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L’augmentation de la circulation collatérale non coronarienne : l’hypothèse d’une méthode alternative de revascularisation myocardique / Enhancement of noncornary collateral circulation : the hypothesis of an alternative method of myocardial revascularizationPicichè, Marco 21 September 2011 (has links)
La circulation collatérale non coronarienne (CCNC) perfuse le cœur en provenant d’artères bronchiques, médiastinales et péricardiques. L’éventualité que la CCNC puisse être artificiellement augmentée pour fournir un traitement alternatif pour les patients ischémiques représente une hypothèse intrigante sans réponse en raison de la nature difficile de ce champ de recherche. En se basant sur plusieurs aspects, tel que (1) l’existence des collatérales naturelles entre les artères coronaires et les artères thoraciques internes (ATIs), (2) les effets potentiels de la ligature des ATIs; (3) la capacité des ATIs de développer d’importantes branches collatérales ; (4) et la disponibilité actuelle des facteurs de croissance vasculaire, l’hypothèse ici décrite est que l’augmentation de la CCNC pourrait représenter une stratégie alternative d’apport sanguin au coeur.Ainsi, l’association d’occlusion des ATIs et de l’administration des facteurs de croissance pourrait représenter un moyen de poursuivre cet objectif. Pour le premier travail de recherche, nous avons établi un modèle canin. / Noncoronary collateral circulation (NCCC) comes to the heart from mediastinal, bronchial, and pericardial channels. Whether NCCC can somehow be augmented to provide an alternative therapy for ischemic patients is an intriguing hypothesis with no clear answer yet due to the challenging nature of this research field. Based on several aspects, such as (1) the occurrence of natural collaterals between coronary and the internal thoracic arteries (ITAs), (2) the potentialhemodynamic effects of ITAs ligation, (3) the potential of ITAs for developing important collateral branches, and (4) the current availability of angiogenic growth factors, the hypothesis herein is that enhancement of NCCC may represent an alternative myocardial blood supply strategy, and that combining ITAs occlusion with angiogenic growth factors may represent a way to achieve this objective. We established an ischemic canine model for first experiment.
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Improving care for patients with non-cardiac chest pain : Description of psychological distress and costs, and evaluation of an Internet-delivered interventionMourad, Ghassan January 2015 (has links)
Introduction: More than half of all patients seeking care for chest pain do not have a cardiac cause for this pain. Despite recurrent episodes of chest pain, many patients are discharged without a clear explanation of the cause for their pain. A lack of explanation may result in a misinterpretation of the pain as being cardiac-related, causing worry and uncertainty, which in turn leads to substantial use of healthcare resources. Psychological distress has been associated with non-cardiac chest pain (NCCP), but there is limited research regarding the relationship between different psychological factors and their association with healthcare utilization. There is a need for interventions to support patients to manage their chest pain, decrease psychological distress, and reduce healthcare utilization and costs. Aim: The overall aim of this thesis was to improve care for patients with non-cardiac chest pain by describing related psychological distress, healthcare utilization and societal costs, and by evaluating an Internet-delivered cognitive behavioural intervention. Designs and methods: This thesis presents results from four quantitative studies. Studies I and II had a longitudinal descriptive and comparative design. The studies used the same initial cohort. Patients were consecutively approached within 2 weeks from the day of discharge from a general hospital in southeast Sweden. In study I, 267 patients participated (131 with NCCP, 66 with acute myocardial infarction (AMI), and 70 with angina pectoris (AP)). Out of these, 199 patients (99 with NCCP, 51 with AMI, 49 with AP) participated in study II. Participants were predominantly male (about 60 %) with a mean age of 67 years. Data was collected on depressive symptoms (Study I), healthcare utilization (Study I, II), and societal costs (Study II). Study III had a cross-sectional explorative and descriptive design. Data was collected consecutively on depressive symptoms, cardiac anxiety and fear of body sensations in 552 patients discharged with diagnoses of NCCP (51 % women, mean age 64 years) from four hospitals in southeast Sweden. Patients were approached within one month from the day of discharge. Study IV was a pilot randomized controlled study including nine men and six women with a median age of 66 years, who were randomly assigned to an intervention (n=7) or control group (n=8). The intervention consisted of a four-session guided Internet-delivered cognitive behavioural therapy (CBT) program containing psychoeducation, exposure to physical activity, and relaxation. The control group received usual care. Data was collected on chest pain frequency, cardiac anxiety, fear of body sensations, and depressive symptoms. Results: Depressive symptoms were prevalent in 20 % (Study IV) and 25 % (Study I, III) of the patients, and more than half of the patients still experienced depressive symptoms one year later (Study I). There were no significant differences in prevalence and severity of depressive symptoms between patients diagnosed with NCCP, AMI or AP. Living alone and younger age were independently related to more depressive symptoms (Study I). Cardiac anxiety was reported by 42 % of the patients in study III and 67 % of the patients in study IV. Fear of body sensations was reported by 62 % of the patients in study III and 93 % of the patients in study IV. On average, patients with NCCP had 54 contacts with primary care or the outpatient clinic per patient during the two-year study period. This was comparable to the number of contacts among patients with AMI (50 contacts) and AP (65). Patients with NCCP had on average 2.6 hospital admissions during the two years, compared to 3.6 for patients with AMI and 3.9 for patients with AP (Study II). Four out of ten patients reported seeking healthcare at least twice during the last year due to chest pain (Study III). On average, 14 % of patients with NCCP were on sick-leave annually, compared to 18 % for patient with AMI and 25 % for patient with AP. About 11-12 % in each group received a disability pension. The mean annual societal costs for patients with NCCP, AMI and AP were €10,068, €15,989 and €14,737 (Study II). Depressive symptoms (Study I, III), cardiac anxiety (Study III) and fear of body sensations (Study III) were related to healthcare utilization. Cardiac anxiety was the only variable independently associated with healthcare utilization (Study III). In the intervention study (Study IV), almost all patients in both the intervention and control groups improved with regard to chest pain frequency, cardiac anxiety, fear of body sensations, and depressive symptoms. There was no significant difference between the groups. The intervention was perceived as feasible and easy to manage, with comprehensible language, adequate and varied content, and manageable homework assignments. Conclusions: Patients with NCCP experienced recurrent and persistent chest pain and psychological distress in terms of depressive symptoms, cardiac anxiety and fear of body sensations. The prevalence and severity of depressive symptoms in patients with NCCP did not differ from patients with AMI and patients with AP. NCCP was significantly associated with healthcare utilization and patients had similar amount of primary care and outpatient clinic contacts as patients with AMI. The estimated cumulative annual national societal cost for patients with NCCP was more than double that of patients with AMI and patients with AP, due to a larger number of patients with NCCP. Depressive symptoms, cardiac anxiety and fear of body sensations were related to increased healthcare utilization, but cardiac anxiety was the only variable independently associated with healthcare utilization. These findings imply that screening and treatment of psychological distress should be considered for implementation in the care of patients with NCCP. By reducing cardiac anxiety, patients may be better prepared to handle chest pain. A short guided Internet-delivered CBT program seems to be feasible. In the pilot study, patients improved with regard to chest pain frequency, cardiac anxiety, fear of body sensations, and depressive symptoms, but this did not differ from the patients in the control group who received usual care. Larger studies with longer follow-up are needed to evaluate both the short and long- term effects of this intervention.
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Physical Activity and Cardiovascular DiseaseAndersen, Kasper January 2014 (has links)
The aim was to investigate associations of fitness and types and levels of physical activity with subsequent risk of cardiovascular disease. Four large-scale longitudinal cohort studies were used. The exposures were different measures related to physical activity and the outcomes were obtained through linkage to the Swedish In-Patient Register. In a cohort of 466 elderly men without pre-existing cardiovascular disease, we found that skeletal muscle morphology was associated with risk of cardiovascular events. A high amount of type I (slow-twitch, oxidative) skeletal muscle fibres was associated with lower risk of cardiovascular events and high amount of type IIx was associated with higher risk of cardiovascular events. This association was only seen among physically active men. Among 39,805 participants in a fundraising event, higher levels of both total and leisure time physical activity were associated with lower risk of heart failure. The associations were strongest for leisure time physical activity. In a cohort of 53,755 participants in the 90 km skiing event Vasaloppet, a higher number of completed races was associated with higher risk of atrial fibrillation and a higher risk of bradyarrhythmias. Further, better relative performance was associated with a higher risk of bradyarrhythmias. Among 1,26 million Swedish 18-year-old men, exercise capacity and muscle strength were independently associated with lower risk of vascular disease. The associations were seen across a range of major vascular disease events (ischemic heart disease, heart failure, stroke and cardiovascular death). Further, high exercise capacity was associated with higher risk of atrial fibrillation and a U-shaped association with bradyarrhythmias was found. Higher muscle strength was associated with lower risk of bradyarrhythmias and lower risk of ventricular arrhythmias. These findings suggest a higher rate of atrial fibrillation with higher levels of physical activity. The higher risk of atrial fibrillation does not appear to lead to a higher risk of stroke. In contrast, we found a strong inverse association of higher exercise capacity and muscle strength with vascular disease. Further, high exercise capacity and muscle strength are related to lower risk of cardiovascular death, including arrhythmia deaths. From a population perspective, the total impact of physical activity on cardiovascular disease is positive.
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Relación de la práctica de actividad física y la posición socioeconòmoica con los factores de riesgo cardiovascular y el riesgo de infarto agudo de miocardioRedondo Noya, Ana Belén, 1977- 21 November 2012 (has links)
La posición socioeconómica y la práctica de actividad física (AF), como estilo de vida, son dos determinantes que influyen en la salud individual y poblacional. En esta tesis se ha analizado la relación y la tendencia en el periodo 1995-2005 de estos dos determinantes con los factores de riesgo cardiovascular (FRCV) y el riesgo de infarto agudo de miocardio (IAM).
Se han utilizado datos de tres estudios transversales de base poblacional (1995-2000-2005) realizados en la población de Girona y que incluyen más de 9.000 individuos y datos de un estudio caso-control que incluye más de 1.000 casos de IAM y 1.000 controles.
Se ha demostrado que las clases sociales menos favorecidas tienen mayor prevalencia de FRCV, no obstante, las diferencias entre clases en relación al conocimiento, tratamiento y control de los FRCV clásicos que existían en 1995, han desaparecido. Sin embargo, las diferencias entre clases están aumentando durante el periodo analizado respecto a los estilos de vida (tabaquismo, sobrepeso/obesidad y sedentarismo).
En relación a la práctica de AF, la prevalencia de sedentarismo ha disminuido de 1995 a 2005. La edad, el género femenino y la clase social menos favorecida se asocian con mayor prevalencia. Al analizar la relación dosis-respuesta de la AF y la salud cardiovascular, se ha observado que la AF ligera no se asocia con un mejor perfil de FRCV pero si con menor riesgo de IAM en mayores de 64 años. La AF moderada-intensa mejora los perfiles de los FRCV con un beneficio máximo en 600-700 MET•minuto/semana y disminuye el riesgo de IAM con un beneficio máximo en 1.500-2.000 MET•minuto/semana. / Socioeconomic status and physical activity practice (PA) (as lifestyle) are two major factors in individual and population health. In this thesis, we analyzed the relationship and the trend in the period 1995-2005 of both two determinants with cardiovascular risk factors and myocardial infarction risk.
We used data from three independent population-based cross-sectional studies performed in Girona across 1995-2005 period with 9,546 individuals and data from population based age- and sex-matched case-control study with 1,000 cases and 1,000 controls.
This thesis shows that the lower social classes have higher prevalence of cardiovascular risk factors, however, differences in awareness, treatment and control of classical cardiovascular risk factors between groups have disappeared and the disparities in healthy lifestyles between groups are widening.
The prevalence of sedentary lifestyle has decreased in the period. Age, female gender and lower educational level were associated with a higher prevalence of physical inactivity. Light intensity PA reduced myocardial infarction risk in subjects older than 64 years and moderate-high intensity PA were associated with a better cardiovascular risk factors profile with a maximum benefit around 600-700 MET・min/week and also with a lower myocardial infarction risk with a maximum benefit around 1500-2000 MET・min/week.
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Vitální kapacita plic po operaci srdce v Institutu klinické a experimentální medicíny Praha / Vital capacity of lungs after operation hearts IKEM PragueCHVOJKOVÁ, Lenka January 2011 (has links)
Cardiovascular diseases in the Czech Republic represent the main cause of death and significantly contribute to the sickness rate and premature disability. Possibilities of treatment of cardiovascular diseases keep developing increasingly these days. An important part is the follow up spa treatment as well as sufficiently performed effective cardio rehabilitation. The theoretical part characterizes functional examination of the lungs and stress tests in cardiology. Simultaneously it describes early spa treatment and defines quality of life. The aim of the diploma thesis, which deals with the vital capacity of the lungs, was to prove positive effect of early spa treatment on the vital capacity of the lungs and on improvement of quality of life, specifically with respect to positive perception of one´s overall physical health. Hypotheses - H1: An early spa therapy positively affects spirometry values. H2: Patients with an early spa therapy better perceive their overall physical health. A form of quantitative research was chosen, in order to verify the determined aims and hypotheses of the diploma thesis. A standardized international Short Form SF - 36 questionnaires on quality of life was used for the data collection. Spirometry was utilized for ascertaining objective functional parameters. Values of spirometry examination were used for comparison. 32 patients after cardiovascular surgery were included in the research, who were transferred to Lázně Poděbrady on the 6th - 8th day after the surgery, 22 of them being men (69%) and 10 women (31 %). The average age of patients under research was 66,06 + 11,48 years. The check group consisted of 10 healthy volunteers. 8 women (80 %) and 2 men (20 %) at the average age of 37,1 + 13,3 years were included in the research. It follows from the spirometry results measured before the heart surgery at IKEM cardio center that a difference in results between the second and third spirometry occurred. The second and third spirometrical examination is the period of time, when the respondent undergoes the early spa treatment. After the heart surgery spirometry values worsen and improve in the course of the spa therapy. The research showed that the perception of overall physical health after the heart surgery is subject to perception of pain, which negatively affected sense of overall perception of physical health. H1 was confirmed and H2 was not confirmed. In order to improve current situation, it would be suitable to devote not only to cardio rehabilitation but also to improvement of perception of pain, e.g. by means of psychotherapy (art therapy, music therapy?). It is also important to widen a possibility of outpatient cardio rehabilitation in each cardio center for patients after heart surgery.
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Kineziofobie, její prediktory a souvislosti u vybraných chronických onemocnění - teoretický přehled / Kinesiophobia, her predictors and consequences in selected chronic diseases - theoretical reviewSchwarzová, Kristýna January 2021 (has links)
Title: Kinesiophobia, her predictors and consequences in selected chronic diseases - theoretical review Objectives: To review the issue of the occurrence of kinesophobia in various chronic diseases and to identify its predictors. Methods: The diploma thesis was prepared in the form of a literature search using electronic resources of the National Medical Library, the Central Physical Education Library and professional databases Pubmed, EBSCO, SCORPUS, Medline, Web of Science. The first half of the work summarized all the theoretical background and knowledge of kinesophobia and selected chronic diseases. The second half was focused on the processing of the issue of kinesophobia in selected chronic diseases and on the mapping of their predictors. Results: Based on the processing of available resources dealing with the issue of kinesophobia in selected chronic diseases, a comprehensive overview was created. In patients with chronic low back pain, high levels of kinesophobia were most often associated with chronic pain, functional impairment associated with the disease, obesity, low levels of education, and emotional states (anxiety, depression). In coronary heart disease, high levels of kinesophobia were associated with a lack of understanding of the need for physical activity, social support,...
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Women's hearts : ischaemic heart disease and stress management in womenClaesson, Maria January 2006 (has links)
Acute myocardial infarction (AMI), caused by ischaemic heart disease (IHD), is a leading cause of death in both men and women in the western society. Hypertension, diabetes, and smoking are examples of well-known risk factors of IHD, but also there are psychosocial factors, such as stress, vital exhaustion (unusual fatigue, irritability, and demoralization) and depression that have been associated with an increased risk in both genders. After an AMI, however, women are more likely than men to be psychosocially impaired resulting in suffering and a presumed increase in the risk of recurrent cardiac events. Psychosocial factors may be targeted in secondary prevention, complementary to drug treatment and conventional lifestyle advice. There is some evidence of beneficial effects on both psychosocial well-being and cardiac outcomes by psychosocial interventions in men. Far fewer women have been studied and the results have been inconsistent. It is not clear how psychosocial factors convey the increased risk of cardiac events, but many possible psychopathological mechanisms, including biochemical and physiological links, have been suggested. In the Women’s Hearts study we have, in a randomised controlled trial, evaluated a one-year cognitive-behavioural stress management programme designed specifically for women with IHD. We included 198 women with IHD, with a mean age of 61 years and from the county of Västerbotten in Northern Sweden, who were randomised to either conventional treatment and follow-up, or to stress management in addition to conventional care. Extensive questionnaires, blood samplings, and biomedical and physiologic data were obtained before randomisation, as well as at follow-ups approximately one and two years after randomisation. Two groups of healthy controls were included for comparisons with women with IHD. Compared to women without IHD, women with IHD reported more stress behaviour and vital exhaustion. Women with IHD also had a lower heart rate variability (HRV) than the healthy controls, possibly reflecting a dysfunctional autonomic nervous regulation of the heart. Reduced HRV has been shown to increase the risk of cardiac arrhythmias and sudden death. At the first follow-up, performed at the end of the one-year stress management programme, women who had participated in the programme had reduced the stress behaviour and vital exhaustion, compared to the women in the conventional care group. We could not find any evidence of a direct cause-effect relationship between stress management and biological cardiovascular risk indicators, or HRV; the intervention and control groups did not differ in insulin resistance, inflammatory, haemostatic and fibrinolytic factors, or HRV. At second follow-up one year later, several additional psychosocial domains were studied. The stress management programme had accelerated psychosocial recovery at the first follow-up over and above that observed in the control group. At the second follow-up, there was further marked improvement in the control group, so the differences in psychosocial variables between the intervention and control groups were no longer significant. In conclusion, a cognitive-behavioural stress management programme could accelerate psychosocial improvement in women with IHD, and thus reduce the amount of psychological and psychosocial suffering. We could not find any evidence that the stress management programme was associated with a concomitant improvement in biological cardiovascular risk indicators, or HRV. Our results suggest that the women with the greatest psychosocial burden should be identified and targeted in new clinical trials of cognitive-behavioural interventions in women with IHD. Future studies within the Women’s Hearts project will evaluate the psychosocial effects at a five-year follow-up, as well as investigations of other possible pathways by which psychosocial interventions might mediate beneficial effects on cardiac events.
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Condições de vida e mortalidade por doenças cardiovasculares na área de influência do Complexo Petroquímico do Estado do Rio de Janeiro - COMPERJ. / Life conditions and mortality from cardiovascular diseases in influence area of Petrochemical Complex of Rio de Janeiro State - COMPERJ.Helen Paredes de Souza 30 April 2014 (has links)
O objetivo desta tese foi identificar e caracterizar áreas com altas taxas de mortalidade por doenças do aparelho circulatório (DAC) e seus dois principais subgrupos de causas: as doenças isquêmicas do coração (DIC) e as doenças cerebrovasculares (DCV), entre os anos de 2008 e 2012 na área de influência do complexo petroquímico do estado do Rio de Janeiro COMPERJ, por meio de métodos estatísticos e sistemas de informações geográficas (SIG). Os resultados da investigação são apresentados na forma de dois manuscritos. O primeiro objetivou descrever o perfil da distribuição espacial da mortalidade por (DAC), caracterizar e predizer territórios com maior risco de morte por esta causa, com base em classificação das unidades espaciais por indicador de qualidade urbana (IQUmod). A análise multivariada foi realizada por meio do método conhecido como árvore de decisão e regressão, baseado em algoritmo CART para a obtenção do modelo preditivo para UVLs com diferentes riscos de mortalidade por DAC. O modelo desenvolvido foi capaz de discriminar sete conjuntos de UVLs, com diferentes taxas médias de mortalidades. O subconjunto que apresenta a maior taxa média (1037/100 mil hab.) apresenta 3 UVLs com mais de 75% de seus domicílios com abastecimento de água inadequado e valor de IQUmod acima de 0.6. Conclui-se que na área de influência do COMPERJ existem áreas onde a mortalidade por DAC se apresenta com maior magnitude e que a identificação dessas áreas pode auxiliar na elaboração, diagnóstico, prevenção e planejamento de ações de saúde direcionadas aos grupos mais susceptíveis. O segundo manuscrito teve por objetivo descrever o perfil da distribuição espacial da mortalidade por DIC e DCV em relação ao contexto socioambiental segundo áreas geográficas. O modelo de regressão linear de Poisson com parâmetro de estimação via quasi-verossimilhança foi usado para verificar associação entre as variáveis. Foram identificados como fatores de risco para mortalidade por DIC e DCV a variável relativa a melhor renda e maior distância entre domicílios e unidades de saúde; a proporção de domicílios em ruas pavimentadas aparece como fator de proteção. A distribuição espacial e as associações encontradas entre os desfechos e preditores sugerem que as populações residentes em localidades mais afastadas dos centros urbanos apresentam maiores taxas de mortalidade por DIC e DCV e que isto pode estar relacionado a contextos rurais de localização das residências e a distância geográfica destas populações aos serviços de saúde. Aponta-se para a necessidade de desenvolvimento de ações que propiciem maior amplitude no atendimento em saúde, no intuito da redução de eventos cardiovasculares mórbidos incidentes naquelas populações.
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Condições de vida e mortalidade por doenças cardiovasculares na área de influência do Complexo Petroquímico do Estado do Rio de Janeiro - COMPERJ. / Life conditions and mortality from cardiovascular diseases in influence area of Petrochemical Complex of Rio de Janeiro State - COMPERJ.Helen Paredes de Souza 30 April 2014 (has links)
O objetivo desta tese foi identificar e caracterizar áreas com altas taxas de mortalidade por doenças do aparelho circulatório (DAC) e seus dois principais subgrupos de causas: as doenças isquêmicas do coração (DIC) e as doenças cerebrovasculares (DCV), entre os anos de 2008 e 2012 na área de influência do complexo petroquímico do estado do Rio de Janeiro COMPERJ, por meio de métodos estatísticos e sistemas de informações geográficas (SIG). Os resultados da investigação são apresentados na forma de dois manuscritos. O primeiro objetivou descrever o perfil da distribuição espacial da mortalidade por (DAC), caracterizar e predizer territórios com maior risco de morte por esta causa, com base em classificação das unidades espaciais por indicador de qualidade urbana (IQUmod). A análise multivariada foi realizada por meio do método conhecido como árvore de decisão e regressão, baseado em algoritmo CART para a obtenção do modelo preditivo para UVLs com diferentes riscos de mortalidade por DAC. O modelo desenvolvido foi capaz de discriminar sete conjuntos de UVLs, com diferentes taxas médias de mortalidades. O subconjunto que apresenta a maior taxa média (1037/100 mil hab.) apresenta 3 UVLs com mais de 75% de seus domicílios com abastecimento de água inadequado e valor de IQUmod acima de 0.6. Conclui-se que na área de influência do COMPERJ existem áreas onde a mortalidade por DAC se apresenta com maior magnitude e que a identificação dessas áreas pode auxiliar na elaboração, diagnóstico, prevenção e planejamento de ações de saúde direcionadas aos grupos mais susceptíveis. O segundo manuscrito teve por objetivo descrever o perfil da distribuição espacial da mortalidade por DIC e DCV em relação ao contexto socioambiental segundo áreas geográficas. O modelo de regressão linear de Poisson com parâmetro de estimação via quasi-verossimilhança foi usado para verificar associação entre as variáveis. Foram identificados como fatores de risco para mortalidade por DIC e DCV a variável relativa a melhor renda e maior distância entre domicílios e unidades de saúde; a proporção de domicílios em ruas pavimentadas aparece como fator de proteção. A distribuição espacial e as associações encontradas entre os desfechos e preditores sugerem que as populações residentes em localidades mais afastadas dos centros urbanos apresentam maiores taxas de mortalidade por DIC e DCV e que isto pode estar relacionado a contextos rurais de localização das residências e a distância geográfica destas populações aos serviços de saúde. Aponta-se para a necessidade de desenvolvimento de ações que propiciem maior amplitude no atendimento em saúde, no intuito da redução de eventos cardiovasculares mórbidos incidentes naquelas populações.
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Identification en thérapie cellulaire des patrons d’expression transcriptomique de cellules souches utilisées pour traiter la défaillance cardiaque afin d’en améliorer le potentiel thérapeutiqueSauvé, Jean-Alexandre 12 1900 (has links)
La cardiopathie ischémique incluant l’insuffisance cardiaque est la deuxième cause de mortalité annuelle au Canada. Bien que de nombreuses stratégies préventives et des thérapies pharmacologiques retardent la progression de la maladie, il n’existe aucune solution qui module directement aux les remaniements pathologiques et la perte de cardiomyocytes. Au cours des 25 dernières années, de multiples progrès dans les domaines de la médecine régénérative et de la thérapie cellulaire ont annoncé des résultats prometteurs, mais les résultats d’études cliniques contemporaines demeurent plutôt mitigés. COMPARE-AMI, une étude randomisée-contrôlée de phase II, a évalué l’effet d’injections intracoronariennes de cellules souches hématopoïétiques CD133+ chez des patients souffrant d’infarctus aigu. IMPACT-CABG, une ÉRC de phase II a également évalué l’effet d’injections intramyocardiques de cellules CD133+ chez les patients souffrant de cardiomyopathie ischémique chronique nécessitant une revascularisation chirurgicale. Nous avons émis l’hypothèse que les cellules CD133+ utilisées dans des études cliniques de cardiomyopathies ischémiques aiguës et chroniques des patients répondant à la thérapie cellulaire exhibent des signatures transcriptomiques communes responsables de leur effet thérapeutique. En classant les patients en tant que répondants et non-répondants selon leur fonction cardiaque, nous avons évalué, a posteriori, ces patrons d’expression. Les cellules CD133+ autologues de patients jugés répondants expriment des signatures qui sont hautement conservées entre elles (incluant l’angiogénèse, la régulation de la réponse au stress et la survie cellulaire) et uniques d’un modèle à l’autre et qui pourraient, en partie, exprimer les issus cliniques des patients. Afin de maximiser les effets de la thérapie cellulaire aux cellules souches, nous avons par la suite tenté de reproduire ces phénotypes par stimulation pharmacologique avec des inhibiteurs d’HSP90 pour leurs effets qui semblent reproduire ces signatures. Ainsi, nous avons démontré qu’une stimulation de cellules souches mésenchymateuses humaines (CSMh) au Célastrol (inhibiteur HSP90) pouvait répliquer certains de ces phénotypes. Notamment, des CSMh conditionnées activent des voies de signalisation de type ‘RISK’ et augmentent leur sécrétion de protéines en lien avec la réponse au stress ainsi que d’exosomes contenant des molécules impliquées dans la communication intercellulaire sans être liées à un changement de type cellulaire. De plus, les CSMh traitées semblent améliorer la guérison de plaie par activité paracrine et sont plus résistante à la sénescence oxydative. Ces résultats encourageants nous permettent d’envisager des stratégies plus poussées de pré-conditionnement cellulaire ex vivo de cellules CD133+ avant leur implantation. À terme, cela pourrait mener à une optimisation de la thérapie cellulaire afin d’en maximiser les bénéfices cliniques et d’en exploiter leur plein potentiel. / Ischemic cardiomyopathy and heart failure are the second annual cause of mortality in Canada.
Despite rigorous prevention strategies and drug regimens preventing progression, no therapeutic
modality can currently reverse the pathologic modifications of the disease. In the last quarter century,
numerous advances in the field of regenerative medicine and cell therapy have demonstrated promising
effects. COMPARE-AMI, a phase II randomized controlled trial (RCT), evaluated the effect of intracoronary
injection of CD133+ cells in acute myocardial infarction following percutaneous intervention. IMPACTCABG,
also a phase II RCT, evaluated the effect of intramyocardial injection of CD133+ hematopoietic stem
cells in chronic ischemic cardiomyopathy at the time of surgical revascularization. That being said, we
believe that the CD133+ cells used in therapy have shared transcriptomic signatures that are responsible
for their clinical effects. By classifying patients into responders and non-responders according to an
improvement in ejection fraction, we evaluated, a posteriori, those expression patterns. Autologous
CD133+ cells of patients classified as responders expressed highly conserved transcriptomic signatures
that could be responsible for the clinical outcomes of patients. Notably, these signatures were related to
cardioprotective mechanisms including angiogenesis, stress response regulation and cell survival. In order
to harness the full potential of stem cell therapy, we attempted to reproduce the identified phenotypes
by pharmacological intervention with HSP90 inhibitors which are known to mimic some of these effets.
Conditioned human mesenchymal stem cells (hMSC) activated ‘RISK’-type signaling pathways and
augmented exosome and protein secretion relating to the response to cellular stress; this activation was
unrelated to a switch of cell type. Furthermore, treated hMSC seemed to favour improved wound healing
by paracrine activity and were more resistant to oxidative senescence. These encouraging results allow
us to develop novel, more advance, strategies of ex vivo cell preconditioning before implantation,
including of CD133+ cells. Ultimately, we hope that optimisation of cells through this mechanism and
others will allow us to unleash the full potential of stem cell therapy.
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