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Background. Insight into blood viscosity in terms of its physical and biochemical properties carries significant clinical value. By understanding the relationship between the physical properties of blood and physiology, a potentially powerful tool for diagnosing early signs of many diseases can be discovered. Purpose. To identify the effect of fibrinogen on tensio- and rheometric characteristics of blood plasma and serum in patients with coronary heart disease and with mitral and/or aortic valve disease. Materials and methods. Prospective non-randomized study. The study of dynamic, equilibrium surface tension and viscoelastic modulus was performed by the pendant drop method using a PAT-1 device (Sinterface Technologies, Germany). We measured parameters characterizing the surface tension and dilatation rheology of blood serum such as: dynamic surface tension at an adsorption time of 100 s (γ), equilibrium surface tension (γ ∞) (adsorption time 2500 s), viscoelastic modulus |E|, and phase angle (φ) at frequencies of 0.1 and 0.01 Hz. All patients under study were divided into 3 groups. The healthy volunteers (30 subjects) without chronic diseases and active complaints aged 49 to 78 years (mean age, 61.1±1.1 years) comprised the comparison group (group 1). Group 2 - 40 patients with coronary heart disease (CHD) aged 49 to 77 years (mean age 62.2±1.3 years) who underwent bypass surgery to treat atherosclerotic coronary vessels (2 to 5 bypasses). Group 3 - 30 patients with cardiac mitral and/or aortic valve lesions aged 52 to 78 years (mean age 61.3±1.2 years). They underwent mitral and/or aortic valve replacement with mechanical prostheses. The most common pathophysiological syndrome in patients due to coronary artery or heart valve lesions was chronic heart failure (CHF) (stage 2A-2B according to Vasilenko-Strazhesko classification). Results. Characteristic γ100s of blood serum and plasma had significant difference in both patients’ groups, possibly due to the role of coagulation and anti-coagulation system proteins’ role in dynamic surface tension of plasma in a shorter timeframe (up to 100 s.). The increase in Δγ100s in both patients’ groups by day 7 of the postoperative period indicates an increasing dynamic surface tension of serum compared to plasma. Plasma of perioperative patients does not differ from the comparison group by its surface-equilibrium properties. Accordingly, the Δγ∞s values in groups 1 and 2 both before surgery and on days 1 and 7 of the postoperative period are almost identical, pointing to no difference in the amount of surfactants tending to adsorb on the droplet surface. Alterations of viscoelastic modulus |E| and phase angle (φ) at 0.1 and 0.01 Hz in the perioperative period indicate changes in qualitative and quantitative characteristics of circulating blood with variation in individual homeostasis characteristics, resulting in an increase in surface elasticity combined with an almost unchanged surface viscosity. Conclusion. Dynamic and equilibrium surface tension parameters in patients’ plasma differ from those in serum due to the presence of fibrinogen and other proteins of the blood coagulation system.

miRNAs have recently attracted investigators’ interest as regulators of valvular diseases pathogenesis, diagnostic biomarkers, and therapeutical targets. Evidence from in-vivo and in-vitro studies demonstrated stimulatory or inhibitory roles in mitral valve prolapse development, aortic leaflet fusion, and calcification pathways, specifically osteoblastic differentiation and transcription factors modulation. Tissue expression assessment and comparison between physiological and pathological phenotypes of different disease entities, including mitral valve prolapse and mitral chordae tendineae rupture, emerged as the best strategies to address miRNAs over or under-representation and thus, their impact on pathogeneses. In this review, we discuss the fundamental intra- and intercellular signals regulated by miRNAs leading to defects in mitral and aortic valves, congenital heart diseases, and the possible therapeutic strategies targeting them. These miRNAs inhibitors are comprised of antisense oligonucleotides and sponge vectors. The miRNA mimics, miRNA expression vectors, and small molecules are instead possible practical strategies to increase specific miRNA activity. Advantages and technical limitations of these new drugs, including instability and complex pharmacokinetics, are also presented. Novel delivery strategies, such as nanoparticles and liposomes, are described to improve knowledge on future personalized treatment directions.

Introduction: Low output syndrome (LOS) is a dangerous postoperative complication, which significantly worsens the prognosis; it is an essential risk factor of postoperative death. The aim of the study was to analyze the predictors of postoperative low cardiac output syndrome in patients subjected to aortic valve replacement due to aortic stenosis or regurgitation. Material and methods: Three hundred (300) patients with significant isolated aortic valve defect due to either aortic stenosis (n=150) or regurgitation (n=150), who underwent isolated aortic valve replacement were included in the study. Low cardiac output syndrome (LOS) was defined as the need for high dosages of inotropic medication, and/or intra-aortic balloon pumping to sustain adequate hemodynamic status. Results: Postoperative low cardiac output syndrome was developed in 86 patients (28.6%), including 39 patients with aortic stenosis (26.0%) and 47 patients with aortic regurgitation (31.3%). We selected the following independent predictors of postoperative LOS (odds ratio in parentheses): (1) aortic stenosis group – advanced age (4.7), end-systolic (5.5) and end-diastolic intraventricular septum thickness (4.2) before the surgery, LVEF Ł50% (5.4) and insignificant mitral regurgitation (4.1) in the early postoperative period; (2) aortic regurgitation group – obesity (4.8), left ventricular end-systolic (4.5) and end-diastolic diameters (6.4) in the preoperative period and left ventricular end-systolic (4.7) and end-diastolic diameters (6.1), and left ventricular ejection fraction Ł50% (7.2) in the early postoperative period. Conclusions: The patients at high risk for the development of low cardiac output syndrome should be the focus of trials of new techniques of myocardial protection to effectively resuscitate the ischemic myocardium and optimization of preexisting heart failure symptoms.

miRNAs have recently attracted investigators' interest as regulators of valvular diseases pathogenesis, diagnostic biomarkers, and therapeutical targets. Evidence from in-vivo and in-vitro studies demonstrated stimulatory or inhibitory roles in mitral valve prolapse development, aortic leaflet fusion, and calcification pathways, specifically osteoblastic differentiation and transcription factors modulation. Tissue expression assessment and comparison between physiological and pathological phenotypes of different disease entities, including mitral valve prolapse and mitral chordae tendineae rupture, emerged as the best strategies to address miRNAs over or under-representation and thus, their impact on pathogeneses. In this review, we discuss the fundamental intra- and intercellular signals regulated by miRNAs leading to defects in mitral and aortic valves, congenital heart diseases, and the possible therapeutic strategies targeting them. These miRNAs inhibitors are comprised of antisense oligonucleotides and sponge vectors. The miRNA mimics, miRNA expression vectors, and small molecules are instead possible practical strategies to increase specific miRNA activity. Advantages and technical limitations of these new drugs, including instability and complex pharmacokinetics, are also presented. Novel delivery strategies, such as nanoparticles and liposomes, are described to improve knowledge on future personalized treatment directions. [ABSTRACT FROM AUTHOR]

Background: Bovine pericardium can be used for cardiovascular repair surgeries, but challenges involving biocompatibility and durability remain. This study aimed to carry out pre-clinical testing of aortic valve replacement using an aortic valve prosthesis made of bovine pericardium modified with glutaraldehyde (GA) and 2,3-butanediol (BD)., Methods: The mechanical, plasma protein adsorption, platelet adhesion, collagenase digestion, and ninhydrin properties of the material (control vs. GA vs. GA + BD) were tested. All 3 tissues were implanted in rats and observed after 8 weeks under microscopy with alizarin red staining for calcification. Aortic valves made from the fully-treated material were implanted in sheep. A commercial bioprosthesis was used as control. Effectiveness and safety indicators were observed at 180 days after implantation., Results: Compared with the control group, the GA + BD material showed higher elongation at breaking and tensile load (both P<0.05), lower plasma protein adsorption, lower platelet adhesion, lower collagenase digestion, lower ninhydrin value, and higher cross-linking (all P<0.05). After implantation in rat models, the GA + BD material showed little or no dissolution; there was no obvious calcification; and it was surrounded by a small amount of fibrosis, with peripheral capillary proliferation. After implantation in sheep models, the aortic valve leaflets of the experimental animals freely opened and closed, their surface was smooth, and no abnormal echo was observed. The echocardiographic results and hemodynamic were comparable between the two groups. All safety parameters were normal., Conclusions: Modification of bovine pericardium with GA and BD results in a biomaterial with favorable properties for use as an aortic valve prosthesis., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/atm-20-7803). The authors have no conflicts of interest to declare., (2020 Annals of Translational Medicine. All rights reserved.)