Right heart condition in patients with COVID-19 pneumonia

Aim. To assess right heart condition in patients with coronavirus disease 2019 (COVID-19) pneumonia.Material and methods. One hundred and five patients with COVID-19 pneumonia were divided into 3 groups depending on the involvement of lung parenchyma: group I — 0-25%, II — 25-50%, III — 50-75%. The clinical status of patients was assessed using the NEWS2 and SHOKS-COVID scales. A complete blood count and biochemical blood tests were performed to determine the level of N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin I. Echocardiography was performed to assess the right heart structural, hemodynamic and functional parameters.Results. In patients with COVID-19 pneumonia, with an increase in lung parenchyma involvement, the intensity of systemic inflammatory response increased: C-reactive protein, group I — (4 [1,9; 35] mg/l), in III — (70,5 [33; 144] mg/l) (pI-III=0,012); myocardial stress marker level increased: NT-proBNP, group I — 77 [48; 150] ng/l, group III — 165 [100; 287] ng/l (pI-III=0,047). The dependence of NT-proBNP on C-reactive protein level was revealed (r=0,335, p=0,03). Intergroup comparison did not reveal significant differences between the main right heart functional parameters: TAPSE, Tei index (PW and TDI), FAC of the right ventricle (RV) (p>0,05). However, differences in the tricuspid annular peaks were found as follows: group I — 0,14 [0,12; 0,14] m/s, group II — 0,14 [0,12; 0,15] m/s, group III — 0,16 [0,14; 0,17] m/s (pI-II=0,012, pI-III=0,014) and RV global longitudinal strain: group I — 19,63±7,72%, group III — 27,4±5,93% (pI-III=0,014). The relationship between the RV global longitudinal strain and SHOKS-COVID score was confirmed (r=0,381; p=0,024).Conclusion. Patients with COVID-19 pneumonia showed no signs of right heart dysfunction. The development of RV hyperfunction was noted. Most likely, this is a compensatory mechanism in response to acute RV afterload. NT-proBNP increase under conditions of an inflammatory response may indicate myocardial stress. The results obtained allow to expand our understanding of the right heart condition in patients with COVID-19 pneumonia.

Assesment of Markers of Endothelial Dysfunction and Myocardial Stress in Patients with Hypertrophic Cardyomyopathy

Aim. To study the level of serum biomarkers of endothelial dysfunction and myocardial stress in patients with various types of hypertrophic cardiomyopathy (HCM).Material and Methods. 48 patients with hypertrophic cardiomyopathy (27 men and 21 women) were examined, the mean age was 54±13 years. The patients were divided into two groups according to the course options: group 1 - symptomatic stable course (n=14); group 2 - progressive course of symptomatic HCM (n=34). In accordance with the assigned tasks, all patients underwent determination of biological markers of neurohumoral systems in blood serum using immunofluorescence assay analysis: N-terminal fragment of brain natriuretic peptide (NT-proBNP), von Willebrand factor (vWF), endothelin-1, E-selectin with subsequent evaluation and correlation of results with clinical and instrumental characteristics of patients. When performing echocardiography following parameters were assessed: dimensions of the heart chambers, the thickness of the interventricular septum, the thickness of the posterior wall of the left ventricle (LV), LV mass, LV mass index, the ratio between LV filling in diastole (peak E) and atrial systole (peak A)-(E/A), relative myocardial thickness index, left atrial volume index.Results. Both groups showed increased levels of NT-proBNP and endothelin-1. E-selectin and vonWillebrand factor remained within the normal range. There was no statistically significant intergroup difference. There was a correlation between the level of the index of the relative myocardial thickness and the level of NT-proBNP (r=0.30; p=0.04). A correlation was found between the level of the vWF marker and the left atrial volume index (r=0.32; p=0.04). When assessing the association of indicators of intracardiac hemodynamics with other markers (E-selectin and endothelin-1, no statistically significant relationships were found.Conclusion. In the course of the research, it was found that the high activity of endothelin-1 and NT-proBNP reflects endothelial dysfunction and myocardial stress in patients with HCM, especially in patients with a progressive variant of HCM. However, we did not find any changes in the levels of E-selectin and von Willebrand factor, as well as their intergroup differences. These results require additional studies to assess endothelial dysfunction in patients with HCM.

Predicting long-term cardiovascular outcomes in myocardial infarction survivors using multiple biomarkers

Aim: Although there are short- and long-term prognostic studies in patients with myocardial infarction (MI), the data that can be used to predict the clinical outcome following discharge is limited. Materials & methods: We analyzed creatinine kinase-MB and troponin related to myonecrosis, suppression of tumorigenicity 2 and NT-pro B-type natriuretic peptide related to myocardial stress, C-reactive protein and procalcitonin related to inflammation in 259 MI patients. Results: Being in the high group for myocardial stress (odds ratio [OR]: 3.45, 95% CI: 1.398–8.547, p = 0.004) and inflammation markers (OR: 4.30, 95% CI: 1.690–10.899, p = 0.001) predicted major cardiovascular adverse events while myonecrosis markers could not (OR: 1.70, 95% CI: 0.671–4.306, p = 0.263). Conclusion: Using multimarker risk stratification composed of inflammation and myocardial stress biomarkers improves the prediction of major cardiovascular adverse events in MI survivors.

Molecular Perspectives of Mitophagy in Myocardial Stress: Pathophysiology and Therapeutic Targets

A variety of complex risk factors and pathological mechanisms contribute to myocardial stress, which ultimately promotes the development of cardiovascular diseases, including acute cardiac insufficiency, myocardial ischemia, myocardial infarction, high-glycemic myocardial injury, and acute alcoholic cardiotoxicity. Myocardial stress is characterized by abnormal metabolism, excessive reactive oxygen species production, an insufficient energy supply, endoplasmic reticulum stress, mitochondrial damage, and apoptosis. Mitochondria, the main organelles contributing to the energy supply of cardiomyocytes, are key determinants of cell survival and death. Mitophagy is important for cardiomyocyte function and metabolism because it removes damaged and aged mitochondria in a timely manner, thereby maintaining the proper number of normal mitochondria. In this review, we first introduce the general characteristics and regulatory mechanisms of mitophagy. We then describe the three classic mitophagy regulatory pathways and their involvement in myocardial stress. Finally, we discuss the two completely opposite effects of mitophagy on the fate of cardiomyocytes. Our summary of the molecular pathways underlying mitophagy in myocardial stress may provide therapeutic targets for myocardial protection interventions.

MO442ACUTE ADVERSE EFFECTS OF LOW POTASSIUM ON HEART AND KIDNEY*

Background and Aims Chronic hypokalemia causes kidney fibrosis with cystic lesions and arterial hypertension. In contrast, potassium-rich diet lowers blood pressure. The acute effects of hypo- and hyperkalemia on heart and kidney are not well understood. Method Wild-type mice were fed with low (LK), normal (NK) and high (HK) potassium diet for 4 and 20 days. Kidneys were examined for site of acute injury, inflammation and fibrosis. Blood analysis of electrolytes and kidney parameters were analyzed. Echocardiography and ECG were used to assess heart function. Further, KCNJ10 knockout mice were used to investigate kidney damage in a genetically induced hypokalemia model. Results Proximal tubule injury as detected by KIM-1+ staining and yH2AX+ DNA-damage was observed after 4 and 20 days of LK diet. Injury was associated with strong Ki-67+ proliferation of proximal tubule cells. No injury was detected in mice on NK and HK diet. After 20 days of LK diet, F4/80+ inflammation and aSMA+ extracellular matrix accumulation, typical for fibrosis, were observed. LK mice developed polyurie, volume depletion, loss of body weight and high BUN. Lower cardiac output and signs of myocardial stress was seen in echocardiography and ECG. Consistent with WT mice on LK diet, KCNJ10 knockout mice developed same pattern of kidney injury. Nine months after deletion of KCNJ10, cysts were observed in the proximal tubule in outer medzulla. Conclusion Acute hypokalemia causes kidney injury and myocardial stress. Cystic lesions originate from late proximal tubule. Hypokalemia should be corrected rapidly to stop progression into kidney fibrosis.

A Heterozygous Mutation in Cardiac Troponin T Promotes Ca2+ Dysregulation and Adult Cardiomyopathy in Zebrafish

Cardiomyopathies are a group of heterogeneous diseases that affect the muscles of the heart, leading to early morbidity and mortality in young and adults. Genetic forms of cardiomyopathy are caused predominantly by mutations in structural components of the cardiomyocyte sarcomeres, the contractile units of the heart, which includes cardiac Troponin T (TnT). Here, we generated mutations with CRISPR/Cas9 technology in the zebrafish tnnt2a gene, encoding cardiac TnT, at a mutational “hotspot” site to establish a zebrafish model for genetic cardiomyopathies. We found that a heterozygous tnnt2a mutation deleting Arginine at position 94 and Lysine at position 95 of TnT causes progressive cardiac structural changes resulting in heart failure. The cardiac remodeling is presented by an enlarged atrium, decreased ventricle size, increased myocardial stress as well as increased fibrosis. As early as five days post fertilization, larvae carrying the TnT RK94del mutation display diastolic dysfunction and impaired calcium dynamics related to increased Ca2+ sensitivity. In conclusion, adult zebrafish with a heterozygous TnT-RK94del mutation develop cardiomyopathy as seen in patients with TnT mutations and therefore represent a promising model to study disease mechanisms and to screen for putative therapeutic compounds.

The Value of Biomarkers in the Diagnosis and Prognosis of Heart Failure in Older Age

The search for reliable algorithms for diagnosing heart failure with preserved left ventricular ejection fraction (LVEF) in elderly patients is an urgent problem due to the low specificity of clinical manifestations and the peculiarities of involutive processes occurring in the human body. As an alternative diagnostic approach, it is possible to determine in the blood laboratory biochemical markers — a promising method of diagnosis, prognosis and control of the effectiveness of treatment. The article examines the significance of myocardial stress markers (brain natriuretic peptide, N-terminal brain natriuretic peptide, median fragment of atrial natriuretic peptide); «mechanical» myocardial stress (soluble stimulating growth factor expressed by gene 2 — sST2), copeptin, galectin-3 in patients with heart failure and preserved LVEF, including older persons, as well as the possibility of their use in outpatient practice to predict the course of heart failure. The contribution of the multimarker model for a comprehensive assessment of prognosis is discussed, taking into account both the «hemodynamic» side of myocardial stress (pressure or volume overload, markers — natriuretic peptides), and «mechanical» (fibrosis / hypertrophy / heart remodeling, marker — sST2) myocardial changes.