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BACKGROUND: In patients with left ventricular assist devices (LVADs), ischemic and hemorrhagic stroke are dreaded complications. Predictive markers for these events are lacking. This study aimed to investigate the prevalence and predictive value of microembolic signals (MES) for stroke, detected by Transcranial Doppler sonography (TCD) in patients with HeartMate 3 (HM 3) or HeartWare (HW). METHODS: A thirty-minute bilateral TCD monitoring of the middle cerebral artery (MCA) was performed in 62 outpatients with LVAD (HM 3 N = 31, HW N = 31) and 31 healthy controls. Prevalence and quantity of MES were investigated regarding clinical and laboratory parameters. Cerebrovascular events (CVE) were recorded on follow-up at 90 and 180 days. RESULTS: MES were detected in six patients with HM 3, three patients with HW, and three controls. Within the LVAD groups, patients on monotherapy with vitamin-K-antagonist (VKA) without antiplatelet therapy were at risk for a higher count of MES (negative binomial regression: VKA: 1; VKA + ASA: Exp(B) = 0.005, 95%CI 0.001-0.044; VKA + clopidogrel: Exp(B) = 0.012, 95%CI 0.002-0.056). There was no association between the presence of MES and CVE or death on follow-up (p > 0.05). CONCLUSION: For the first time, the prevalence of MES was prospectively investigated in a notable outpatient cohort of patients with HM 3 and HW. Despite optimized properties of the latest LVAD, MES remain detectable depending on antithrombotic therapy. No association between MES and CVE could be detected.
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Corazón Auxiliar , Accidente Cerebrovascular , Humanos , Fibrinolíticos/efectos adversos , Accidente Cerebrovascular/etiología , Anticoagulantes/uso terapéutico , Clopidogrel , Corazón Auxiliar/efectos adversos , Ultrasonografía Doppler TranscranealRESUMEN
In patients with left ventricular assist devices (LVAD), exercise capacity is a decisive factor regarding the quality of life. When evaluating exercise capacity, precise information about the total cardiac output generated is crucial. To date, complex measurements using a right-heart catheter were necessary in order to determine total cardiac output. The inert gas rebreathing method facilitates non-invasive, direct and valid measurement of total cardiac output as well as associated parameters, like the difference in arteriovenous oxygen saturation, both at rest and during exercise. It is the aim of this paper to focus on this conclusive method which is, despite its simplicity and low-risk reproducibility, rarely used within the framework of LVAD patient treatment at the present time. The test protocol used at our hospital is presented to facilitate the implementation of this helpful tool in other interested institutions.
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Gasto Cardíaco , Prueba de Esfuerzo/métodos , Corazón Auxiliar , Óxido Nitroso/administración & dosificación , Hexafluoruro de Azufre/administración & dosificación , Función Ventricular Izquierda , Administración por Inhalación , Adulto , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Calidad de Vida , RespiraciónRESUMEN
BACKGROUND: In comparison with men, women have a better prognosis when experiencing aortic valve stenosis, hypertrophic cardiomyopathy, or heart failure. Recent data suggest that androgens like testosterone or the more potent dihydrotestosterone contribute to the development of cardiac hypertrophy and failure. Therefore, we analyzed whether antiandrogenic therapy with finasteride, which inhibits the generation of dihydrotestosterone by the enzyme 5-α-reductase, improves pathological ventricular remodeling and heart failure. METHODS AND RESULTS: We found a strongly induced expression of all 3 isoforms of the 5-α-reductase (Srd5a1 to Srd5a3) in human and mouse hearts with pathological hypertrophy, which was associated with increased myocardial accumulation of dihydrotestosterone. Starting 1 week after the induction of pressure overload by transaortic constriction, mice were treated with finasteride for 2 weeks. Cardiac function, hypertrophy, dilation, and fibrosis were markedly improved in response to finasteride treatment in not only male, but also in female mice. In addition, finasteride also very effectively improved cardiac function and mortality after long-term pressure overload and prevented disease progression in cardiomyopathic mice with myocardial Gαq overexpression. Mechanistically, finasteride, by decreasing dihydrotestosterone, potently inhibited hypertrophy and Akt-dependent prohypertrophic signaling in isolated cardiac myocytes, whereas the introduction of constitutively active Akt blunted these effects of finasteride. CONCLUSIONS: Finasteride, which is currently used in patients to treat prostate disease, potently reverses pathological cardiac hypertrophy and dysfunction in mice and might be a therapeutic option for heart failure.
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Antagonistas de Andrógenos/uso terapéutico , Cardiomegalia/tratamiento farmacológico , Finasterida/uso terapéutico , Disfunción Ventricular Izquierda/tratamiento farmacológico , Antagonistas de Andrógenos/farmacología , Animales , Animales Recién Nacidos , Cardiomegalia/patología , Células Cultivadas , Femenino , Finasterida/farmacología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Ratas , Ratas Sprague-Dawley , Disfunción Ventricular Izquierda/patologíaRESUMEN
Objectives: In recent years, minimally invasive approaches have been used with increasing frequency, even for more complex aortic procedures. However, evidence on the practicability and safety of expanding minimally invasive techniques from isolated operations of the ascending aorta towards more complex operations such as the hemiarch replacement is still scarce to date. Methods: A total of 86 patients undergoing elective surgical replacement of the ascending aorta with (n = 40) or without (n = 46) concomitant proximal aortic arch replacement between 2009 and 2023 were analyzed in a retrospective single-center analysis. Groups were compared regarding operation times, intra- and postoperative complications and long-term survival. Results: Operation times and ventilation times were significantly longer in the hemiarch replacement group. Despite this, no statistically significant differences between the two groups were observed for the duration of the ICU and hospital stay and postoperative complication rates. At ten-year follow-up, overall survival was 82.6% after isolated ascending aorta replacement and 86.3% after hemiarch replacement (p = 0.441). Conclusions: Expanding the indication for minimally invasive aortic surgery towards the proximal aortic arch resulted in comparable postoperative complication rates, length of hospital stay and overall long-term survival compared to the well-established minimally invasive isolated supracommissural ascending aorta replacement.
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The edge-to-edge mitral valve repair technique, invented by Alfieri and colleagues, introduced valve repair as a treatment option for patients with complex diseases where standard annuloplasty and related repair techniques are insufficient, due to annular calcification and patient frailty. We retrospectively evaluated the results of a transaortic edge-to-edge mitral valve repair (Alfieri stitch) in high-risk patients who were undergoing aortic valve replacement. From February, 2012 to December, 2017, 43 patients underwent transaortic edge-to-edge mitral valve repair with concomitant aortic valve replacement at a single institution. Preoperative and postoperative echocardiograms were compared. Home telephone follow up was conducted and postoperative morbidity was examined, including the need for reoperation, stroke and cardiac arrhythmia. 30-day and long-term survival rates were also determined. Mitral regurgitation (MR) was graded semi-quantitatively as 0 (trace and/or none), mild (1), moderate (2) or moderate to severe (3-4). The patients were 74 ± 7.8 years old. 65% of the patients were male. Mean cardiopulmonary bypass time was 115 ± 37 minutes and mean cross-clamp time was 71 ± 23 minutes. There was a significant improvement in preoperative vs postoperative median MR grade (2 (IQR 2-3) vs 0 (IQR 0-1); P = 0.05). Follow-up transthoracic echocardiograms in 29 patients obtained at a median of 9 months' (range 3 - 19 months') and in 16 patients at a median of 34 months' postoperatively (range 21 - 53 months') showed mild (1 (IQR 1-2)) grade of mitral regurgitation. 30-day survival was 98%. Long term survival at 12 and 24 months' were 88% and 81% respectively. Mitral valve reoperation was conducted in 1 patient (2%), who was suffering of endocarditis. Stroke occurred in 2 patients (7%). Cardiac arrhythmia was observed in 15 patients (35%). 8 patients (19%) suffered from atrial fibrillation and 7 patients (16%) displayed atrioventricular blockage. 10 patients (23%) could be treated conservatively and 5 patients (12%) needed implantation of a pacemaker. Transaortic edge-to-edge mitral valve repair can be safely performed during aortic valve replacement in high-risk patients and improves even long-term MR grade. Postoperative cardiac arrhythmia occurs frequently. 66% of them could be treated successfully by conservative procedures.
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Implantación de Prótesis de Válvulas Cardíacas , Anuloplastia de la Válvula Mitral , Insuficiencia de la Válvula Mitral , Accidente Cerebrovascular , Anciano , Anciano de 80 o más Años , Femenino , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/métodos , Humanos , Masculino , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/cirugía , Anuloplastia de la Válvula Mitral/efectos adversos , Anuloplastia de la Válvula Mitral/métodos , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/cirugía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: A growing number of patients suffering from heart failure is living with a left ventricular assist device (LVAD) and is in the need for non-cardiac surgery. Vascular procedures due to ischemia, bleeding, or other device-related complications may be required and pose a challenge to the caregivers in terms of monitoring and management of these patients. Therefore, we reviewed our experience with LVAD patients undergoing vascular surgery. METHODS: From January 2010 until March 2017, a total of 54 vascular procedures were performed on 41 LVAD patients at our institution. Patient records were reviewed retrospectively in terms of incidence of LVAD-related complications, including thrombosis, stroke, bleeding, wound healing, and survival associated with vascular surgery. The type of surgery was recorded, as well as various clinical demographic variables. RESULTS: Vascular procedures were performed in 35 men (85.4%) and 6 women (14.6%) with LVADs. There were no perioperative strokes, device thromboses, or device malfunctions. Thirty-day mortality overall was 26.8% (eleven patients), with most patients dying within 30 days after LVAD implantation due to multi-organ failure. In 25 procedures (46.3%), a blood transfusion was necessary. CONCLUSION: Patients on LVAD support are a complex cohort with a high risk for perioperative complications. In a setting where device function and anticoagulation are monitored closely, vascular surgery in these patients is feasible with an acceptable perioperative risk.
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Drowning and near-drowning is often associated with severe hypothermia requiring active core rewarming.We performed rewarming by cardiopulmonary bypass(CPB). Between 1987 and 2007, 13 children (9 boys and 4 girls) with accidental hypothermia were rewarmed by extracorporeal circulation (ECC) in our institution. The average age of the patients was 3.2 years. Resuscitation was started immediately upon the arrival of the rescue team and was continuously performed during the transportation.All patients were intubated and ventilated. Core temperature at admission ranged from 20 to 29°C (mean 25.3°C). Connection to the CPB was performed by thoracic (9 patients) or femoral/iliac means (4 patients). Restoration of circulation was achieved in 11 patients (84.6%). After CPB termination two patients needed an extracorporeal membrane oxygenation system due to severe pulmonary edema.Five patients were discharged from hospital after prolonged hospital stay. During follow-up, two patients died(10 and 15 months, respectively) of pulmonary complications and one patient was lost to follow-up. The two remaining survivors were without neurological deficit.Modes of rewarming, age, sex, rectal temperature, and serum electrolytes did not influence mortality. In conclusion,drowning and near-drowning with severe hypothermia remains a challenging emergency. Rewarming by ECC provides efficient rewarming and full circulatory support.Although nearly half of the children may survive after rewarming by ECC, long-term outcome is limited by pulmonary and neurological complications.
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Accidentes , Puente Cardiopulmonar , Ahogamiento , Hipotermia/terapia , Ahogamiento Inminente/terapia , Resucitación/métodos , Recalentamiento/métodos , Choque/terapia , Temperatura Corporal , Distribución de Chi-Cuadrado , Niño , Preescolar , Ahogamiento/mortalidad , Ahogamiento/fisiopatología , Oxigenación por Membrana Extracorpórea , Femenino , Hemodinámica , Humanos , Hipotermia/etiología , Hipotermia/mortalidad , Hipotermia/fisiopatología , Masculino , Ahogamiento Inminente/complicaciones , Ahogamiento Inminente/fisiopatología , Medición de Riesgo , Factores de Riesgo , Choque/etiología , Choque/mortalidad , Choque/fisiopatología , Factores de Tiempo , Resultado del TratamientoRESUMEN
The optimal treatment of congenital aortic valve lesions is a controversial issue. This study was performed to evaluate the outcome after surgical treatment of aortic valve lesions in congenital aortic valve disease. Between the years of 2000 and 2008, 61 patients (mean age: 12.6 +/- 9.6 years, range: 1 day to 40 years) underwent aortic valve surgery for congenital aortic valve disease. Twenty-four patients had undergone previous cardiovascular operations. Indications for surgery were aortic regurgitation in 14.7% (n = 9), aortic stenoses in 26.2% (n = 16), and mixed disease in 59.1% (n = 36). The Ross procedure was performed in 37.7% (n = 23), aortic valve replacement with biological or mechanical prostheses in 29.5% (n = 18). Concomitant procedures were performed in 91.8% (n = 56) due to associated congenital cardiac defects. The overall mortality rate was 5%. Six patients needed reoperation. Implantation of permanent pacemakers occurred in six patients for permanent atrioventricular block. At the latest clinical evaluation, all survivors are in New York Heart Association class I-II and are living normal lives. Aortic valve surgeries in patients with congenital heart disease have had low mortality and morbidity rates in our series. Surgical technique as well as timing should be tailored for each patient. Aortic valve replacement should be delayed until the implantation of an adult-sized prosthesis is possible.
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Insuficiencia de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Procedimientos Quirúrgicos Cardíacos , Cardiopatías Congénitas/cirugía , Implantación de Prótesis de Válvulas Cardíacas , Adolescente , Adulto , Válvula Aórtica/anomalías , Válvula Aórtica/crecimiento & desarrollo , Insuficiencia de la Válvula Aórtica/etiología , Insuficiencia de la Válvula Aórtica/mortalidad , Insuficiencia de la Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/etiología , Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/fisiopatología , Bloqueo Atrioventricular/etiología , Bloqueo Atrioventricular/terapia , Bioprótesis , Estimulación Cardíaca Artificial , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/mortalidad , Niño , Preescolar , Femenino , Alemania , Cardiopatías Congénitas/complicaciones , Cardiopatías Congénitas/mortalidad , Cardiopatías Congénitas/fisiopatología , Prótesis Valvulares Cardíacas , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Implantación de Prótesis de Válvulas Cardíacas/mortalidad , Humanos , Lactante , Recién Nacido , Estimación de Kaplan-Meier , Masculino , Selección de Paciente , Diseño de Prótesis , Reoperación , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
Friedreich's ataxia (FRA) is an autosomal recessive disease of the central nervous system that is associated with familial cardiomyopathy. Cardiac involvement is seen in more than 90% of the patients and is the most common cause of death in these patients. We present a case series and discuss the indications for implantable cardioverter defibrillator (ICD) implantation in FRA with review of the literature. Five pediatric patients who suffer from FRA (four female and one male, mean age 17.4 years) underwent ICD implantation between 2007 and 2008 in the University Hospital of Goettingen. The diagnosis of FRA was established by standard clinical criteria and proven in each case by genotyping at the frataxin locus. The time from diagnosis to ICD implantation was 10.4±1.73 years (range 8-15 years). All patients received transvenous lead systems. There were no intraoperative and postoperative complications. At the latest follow-up, the neuromuscular symptoms exhibited no further progress and no ICD activations were noticed. Only minor repolarization changes were seen on electrocardiogram. All patients had normal echocardiographic findings and no angina has been reported. Coronary angiographies were normal. It is evident that many FRA patients develop ventricular dysfunction. In the absence of a definitive surgical cure an ICD is generally indicated in young patients with hemodynamically significant sustained ventricular tachyarrhythmias for prevention of sudden cardiac death. Our experience implies the safe use of ICD in children with FRA.
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Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Ataxia de Friedreich/complicaciones , Taquicardia Ventricular/prevención & control , Adolescente , Adulto , Angiografía Coronaria , Muerte Súbita Cardíaca/etiología , Ecocardiografía , Electrocardiografía , Estudios de Factibilidad , Femenino , Humanos , Masculino , Estudios Retrospectivos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiología , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Heart failure is one of the most expensive chronic diseases, as it leads to considerable expenses due to increasing hospitalisation rates. In addition to the implications of the demographic transition and the lack of available organs for transplantation, a major challenge in this context is that conservative treatment options are limited. This has led to the research and development of mechanical circulatory assist systems. Telemonitoring is anticipated to be an effective tool in outpatient management, which may be a key to improved outcomes of left ventricular assist devices therapy. In patients with chronic cardiac diseases, telemedicine is already used and has been shown to reduce premature mortality. This study aims to provide insights into the left ventricular assist device-specific requirements for telemonitoring and infrastructural translation from caregivers' and patients' points of view. METHOD: A qualitative investigation based on guided interview and focus group techniques was conducted at two German heart centres. The study included 15 patients and 7 caregivers (4 cardiac surgeons, 3 ventricular assist device coordinators). Qualitative content analysis was used for data analysis. The categories for analysis were (1) benefits for patients, (2) benefits for hospitals and the healthcare system, (3) acceptance and causative factors and (4) infrastructural implementation. RESULTS: Patients and experts expect the following benefits for telemonitored patients: added safety, early detection of complications, rapid intervention in case of emergency, regular inspection of pump parameters, fewer outpatient clinic visits and the ability to provide more informed feedback and instructions to the family members who take care of the patient. However, the expected acceptance of telemonitoring in left ventricular assist device therapy differed among the interviewed groups. Alongside the aforementioned expected benefits, patients and clinical experts criticised the reduced self-determination for the patient, probable large amounts of time/effort required of the patient and caregiver and data protection/integrity issues (data misuse, device manipulation and mistransfer). Interviewees expected easy handling, proper education and safe data transmission to be necessary factors leading to acceptance. Complication rate reduction, fewer hospitalisations and cost reductions were benefits recorded for the healthcare system and clinics. Clinical experts preferred a telemonitoring centre run by ventricular assist device coordinators. CONCLUSION: Although positive expectations are associated with the use of telemonitoring in left ventricular assist device therapy, further action is needed. For example, software and infrastructure developers will need to address issues such as variations among patients and may need to find a balance between designing individualised solutions for compliant patients and a safe and easy-to-handle set-up. In addition, proper elucidation of users will contribute to the successful implementation of a left ventricular assist device telemonitoring programme among patients and caregivers.
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Necesidades y Demandas de Servicios de Salud , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Anciano , Femenino , Grupos Focales , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , TelemedicinaRESUMEN
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an attractive model to investigate CM function and disease mechanisms. One characteristic marker of ventricular specificity of human CMs is expression of the ventricular, slow ß-myosin heavy chain (MyHC), as opposed to the atrial, fast α-MyHC. The main aim of this study was to investigate at the single-cell level whether contraction kinetics and electrical activity of hESC-CMs are influenced by the relative expression of α-MyHC versus ß-MyHC. For effective assignment of functional parameters to the expression of both MyHC isoforms at protein and mRNA levels in the very same hESC-CMs, we developed a single-cell mapping technique. Surprisingly, α- versus ß-MyHC was not related to specific contractile or electrophysiological properties of the same cells. The multiparametric cell-by-cell analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and MyHCs is independently regulated.
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Potenciales de Acción , Miosinas Cardíacas/metabolismo , Células Madre Embrionarias Humanas/citología , Contracción Miocárdica , Miocitos Cardíacos/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Miosinas Cardíacas/genética , Diferenciación Celular , Células Cultivadas , Células Madre Embrionarias Humanas/metabolismo , Humanos , Miocitos Cardíacos/citología , Miocitos Cardíacos/fisiología , Cadenas Pesadas de Miosina/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Análisis de la Célula IndividualRESUMEN
OBJECTIVE: Various methods for cardiothoracic, cardiovascular, and cardiac surgical training exist across the globe, with the common goal of producing safe, independent surgeons. A comparative analysis of international training paradigms has not been undertaken, and our goal in doing so was to offer insights into how to best prepare future trainees and ensure the health of our specialty. METHODS: We performed a comparative analysis of available publications offering detailed descriptions of various cardiothoracic, cardiovascular, and cardiac surgical training paradigms. Corresponding authors from previous publications and other international collaborators were also reached directly for further data acquisition. RESULTS: We report various approaches to common challenges surrounding (1) selection of trainees and plans for the future surgical workforce; (2) trainee assessments and certification of competency before independent practice; and (3) challenges related to a changing practice landscape. CONCLUSIONS: Cardiothoracic surgery remains a dynamic and rewarding specialty. Current and future trainees face several challenges that transcend national borders. To foster collaboration and adoption of best practices, we highlight international strengths and weaknesses of various nations in terms of workforce selection, trainee operative experience and assessment, board certification, and preparation for future changes anticipated in cardiothoracic surgery.
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Due to improved outcome after surgery for congenital heart defects, children, adolescents, and grown-ups with congenital heart defects become an increasing population. In order to evaluate operative risk and early outcome after mechanical aortic valve replacement (AVR) in this population, we reviewed patients who underwent previous repair of congenital heart defects. Between July 2002 and November 2008, 15 (10 male and 5 female) consecutive patients (mean age 14.5 +/- 10.5 years) underwent mechanical AVR. Hemodynamic indications for AVR were aortic stenosis in four (27%), aortic insufficiency in eight (53%), and mixed disease in three (20%) after previous repair of congenital heart defects. All patients had undergone one or more previous cardiovascular operations due to any congenital heart disease. Concomitant cardiac procedures were performed in all of them. In addition to AVR, in two patients, a mitral valve exchange was performed. One patient received a right ventricle-pulmonary artery conduit replacement as concomitant procedure. The mean size of implanted valves was 23 mm (range 17-29 mm). There were neither early deaths nor late mortality until December 2008. Reoperations were necessary in five (33%) and included implantation of a permanent pacemaker due to complete atrioventricular block in two (15%), mitral valve replacement with a mechanical prosthesis due to moderate to severe mitral regurgitation in one (7%), aortocoronary bypass grafting due to stenosis of a coronary artery in one (7%), and in one (7%), a redo subaortic stenosis resection was performed because of a secondary subaortic stenosis. At the latest clinical evaluation, all patients were in good clinical condition without a pathological increased gradient across the aortic valve prosthesis or paravalvular leakage in echocardiography. Mechanical AVR has excellent results in patients after previous repair of congenital heart defects in childhood, even in combination with complex concomitant procedures. Previous operations do not significantly affect postoperative outcome.
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Válvula Aórtica/cirugía , Cardiopatías Congénitas/cirugía , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Adolescente , Adulto , Niño , Preescolar , Ecocardiografía , Femenino , Estudios de Seguimiento , Prótesis Valvulares Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/mortalidad , Humanos , Masculino , Estudios Retrospectivos , Adulto JovenRESUMEN
Although a large variety of animal models for acute ischemia and acute heart failure exist, valuable models for studies on the effect of ventricular assist devices in chronic heart failure are scarce. We established a stable and reproducible animal model of chronic heart failure in sheep and aimed to investigate the hemodynamic changes of this animal model of chronic heart failure in sheep. In five sheep (n = 5, 77 +/- 2 kg), chronic heart failure was induced under fluoroscopic guidance by multiple sequential microembolization through bolus injection of polysterol microspheres (90 microm, n = 25.000) into the left main coronary artery. Coronary microembolization (CME) was repeated up to three times in 2 to 3-week intervals until animals started to develop stable signs of heart failure. During each operation, hemodynamic monitoring was performed through implantation of central venous catheter (central venous pressure [CVP]), arterial pressure line (mean arterial pressure [MAP]), implantation of a right heart catheter {Swan-Ganz catheter (mean pulmonary arterial pressure [PAP mean])}, pulmonary capillary wedge pressure (PCWP), and cardiac output [CO]) as well as pre- and postoperative clinical investigations. All animals were followed for 3 months after first microembolization and then sacrificed for histological examination. All animals developed clinical signs of heart failure as indicated by increased heart rate (HR) at rest (68 +/- 4 bpm [base] to 93 +/- 5 bpm [3 mo][P < 0.05]), increased respiratory rate (RR) at rest (28 +/- 5 [base] to 38 +/- 7 [3 mo][P < 0.05]), and increased body weight 77 +/- 2 kg to 81 +/- 2 kg (P < 0.05) due to pleural effusion, peripheral edema, and ascites. Hemodynamic signs of heart failure were revealed as indicated by increase of HR, RR, CVP, PAP, and PCWP as well as a decrease of CO, stroke volume, and MAP 3 months after the first CME. Multiple sequential intracoronary microembolization can effectively induce myocardial dysfunction with clinical and hemodynamic signs of chronic ischemic cardiomyopathy. The present model may be suitable in experimental work on heart failure and left ventricular assist devices, for example, for studying the impact of mechanical unloading, mechanisms of recovery, and reverse remodeling.
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Modelos Animales de Enfermedad , Insuficiencia Cardíaca/fisiopatología , Hemodinámica , Animales , Electrocardiografía , Embolia/cirugía , Femenino , Corazón/fisiopatología , Insuficiencia Cardíaca/cirugía , Microesferas , Miocardio/patología , OvinosRESUMEN
Low haemocompatibility of left ventricular assist devices (LVAD) surfaces necessitates anticoagulative therapy. Endothelial cell (EC) seeding can support haemocompatibility, however, the availability of autologous ECs is limited. In contrast, allogeneic ECs are readily available in sufficient quantity, but HLA disparities induce harmful immune responses causing EC loss. In this study, we investigated the feasibility of using allogeneic low immunogenic ECs to endothelialize LVAD sintered inflow cannulas (SIC). To reduce the immunogenicity of ECs, we applied an inducible lentiviral vector to deliver short-hairpins RNA to silence HLA class I expression. HLA class I expression on ECs was conditionally silenced by up to 70%. Sufficient and comparable endothelialization rates were achieved with HLA-expressing or HLA-silenced ECs. Cell proliferation was not impaired by cell-to-Sintered Inflow Cannulas (SIC) contact or by silencing HLA expression. The levels of endothelial phenotypic and thrombogenic markers or cytokine secretion profiles remained unaffected. HLA-silenced ECs-coated SIC exhibited reduced thrombogenicity. In contrast to native ECs, HLA-silenced ECs showed lower cell lysis rates when exposed to allogeneic T cells or specific anti-HLA antibodies. Allogeneic HLA-silenced ECs could potentially become a valuable source for LVAD endothelialization to reduce immunogenicity and correspondingly the need for anticoagulative therapy which can entail severe side effects.
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Células Alogénicas/inmunología , Bioprótesis , Células Endoteliales/inmunología , Corazón Auxiliar , Células Alogénicas/citología , Células Alogénicas/metabolismo , Bioprótesis/efectos adversos , Proliferación Celular , Células Cultivadas , Células Endoteliales/citología , Células Endoteliales/metabolismo , Genes MHC Clase I , Corazón Auxiliar/efectos adversos , Humanos , Ensayo de Materiales , Interferencia de ARN , ARN Interferente Pequeño/genética , Trombosis/etiologíaRESUMEN
OBJECTIVE: Endothelin is the most potent endogenous vasoconstrictor and is involved in several vascular disorders such as arterial hypertension. Its intense interaction with other vasoactive hormone systems revealed the consideration about the endothelin gene as an interesting candidate for influencing the development of essential hypertension and hypertensive endorgan damage. The purpose of this study was to investigate the role of endothelin-1 Lys198Asn polymorphism in patients with severe arterial hypertension as well as associated endorgan damages. METHODS: In 400 hypertensive patients and 150 normotensive controls we examined the endothelin-1 Lys198Asn polymorphism by DNA sequencing and patients were divided according to their genotype (GG, GT, and TT). Moreover, the frequency of endothelin-1 Lys198Asn polymorphism was investigated with respect to the prevalence of several actual or historical endorgan damages (renal disorder, coronary artery disease, vascular events, vascular damage, and congestive heart failure) in hypertensive patients. RESULTS: Genotype distribution for endothelin-1 Lys198Asn polymorphism was 57.3% (GG), 41.3% (GT), and 1.43% (TT) in normotensive individuals; and in hypertensive individuals was 54.75% (GG), 43% (GT) and 2.25% (TT). Genotype distribution was unaffected in patients with severe hypertension, renal disorder, vascular events, vascular damage, and congestive heart failure. We, however, found a significant difference in hypertensive individuals with coronary artery disease and TT genotype (P=0.004). CONCLUSION: Homozygous TT carrier contributes to a higher prevalence of coronary artery disease, especially for three-vessel disease in hypertensive individuals. Thus, the polymorphism at position 198 could serve as a possibility to differentiate high-risk subgroups in the heterogeneous population of hypertensive patients.
Asunto(s)
Enfermedad de la Arteria Coronaria/genética , Endotelina-1/genética , Hipertensión/genética , Polimorfismo Genético , Adulto , Anciano , Aterosclerosis/genética , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Insuficiencia Cardíaca/genética , Homocigoto , Humanos , Hipertensión/complicaciones , Enfermedades Renales/genética , Masculino , Persona de Mediana Edad , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
Donor-specific antibodies (DSA) are integral to the development of antibody-mediated rejection (AMR). Chronic AMR is associated with high mortality and an increased risk for cardiac allograft vasculopathy (CAV). Anti-donor HLA antibodies are present in 3-11% of patients at the time of heart transplantation (HTx), with de novo DSA (predominantly anti-HLA class II) developing post-transplant in 10-30% of patients. DSA are associated with lower graft and patient survival after HTx, with one study suggesting a three-fold increase in mortality in patients who develop de novo DSA (dnDSA). DSA against anti-HLA class II, notably DQ, are at particularly high risk for graft loss. Although detection of DSA is not a criterion for pathologic diagnosis of AMR, circulating DSA are found in almost all cases of AMR. MFI thresholds of ~5000 for DSA against class I antibodies, 2000 against class II antibodies, or an overall cut-off of 5-6000 for any DSA, have been suggested as being predictive for AMR. There is no firm consensus on pre-transplant strategies to treat HLA antibodies, or for the elimination of antibodies after diagnosis of AMR. Minimizing the risk of dnDSA is rational but data on risk factors in HTx are limited. The effect of different immunosuppressive regimens is largely unexplored in HTx, but studies in kidney transplantation emphasize the importance of adherence and maintaining adequate immunosuppression. One study has suggested a reduced risk for dnDSA with rabbit antithymocyte globulin induction. Management of DSA pre- and post-HTx varies but typically most centers rely on a plasmapheresis or immunoadsorption, with or without rituximab and/or intravenous immunoglobulin. Based on the literature and a multi-center survey, an algorithm for a suggested surveillance and therapeutic strategy is provided.
Asunto(s)
Anticuerpos/fisiología , Rechazo de Injerto/inmunología , Trasplante de Corazón/efectos adversos , Rechazo de Injerto/prevención & control , HumanosRESUMEN
Pediatric heart transplantation (pHTx) represents only a small proportion of cardiac transplants. Due to these low numbers, clinical data relating to induction therapy in this special population are far less extensive than for adults. Induction is used more widely in pHTx than in adults, mainly because of early steroid withdrawal or complete steroid avoidance. Antithymocyte globulin (ATG) is the most frequent choice for induction in pHTx, and rabbit antithymocyte globulin (rATG, Thymoglobulin®) (Sanofi Genzyme) is the most widely-used ATG preparation. In the absence of large, prospective, blinded trials, we aimed to review the current literature and databases for evidence regarding the use, complications, and dosages of rATG. Analyses from registry databases suggest that, overall, ATG preparations are associated with improved graft survival compared to interleukin-2 receptor antagonists. Advantages for the use of rATG have been shown in low-risk patients given tacrolimus and mycophenolate mofetil in a steroid-free regimen, in sensitized patients with pre-formed alloantibodies and/or a positive donor-specific crossmatch, and in ABO-incompatible pHTx. Registry and clinical data have indicated no increased risk of infection or post-transplant lymphoproliferative disorder in children given rATG after pHTx. A total rATG dose in the range 3.5-7.5 mg/kg is advisable.
Asunto(s)
Suero Antilinfocítico/uso terapéutico , Trasplante de Corazón/métodos , Linfocitos T/inmunología , Sistema del Grupo Sanguíneo ABO/inmunología , Animales , Suero Antilinfocítico/administración & dosificación , Suero Antilinfocítico/efectos adversos , Niño , Supervivencia de Injerto , Trasplante de Corazón/efectos adversos , Trasplante de Corazón/mortalidad , Humanos , Terapia de Inmunosupresión/efectos adversos , Terapia de Inmunosupresión/métodos , Inmunosupresores/administración & dosificación , Inmunosupresores/efectos adversos , Inmunosupresores/uso terapéutico , Infecciones/etiología , Trastornos Linfoproliferativos/etiología , Conejos , Receptores de Interleucina-2/antagonistas & inhibidores , Sistema de Registros , Estudios Retrospectivos , Esteroides/administración & dosificaciónRESUMEN
For the treatment of terminal heart failure, the therapy with left-ventricular assist devices has already been established. In the systems used today, pump speed does not adjust during physical activity so that cardiac output and exercise capacity remain markedly limited. It is the aim of this study to develop an automatic pump speed control based on filling pressure values in order to improve exercise capacity and quality of life in these patients. Different approaches are planned, to be tested in an in vitro patient simulator. The algorithms aim to match the pump speed with the increased venous return. In addition, preservation of aortic valve function should be taken into account.