Long-term bio-functional performance of a novel, self-positioning balloon expandable transcatheter biological aortic valve system in the ovine aortic banding model.

BACKGROUND: The aim of the study was to evaluate bio-functionality of a novel, proprietary balloon-expandable biological transcatheter aortic valve implantation (TAVI) system (InFlow, CardValve Consortium, Poland) in an ovine model of aortic banding. METHODS: Surgical ascending aorta banding was created in 21 sheep. Two weeks later, 18 biological valves were implanted within the model using 15-16 F InFlow TAVI systems and carotid cut-down approach. Follow-up transthoracic echocardiography was performed at 30, 90, and 180-day. At designated time, animals were euthanized and valves harvested for analysis. RESULTS: All sheep survived the banding procedure. There were 4 (22%) procedure related deaths within a 7-day period. During the observation an additional 2 sheep died. In one, the valve dislocated after the procedure - the animal was excluded. Two animals completed 30-day follow up, five 90-day follow-up and four terminal follow-up of 180 days. Valves examined via transesophageal echocardiography showed proper hemodynamic parameters without evidence of structural valve deterioration. The maximum and average flow gradients at 180 days were 31.4 (23.3-37.7) and 17.5 (13.1-20.2) mmHg, respectively. There was one case of moderate insufficiency and no case of perivalvular leaks. By histopathology, there were no inflammation, thrombosis, nor calcifications in any tested valves at long-term follow-up. Neointimal coverage of stent struts increased with time from basal part in "early" groups to nearly 3/4 of stent length in the 180-day group. The pannus tissue showed maturation that increased with time with no stenotic "collar" visible in orthotopically implanted valves. CONCLUSIONS: The study showed good hemodynamic performance, durability and biocompatibility of the novel biological THV.

Autopsy Histopathologic Lung Findings in Patients Treated With Extracorporeal Membrane Oxygenation.

CONTEXT.­: Extracorporeal membrane oxygenation (ECMO) is increasingly used in the treatment of respiratory and cardiac failure, but data describing lung histopathology in ECMO recipients are limited. OBJECTIVE.­: To examine pulmonary histopathologic findings in patients who underwent venovenous (VV) ECMO for pulmonary reasons, or venoarterial (VA) ECMO for cardiac indications shortly before death, and to determine if the pulmonary changes provided insights into therapy that may prevent complications and improve outcome. DESIGN.­: We conducted a retrospective study of lung autopsies, from VV and VA ECMO recipients and patients with acute respiratory distress syndrome (ARDS) and non-ECMO treatment, between 2008 and 2020 in Silesia Center for Heart Diseases in Zabrze, Poland. RESULTS.­: Among 83 ECMO patients (42-64 years; male, 57 [68.7%]), the most common histopathologic findings were bronchopneumonia (44 [53.0%]), interstitial edema (40 [48.2%]), diffuse alveolar damage (DAD; 32 [38.6%]), hemorrhagic infarct (28 [33.7%]), and pulmonary hemorrhage (25 [30.1%]). DAD was associated with longer ECMO treatment and longer hospital stay. The use of VV ECMO was a predictor of DAD in patients with ARDS and undergoing ECMO, but it also occurred in 21 of 65 patients (32.3%) in the VA ECMO group, even though VA ECMO was used for heart failure. CONCLUSIONS.­: Although DAD was significantly more common in lung autopsies of VV ECMO patients, one-third of VA ECMO patients had histopathologic changes characteristic of ARDS. The presence of DAD in lung autopsies of patients treated with VA ECMO indicates that in these patients, protective lung ventilation should be considered.

Impact of local delivery of allogeneic chondrocytes on the biological response and healing of the sternum bones after sternotomy.

Median sternotomy is the surgical method of choice for many procedures where one of the main problems is the long post-operative wound healing process leading to sternal dehiscence and the development of infection. This leads to prolonged hospital stay and increased mortality due to post-operative complications. A promising solution seems to be the use of allogeneic chondrocytes for wound treatment, whose properties in the field of cartilage reconstruction are widely used in medicine, mainly in orthopedics. In the present study, we investigated the effect of local delivery of allogeneic chondrocytes on the biological response and healing of the sternum after sternotomy. We optimized the culture conditions for the isolated chondrocytes, which were then applied to the sternal incision wound. Chondrocytes in the culture were assessed on the basis of the presence of chondrocyte-specific genes: Sox9, Aggrecan and Collagen II. In turn, the histopathological and immunohistochemical evaluation was used to assess the safety of implantation. In our work, we demonstrated the possibility of obtaining a viable culture of chondrocytes, which were successfully introduced into the sternal wound after sternotomy. Importantly, implantation of allogeneic chondrocytes showed no significant side effects. The obtained results open new possibilities for research on the use of allogeneic chondrocytes in the process of accelerating wound healing after median sternotomy.

Histopathological Examination of an Explanted Heart in a Long-Term Responder to Cardiac Stereotactic Body Radiotherapy (STereotactic Arrhythmia Radioablation).

Cardiac stereotactic body radiotherapy is an emerging treatment method for recurrent ventricular tachycardia refractory to invasive treatment methods. The single-fraction delivery of 25 Gy was assumed to produce fibrosis, similar to a post-radiofrequency ablation scar. However, the dynamics of clinical response and recent preclinical findings suggest a possible different mechanism. The data on histopathological presentation of post-radiotherapy hearts is scarce, and the authors provide significantly different conclusions. In this article, we present unique data on histopathological examination of a heart explanted from a patient who had a persistent anti-arrhythmic response that lasted almost a year, until a heart failure exacerbation caused a necessity of a heart transplant. Despite a complete treatment response, there was no homogenous transmural fibrosis in the irradiated region, and the overall presentation of the heart was similar to other transplanted hearts of patients with advanced heart failure. In conclusion, our findings support the theorem of functional changes as a source of the anti-arrhythmic mechanism of radiotherapy and show that durable treatment response can be achieved in absence of transmural fibrosis of the irradiated myocardium.

Temporal, biomechanical evaluation of a novel, transcatheter polymeric aortic valve in ovine aortic banding model.

Objectives: The aim of the study is to evaluate the functionality, durability, and temporal biocompatibility of a novel, balloon-expandable polymeric transcatheter heart valve (ATHV) system (InFlow, CardValve Consortium, Poland). Along with expanding TAVI indications, the demand for new transcatheter valves is increasing. Methods: A surgical ascending aortic banding model was created in 20 sheep. Two weeks later, 16 sheep were implanted with ATHV systems (15-16F). Three animals were euthanized after a 30-day follow-up, four animals after a 90-day follow-up, and six animals after a 180-day follow-up. A follow-up transthoracic echocardiography (TTE) was performed. Results: There was one procedure-related (6,25%) and two model-related deaths (12,5%; banding site calcification with subsequent infection originating externally from banding). TTE revealed the flow gradients (max/average) of 30,75/17,91; 32,57/19,21; and 21,34/10,63 mmHg at 30, 90, and 180 days, respectively. There were two cases of low-degree regurgitation after 180 days with no perivalvular leak observed. Histopathological analysis showed no valve degeneration at terminal follow-up with optimal healing. Small thrombi were present at the aortic wall adjacent to the base of the leaflets, and between the aortic wall and the stent in most of the valves; however, leaflets remained free from thrombi in all cases. Scanty calcifications of leaflets were reported in three animals evaluated 180 days after implantation. Conclusion: This preclinical study in the aortic banding model showed good hemodynamic performance, durability, and biocompatibility of the novel ATHV. Furthermore, regulatory studies with longer follow-ups are warranted.

The clinical value of the routine analysis of cardiac implantable electronic devices after the patient's death in a tertiary cardiovascular center.

INTRODUCTION: The postmortem interrogation of cardiac implantable electronic devices (CIEDs) has not been regularly practiced yet. We presumed that it can provide data not only on the mechanism of the patient's death but also on possible device malfunctions contributing to its occurrence. OBJECTIVES: The study aimed to determine the usefulness of the explantation and interrogation of CIEDs after the patient's death in routine clinical practice, when combined with autopsy findings and clinical follow­up starting from the time after device implantation. PATIENTS AND METHODS: Between August 24, 2008 and August 30, 2018, all patients who underwent autopsy in the tertiary cardiovascular center or partner facilities had the device explanted and interrogated by the qualified electrophysiologist. Clinical characteristics obtained at the time of device implantation and patients' death were obtained from medical records. Device interrogation results were then combined with autopsy report and clinical data. RESULTS: Out of 1200 autopsied patients, the device was removed and analyzed in 61 individuals. Clinical characteristics from the time of implantation and patients' death were available in 53 (86.7%) and 49 (80.3%) patients, respectively. Device­related concerns, undetected during patients' hospital stay, were noted in 6 cases (6.1%) and included 3 programming and 3 hardware issues. CONCLUSIONS: To our knowledge, this is the first study to date to combine the clinical follow­up of patients before death and on admission at the end of life, autopsy results, and postmortem CIED interrogation. Having implemented the device interrogation, we found 6 CIED­related events potentially associated with patients' death, which were not detected before its occurrence.

Percutaneous access to coronary arteries in patients after transcatheter aortic valve implantation procedures - is it a real problem?

Transcatheter aortic valve implantation (TAVI) is still developing and changing our approach to treating patients with severe symptomatic aortic stenosis. Aortic stenosis frequently coexists with coronary artery disease. Both diseases have similar risk factors for their development and one should expect a future progression of coronary artery disease. The current guidelines have expanded TAVI indications to include intermediate-risk patients, and perhaps they will be expanded to include low-risk patients in the future. Survival after TAVI in younger patients will depend on the durability of the aortic valves and methods of coronary artery disease treatment. This paper presents some aspects of performing coronary angiography and percutaneous coronary intervention in patients who had TAVI performed using the two most popular aortic valves - balloon expandable aortic valves (Edward Sapien/Edward Sapien XT/Sapien 3) and self-expandable aortic valves (CoreValve/Evolut R) - on the basis of several examples. This paper also focuses on technical aspects associated with a proper implantation of aortic valves to ensure easy access to coronary arteries, as well as on possible problems when the implantation is not optimal. We discuss interactions between the structure of the aortic valve stent, catheters, commissures of new aortic valves, and coronary ostia.

Myofibrillolysis and fibrosis predicts myocardial insufficiency.

INTRODUCTION: Cardiocyte myofibrillolysis and interstitial fibrosis belong to histopathological changes in cardiomyopathies, leading to heart failure. AIM: To evaluate these changes in apical resection during left ventricular assist device (LVAD) implantation. MATERIAL AND METHODS: The studied group consisted of 40 patients with cardiomyopathy, and apical samples excised during left ventricular assist device implantation were studied (CM/VAD group, mean: 48.1 ±10 y/o). A control group consisted of 6 apical samples from healthy heart graft donors (mean: 29 ±2.3 years old). Area fraction (AF) was calculated for: fibrosis, cardiocytes with myofibrillolysis (MFL), non-myofibrillolytic cardiocytes (non-MFL). RESULTS: Single lymphocytes were seen in 18 (45%) cases in the CM/VAD group. Cardiomyopathy grade evaluated semiquantitatively in CM/VAD was: slight (25% of a group), moderate (35.5%), advanced (35.5%). CM/VAD cases showed nearly ten times higher fibrosis than the control group. The MFL cells occupied nearly a five times larger area in CM/VAD than in the control group, whereas non-MFL cells were found in the control group, as a predominant pattern. The linear regression calculated between fibrosis AF and types of cardiocytes indicated the depletion of cardiomyocytes with fibrosis increase. The control group presented insignificant dependency between fibrosis and MFL cells, suggesting the lack of replacement fibrosis. Significant negative dependence between fibrosis and non-MFL cardiocytes suggested remodeling in controls. Correlation analysis showed a strong relation between depletion of normal cardiocytes and progression of fibrosis. CONCLUSIONS: Progression of cardiomyopathy and fibrosis depends on the loss of cardiocytes rather than degeneration of these cells.

State-of-the-art of transcatheter treatment of aortic valve stenosis and the overview of the InFlow project aiming at developing the first Polish TAVI system.

Initial experience of transcatheter aortic valve implantation (TAVI) or replacement (TAVR) has ap-peared as a promising minimally invasive technology for patients disqualified from surgical treatment (SAVR). Safety and efficacy of TAVI has been analyzed and assessed through numerous registries and trials. Furthermore, results obtained from comparative TAVI vs. SAVR trials proved that both treat¬ments can be considered equal in terms of post-procedural mortality and morbidity in high-risk, as well as lower risk patients. However, there are still some issues that have to be addressed, such as higher chance of paravalvular leakage, vascular injuries, conduction disturbances, malpositioning and the yet unmet problem of insufficient biological valves durability. Recent technological developments along with the learning curve of operators prove a great potential for improvement of TAVI and a chance of surpassing SAVR in various groups of patients in the near future. In pursuit of finding new solutions, the CardValve Consortium consisting of leading scientific and research institutions in Poland has been created. Under the name of InFlow and financial support from the National Center for Research and Development, they have started a project with the aim to design, create and implement into clinical practice the first, Polish, low-profile TAVI valve system, utilizing not only biological but also artificial, polymeric-based prosthesis. This review focuses on current developments in TAVI technologies including the InFlow project.

Cardiomyopathy development protection after myocardial infarction in rats: Successful competition for major dihydropyridines' common metabolite against captopril.

During the last 25 years angiotensin-converting enzyme inhibitors spectacularly conquered the field of cardiovascular diseases therapy. Nevertheless, lack of new studies concerning side effects associated with their chronic administration seems to be rather confusing. In our previous research, we proved that the main furnidipines' metabolite (M-2) possess multiple cardioprotective actions. Currently, we compared effects of post-infarction long-term oral treatment with M-2 and captopril on hemodynamic parameters and "ischemic cardiomyopathy" development in rats. Myocardial infarction was evoked by permanent left anterior descending coronary artery occlusion for 35 days. Surviving rats were treated with captopril (2 × 25 mg/kg) or M-2 (4 mg/kg) from 6th- 35th day. At 35th day rats' hearts were tested on working heart setup, where following parameters were measured: heart rate, preload pressure, aortic systolic and diastolic pressures, aortic maximum rise and fall, aortic and coronary flow, myocardial oxygen consumption and oximetry in perfusate. Subsequently, heart tissue specimens were assessed during morphological estimation. Captopril caused significant heart rate increase and markedly diminished preload pressure in comparison to M-2. Both drugs evoked essential aortic pressure increase. Aortic flow was significantly decreased after M-2, whereas captopril increased this parameter in comparison to M-2. Both agents caused marked coronary flow increase. Morphologic examination in captopril revealed cardiomyopathic process in 70% of hearts, whereas in M-2 this value reached 30%. Neovascularization of post-infarcted myocardium was visible only after M-2 therapy. Concluding, M-2 presented itself as more attractive agent in long-term post-infarction treatment by preventing cardiomyopathy development, angiogenesis stimulation and preserving cardiac performance.

Dihydropyridines' metabolites-induced early apoptosis after myocardial infarction in rats; new outlook on preclinical study with M-2 and M-3.

Our previous studies established cardio-protective effects of furnidipine and its active metabolites called M-2 and M-3. The aim of current research was to compare the effects of single oral pretreatment with 20 mg kg(-1) of M-2 and M-3 on mortality, different forms of arrhythmias, blood pressures parameters and ST-segment changes during occlusion (for 90 min) and reperfusion in the model of myocardial infarction in rats evoked by left anterior descending coronary artery occlusion. Additionally, the development of programmed cell death and biochemical parameters in blood serum were studied at 4th day after infarction. Furnidipines' metabolites effectively reduced mortality index while did not markedly influence on blood pressures parameters, arrhythmias, ST-segment changes as well as biochemical parameters. Intriguingly, programmed cell death study (TUNEL) showed distinct increase in the amount of apoptotic nuclei in post-infarcted myocardium, granulation tissue and what is more in arteriolar walls after M-2 and M-3 application. Moreover, M-2 turned out to be more powerful in stimulation of apoptosis in granulation tissue surrounding infarcted area whereas M-3 presented balanced profile in this matter. Taking into account that programmed cell death plays positive role in post-infarcted heart healing, M-2 presents itself as more attractive agent for oral pretreatment in early stages of ischemia by non-stable individuals due to its more specific action in stimulation repairing processes in granulation tissue as well as in arteriolar walls. While M-2 and M-3 are common metabolites present in degradation pathways of many widely used dihydropyridines in clinic, this key fact put the new outlook on understanding additional mechanism and effects of not only furnidipines' metabolites but also other dihydropyridines.

Biomechanical properties of hybrid heart valve prosthesis utilizing the pigs that do not express the galactose-α-1,3-galactose (α-Gal) antigen derived tissue and tissue engineering technique.

The aim of the study was to estimate the biomechanical properties of heart valves conduit derived from transgenic pigs to determine the usefulness for the preparation of tissue-engineered heart valves. The acellular aortic and pulmonary valve conduits from transgenic pigs were used to estimate the biomechanical properties of the valve. Non-transgenic porcine heart valve conduits were used as a reference. The biomechanics stability of acellular valve conduits decreased both for the transgenic and non-transgenic porcine valves. The energy required to break the native pulmonary valve derived from transgenic pigs was higher (20,475 ± 7,600 J m(-2)) compared with native non-transgenic pigs (12,140 ± 5,370 J m(-2)). After acellularization, the energy to break the valves decreased to 14,600 and 8,800 J m(-2) for the transgenic pulmonary valve and non-transgenic valve, respectively. The native transgenic pulmonary valve showed a higher extensibility (42.70 %) than the non-transgenic pulmonary valve (35.50 %); the extensibility decreased after acellularization to 41.1 and 31.5 % for the transgenic and non-transgenic valves, respectively. The pulmonary valves derived from transgenic pigs demonstrate better biomechanical properties compared with non-transgenic. Heart valves derived from transgenic pigs can be valuable for the preparation of tissue-engineered bioprostheses, because of their biomechanical properties, stability, reduced immune response, making them safer for clinical applications.

Aortic cusp extension valvuloplasty: repair with an extracellular patch.

INTRODUCTION: The proportion of valve repair procedures is increasing in experienced centers. The aim of the study was to assess the clinical and echocardiographic outcomes after aortic valve reconstruction with a novel surgical technique. MATERIAL AND METHODS: The study group consisted of 30 patients (23 male and 7 female) at a mean age of 35 ± 14 years. In patients with aortic root aneurysm the reimplantation or Florida sleeve technique was used. A sub-commissural annuloplasty, plication of the free edge of the cusp, shaving, and commissurotomy were performed. At this stage of surgery aortic repair was then attempted by cusp extension. Since 2013 the strips have been tailored from extracellular matrix. RESULTS: The mean aortic cross-clamp time was 90 ± 32 min. The mean cardiopulmonary bypass time was 126 ± 38 min. There was no in-hospital death. Re-exploration for bleeding was required in 1 patient. During follow-up, 1 patient needed reoperation at 1 year due to endocarditis. All patients remained alive in New York Heart Association (NYHA) functional class I. The echocardiographic findings remained unchanged in all cases during follow-up. CONCLUSIONS: Our modification of aortic valve repair results in a good outcome.

Age-related changes in biomechanical properties of transgenic porcine pulmonary and aortic conduits.

The limitations associated with conventional valve prosthesis have led to a search for alternatives. One potential approach is tissue engineering. Most tissue engineering studies have described the biomechanical properties of heart valves derived from adult pigs. However, because one of the factors affecting the function of valve prosthesis after implantation is appropriate sizing for a given patient, it is important to evaluate the usefulness of a heart valve given the donor animal's weight and age. The aim of this study was to evaluate how the age of a pig can influence the biomechanical and hemodynamical properties of porcine heart valve prosthesis after acellularization. Acellular porcine aortic and pulmonary valve conduits were used. Hearts were harvested from animals differing in weight and age. The biomechanical properties of the valves were then characterized using a uniaxial tensile test. Moreover, computer simulations based on the finite element method (FEM) were used to study the influence of biomechanical properties on the hemodynamic conditions. Studying biomechanical and morphological changes in porcine heart valve conduits according to the weight and age of the animals can be valuable for developing age-targeted therapy using tissue engineering techniques.

Persistent mild lesions in coronary angiography predict poor long-term survival of heart transplant recipients.

BACKGROUND: Even though coronary angiography (CAG) underestimates coronary allograft vasculopathy (CAV) development, especially in the distal parts of arteries, it remains a frame of reference for International Society for Heart and Lung Transplantation (ISHLT) CAV classification. A retrospective analysis was performed to assess the prognostic value of CAG findings. METHODS: Among 310 orthotopic heart transplantation (OHT) recipients with at least 2 CAGs at 2-year intervals, we identified 197 (146 men and 41 women; 55 ± 13 years) without lesions (Group 0), 27 (15 men and 12 women; 58 ± 8 years) in whom mild changes remained in consecutive CAGs (Group 1), 28 (24 men and 4 women; 58 ± 10 years) in whom mild lesions decreased in consecutive CAGs (Group 1REG), and 58 (53 men and 5 women; 56 ± 10 years) in whom the stenosis criteria of ISHLT CAV 2 or 3 were covered (Group 2). We compared survival and other clinical variables among the groups. RESULTS: The average follow-up was 10 ± 4 years. Forty-one (21%) deaths occurred in Group 0, 15 (56%) in Group 1 (p = 0.002), 9(31%) in Group 1REG (p = NS), and 26 (46%) in Group 2 (p = 0.004, chi-square test). Time free from all-cause death was significantly shorter in Group 1 (T1/2 = 8 years) than in Group 0 (T1/2 = 15.5 years; p = 0.00072, log-rank test). Time free from cardiovascular death was significantly shorter in Groups 1 and 2, as was time free from CAV-related death in Groups 1, 1REG, and 2. Multivariate analysis, using a Cox proportional hazards model, revealed that Group 1 inclusion criterion of CAG findings is an independent predictor of all-cause death, cardiovascular death, and CAV-related death. CONCLUSIONS: Persistent mild coronary lesions, observed in consecutive CAG, predicted shorter survival of OHT recipients.