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BACKGROUND: Hospital- and physician-level variation for selection of percutaneous coronary intervention versus coronary artery bypass grafting (CABG) for patients with coronary artery disease has been associated with outcome differences. However, most studies excluded patients treated medically. METHODS AND RESULTS: From 2010 to 2019, adults with 3-vessel or left main coronary artery disease at 3 hospitals (A, B, C) in Alberta, Canada, were categorized by treatment with medical therapy, percutaneous coronary intervention, or CABG. Multilevel regression models determined the proportion of variation in treatment attributable to patient, physician, and hospital factors, and survival models assessed outcomes including death and major adverse cardiovascular events over 5 years. Of 22 580 patients (mean age, 67 years; 80% men): 6677 (29%) received medical management, 9171 (41%) percutaneous coronary intervention, and 6732 (30%) CABG. Hospital factors accounted for 10.8% of treatment variation. In adjusted models (site A as reference), patients at sites B and C had 49% (95% CI, 44%-53%) and 43% (95% CI, 37%-49%) lower rates of medical therapy, respectively, and 31% (95% CI, 24%-38%) and 32% (95% CI, 24%-40%) lower rates of CABG. During 5.0 years median follow-up, 3287 (14.6%) patients died, with no intersite mortality differences. There were no between-site differences in acute coronary syndromes or stroke; patients at sites B and C had 24% lower risk (95% CI, 13%-34% and 11%-35%, respectively) of heart failure hospitalization. CONCLUSIONS: Hospital-level variation in selection of percutaneous coronary intervention, CABG, or medical therapy for patients with complex coronary artery disease was not associated with differences in 5-year mortality rates. Research and quality improvement initiatives comparing revascularization practices should include medically managed patients.
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Puente de Arteria Coronaria , Enfermedad de la Arteria Coronaria , Intervención Coronaria Percutánea , Humanos , Masculino , Femenino , Anciano , Enfermedad de la Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/terapia , Enfermedad de la Arteria Coronaria/cirugía , Intervención Coronaria Percutánea/estadística & datos numéricos , Intervención Coronaria Percutánea/mortalidad , Puente de Arteria Coronaria/estadística & datos numéricos , Puente de Arteria Coronaria/mortalidad , Alberta/epidemiología , Persona de Mediana Edad , Toma de Decisiones Clínicas , Resultado del Tratamiento , Pautas de la Práctica en Medicina/tendencias , Hospitales/estadística & datos numéricos , Factores de RiesgoRESUMEN
BACKGROUND: Pericardial fluid (PF) contains cells, proteins, and inflammatory mediators, such as cytokines, chemokines, growth factors, and matrix metalloproteinases. To date, we lack an adequate understanding of the inflammatory response that acute injury elicits in the pericardial space. OBJECTIVE: To characterize the inflammatory profile in the pericardial space acutely after ischemia/reperfusion. METHODS: Pigs were used to establish a percutaneous ischemia/reperfusion injury model. PF was removed from pigs at different time points postanesthesia or postischemia/reperfusion. Flow cytometry was used to characterize the immune cell composition of PF, while multiplex analysis was performed on the acellular portion of PF to determine the concentration of inflammatory mediators. There was a minimum of 3 pigs per group. RESULTS: While native PF mainly comprises macrophages, we show that neutrophils are the predominant inflammatory cell type in the pericardial space after injury. The combination of acute ischemia/reperfusion (IR) and repeatedly accessing the pericardial space significantly increases the concentration of interleukin-1 beta (IL-1ß) and interleukin-1 receptor antagonist (IL-1ra). IR significantly increases the pericardial concentration of TGFß1 but not TGFß2. We observed that repeated manipulation of the pericardial space can also drive a robust pro-inflammatory response, resulting in a significant increase in immune cells and the accumulation of potent inflammatory mediators in the pericardial space. CONCLUSION: In the present study, we show that both IR and surgical manipulation can drive robust inflammatory processes in the pericardial space, consisting of an increase in inflammatory cytokines and alteration in the number and composition of immune cells.
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Modelos Animales de Enfermedad , Mediadores de Inflamación , Animales , Mediadores de Inflamación/metabolismo , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/inmunología , Daño por Reperfusión Miocárdica/metabolismo , Porcinos , Líquido Pericárdico/metabolismo , Neutrófilos/inmunología , Neutrófilos/metabolismo , Neutrófilos/patología , Sus scrofa , Pericardio/patología , Pericardio/inmunología , Pericardio/metabolismo , Macrófagos/inmunología , Macrófagos/patología , Macrófagos/metabolismo , Factores de Tiempo , Citocinas/metabolismoRESUMEN
Cardiac fibrosis is a significant driver of congestive heart failure, a syndrome that continues to affect a growing patient population globally. Cardiac fibrosis results from a constellation of complex processes at the transcription, receptor, and signaling axes levels. Various mediators and signaling cascades, such as the transformation growth factor-beta pathway, have been implicated in the pathophysiology of cardiac tissue fibrosis. Our understanding of these markers and pathways has improved in recent years as more advanced technologies and assays have been developed, allowing for better delineation of the crosstalk between specific factors. There is mounting evidence suggesting that epigenetic modulation plays a pivotal role in the progression of cardiac fibrosis. Transcriptional regulation of key pro- and antifibrotic pathways can accentuate or blunt the rate and extent of fibrosis at the tissue level. Exosomes, micro-RNAs, and long noncoding RNAs all belong to factors that can impact the epigenetic signature in cardiac fibrosis. Herein, we comprehensively review the latest literature about exosomes, their contents, and cardiac fibrosis. In doing so, we highlight the specific transcriptional factors with pro- or antifibrotic properties. We also assimilate the data supporting these mediators' potential utility as diagnostic or prognostic biomarkers. Finally, we offer insight into where further work can be done to fill existing gaps to translate preclinical findings better and improve clinical outcomes.
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Epigénesis Genética , Exosomas , Fibrosis , Miocardio , Humanos , Animales , Exosomas/genética , Exosomas/metabolismo , Exosomas/patología , Miocardio/patología , Miocardio/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Transducción de Señal , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Cardiomiopatías/genética , Cardiomiopatías/patología , Cardiomiopatías/metabolismo , Predisposición Genética a la EnfermedadRESUMEN
The potential of the pericardial space as a therapeutic delivery tool for cardiac fibrosis and heart failure (HF) treatment has yet to be elucidated. Recently, miRNAs and exosomes have been discovered to be present in human pericardial fluid (PF). Novel studies have shown characteristic human PF miRNA compositions associated with cardiac diseases and higher miRNA expressions in PF compared to peripheral blood. Five key studies found differentially expressed miRNAs in HF, angina pectoris, aortic stenosis, ventricular tachycardia, and congenital heart diseases with either atrial fibrillation or sinus rhythm. As miRNA-based therapeutics for cardiac fibrosis and HF showed promising results in several in vivo studies for multiple miRNAs, we hypothesize a potential role of miRNA-based therapeutics delivered through the pericardial cavity. This is underlined by the favorable results of the first phase 1b clinical trial in this emerging field. Presenting the first human miRNA antisense drug trial, inhibition of miR-132 by intravenous administration of a novel antisense oligonucleotide, CDR132L, established efficacy in reducing miR-132 in plasma samples in a dose-dependent manner. We screened the literature, provided an overview of the miRNAs and exosomes present in PF, and drew a connection to those miRNAs previously elucidated in cardiac fibrosis and HF. Further, we speculate about clinical implications and potential delivery methods.
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Exosomas , Fibrosis , MicroARNs , Humanos , Exosomas/genética , Exosomas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Animales , Miocardio/patología , Miocardio/metabolismo , Cardiopatías/genética , Cardiopatías/patología , Cardiopatías/metabolismo , Líquido Pericárdico/metabolismo , Pericardio/metabolismo , Pericardio/patologíaRESUMEN
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Abstract This consensus of nomenclature and classification for congenital bicuspid aortic valve and its aortopathy is evidence-based and intended for universal use by physicians (both pediatricians and adults), echocardiographers, advanced cardiovascular imaging specialists, interventional cardiologists, cardiovascular surgeons, pathologists, geneticists, and researchers spanning these areas of clinical and basic research. In addition, as long as new key and reference research is available, this international consensus may be subject to change based on evidence-based data1.
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BACKGROUND AND OBJECTIVE: Pericardial Fluid (PF) is a rich reservoir of biologically active factors. Due to its proximity to the heart, the biochemical structure of PF may reflect the pathological changes in the cardiac interstitial environment. This manuscript aimed to determine whether the PF level of cardiac troponins changes in patients undergoing cardiac surgery. METHODS: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, EMBASE, Cochrane, ClinicalTrials.gov, and Google Scholar databases were electronically searched for primary studies using the keywords "pericardial fluid," "troponin," and "cardiac surgery." The primary outcome of interest was changes in troponin levels within the PF preoperatively and postoperatively. Secondary outcomes of interest included comparisons between troponin level changes in the PF compared to plasma. RESULTS: A total of 2901 manuscripts were screened through a title and abstract stage by two independent blinded reviewers. Of those, 2894 studies were excluded, and the remaining seven studies underwent a full-text review. Studies were excluded if they did not provide data or failed to meet inclusion criteria. Ultimately, six articles were included that discussed cardiac troponin levels within the PF in patients who had undergone cardiac surgery. Pericardial troponin concentration increased over time after surgery, and levels were significantly higher in PF compared to serum. All studies found that the type of operation did not affect these overall observations. CONCLUSION: Our review of the literature suggest that the PF level of cardiac troponins increases in patients undergoing cardiac surgery, irrespective of the procedure type. However, these changes' exact pattern and clinical significance remain undefined.
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Procedimientos Quirúrgicos Cardíacos , Líquido Pericárdico , Troponina , Humanos , Líquido Pericárdico/química , Líquido Pericárdico/metabolismo , Troponina/análisis , Troponina/sangre , Troponina/metabolismoRESUMEN
Cardiac fibrosis is a significant contributor to heart failure, a condition that continues to affect a growing number of patients worldwide. Various cardiovascular comorbidities can exacerbate cardiac fibrosis. While fibroblasts are believed to be the primary cell type underlying fibrosis, recent and emerging data suggest that other cell types can also potentiate or expedite fibrotic processes. Over the past few decades, clinicians have developed therapeutics that can blunt the development and progression of cardiac fibrosis. While these strategies have yielded positive results, overall clinical outcomes for patients suffering from heart failure continue to be dire. Herein, we overview the molecular and cellular mechanisms underlying cardiac tissue fibrosis. To do so, we establish the known mechanisms that drive fibrosis in the heart, outline the diagnostic tools available, and summarize the treatment options used in contemporary clinical practice. Finally, we underscore the critical role the immune microenvironment plays in the pathogenesis of cardiac fibrosis.
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Fibrosis , Miocardio , Medicina de Precisión , Humanos , Miocardio/patología , Miocardio/inmunología , Animales , Insuficiencia Cardíaca/patología , Transducción de Señal , Fibroblastos/patología , Fibroblastos/metabolismoRESUMEN
This consensus of nomenclature and classification for congenital bicuspid aortic valve and its aortopathy is evidence-based and intended for universal use by physicians (both pediatricians and adults), echocardiographers, advanced cardiovascular imaging specialists, interventional cardiologists, cardiovascular surgeons, pathologists, geneticists, and researchers spanning these areas of clinical and basic research. In addition, as long as new key and reference research is available, this international consensus may be subject to change based on evidence-based data1.
Este consenso de nomenclatura y clasificación para la válvula aórtica bicúspide congénita y su aortopatía está basado en la evidencia y destinado a ser utilizado universalmente por médicos (tanto pediatras como de adultos), médicos ecocardiografistas, especialistas en imágenes avanzadas cardiovasculares, cardiólogos intervencionistas, cirujanos cardiovasculares, patólogos, genetistas e investigadores que abarcan estas áreas de investigación clínica y básica. Siempre y cuando se disponga de nueva investigación clave y de referencia, este consenso internacional puede estar sujeto a cambios de acuerdo con datos basados en la evidencia1.
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AIMS: Patients with bicuspid aortic valve (BAV) and aortic regurgitation have higher rate of aortic complications compared with patients with BAV and stenosis, as well as BAV without valvular disease. Aortic regurgitation alters blood haemodynamics not only in systole but also during diastole. We therefore sought to investigate wall shear stress (WSS) during the whole cardiac cycle in BAV with aortic regurgitation. METHODS AND RESULTS: Fifty-seven subjects that underwent 4D flow cardiovascular magnetic resonance imaging were included: 13 patients with BAVs without valve disease, 14 BAVs with aortic regurgitation, 15 BAVs with aortic stenosis, and 22 normal controls with tricuspid aortic valve. Peak and time averaged WSS in systole and diastole and the oscillatory shear index (OSI) in the ascending aorta were computed. Student's t-tests were used to compare values between the four groups where the data were normally distributed, and the non-parametric Wilcoxon rank sum tests were used otherwise. BAVs with regurgitation had similar peak and time averaged WSS compared with the patients with BAV without valve disease and with stenosis, and no regions of elevated WSS were found. BAV with aortic regurgitation had twice as high OSI as the other groups (P ≤ 0.001), and mainly in the outer mid-to-distal ascending aorta. CONCLUSION: OSI uniquely characterizes altered WSS patterns in BAVs with aortic regurgitation, and thus could be a haemodynamic marker specific for this specific group that is at higher risk of aortic complications. Future longitudinal studies are needed to verify this hypothesis.
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Insuficiencia de la Válvula Aórtica , Enfermedad de la Válvula Aórtica Bicúspide , Humanos , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Estudios Transversales , Constricción Patológica , Imagen por Resonancia Magnética , Válvula Aórtica/diagnóstico por imagen , Hemodinámica , Espectroscopía de Resonancia Magnética , Estrés MecánicoRESUMEN
BACKGROUND: ß-AR (ß-adrenergic receptor) stimulation regulates atrial electrophysiology and Ca2+ homeostasis via cAMP-dependent mechanisms; however, enhanced ß-AR signaling can promote atrial fibrillation (AF). CNP (C-type natriuretic peptide) can also regulate atrial electrophysiology through the activation of NPR-B (natriuretic peptide receptor B) and cGMP-dependent signaling. Nevertheless, the role of NPR-B in regulating atrial electrophysiology, Ca2+ homeostasis, and atrial arrhythmogenesis is incompletely understood. METHODS: Studies were performed using atrial samples from human patients with AF or sinus rhythm and in wild-type and NPR-B-deficient (NPR-B+/-) mice. Studies were conducted in anesthetized mice by intracardiac electrophysiology, in isolated mouse atrial preparations using high-resolution optical mapping, in isolated mouse and human atrial myocytes using patch-clamping and Ca2+ imaging, and in mouse and human atrial tissues using molecular biology. RESULTS: Atrial NPR-B protein levels were reduced in patients with AF, and NPR-B+/- mice were more susceptible to AF. Atrial cGMP levels and PDE2 (phosphodiesterase 2) activity were reduced in NPR-B+/- mice leading to larger increases in atrial cAMP in the presence of the ß-AR agonist isoproterenol. NPR-B+/- mice displayed larger increases in action potential duration and L-type Ca2+ current in the presence of isoproterenol. This resulted in the occurrence of spontaneous sarcoplasmic reticulum Ca2+ release events and delayed afterdepolarizations in NPR-B+/- atrial myocytes. Phosphorylation of the RyR2 (ryanodine receptor) and phospholamban was increased in NPR-B+/- atria in the presence of isoproterenol compared with the wildtypes. C-type natriuretic peptide inhibited isoproterenol-stimulated L-type Ca2+ current through PDE2 in mouse and human atrial myocytes. CONCLUSIONS: NPR-B protects against AF by preventing enhanced atrial responses to ß-adrenergic receptor agonists.
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Fibrilación Atrial , Humanos , Ratones , Animales , Fibrilación Atrial/prevención & control , Fibrilación Atrial/metabolismo , Isoproterenol/farmacología , Péptido Natriurético Tipo-C/farmacología , Atrios Cardíacos , Miocitos Cardíacos/metabolismoRESUMEN
Abdominal aortic aneurysm (AAA) represents a debilitating vascular disease characterized by aortic dilatation and wall rupture if it remains untreated. We aimed to determine the effects of Ang 1-7 in a murine model of AAA and to investigate the molecular mechanisms involved. Eight- to 10-week-old apolipoprotein E-deficient mice (ApoEKO) were infused with Ang II (1.44 mg/kg/day, s.c.) and treated with Ang 1-7 (0.576 mg/kg/day, i.p.). Echocardiographic and histological analyses showed abdominal aortic dilatation and extracellular matrix remodeling in Ang II-infused mice. Treatment with Ang 1-7 led to suppression of Ang II-induced aortic dilatation in the abdominal aorta. The immunofluorescence imaging exhibited reduced smooth muscle cell (SMC) density in the abdominal aorta. The abdominal aortic SMCs from ApoEKO mice exhibited markedly increased apoptosis in response to Ang II. Ang 1-7 attenuated cell death, as evident by increased SMC density in the aorta and reduced annexin V/propidium iodide-positive cells in flow cytometric analysis. Gene expression analysis for contractile and synthetic phenotypes of abdominal SMCs showed preservation of contractile phenotype by Ang 1-7 treatment. Molecular analyses identified increased mitochondrial fission, elevated cellular and mitochondrial reactive oxygen species (ROS) levels, and apoptosis-associated proteins, including cytochrome c, in Ang II-treated aortic SMCs. Ang 1-7 mitigated Ang II-induced mitochondrial fission, ROS generation, and levels of pro-apoptotic proteins, resulting in decreased cell death of aortic SMCs. These results highlight a critical vasculo-protective role of Ang 1-7 in a degenerative aortic disease; increased Ang 1-7 activity may provide a promising therapeutic strategy against the progression of AAA.
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Angiotensina II , Aneurisma de la Aorta Abdominal , Animales , Ratones , Especies Reactivas de Oxígeno/metabolismo , Angiotensina II/metabolismo , Aneurisma de la Aorta Abdominal/inducido químicamente , Aneurisma de la Aorta Abdominal/tratamiento farmacológico , Aneurisma de la Aorta Abdominal/prevención & control , Aorta Abdominal/metabolismo , Aorta Abdominal/patología , Proteínas Reguladoras de la Apoptosis/metabolismo , Miocitos del Músculo Liso/metabolismo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BLRESUMEN
After ischemic injury, immune cells mediate maladaptive cardiac remodeling. Extracellular matrix biomaterials may redirect inflammation toward repair. Pericardial fluid contains pro-reparative immune cells, potentially leverageable by biomaterials. Herein, we explore how pericardial delivery of a micronized extracellular matrix biomaterial affects cardiac healing. In noninfarcted mice, pericardial delivery increases pericardial and myocardial eosinophil counts. This response is sustained after myocardial infarction, stimulating an interleukin 4 rich milieu. Ultimately, the biomaterial improves postinfarct vascularization and cardiac function; and eosinophil-knockout negates these benefits. For the first time, to our knowledge, we demonstrate the therapeutic potential of pericardial biomaterial delivery and the eosinophil's critical role in biomaterial-mediated postinfarct repair.
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Background: The NeoChord DS1000 system implants artificial neochords transapically, through a left mini-thoracotomy to treat degenerative mitral valve regurgitation (MR). Performed without cardiopulmonary bypass, neochord implantation and length adjustment is guided by transesophageal echocardiography. We describe imaging and clinical outcomes for a single center case series using this innovative device platform. Methods: In this prospective series, all study patients had degenerative MR and were considered for conventional mitral valve surgery. Moderate to high-risk candidates were screened for NeoChord DS1000 eligibility based on echocardiographic criteria. Study criteria included isolated posterior leaflet prolapse, leaflet-to-annulus index greater than 1.2, and coaptation length index greater than 5â mm. Patients with bileaflet prolapse, mitral annular calcification, and ischemic MR were excluded from our early experience. Results: Ten patients underwent the procedure, including 6 males and 4 females, with a mean age of 76 ± 9.5 years. All patients had severe chronic MR and normal left ventricular function. One patient required conversion to an open procedure for failure to deploy neochords with the device transapically. The median number of NeoChord sets was 3 (IQR 2.3-3.8). Immediate post-procedure (POD#0) degree of MR on echocardiography ranged from mild or less, and on postoperative day 1 (POD#1) from moderate or less. Average length of coaptation was 0.85 ± 0.21â cm and average depth of coaptation was 0.72 ± 0.15â cm. At 1-month follow-up echocardiography, MR was graded from trivial to moderate and left ventricular inner diameter dimensions decreased from an average of 5.4 ± 0.4â cm to 4.6 ± 0.3â cm. None of the patients who had successful NeoChord implantation required blood products. There was 1 perioperative stroke with no residual deficits. There were no device-related complications or serious adverse events. The median length of hospital stay was 3 (IQR 2.3-10) days. 30-day and 6-weeks postoperative mortality and readmission rates were 0%. Conclusion: We report the first Canadian case series using the NeoChord DS1000 system for off-pump, transapical, beating heart mitral valve repair, through a left mini-thoracotomy. The early surgical outcomes suggest this approach is feasible, safe, and effective in reducing MR. This novel procedure has the advantage of offering a minimally invasive, off-pump option for select patients with high surgical risk.
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Postoperative atrial fibrillation (POAF) is a common dysrhythmia that affects a significant number of patients undergoing cardiac surgery. Many studies aim to better understand this complex postsurgical complication by analysing circulating biomarkers in patients who develop POAF. More recently, the pericardial space was shown to contain inflammatory mediators that could trigger POAF. In this review we summarise recent studies that examine the immune mediators present in the pericardial space and their potential implications for the pathophysiology of POAF in cardiac surgery patients. Ongoing research in this area should better delineate the multifactorial etiology of POAF, where specific markers may be targeted to reduce the incidence of POAF and improve outcomes for this patient population.
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Fibrilación Atrial , Procedimientos Quirúrgicos Cardíacos , Humanos , Fibrilación Atrial/etiología , Fibrilación Atrial/prevención & control , Fibrilación Atrial/epidemiología , Mediadores de Inflamación , Complicaciones Posoperatorias/epidemiología , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Pericardio , Factores de RiesgoRESUMEN
Bacterial nanocellulose (BNC) is a naturally derived hydrogel that has recently paved its way in several biomedical applications. Despite its remarkable tissue-like properties, BNC does not express innate anticoagulant or antimicrobial properties; therefore, appropriate post-modification procedures are required to prevent nonspecific adhesion and enhance the hemocompatibility properties of BNC-based biointerface. Here, we report a new class of flexible, lubricant-infused BNC membranes with superior antithrombotic and antibacterial properties. Using chemical vapor deposition, porous BNC membranes were functionalized with fluorosilane molecules and further impregnated with a fluorocarbon-based lubricant. Compared with unmodified BNC membranes and commercially available poly(tetrafluoroethylene) (PTFE) felts, our developed lubricant-infused BNC samples significantly attenuated plasma and blood clot formation, and prevented bacterial migration, adhesion, and biofilm formation and exhibited superior fat and enzyme repellency properties. Moreover, when subjected to mechanical testing, the lubricant-infused BNC membranes demonstrated a significantly higher tensile strength and greater fatigue resistance when compared with unmodified BNC samples and PTFE felts. Overall, the superior mechanical strength and antithrombotic, antibacterial, and fat/enzyme resistant properties observed in the developed super-repellent BNC-based membranes render their application promising for various biofluid-contacting medical implants and tissue engineering constructs.
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Fibrinolíticos , Lubricantes , Lubricantes/farmacología , Lubricantes/química , Bacterias , Antibacterianos/farmacología , PolitetrafluoroetilenoRESUMEN
In this research, a pipeline was developed to assess the out-of-sample predictive capability of structure-based constitutive models of ascending aortic aneurysmal tissue. The hypothesis being tested is that a biomarker can help establish similarities among tissues sharing the same level of a quantifiable property, thus enabling the development of biomarker-specific constitutive models. Biomarker-specific averaged material models were constructed from biaxial mechanical tests of specimens that shared similar biomarker properties such as level of blood-wall shear stress or microfiber (elastin or collagen) degradation in the extracellular matrix. Using a cross-validation strategy commonly used in classification algorithms, biomarker-specific averaged material models were assessed in contrast to individual tissue mechanics of out of sample specimens that fell under the same category but did not contribute to the averaged model's generation. The normalized root means square errors (NRMSE) calculated on out-of-sample data were compared with average models when no categorization was performed versus biomarker-specific models and among different level of a biomarker. Different biomarker levels exhibited statistically different NRMSE when compared among each other, indicating more common features shared by the specimens belonging to the lower error groups. However, no specific biomarkers reached a significant difference when compared to the average model created when No Categorization was performed, possibly on account of unbalanced number of specimens. The method developed could allow for the screening of different biomarkers or combinations/interactions in a systematic manner leading the way to larger datasets and to more individualized constitutive approaches.
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Aorta Torácica , Aneurisma de la Aorta Torácica , Humanos , Aorta , Estrés Mecánico , Colágeno/metabolismo , Biomarcadores , Fenómenos BiomecánicosRESUMEN
OBJECTIVE: In this study we aimed to conclusively determine whether altered aortic biomechanics are associated with wall shear stress (WSS) independent of region of tissue collection. Elevated WSS in the ascending aorta of patients with bicuspid aortic valve has been shown to contribute to local maladaptive aortic remodeling and might alter biomechanics. METHODS: Preoperative 4-dimensional flow magnetic resonance imaging was performed on 22 patients who underwent prophylactic aortic root and/or ascending aorta replacement. Localized elevated WSS was identified in patients using age-matched healthy atlases (n = 60 controls). Tissue samples (n = 78) were collected and categorized according to WSS (elevated vs normal) and region. Samples were subjected to planar biaxial testing. To fully quantify the nonlinear biomechanical response, the tangential modulus (local stiffness) at a low-stretch (LTM) and high-stretch (HTM) linear region and the onset (TZo) and end stress of the nonlinear transition zone were measured. A linear mixed effect models was implemented to determine statistical relationships. RESULTS: A higher LTM in the circumferential and axial direction was associated with elevated WSS (P = .007 and P = .018 respectively) independent of collection region. Circumferential TZo and HTM were higher with elevated WSS (P = .024 and P = .003); whereas the collection region was associated with variations in axial TZo (P = .013), circumferential HTM (P = .015), and axial HTM (P = .001). CONCLUSIONS: This study shows strong evidence that biomechanical changes in the aorta are strongly associated with hemodynamics, and not region of tissue collection for bicuspid valve aortopathy patients. Elevated WSS is associated with tissue behavior at low stretch ranges (ie, LTM and TZo).
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PURPOSE OF REVIEW: Bicuspid aortic valve (BAV) disease is observed in 1-2% of the general population. In addition to valve-related complications (such as aortic stenosis and aortic regurgitation), individuals with BAV often develop dilatation of the proximal aorta (aortic root and ascending aorta), a condition termed BAV aortopathy. The development of BAV aortopathy can occur independent of valvular alterations and can lead to aneurysm formation, aortic dissection or aortic rupture. This review aims to update the clinician with an approach to BAV aortopathy decision making in keeping with the 2022âAmerican College of Cardiology (ACC)/American Heart Association (AHA) Guideline recommendations. RECENT FINDINGS: The ACC/AHA 2022 guidelines provide a contemporary and comprehensive approach to the diagnosis and treatment of aortic pathologies. We review the thresholds for replacement of the aortic root and/or ascending aorta along with the strength and level of evidence recommendations. We also review the various Class 2A and 2B recommendations for earlier intervention, which emphasize the importance of experienced surgeons, and multidisciplinary aortic teams (MATs). SUMMARY: BAV aortopathy is a common and heterogenous clinical problem. The decision making around timing of intervention requires a personalized approach that is based on the aortic dimensions, valve function, rate of growth, family history, patient factors, and surgical experience within MATs.