyngeal dryness, primary Sjögren's syndrome was diagnosed. In conclusion, though biopsy results could not distinguish a cause of the disease, SARS-CoV-2 infection can be discussed as a likely trigger for the patient's autoimmune reactions.

Culprit site extracellular DNA and microvascular obstruction in ST-elevation myocardial infarction.

AIMS: Extracellular chromatin and deoxyribonuclease (DNase) have been identified as important players of thrombosis, inflammation, and homeostasis in a murine model. We previously demonstrated that activated neutrophils release neutrophil extracellular traps (NETs) at the culprit site in ST-elevation myocardial infarction (STEMI), which significantly contribute to extracellular chromatin burden, and are associated with larger infarcts. To understand the correlation between neutrophil activation, extracellular chromatin, and infarct size (IS), we investigated these parameters in a porcine myocardial infarction model, and at different time points and sites in a prospective STEMI trial with cardiac magnetic resonance (CMR) endpoints. METHODS AND RESULTS: In a prospective STEMI trial (NCT01777750), 101 STEMI patients were included and blood samples were obtained from first medical contact until 6 months after primary percutaneous coronary intervention (pPCI) including direct sampling from the culprit site. CMR was performed 4 ± 2 days and 6 months after pPCI. Neutrophil counts, markers of extracellular chromatin, and inflammation were measured. Double-stranded deoxyribonucleic acid (dsDNA), citrullinated histone 3, nucleosomes, myeloperoxidase, neutrophil elastase, and interleukin (IL)-6 were significantly increased, while DNase activity was significantly decreased at the culprit site in STEMI patients. High neutrophil counts and dsDNA levels at the culprit site correlated with high microvascular obstruction (MVO) and low ejection fraction (EF). High DNase activity at the culprit site correlated with low MVO and high EF. In correspondence, dsDNA correlated with IS in the porcine myocardial infarction model. In porcine infarcts, neutrophils and extracellular chromatin were detected in congested small arteries corresponding with MVO. Markers of neutrophil activation, extracellular chromatin, DNase activity and CMR measurements correlated with markers of systemic inflammation C-reactive protein and IL-6 in patients. CONCLUSIONS: NETs and extracellular chromatin are important determinants of MVO in STEMI. Rapid degradation of extracellular chromatin by DNases appears to be crucial for microvascular patency and outcome.

Deoxyribonuclease is prognostic in patients undergoing transcatheter aortic valve replacement.

Degenerative aortic valve stenosis is an inflammatory process that resembles atherosclerosis. Neutrophils release their DNA upon activation and form neutrophil extracellular traps (NETs), which are present on degenerated aortic valves. NETs correlate with pressure gradients in severe aortic stenosis. Transcatheter aortic valve replacement (TAVR) is an established treatment option for aortic valve stenosis. Bioprosthetic valve deterioration promoted by inflammatory, fibrotic and thrombotic processes limits outcome. Deoxyribonuclease is a natural counter mechanism to degrade DNA in circulation. In the present observational study, we investigated plasma levels of double-stranded DNA, deoxyribonuclease activity and outcome after TAVR. 345 consecutive patients undergoing TAVR and 100 healthy reference controls were studied. Double-stranded DNA was measured by fluorescence assays in plasma obtained at baseline and after TAVR. Deoxyribonuclease activity was measured at baseline using single radial enzyme diffusion assays. Follow-up was performed at 12 months, and mean aortic pressure gradient and survival were evaluated. Receiver operating characteristic, Kaplan-Meier curves and Cox regression models were calculated. Baseline double-stranded DNA in plasma was significantly higher compared to healthy controls, was increased at 3 and 7 days after TAVR, and declined thereafter. Baseline deoxyribonuclease activity was decreased compared to healthy controls. Interestingly, low deoxyribonuclease activity correlated with higher C-reactive protein and higher mean transaortic gradient after 12 months. Finally, deoxyribonuclease activity was a strong independent predictor of outcome 12 months after TAVR. Deoxyribonuclease activity is a potential biomarker for risk stratification after TAVR. Pathomechanisms of bioprosthetic valve deterioration involving extracellular DNA and deoxyribonuclease merit investigation.