Changes in Prescribing Antithrombotic Therapy in Patients with Atrial Fibrillation in the Multidisciplinary Hospital in Volgograd from 2012 to 2020

Aim. To study the frequency of prescribing antithrombotic agents in patients with non-valvular atrial fibrillation (AF) in real clinical practice, to evaluate changes of prescriptions from 2012 till 2020.Material and methods. The medical records of inpatients (Form 003/y) with the diagnosis AF, hospitalized in the cardiological department were analyzed. According to the inclusion criteria, the patients were over 18 years of age, established diagnosis of non-valvular AF. There were two exclusion criteria: congenital and acquired valvular heart disease and prosthetic heart valves. In retrospective analysis we have included 263 case histories in 2012, 502 ones in 2016 and 524 in 2020. CHA2DS2-VASc score was used for individual stroke risk assessment in AF. The rational use of the antithrombotic therapy was evaluated according with current clinical practice guidelines at analyzing moment.Results. During period of observation the frequency of antiplatelet therapy significantly decreased from 25,5% to 5,5% (р<0.001), decreased the frequency of administration of warfarin from 71,9% to 18,3% (р<0.001). The frequency of use of direct oral anticoagulants increased in 2020 compared to 2016 (р<0.001). For patients with a high risk of stroke anticoagulant therapy was administered in 71.8% of cases in 2012, 88.5% in 2016 and 92.5% in 2020. Before discharge from hospital majority of patients (72%) achieved a desired minimum international normalized ratio (INR) from 2.0 to 3.0 in 2012. In 2016 and 2020 an only 33% and 40.6% of patients achieved INR (2.0-3.0).Conclusion. Doctors have become more committed to following clinical guidelines during the period of the investigation. In 2020 antithrombotic therapy for atrial fibrillation was suitable according to current clinical guidelines.

Less invasive treatments for pure aortic insufficiency: Are we there yet?

The gold standard for the treatment of pure aortic insufficiency (PAI) is surgical valve repair or replacement.1 With the newest transcatheter heart valve technologies and the accumulating years of experience of heart teams with the current transcatheter aortic valve replacement (TAVR) prostheses, implanters have push the envelope with off-label use of those valves designed and approved for aortic stenosis, in patients with pure aortic insufficiency especially those at higher risks or for compassionate use.3 However, new prostheses are currently under investigation in clinical use and evidences are provided on the safety and efficacy of those latter. It will be discussed in this commentary, the actual clinical evidences and the use of transcatheter heart valves, in and off label, for the treatment of pure aortic insufficiency.

Antibiofilm Activities of Biogenic Silver Nanoparticles Against Candida albicans

Biofilms are microbial colonies that are encased in an organic polymeric matrix and are resistant to antimicrobial treatments. Biofilms can adhere to both biotic and abiotic surfaces, allowing them to colonize medical equipment such as urinary and intravenous catheters, mechanical heart valves, endotracheal tubes, and prosthetic joints. Candida albicans biofilm is the major etiological cause of the pathogenesis of candidiasis in which its unobstructed growth occurs in the oral cavity; trachea, and catheters that progress to systemic infections in the worst scenarios. There is an urgent need to discover novel biofilm preventive and curative agents. In the present investigation, an effort is made to observe the role of cyanobacteria-derived AgNPs as a new antibiofilm agent with special reference to candidiasis. AgNPs synthesized through the green route using Anabaena variabilis cell extract were characterized by UV–visible spectroscopy. The nanoparticles were spherical in shape with 11–15 nm size and were monodispersed. The minimum inhibitory concentration (MIC) of AgNPs was obtained at 12.5 μg/mL against C. albicans. AgNPs 25 μg/mL showed 79% fungal cell membrane permeability and 22.2% ROS production. AgNPs (25 μg/mL) also facilitated 62.5% of biofilm inhibition and degradation. Therefore, AgNPs could be considered as a promising antifungal agent to control biofilm produced by C. albicans.

Biodegradable Poly-ε-Caprolactone Scaffolds with ECFCs and iMSCs for Tissue-Engineered Heart Valves

Clinically used heart valve prostheses, despite their progress, are still associated with limitations. Biodegradable poly-ε-caprolactone (PCL) nanofiber scaffolds, as a matrix, were seeded with human endothelial colony-forming cells (ECFCs) and human induced-pluripotent stem cells-derived MSCs (iMSCs) for the generation of tissue-engineered heart valves. Cell adhesion, proliferation, and distribution, as well as the effects of coating PCL nanofibers, were analyzed by fluorescence microscopy and SEM. Mechanical properties of seeded PCL scaffolds were investigated under uniaxial loading. iPSCs were used to differentiate into iMSCs via mesoderm. The obtained iMSCs exhibited a comparable phenotype and surface marker expression to adult human MSCs and were capable of multilineage differentiation. EFCFs and MSCs showed good adhesion and distribution on PCL fibers, forming a closed cell cover. Coating of the fibers resulted in an increased cell number only at an early time point; from day 7 of colonization, there was no difference between cell numbers on coated and uncoated PCL fibers. The mechanical properties of PCL scaffolds under uniaxial loading were compared with native porcine pulmonary valve leaflets. The Young’s modulus and mean elongation at Fmax of unseeded PCL scaffolds were comparable to those of native leaflets (p = ns.). Colonization of PCL scaffolds with human ECFCs or iMSCs did not alter these properties (p = ns.). However, the native heart valves exhibited a maximum tensile stress at a force of 1.2 ± 0.5 N, whereas it was lower in the unseeded PCL scaffolds (0.6 ± 0.0 N, p < 0.05). A closed cell layer on PCL tissues did not change the values of Fmax (ECFCs: 0.6 ± 0.1 N; iMSCs: 0.7 ± 0.1 N). Here, a successful two-phase protocol, based on the timed use of differentiation factors for efficient differentiation of human iPSCs into iMSCs, was developed. Furthermore, we demonstrated the successful colonization of a biodegradable PCL nanofiber matrix with human ECFCs and iMSCs suitable for the generation of tissue-engineered heart valves. A closed cell cover was already evident after 14 days for ECFCs and 21 days for MSCs. The PCL tissue did not show major mechanical differences compared to native heart valves, which was not altered by short-term surface colonization with human cells in the absence of an extracellular matrix.

Residual Bioprosthetic Valve Immunogenicity: Forgotten, Not Lost

Despite early realization of the need to control inherent immunogenicity of bioprosthetic replacement heart valves and thereby mitigate the ensuing host response and its associated pathology, including dystrophic calcification, the problem remains unresolved to this day. Concerns over mechanical stiffness associated with prerequisite high cross-link density to effect abrogation of this response, together with the insinuated role of leaching glutaraldehyde monomer in subsequent dystrophic mineralization, have understandably introduced compromises. These have become so entrenched as a benchmark standard that residual immunogenicity of the extracellular matrix has seemingly been relegated to a very subordinate role. Instead, focus has shifted toward the removal of cellular compartment antigens renowned for their implication in the failure of vascularized organ xenotransplants. While decellularization certainly offers advantages, this review aims to refocus attention on the unresolved matter of the host response to the extracellular matrix. Furthermore, by implicating remnant immune and inflammatory processes to bioprosthetic valve pathology, including pannus overgrowth and mineralization, the validity of a preeminent focus on decellularization, in the context of inefficient antigen and possible residual microbial remnant removal, is questioned.