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Tissue engineering has significant potential for solving the problems of durability of biological tissues when used in cardiac and vascular reconstructive surgery. A decellularization technology has been proposed for obtaining a biomaterial, morphologically and functionally similar to the damaged human heart tissue. This review discusses various aspects and models of biological tissue decellularization, including the modern technology of using supercritical carbon dioxide as the most eco-friendly and promising method.

Objective. Evaluation of heart rate variability in patients with rheumatic heart disease. Material and methods . The study enrolled 230 patients, of whom 156 patients with mitral stenosis (CRHD), 36 patients with mitral valve regurgitation, and 38 patients with acquired aortic stenosis were selected. CHF functional class was determined using a 6-minute walk test according to the standard method; there were no patients with FC IV. HRV values were obtained using the Kardiotekhnika-04-3R (M) cardiorespiratory monitor with an estimation of time domain and frequency domain. Results. The CRHD patients had lower HRV indicators in the time (SDNN - 126.38 ms, SDANN - 112.07 ms, RMSSD - 32.79 ms) and frequency domain (VLF - 2,098.59 ms 2 ; LF - 865.39 ms 2 , HF - 323.48 ms 2 ) compared with patients with mitral valve regurgitation and aortic stenosis. Evaluation of HRV within patients with CRHD, depending on the presence or absence of combined mitral-aortic stenosis, did not show differences in the general and sympathetic tone of the ANS. In patients with combined mitral-aortic stenosis, only a decrease in parasympathetic tone was revealed: RMSSD - 31.18 ms, HF - 286.36 ms 2 . Stratification of patients according to FC CHF showed an increase in parasympathetic tone: RMSSD was 26.67 ms for FC I and 43.69 ms for FC III; HF was 254.67 ms 2 for FC I and 541.23 ms 2 for FC III. The sympathetic and general tone of the ANS was minimal in patients with FC II CHF. A study of the change of indicators over 5 years did not demonstrate a significant increase in the time domain, and the main indicators of the frequency domain decreased significantly: VLF from (1,882.73 ± 119.48) to (1,603.54 ± 99.22) ms 2 ; HF from (334.34 ± 33.13) to (252.87 ± 17.84) ms 2 , LF from (819.48 ± 94.41) to (647.01 ± 42.50) ms 2 . A decrease in the frequency domain was also observed when comparing the HRV results of survived and deceased patients. Conclusions. The patients with CRHD had lower values of the ANS tone in comparison with patients with other acquired heart valve disease. The smallest values of the general tone of the ANS and SNS were observed in those studied with CRHD with FC II CHF, and the activity of the PNS was maximum at FC III. After 5 years of follow-up, only the frequency indices of HRV were significantly reduced.

Aim. To study the expression patterns of matrix metalloproteinases (MMPs) -1, -2, -9, -12 in the leaflets of the epoxy-treated bioprostheses explanted due to dysfunction and to identify the pathways for the accumulation of these enzymes in the xenogenic tissues.Methods. 19 leaflets from seven epoxy-treated bioprostheses (Kemcor (n = 2), PeriCor (n = 2), UniLine (n = 2) and TiAra (n = 1)) explanted from the mitral or aortic positions during repeat heart valve replacements were included in a study. Sections for microscopic studies were cut on a standard rotary microtome. Cell typing and the expression of MMP-1, -2, -9, -12 were evaluated using immunohistochemical staining with the antibodies against PTPRC/CD45, CD68, neutrophil myeloperoxidase and the corresponding MMPs. Stained samples were examined by light microscopy.Results. Sporadic cell infiltrates, mainly composed of macrophages (PTPRC/CD45+, CD68+), were found in 17 leaflets from six explanted bioprostheses. Positive staining for MMP-1, -2, -9, -12 was colocalized with immune cell infiltrates. It is worth noting that MMP-9 staining was visualized even in the absence of cell infiltration, while more intense staining was found in the areas with a loose extracellular matrix. There were no signs of macrophage infiltration or MMP expression in xenotissues of pericardial bioprostheses failed due to thrombosis and explanted two days after implantation. However, a blood clot formed on its surface showed intense MMP-9 staining and included a large proportion of neutrophils positive for myeloperoxidase.Conclusion. Macrophages and other immune cells that infiltrate xenotissues of epoxy-treated bioprostheses are sources of MMP-1, -2, -9, -12. In addition, MMP-9 can diffuse into bioprosthetic valve leaflets from blood plasma of patients. Thus, MMPs deposition in xenotissues may contribute to the leaflet ruptures and calcifications leading to the development of bioprosthetic valve dysfunction.

OBJECTIVE. The study investigated the role of stenosis of brachiocephalic arteries in development of postoperative complications in patients, who underwent the coronary bypass grafting (CABG) and operations concerning heart valve pathology in conditions of extracorporeal circulation. There were observed such complications as stroke (n = 4) and hypoxic ischemic encephalopathy with delirium in postoperative period. MATERIAL AND METHODS. The research was carried out in 21 patients on the base of Center of сardiosurgery and interventional cardiology of St. Petersburg Multifield Center. All the patients were male aged 64±6,9 years. RESULTS. The study showed that risk of cerebral complications, especially hypoxic ischemic encephalopathy with delirium, could increase in case of bilateral carotid stenosis combined with hemodynamically insignificant unilateral vertebral artery stenosis. The significant hemodynamic branchiocephalic arterial stenosis caused chronic and acute clinical signs of cerebrovascular insufficiency in anamnesis. CONCLUSIONS. The high risk of development of severe cerebral complications was associated with hemodynamically significant bilateral carotid stenosis accompanied by hemodynamically significant uni- and bilateral stenosis or one-sided occlusion of cerebral artery. Management of treatment should take into account risk factors of cardiosurgical patients.

The aim of the study was to perform a series of in vitro tests of a prototype of the developing heart valve prosthesis to evaluate its functional characteristics. Materials and methods. In this work we have used the frames and full prototypes of the prosthesis, consisting of a stent-like stainless steel support frame with mounted biological leaflets and cover. The authors evaluated the calculated and experimental forces necessary for the displacement of the sutureless implanted prosthesis using the test machine under uniaxial tension. The risk of defects and damages to the supporting framework as a result of implantation was evaluated by scanning electron microscopy. The hydrodynamic characteristics of the prosthesis were investigated under physiological conditions and «valvein-valve» implantation. Evaluation of the ergonomics and applicability of the proposed construction on the cadaver heart model of cattle was carried out. Results. As a result of the forces assessment, it was found that the force required to shear the prosthesis was 3.12 ± 0.37 N, while the calculated value was 1.7 N, which is significantly lower than the obtained value. The comparison of the images obtained with small and large magnifications demonstrated the absence of critical surface defects. Additional analysis under the super-large magnifications also did not reveal problem areas. During the hydrodynamic study, it was shown that the average transplant gradient increased slightly from 2.8–3.4 to 3.2–4.5 mm Hg for the initial prosthesis and the «valve-in-valve» complex, respectively. The decrease of the effective orifice area was 6–9% relative to the initial one. Evaluation of the implantation technique demonstrated the consistency of the approach: the use of the developed holder in combination with the balloon implantation system made it possible to position the prosthesis throughout the procedure. Conclusion. The series of tests demonstrates the consistency of the developed design, intended for the replacement of a failed prosthetic valve of the heart with the «valve-in-valve» implantation.

В данной работе представлена разработка динамической модели створки аортального клапана. В основе модели лежит анализ зависимости геометрической площади отверстия аортального клапана от времени во Ð²ÑÐµÑ Ñ„Ð°Ð·Ð°Ñ ÑÐµÑ€Ð´ÐµÑ‡Ð½Ð¾Ð³Ð¾ цикла. Качественно кинематика разработанной модели совпадает с уже существующими результатами Ð½Ð°ÑƒÑ‡Ð½Ñ‹Ñ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ð¹. Полученная динамическая модель предназначена для использования в Ð½ÐµÑÐ¾Ð¿Ñ€ÑÐ¶ÐµÐ½Ð½Ñ‹Ñ Ð³Ð¸Ð´Ñ€Ð¾Ð´Ð¸Ð½Ð°Ð¼Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Ñ€Ð°ÑÑ‡ÐµÑ‚Ð°Ñ ÐºÑ€Ð¾Ð²Ð¾Ñ‚Ð¾ÐºÐ° аортального клапана., In the given work the dynamic aortic valve leaflet simulation is exhibited. Review of the geometric orifice area plotted against time, calculations of the opening leaflet angles, rapid valve closing time and rapid valve closing speed confirm that leaflet kinematics of the model is reconciled with previous studies in this filed. The aim of this work is to create a dynamic model that can be used for fluid-structure interaction analysis of the aortic valve blood flow.

We analysed results of left atrial and biatrial anatomic scheme of radiofrequency (RF) ablation of the atria in patients with valvular heart. From 2007 to 2011, RF ablation procedure performed 283 patients with atrial fibrillation and heart valve disease. Patients were divided into two groups - group I performed a complete circuit biatrial procedure (procedure maze IV) - 131 patients, in group II only ablation of the left atrium -152 patients. Most of the patients had long-term persistent AF. The main problem of early postoperative period is dysfunction of pacemaker complex, which observed in 64.9% and 50.7% patients for group I and II, respectively (p = 0.031). Permanent dysfunction of pacemaker complex required implantation of permanent pacemaker (9.2% and 4.6% of cases for group I and II, respectively, p = 0,023). Predictors of dysfunction of the pacemaker complex were biatrial execution method and duration of AF. Freedom from AF and AT during 36 months after surgery was 80.4% for patients in group I and 78.5% for patients in group II, with no statistically significant difference (log-rank test, p = 0.621). Atrial transport function has not revealed that the active fraction of the right atrium was 29.8% higher than in group II in the early postoperative phase and by 17.9% in the long term, with no difference between groups for the left atrium has been received.

Aim . To analyze approaches to pretransplant treatment of potential heart recipients and heart donation criteria, directed to reduction of mortality on a waiting list and to increase of volume and effi ciency of heart transplantations. Methods and results. Data on 285 HT recipients (performed in 2008–2013) were analyzed. The analysis and comparison of patients with circulatory support before heart transplantation, using «high-risk» donors (aged over 40 years, with left ventricular hypertrophy ≥ 1.5 cm, after cardiopulmonary resuscitation, with the reduced systolic function of the left ventricle (< 40%), with potentially repair pathology of the heart valve and coronary arteries); to high risk recipients (over 60 years, with high pulmonary hypertension and earlier operated) were made. Conclusion . The proposed scientifi c, technological and organizational solutions made possible the timely performance of heart transplantation to patients with an inevitable lethal outcome as a result of heart failure.