Fourier transform infrared spectroscopy coupled with machine learning classification for identification of oxidative damage in freeze-dried heart valves.

Freeze-drying can be used to ensure off-the-shelf availability of decellularized heart valves for cardiovascular surgery. In this study, decellularized porcine aortic heart valves were analyzed by nitroblue tetrazolium (NBT) staining and Fourier transform infrared spectroscopy (FTIR) to identify oxidative damage during freeze-drying and subsequent storage as well as after treatment with H2O2 and FeCl3. NBT staining revealed that sucrose at a concentration of at least 40% (w/v) is needed to prevent oxidative damage during freeze-drying. Dried specimens that were stored at 4 °C depict little to no oxidative damage during storage for up to 2 months. FTIR analysis shows that fresh control, freeze-dried and stored heart valve specimens cannot be distinguished from one another, whereas H2O2- and FeCl3-treated samples could be distinguished in some tissue section. A feed forward artificial neural network model could accurately classify H2O2 and FeCl3 treated samples. However, fresh control, freeze-dried and stored samples could not be distinguished from one another, which implies that these groups are very similar in terms of their biomolecular fingerprints. Taken together, we conclude that sucrose can minimize oxidative damage caused by freeze-drying, and that subsequent dried storage has little effects on the overall biochemical composition of heart valve scaffolds.

Protective Effects of Fucoxanthin on Hydrogen Peroxide-Induced Calcification of Heart Valve Interstitial Cells.

Cardiovascular diseases such as atherosclerosis and aortic valve sclerosis involve inflammatory reactions triggered by various stimuli, causing increased oxidative stress. This increased oxidative stress causes damage to the heart cells, with subsequent cell apoptosis or calcification. Currently, heart valve damage or heart valve diseases are treated by drugs or surgery. Natural antioxidant products are being investigated in related research, such as fucoxanthin (Fx), which is a marine carotenoid extracted from seaweed, with strong antioxidant, anti-inflammatory, and anti-tumor properties. This study aimed to explore the protective effect of Fx on heart valves under high oxidative stress, as well as the underlying mechanism of action. Rat heart valve interstitial cells under H2O2-induced oxidative stress were treated with Fx. Fx improved cell survival and reduced oxidative stress-induced DNA damage, which was assessed by cell viability analysis and staining with propidium iodide. Alizarin Red-S analysis indicated that Fx has a protective effect against calcification. Furthermore, Western blotting revealed that Fx abrogates oxidative stress-induced apoptosis via reducing the expression of apoptosis-related proteins as well as modulate Akt/ERK-related protein expression. Notably, in vivo experiments using 26 dogs treated with 60 mg/kg of Fx in combination with medical treatment for 0.5 to 2 years showed significant recovery in their echocardiographic parameters. Collectively, these in vitro and in vivo results highlight the potential of Fx to protect heart valve cells from high oxidative stress-induced damage.

From organic and inorganic phosphates to valvular and vascular calcifications.

Calcification of the arterial wall and valves is an important part of the pathophysiological process of peripheral and coronary atherosclerosis, aortic stenosis, ageing, diabetes, and chronic kidney disease. This review aims to better understand how extracellular phosphates and their ability to be retained as calcium phosphates on the extracellular matrix initiate the mineralization process of arteries and valves. In this context, the physiological process of bone mineralization remains a human model for pathological soft tissue mineralization. Soluble (ionized) calcium precipitation occurs on extracellular phosphates; either with inorganic or on exposed organic phosphates. Organic phosphates are classified as either structural (phospholipids, nucleic acids) or energetic (corresponding to phosphoryl transfer activities). Extracellular phosphates promote a phenotypic shift in vascular smooth muscle and valvular interstitial cells towards an osteoblast gene expression pattern, which provokes the active phase of mineralization. A line of defense systems protects arterial and valvular tissue calcifications. Given the major roles of phosphate in soft tissue calcification, phosphate mimetics, and/or prevention of phosphate dissipation represent novel potential therapeutic approaches for arterial and valvular calcification.

Macrophage lineages in heart valve development and disease.

Heterogeneous macrophage lineages are present in the aortic and mitral valves of the heart during development and disease. These populations include resident macrophages of embryonic origins and recruited monocyte-derived macrophages prevalent in disease. Soon after birth, macrophages from haematopoietic lineages are recruited to the heart valves, and bone marrow transplantation studies in mice demonstrate that haematopoietic-derived macrophages continue to invest adult valves. During myxomatous heart valve disease, monocyte-derived macrophages are recruited to the heart valves and they contribute to valve degeneration in a mouse model of Marfan syndrome. Here, we review recent studies of macrophage lineages in heart valve development and disease with discussion of clinical significance and therapeutic applications.

Vitrification of Heart Valve Tissues.

Application of the original vitrification protocol used for pieces of heart valves to intact heart valves has evolved over time. Ice-free cryopreservation by Protocol 1 using VS55 is limited to small samples (1-3 mL total volume) where relatively rapid cooling and warming rates are possible. VS55 cryopreservation typically provides extracellular matrix preservation with approximately 80% cell viability and tissue function compared with fresh untreated tissues. In contrast, ice-free cryopreservation using VS83, Protocols 2 and 3, permits preservation of large samples (80-100 mL total volume) with several advantages over conventional cryopreservation methods and VS55 preservation, including long-term preservation capability at -80 °C; better matrix preservation than freezing with retention of material properties; very low cell viability, reducing the risks of an immune reaction in vivo; reduced risks of microbial contamination associated with use of liquid nitrogen; improved in vivo functions; no significant recipient allogeneic immune response; simplified manufacturing process; increased operator safety because liquid nitrogen is not used; and reduced manufacturing costs. More recently, we have developed Protocol 4 in which VS55 is supplemented with sugars resulting in reduced concerns regarding nucleation during cooling and warming. This method can be used for large samples resulting in retention of cell viability and permits short-term exposure to -80 °C with long-term storage preferred at or below -135 °C.

Incidence of Cabergoline-Associated Valvulopathy in Primary Care Patients With Prolactinoma Using Hard Cardiac Endpoints.

BACKGROUND: Controversy exists as to whether low-dose cabergoline is associated with clinically significant valvulopathy. Few studies examine hard cardiac endpoint data, most relying on echocardiographic findings. OBJECTIVES: To determine the prevalence of valve surgery or heart failure in patients taking cabergoline for prolactinoma against a matched nonexposed population. DESIGN: Population-based cohort study based on North East London primary care records. METHODS: Data were drawn from ~1.5 million patients' primary care records. We identified 646 patients taking cabergoline for >6 months for prolactinoma. These were matched to up to 5 control individuals matched for age, gender, ethnicity, location, diabetes, hypertension, ischemic heart disease, and smoking status. Cumulative doses/durations of treatment were calculated. Cardiac endpoints were defined as cardiac valve surgery or heart failure diagnosis (either diagnostic code or prescription code for associated medications). RESULTS: A total of 18 (2.8%) cabergoline-treated patients and 62 (2.33%) controls reached a cardiac endpoint. Median cumulative cabergoline dose was 56 mg (interquartile range [IQR] 27-123). Median treatment duration was 27 months (IQR 15-46). Median weekly dose was 2.1 mg. Neither univariate nor multivariate analysis demonstrated a significant association between cabergoline treatment at any cumulative dosage/duration and an increased incidence of cardiac endpoints. In a matched analysis, the relative risk for cardiac complications in the cabergoline-treated group was 0.78 (95% CI, 0.41-1.48; P = 0.446). Reanalysis of echocardiograms for 6/18 affected cabergoline-treated patients showed no evidence of ergot-derived drug valvulopathy. CONCLUSIONS: The data did not support an association between clinically significant valvulopathy and low-dose cabergoline treatment and provide further evidence for a reduction in frequency of surveillance echocardiography.

RADIOTHERAPY-ASSOCIATED CARDIOVASCULAR COMPLICATIONS IN CANCER (review). / SERTsEVO-SUDYNNI USKLADNENNIa, ASOTsIIOVANI Z PROMENEVOIu TERAPIIeIu (ogliad literatury).

The review is devoted to the current issues of radiation-induced cardiovascular complications, their diagnostics andincidence depending on the radiation doses and exposure regimens, potential efficiency of the screening strategiesfor cardiotoxicity monitoring after radiotherapy in cancer patients by analyzing the data from literature and clinical trials, based on recommendations of European Society of Cardiology and European Society of Medical Oncology.

Chemotherapy-associated nonbacterial thrombotic endocarditis: A radiological mimicker of cardiac amyloidosis requiring histopathologic examination for definitive diagnosis.

Nonbacterial thrombotic endocarditis is a form of a thrombotic angiopathy involving the endothelial lined endocardial surfaces of the heart which includes valves and the chamber walls. Underlying etiologies for nonbacterial thrombotic endocarditis include autoimmune diseases, hypercoagulable states, in the setting of certain malignant neoplasms, and physical injury. The pathogenesis for these processes is that of primary endothelial injury resulting in a thrombotic angiopathy. We present a patient with heart failure being evaluated before hematopoietic stem cell transplantation who had previously been provided with chemotherapy and whose cardiac magnetic resonance imaging reveals findings suggestive of amyloidosis. A subsequent endomyocardial biopsy instead showed nonbacterial thrombotic endocarditis characterized by the endocardium with fibromyxoid thickening and overlying fresh fibrin. This case highlights histopathologic findings of chemotherapy-associated nonbacterial thrombotic endocarditis involving the right ventricle wall of the endocardium, therefore expanding the radiological differential in patients with cardiac magnetic resonance imaging findings suggestive of amyloidosis.

Changes of the Heart Valves in the Long Term After Chemoradiotherapy According to Different Protocols for Hodgkin's Lymphoma in Children and Adolescents.

Purpose: The purpose of our work was to study late cardiac complications after treatment for Hodgkin's lymphoma (HL) in children and adolescents. Methods: Sixty-seven patients were examined in the long term (>5 years) after chemoradiotherapy for HL according to two different programs of treatment (groups I and II). Mean total doses of radiotherapy (RT) to the mediastinum were 37.2 and 28.9 Gy, respectively. The status of the heart was assessed at the mean age of 22.7 years with electrocardiography (ECG) and echocardiography (EchoCG). Mean terms of follow-up were 16.4 and 9.5 years for group I and group II, respectively. Results: Incidence of ECG changes was equal between the groups (88% and 90%). The prevalence of signs of valvular calcifications and fibrosis was 70.9% after mediastinal doses ≥30 Gy, and 16.6% after lower doses (p = 0.002). Those changes led to considerable valvular dysfunction in four patients. EchoCG signs of pulmonary hypertension were seen in 33.3% patients of group I versus 4.8% in group II (p = 0.047). Pericardial effusion was observed in 7.4% and 5.1%, respectively (p = 1.0). Left ventricular ejection fraction decreased slightly only in two patients (one in each group). Conclusions: The RT mediastinal dose level is the important risk factor of late heart complications. Nevertheless, the differences in the rate and severity of those complications between the groups should be viewed with caution because of differences in the age at baseline and in follow-up terms. The survivors of HL should undergo life-long regular examinations of the heart status.

Effects on human heart valve immunogenicity in vitro by high concentration cryoprotectant treatment.

It has been shown previously that cryopreservation, using an ice-free cryopreservation method with the cryoprotectant formulation VS83, beneficially modulated immune reactions in vivo and in vitro when compared with conventionally frozen tissues. In this study, we assessed the impact of a VS83 post-treatment of previously conventionally frozen human tissue on responses of human immune cells in vitro. Tissue punches of treated and non-treated (control) aortic heart valve tissue (leaflets and associated aortic root) were co-cultured for 7 days with peripheral blood mononuclear cells or enriched CD14+ monocytes. Effects on cellular activation markers, cytokine secretion and immune cell proliferation were analysed by flow cytometry. Flow cytometry studies showed that VS83 treatment of aortic root tissue promoted activation and differentiation of CD14+ monocytes, inducing both up-regulation of CD16 and down-regulation of CD14. Significantly enhanced expression levels for the C-C chemokine receptor (CCR)7 and the human leukocyte antigen (HLA)-DR on monocytes co-cultured with VS83-treated aortic root tissue were measured, while the interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 release was suppressed. However, the levels of interferon (IFN)γ and tumour necrosis factor (TNF)α remained undetectable, indicating that complete activation into pro-inflammatory macrophages did not occur. Similar, but non-significant, changes occurred with VS83-treated leaflets. Additionally, in co-cultures with T cells, proliferation and cytokine secretion responses were minimal. In conclusion, post-treatment of conventionally cryopreserved human heart valve tissue with the VS83 formulation induces changes in the activation and differentiation characteristics of human monocytes, and thereby may influence long-term performance following implantation. Copyright © 2017 John Wiley & Sons, Ltd.

Prospective, long-term study of the effect of cabergoline on valvular status in patients with prolactinoma and idiopathic hyperprolactinemia.

Since the 1990's cabergoline has been the treatment of choice in prolactinoma, as it permits rapid and effective hormonal and tumor control in most cases. Evidence of cardiac valvulopathy was demonstrated in Parkinson's disease patients treated with dopamine agonists. Retrospective studies in prolactinoma patients treated with cabergoline at lower doses did not show such an effect. However, few prospective data with long-term follow-up are available. The aim of this study was to assess the safety of cabergoline regarding cardiac valvular status during prospective follow-up in patients treated for prolactinoma or idiopathic hyperprolactinemia. We report here a series of 100 patients (71F; median age at diagnosis: 41.5 years) treated with cabergoline for endocrine diseases (prolactinoma n = 89, idiopathic hyperprolactinemia n = 11). All patients underwent complete transthoracic echocardiographic studies at baseline and during long-term prospective surveillance using the same equipment and performed by the same technicians. The median interval between baseline and last follow-up echocardiographic studies while on cabergoline was 62.5 months (interquartile range: 34.75-77.0). The median total duration of cabergoline treatment was 124.5 months (interquartile range: 80.75-188.75) and the median cumulative total dose of cabergoline was 277.8 mg (interquartile range : 121.4-437.8 mg) at last follow-up. We found no clinically relevant alterations in cardiac valve function or valvular calcifications with cabergoline treatment. Our data suggest that findings from retrospective analyses are correct and that cabergoline is a safe chronic treatment at the doses used typically in endocrinology.

Stem Cell Banking and Its Impact on Cardiac Regenerative Medicine.

Cardiovascular diseases, including heart failure, are the most frequent cause of death annually, even higher than any other pathologies. Specifically, patients who suffer from myocardial infarction may encounter adverse remodeling processes of the heart that can ultimately lead to heart failure. Prognosis of patients affected by heart failure is very poor with 5-year mortality close to 50 %. Despite the impressive progress in the clinical treatment of heart failure in recent years, heart transplantation is still required to avoid death as the result of the inexorable decline in cardiac function. Unfortunately, the availability of donor human hearts for transplantation largely fails to cover the number of potential recipient requests. From this urgent unmet clinical need the interest in stem cell applications for heart regeneration made its start, and has rapidly grown in the last decades. Indeed, the discovery and application of stem and progenitor cells as therapeutic agents has raised substantial interest with the objective of reversing these processes, and ultimately inducing cardiac regeneration. In this scenario, the role of biobanking may play a remarkable role to provide cells at the right time according to the patient's clinical needs, mostly for autologous use in the acute setting of myocardial infarction, largely reducing the time needed for cell preparation and expansion before administration.

Promotion of adhesion and proliferation of endothelial progenitor cells on decellularized valves by covalent incorporation of RGD peptide and VEGF.

Tissue engineered heart valve is a promising alternative to current heart valve surgery, for its capability of growth, repair, and remodeling. However, extensive development is needed to ensure tissue compatibility, durability and antithrombotic potential. This study aims to investigate the biological effects of multi-signal composite material of polyethyl glycol-cross-linked decellularized valve on adhesion and proliferation of endothelial progenitor cells. Group A to E was decellularized valve leaflets, composite material of polyethyl glycol-cross-linked decellularized valves leaflets, vascular endothelial growth factor-composite materials, Arg-Gly-Asp peptide-composite materials and multi-signal modified materials of polyethyl glycol-cross-linked decellularized valve leaflets, respectively. The endothelial progenitor cells were seeded for each group, cell adhesion and proliferation were detected and neo-endothelium antithrombotic function of the multi-signal composite materials was evaluated. At 2, 4, and 8 h after the seeding, the cell numbers and 3H-TdR incorporation in group D were the highest. At 2, 4, and 8 days after the seeding, the cell numbers and 3H-TdR incorporation were significantly higher in groups C, D, and E compared with groups A and B (P < 0.05) and cell numbers and the expression of t-PA and eons in the neo-endothelium were quite similar to those in the human umbilical vein endothelial cells at 2, 4, and 8 days after the seeding. The Arg-Gly-Asp- peptides (a sequential peptide composed of arginine (Arg), glycine (Gly) and aspartic acid (Asp)) and VEGF-conjugated onto the composite material of PEG-crosslinked decellularized valve leaflets synergistically promoted the adhesion and proliferation of endothelial progenitor cells on the composite material, which may help in tissue engineering of heart valves.

Current Hypotheses in Cardiac Surgery: Biofilm in Infective Endocarditis.

Despite recent advances in diagnostics and treatments, infective endocarditis is still associated with substantial morbidity and mortality. Even prolonged courses of broad-spectrum antimicrobials often fail to eradicate the infection, making surgical intervention necessary in many cases. In this review, we present recent advances in molecular microbiology techniques that have uncovered a plausible explanation for this resistance to treatment: the recently discovered social behavior of some microbes, in which colonies form a nearly impenetrable barrier around themselves called a biofilm. These biofilm structures isolate the colony from the body׳s immune response and antimicrobial drugs. We also present current thinking about possible ways biofilms can be destroyed.

Predicted Coverage and Immuno-Safety of a Recombinant C-Repeat Region Based Streptococcus pyogenes Vaccine Candidate.

The C-terminal region of the M-protein of Streptococcus pyogenes is a major target for vaccine development. The major feature is the C-repeat region, consisting of 35-42 amino acid repeat units that display high but not perfect identity. SV1 is a S. pyogenes vaccine candidate that incorporates five 14mer amino acid sequences (called J14i variants) from differing C-repeat units in a single recombinant construct. Here we show that the J14i variants chosen for inclusion in SV1 are the most common variants in a dataset of 176 unique M-proteins. Murine antibodies raised against SV1 were shown to bind to each of the J14i variants present in SV1, as well as variants not present in the vaccine. Antibodies raised to the individual J14i variants were also shown to bind to multiple but different combinations of J14i variants, supporting the underlying rationale for the design of SV1. A Lewis Rat Model of valvulitis was then used to assess the capacity of SV1 to induce deleterious immune response associated with rheumatic heart disease. In this model, both SV1 and the M5 positive control protein were immunogenic. Neither of these antibodies were cross-reactive with cardiac myosin or collagen. Splenic T cells from SV1/CFA and SV1/alum immunized rats did not proliferate in response to cardiac myosin or collagen. Subsequent histological examination of heart tissue showed that 4 of 5 mice from the M5/CFA group had valvulitis and inflammatory cell infiltration into valvular tissue, whereas mice immunised with SV1/CFA, SV1/alum showed no sign of valvulitis. These results suggest that SV1 is a safe vaccine candidate that will elicit antibodies that recognise the vast majority of circulating GAS M-types.

Valvular Dysfunction in Lymphoma Survivors Treated With Autologous Stem Cell Transplantation: A National Cross-Sectional Study.

OBJECTIVES: This study assessed the prevalence and associated risk factors for valvular dysfunction (VD) observed in adult lymphoma survivors (LS) after autologous hematopoietic stem cell transplantation (auto-HCT), and to determine whether anthracycline-containing chemotherapy (ACCT) alone in these patients is associated with VD. BACKGROUND: The prevalence of and risk factors for VD in LS after auto-HCT is unknown. Anthracyclines may induce heart failure, but any association with VD is not well-defined. METHODS: This national cross-sectional study included all adult LS receiving auto-HCT from 1987 to 2008 in Norway. VD was defined by echocardiography as either more than mild regurgitation or any stenosis. Observations in LS were compared with a healthy age- and gender-matched (1:1) control group. RESULTS: In total, 274 LS (69% of all eligible) participated. Mean age was 56 ± 12 years, mean follow-up time after lymphoma diagnosis was 13 ± 6 years, and 62% of participants were males. Mean cumulative anthracycline dosage was 316 ± 111 mg/m(2), and 35% had received radiation therapy involving the heart (cardiac-RT). VD was observed in 22.3% of the LS. Severe VD was rare (n = 9; 3.3% of all LS) and mainly aortic stenosis (n = 7). We observed VD in 16.7% of LS treated with ACCT alone (n = 177), corresponding with a 3-fold increased VD risk (odds ratio: 2.9; 95% confidence interval: 1.5 to 5.8; p = 0.002) compared with controls. Furthermore, the presence of aortic valve degeneration was increased in the LS after ACCT alone compared with controls (13.0% vs. 2.9%; p < 0.001). Female sex, age >50 years at lymphoma diagnosis, ≥3 lines of chemotherapy before auto-HCT, and cardiac-RT >30 Gy were identified as independent risk factors for VD in the LS. CONCLUSIONS: In LS, ACCT alone was significantly associated with VD and related to valvular degeneration. Overall, predominantly moderate VD was prevalent in LS, and longer observation time is needed to clarify the clinical significance of this finding.

Amiodarone Induces Overexpression of Similar to Versican b to Repress the EGFR/Gsk3b/Snail Signaling Axis during Cardiac Valve Formation of Zebrafish Embryos.

Although Amiodarone, a class III antiarrhythmic drug, inhibits zebrafish cardiac valve formation, the detailed molecular pathway is still unclear. Here, we proved that Amiodarone acts as an upstream regulator, stimulating similar to versican b (s-vcanb) overexpression at zebrafish embryonic heart and promoting cdh-5 overexpression by inhibiting snail1b at atrioventricular canal (AVC), thus blocking invagination of endocardial cells and, as a result, preventing the formation of cardiac valves. A closer investigation showed that an intricate set of signaling events ultimately caused the up-regulation of cdh5. In particular, we investigated the role of EGFR signaling and the activity of Gsk3b. It was found that knockdown of EGFR signaling resulted in phenotypes similar to those of Amiodarone-treated embryos. Since the reduced phosphorylation of EGFR was rescued by knockdown of s-vcanb, it was concluded that the inhibition of EGFR activity by Amiodarone is s-vcanb-dependent. Moreover, the activity of Gsk3b, a downstream effector of EGFR, was greatly increased in both Amiodarone-treated embryos and EGFR-inhibited embryos. Therefore, it was concluded that reduced EGFR signaling induced by Amiodarone treatment results in the inhibition of Snail functions through increased Gsk3b activity, which, in turn, reduces snail1b expression, leading to the up-regulation the cdh5 at the AVC, finally resulting in defective formation of valves. This signaling cascade implicates the EGFR/Gsk3b/Snail axis as the molecular basis for the inhibition of cardiac valve formation by Amiodarone.

Effects of single nucleotide polymorphisms in c-Myc on stable warfarin doses in patients with cardiac valve replacements.

AIM: This study aimed to investigate an association between c-Myc SNPs and stable warfarin doses. MATERIALS & METHODS: The influences of genetic polymorphisms on dose requirements were investigated by genotyping ten SNPs in 201 patients with stable warfarin doses; VKORC1 (rs9923231), CYP2C9 (rs1057910), CYP4F2 (rs2108622), GATA4 (rs10090884), c-Myc (rs4645962, rs4645943, rs4645948 and rs4645974) and 8q24 (rs1447295 and rs16901979). RESULTS: Around 44.3% of the overall interindividual variability in warfarin dose requirements was explained by the multivariate regression model; VKORC1 genotype accounted for 26.4%, CYP2C9 genotype for 4.9%, age for 3.4%, c-Myc genotypes for 5.2% (rs4645974 for 2.4% and rs4645943 for 2.8%), CYP4F2 genotype for 2.9% and diuretic use for 1.5%. CONCLUSION: Our results revealed that c-Myc could be a determinant of stable warfarin doses.