Paper A: In this paper, the development and implementation of a contact algorithm based on C2-continuous surface representations is discussed. In 3D contact simulations involving models with arbitrarily curved surfaces (as in the case of vessel walls), the discretization of the contact surfaces by means of facet-based techniques could lead to numerical instabilities and finally loss of quadratic convergence. These instabilities arise mainly due to the sliding of contractor (slave) nodes over the boundaries of target (master) contact facets, where jumps of the normal vector are experienced. The paper addresses successfully this problem, by discretization of the target surfaces by means of C2-continuous parameterization schemes. Initially, the uniform cubic B-spline surfaces are introduced. Next, in an attempt for more accurate representations of the geometric models of the contact surfaces, a new parameterization based on the expression of cubic B-splines is developed. The two approaches are implemented into a finite element framework and more specifically, into the multipurpose finite element analysis program FEAP. The special merits of the developed algorithms and the advantages of the smooth surfaces over facet-based approaches are exhibited through a classical contact mechanics problem, considering incompressibility, finite deformations and large slidings. Next, a simulation of balloon angioplasty with stenting is presented, where the contact between both medical devices (balloon and stent) with the arterial wall is modeled. The arterial wall is modeled in this first approach, as hyperelastic, homogeneous, isotropic, while a cylindrically orthotropic model is developed to capture the nonlinear, anisotropic behavior of the balloon catheter under pressure. Two stents with the same geometry but different strut thickness, are studied. Both are considered elasto-plastic. The performed simulations point out the outcome of the balloon angioplasty and stenting in terms of luminal gain and mechanical strains. Finally, a comparison between the two stent configurations is presented. Paper B: The second paper makes use of the contact tool developed in Paper A and focuses on the changes of the mechanical environment of the arterial wall due to stenting, as a function of a set of stent design parameters. In particular, Paper B presents a detailed geometric and material model of a postmortem human iliac artery, composed by distinct tissue components, each associated with specific mechanical properties. The constitutive formulation for the artery considers anisotropic, highly nonlinear mechanical characteristics under supraphysiological loadings. The material and structural parameters of the arterial model are obtained through uniaxial tensile tests on stripes extracted from the several arterial tissues that form the stenosis, axially and circumferentially oriented. Through cooperation with a well-established stent manufacturing company, an iliac stent was acquired. The dimensions of the stent are measured under a reflected-light microscope, while it is parameterized in such a way as to enable new designs to be simply generated through variations of its geometric parameters. The 3D balloon-stent-artery interaction is simulated by making use of the smooth contact surfaces with C2-continuity, as previously mentioned. Next, scalar quantities attempt to characterize the arterial wall changes after stenting, in form of contact forces induced by the stent struts, stresses within the individual components and luminal change. These numerically derived quantities allow the determination of the most appropriate stent configuration for an individual stenosis. Therefore, the proposed methodology has the potential to provide a scientific basis for optimizing treatment procedures, stent material and geometries on a patient-specific level. / <p>QC 20101118</p>

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia with a prevalence of 15% of patients over 80 years. Coronary artery disease co-exists in 20–30% of patients with atrial fibrillation. The need for triple anticoagulation therapy makes the management of these patients challenging following PCI. Methods: Nationwide inpatient sample which is a set of longitudinal hospital inpatient databases was used to evaluate the outcome of patients with AF who underwent PCI. All patients undergoing PCI between 2002 and 2011 were included in the study. Specific ICD-9-CM codes were used to identify the study patients and their outcomes. Results: There were 3,226,405 PCIs during the time period of the study of which 472,609 (14.6%) patients had AF. AF patients were older and predominantly male (60%). The number of PCIs had a declining trend from 2002 to 2011. Age adjusted inpatient mortality was significantly higher in PCI AF group compared to the PCI non-AF group (100.82 ± 9.03 vs 54.07 ± 8.96 per 100,000; P < 0.01). Post PCI predictors of mortality were AF (OR 1.56, CI 1.53–1.59), CKD (OR 1.41, CI 1.37–1.46), PAD (OR 1.20, CI 1.15–1.24), acute myocardial infarction (OR 2.42 CI 2.37–2.46 and cardiogenic shock (OR 13.92 CI 13.60–14.24) P < 0.001. Conclusion: AF is common in patients undergoing PCI and those AF patients have a higher age-adjusted all cause inpatient mortality. There is a decline in total number of PCIs over time in US. Atrial fibrillation, chronic kidney disease, peripheral artery disease, MI and cardiogenic shock were associated with increased mortality following PCI.

No description available.

published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Estudos comparativos prévios com inclusão de lesões de bifurcação selecionadas sugerem ausência de benefício de implante eletivo de dois versus stent único. No entanto, a aplicabilidade do técnica provisional parece ser dependente da complexidade da lesão de bifurcação. A área luminar da lesão após tratamento percutâneo, conforme medida pelo ultrassom intracoronário, tem demonstrado valor preditivo significante na evolução tardia dos pacientes submetidos a ICP. Os objetivos desta análise foram avaliar as dimensões luminares de lesões de bifurcação coronária complexas tratadas por ICP, conforme a análise pelo ultrassom, e correlacionar os achados com os resultados imediatos e tardios. Também objetivou-se identificar preditores angiográficos e ultrassonográficos de falência do ramo lateral nos diferentes passos do tratamento e seguimento. Entre maio de 2008 e agosto de 2009, 59 pacientes portadores de lesão de bifurcação complexa, com comprometimento significativo (estenose > 50%) dos dois ramos e lesão no ramo lateral extendendo-se além do óstio, foram abordados inicialmente com pré-dilatação do ramo lateral, a qual foi realizada com sucesso (estenose < 50%, fluxo TIMI 3, sem dissecção) em 54 pacientes (91,5%). Esse pacientes foram então randomizados para tratamento com stent único (estratégia provisional) (n = 27) versus stent duplo (n = 27). Durante o procedimento, 6 pacientes alocados no grupo stent único apresentaram falência do tratamento no ramo lateral (estenose residual >50%, fluxo TIMI < 3 ou dissecção), sendo que, 5 pacientes receberam stent adicional no ramo lateral para otimizar o resultado angiográfico. Ao final do procedimento, os valores médios e desvios padrão (DP) da área mínima do lúmen no óstio do ramo lateral (desfecho primário) foram 3,37 (1,62) mm2 no grupo stent único versus 5,50 (1,41) mm2 no grupo stent duplo (p < 0,001), conforme a alocação randômica. No seguimento angiográfico de 9 meses, as taxas de reestenose no ramo lateral foram 21,7% no grupo stent único versus 4% no grupo stent duplo (p = 0,06), sendo que, todas as recorrências envolveram a localização ostial. Considerando-se o tratamento recebido, a taxa de reestenose no ramo lateral foi significantemente maior nos pacientes tratados com stent único versus stent duplo (27,8% versus 3,3%, p = 0,01). Os preditores de falência da estratégia provisional foram: excêntricidade da lesão (p = 0,02), área mínima do lúmen (p = 0,08) e diâmetro mínimo do lúmen no óstio do ramo lateral (p = 0,06), extensão da lesão (p = 0,09) e percentual de estenose (p = 0,07) do ramo lateral. Com relação a reestenose angiográfica no ramo lateral, os preditores foram: área mínima do lúmen no óstio do ramo lateral ao final do procedimento (p = 0,03), tratamento com stent duplo (p = 0,02), diâmetro mínimo do lúmen (p = 0,03) e percentual de estenose (p = 0,02) no óstio do ramo lateral ao final do procedimento, ganho imediato no óstio do ramo lateral (p = 0,09) e diâmetro de referência do ramo lateral (p = 0,03). Estes resultados sugerem que lesões de bifurcação coronária complexas beneficiam-se de tratamento percutâneo com abordagem inicial com estratégia de dois stents, sendo que, tal benefício esteve relacionado a obtenção de maior área luminar no óstio do ramo lateral. / Previous comparative studies including selected bifurcation lesions have shown no advantage of elective double stenting implantation versus single stenting. However, the applicability of the provisional technique appears to be dependent on the bifurcation lesion complexity. The lesion luminal area after percutaneous treatment, as assessed by intravascular ultrasound, has demonstrated significant predictive value in the late follow-up of patients undergoing PCI. The objectives of this analysis were to evaluate the lesion luminal dimensions of complex coronary bifurcation lesions, as assessed by intravascular ultrasound, and to correlate such findings with acute and late outcomes. Also, it was aimed to identify angiographic and intravascular ultrasound predictors of side branch failure throughout the procedural steps and follow-up. Between may 2008 and august 2009, 59 patients with complex bifurcation lesions, including significant involvement (> 50% stenosis) of both branches and side branch lesion length extending from its ostium, were approached initially with side branch predilatation, which was successful (< 50% stenosis, TIMI 3 flow, no dissection) in 54 patients (91.5%). These patients were then randomized for treatment with single stenting (provisional strategy) (n = 27) versus double stenting (n = 27). During procedure, 6 patients allocated in the single stenting arm presented side branch failure (> 50% residual stenosis, TIMI flow < 3 or dissection), given that 5 patients received an additional stent in the side branch in order to optimize the angiographic result. At final procedure, the mean value and standard deviation (SD) for minimum lumen area at the side branch ostium (primary endpoint) were 3.37 (1.62) mm2 in single stenting versus 5.50 (1.41) mm2 in double stenting (p < 0.001), according to the randomized allocation. In the angiographic follow-up at 9 months, the restenosis rates in the side branch were 21.7% in single stenting versus 4% in double stenting (p = 0.06), given that all recurrences involved the ostial location. Considering the treatment received, the side branch restenosis rate was significantly increase among patients treated with single stenting versus double stenting (27.8% versus 3.3%, p = 0.01). The predictors of provisional strategy failure were: lesion eccentricity (p = 0.02), minimum lumen area (p = 0.08) and minimum lumen diameter in the side branch ostium (p = 0.06), lesion length (p = 0.09) and percent diameter stenosis (p = 0.07) of the side branch. Regarding angiographic restenosis in the side branch, predictors were: minimum lumen area in the side branch ostium at final procedure (p = 0.03), treatment with double stenting (p = 0.02), minimum lumen diameter (p = 0.03) and percent diameter stenosis (p = 0.02) in the side branch ostium at final procedure, acute gain at the side branch ostium (p = 0.09) and side branch reference diameter (p = 0.03). These results suggest that complex coronary bifurcation lesions may benefit from a primary percutaneous approach with double stenting strategy, given that most such benefit was associated with a larger lumen area obtained at the side branch ostium.

As doenças cardiovasculares (DCV\'s) são as principais causas de morte, morbidade e incapacidade entre os países ocidentais desenvolvidos. Possuem etiologia complexa e multifatorial, em que se destacam os chamados fatores de risco (FR), tradicionais ou psicológicos. Dentre os psicológicos, pode-se citar depressão, estresse e qualidade de vida. No controle das DCV\'s, mudanças comportamentais são requeridas. O Modelo Transteórico de Mudança de Comportamento (MTT) enfatiza a mudança como processo, e que as pessoas possuem diversos estágios de motivação/prontidão para mudar: pré contemplação, contemplação, ação e manutenção. Dentre os tratamentos disponíveis para as DCV\'s, a Angioplastia destaca-se como um procedimento hemodinâmico simples e pouco invasivo, com obtenção de bons resultados. O objetivo do trabalho foi descrever as relações entre variáveis psicológicas e estágios/níveis de prontidão para mudança de comportamentos de risco para cardiopatia em pacientes candidatos à angioplastia pelo período de um ano. A amostra foi composta por 100 pacientes e os instrumentos utilizados foram: entrevista semi estruturada, URICA Adaptada para Comportamento de Estresse, Régua de Prontidão (RP), Inventário Beck de Depressão (BDI), Inventário de Sintomas de Stress para Adultos de Lipp (ISSL) e Questionário Genérico de Avaliação de Qualidade de Vida (SF-36). O estudo foi composto por cinco momentos de avaliação, separados entre si por um tempo médio de três meses. A análise dos dados foi feita por meio do Modelo de Regressão Logística. A Avaliação 1 ocorreu no dia da angioplastia e as demais nos dias das consultas médicas ambulatoriais, ocorrendo uma perda de 57 sujeitos entre a primeira e a última avaliação. Na amostra inicial a média de idade foi 61,4 anos (dp±9,82), 67% do sexo masculino, 69% casados, 67% com baixa renda (entre 1 e 3 SM), 65% aposentados e com média de 4,73 anos de estudo. Quanto aos aspectos psicológicos, 81% estavam na fase de pré contemplação, a alimentação inadequada apresentou a menor prontidão para mudança pela RP, 31% apresentaram sintomas cognitivos e afetivos de depressão e 59% tinham presença de estresse. O SF-36 mostrou os piores índices de percepção da saúde para aspectos emocionais e físicos. Na comparação entre avaliações 1 e 5, foram considerados os 43 sujeitos comuns aos dois momentos, observando-se redução não estatisticamente significante de alimentação inadequada (44,18%), sedentarismo (32,56%), estresse (11,63 pontos percentuais) e prontidão para mudança de estresse (5,17 pontos percentuais), além de um incremento em todos os domínios do SF-36 e de sujeitos que passaram ao estágio de ação (11,62%). Os sintomas cognitivos e afetivos de depressão sofreram um decréscimo significativo ao longo de um ano (p-valor<0,01). A prontidão para mudança do comportamento de estresse associou-se à idade (sujeitos mais jovens) na Avaliação 1 (OR 2,58; 1,04-6,43), Avaliação 3 (OR 4,68; 1,26-17,41), Avaliação 4 (OR 14,00; 1,51-130,01) e Avaliação 5 (OR 4,95; 1,24- 19,96). A associação com estado civil (sem parceiro) manteve-se somente na primeira avaliação (OR 3,89; 1,06-14,22) e com estresse (ausência de sintomas) na Avaliação 1 (OR 4,20; 1,79-9,83), Avaliação 3 (OR 7,18; 1,72-29,97), Avaliação 4 (OR 6,11; 1,34-27,96) e Avaliação 5 (OR 7,20; 1,64-31,71). As características sociodemográficas da amostra condizem com dados apresentados por outros estudos e sugerem intervenções, tanto dos profissionais de saúde quanto das políticas públicas, mais adaptadas e direcionadas a um estrato menos favorecido da população. A incongruência entre conhecimento de FR e esquiva dos mesmos mostra que o simples fornecimento de informações, apesar de importante, não é suficiente para promover mudança de comportamento, reforçando a relevância da inserção do psicólogo nas equipes médicas, com intervenções voltadas para o manejo de aspectos emocionais, as quais devem, sempre que possível ajustar-se ao nível de prontidão para mudança de cada sujeito em particular. / Psychological variables and readiness to change in cardiac patients undergoing angioplasty. 2011. 201 f. Dissertação (Mestrado). Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 2011. Cardiovascular diseases (CVD\'s) are the leading causes of death, morbidity and disability among the developed Western countries. They have complex and multifactorial etiology, which highlightening the importance of the so-called risk factors (RF), traditional or psychological. Among the psychological ones, it can be pointed out depression, stress and quality of life. In the control of CVD\'s, behavioral changes are required. The Transtheoretical Model of Behavioral Change (TTM) emphasizes change as a process and that people have different stages of motivation/readiness to change: pre contemplation, contemplation, action and maintenance. Among the available treatments for CVD\'s, angioplasty stands out as a simple and minimally invasive hemodynamic procedure, with good results. This study objective was to describe the relationship between psychological variables and stages/levels of readiness to change risk behaviors for heart disease in patients eligible for angioplasty in a period of one year. The sample consisted of 100 patients and the instruments used were: semi-structured interviews, URICA Adapted to Stress Behavior, Readiness Ruler (RP), Beck Depression Inventory (BDI), Inventário de Sintomas de Stress para Adultos de Lipp (ISSL) and Medical Outcomes Study 36-Item Short Form Survey (SF-36). The study had five moments of evaluation, on average every three months. Data analysis was performed using the Logistic Regression Model. The first evaluation occurred on the day of angioplasty and the others in the days of outpatient medical consultations, with a loss of 57 subjects between the first and last assessment. In the initial sample, the mean age was 61.4 years (SD±9.82), 67% male, 69% married, 67% with low income (between 1 and 3 MW), 65% were retired, with an average of 4.73 years of study. As for the psychological aspects, 81% were in pre contemplation, poor diet had the lowest readiness to change for RP, 31% had cognitive and affective symptoms of depression and 59% had presence of stress. The SF-36 showed the worst indices of perceived health in emotional and physical aspects. In the comparison between assessments 1 and 5, 43 subjects were considered common to the two moments, and it was observed no statistically significant reduction of inappropriate diet (44.18%), sedentary lifestyle (32.56%), stress (11.63 percentage points ) and readiness for change of stress (5.17 percentage points), and an improvement in all domains of the SF-36 and of subjects who passed to the stage of action (11.62%). Affective and cognitive symptoms of depression experienced a significant decrease over one year (p<0.01). Readiness for change of stressfull behavior was associated with age (younger subjects) in Evaluation 1 (OR 2.58, 1.04-6.43), Evaluation 3 (OR 4.68, 1.26-17, 41), Evaluation 4 (OR 14.00; 1.51-130.01) and Evaluation 5 (OR 4.95, 1.24-19.96). The association with marital status (without partner) remained only in the first assessment (OR 3.89, 1.06-14.22) and stress (no symptoms) in Evaluation 1 (OR 4.20; 1.79-9.83), Evaluation 3 (OR 7.18, 1.72-29.97), Evaluation 4 (OR 6.11, 1.34-27.96) and Evaluation 5 (OR 7.20, 1, 64-31.71). The sample sociodemographic characteristics are consistent with data presented by other studies and suggest interventions, both from health professionals and from the public policies, aimed and tailored to a more disadvantaged strata of the population. The incongruity between knowledge of RF and avoiding them shows that simply providing of information, although important, is not sufficient to promote behavior change, reinforcing the importance of the inclusion of a psychologist in medical teams, with interventions aimed at managing emotional aspects, which should, where posible, to adjust the level of readiness for change to particular subjects.

Os avanços na área da saúde têm resultado na redução da morbidade e permitido maior sobrevida aos pacientes coronariopatas. Entr etanto, a Síndrome Coronariana Aguda (SCA) ainda representa uma das questões de saúde públ ica mais relevante da atualidade. O objetivo geral do estudo foi avaliar a evolução clínica dos pacientes dur ante a primeira internação decorrente da SCA e nos primeiros dois anos a pós a hospitalização. As principais variáveis de interesse investigadas foram: mortalidade, rein ternações e tratamentos de revascularização do miocárdio (Intervenção Coronária Percutânea - ICP e Cirurgia de Revascularização do Miocárdio - CRVM). O delineamento utilizado foi observacional, tipo coorte. A amostra foi composta por pacientes que foram internados em decorrência do prim eiro episódio de uma SCA, entre maio de 2006 e julho de 2009, em um hospital geral público de ensino. Os dados foram coletados em 2011 mediante consultas ao s prontuários dos participantes e ao sistema eletrônico de agendamento do hospital, utilizando-se de um instrumento elaborado pela pesquisadora. Os dados foram analisados utiliz ando testes de associação Qui-quadrado, Exato de Fisher e t de Student para amostras independentes. O nível de significância adotado foi de 0,05. A taxa de mortalidade foi calculada divi dindo o número de óbitos ocorridos em até dois anos de seguimento pela somatória do tempo total de observação do estudo. Participaram da investigação 234 pacientes, sendo 140 (59,8%) diagnosticados com Infarto Agudo do Miocárdio (IAM) e 94 (40,2%) com Angina Instável (AI). A idade média foi de 58 anos (D.P.=12,2 anos), com predomínio de indiví duos do sexo masculino (69,2%). Durante a internação inicial não houve associação entre a presença de complicações e a manifestação clínica da SCA; os pacientes com AI tiveram média de tempo de permanência hospitalar maior que IAM (12,5 e 10 dias, respectivamente), mas essa diferença não foi estatisticamente significante. As ICPs foram mais realizadas nos pacien tes com IAM, enquanto as CRVMs foram mais realizadas nos pacientes com AI , sendo a associação entre essas variáveis estatisticamente significantes. Ao longo do se guimento de até dois anos após a alta da internação inicial, 71,4% dos pacientes foram subm etidos a, pelo menos, um procedimento de revascularização do miocárdio; 27,4% necessita ram de outras hospitalizações, e desses, 71% tiveram uma nova internação e 6,5% reinternaram cinco vezes. Na primeira reinternação, a causa mais prevalente foi a ICP programada e na s internações posteriores foi a angina. A taxa de mortalidade hospitalar foi de 3%, tendo ocorrido 13 óbitos durante todo o seguimento do estudo, sem diferença estatística entre as manifestações da SCA. A taxa de mortalidade geral do estudo foi de 35,75/1000 pessoas por ano. Os resultados do estudo ampliaram nossos conhecimentos sobre como é o perfil deste grupo de pacientes atendidos em decorrência do primeiro episódio de SCA em um hospital geral, de nível terciário, e como se dá a evolução clínica durante a internação e a longo prazo. / The advances in health have led to reduced mo rbidity and improved survival of patients living with coronary diseases. However, Acute Cor onary Syndrome (ACS) represents one of the most relevant public health issues nowadays. The aim of this study was to assess the clinical evolution of patients who suffered from ACS, fr om their first admission to the hospital until two years after that episode. The main interest variables investigated were: mortality, hospital readmissions and myocardial reva scularization therapies (percuta neous coronary intervention - PCI and Coronary Artery Bypass Grafting surg ery - CABG). This research was designed as an observational cohort study. The study sample was patients admitted into a general school hospital due to the first episode of ACS, from May 2006 through July 2009. Data were collected in 2011 from patients\' medical records and the hospital\'s appointment schedule database, using a form designed by the researcher. Data were analyzed by chi-square, Fisher\'s exact test and t-Student association tests for independent samples. The significance level was 0.05. Mortality rate was calculated by dividing the number of deaths occurred up to two years after the first ACS episode by the total period of observation taken within the study. As such, 234 patients took part in the study, 140 (59.8%) were diagnosed with Acute Myocardial Infarction (AMI) and 94 with Unstable Angi na (UA). The mean age was 58 years old (s.d.=12.2), most were male (69.2%). During hosp ital stay there was no association between medical complications and clinical manifest ation of ACS. Patients with UA had mean hospital stay higher than AMI patients (12.5 and 10 days, respectively), alt hough this was not statistically relevant. PCI were more prevalen t in AMI patients, whereas CABG were to UA patients, displaying statistically relevant association between these variables. During the two-year follow up period after hospital discharge, 71.4% of patients were submitted to, at least, a myocardial revascularization pr ocedure. 27.4% of patients were hospitalized again, 71% of this group had to be readmitted and 6.5% had been readmitted five times. At their first readmission, the most prevalent cause was a sc heduled PCI and the following hospitalizations were due to angina. The hospital mortality rate was 3%, as 13 deaths occurred during the period of study, with no statistically significance between the ACS manifestations. The general mortality rate of this study was 35.75/1000 people per year. The results of this study improved our knowledge over the profile of this population admitted into a general tertiary hospital due to their first ACS episode. It also shone some light over the clinical evolution of this disease during hospitalizat ion and at long term period.

La bifurcation coronaire est un site privilégié d’athérosclérose. Jusqu’alors aucune des techniques de stenting provisionnel percutanées avec juxtaposition de ballons n’a démontré de bénéfice clinique. Ces échecs peuvent être expliqués par le non-respect de la géométrie fractale des bifurcations qui pourtant doit toujours guider la revascularisation (correction de la malapposition et optimisation de l’ostium de la branche collatérale). Fort de ce constat, nous avons imaginé une nouvelle technique séquentielle et simple, en 3 temps, le rePOT, associant Proximal Optimizing Technique (POT) initial, ouverture de la branche collatérale et POT final. Son évaluations s’est voulue progressive en 4 étapes : 1) concept, 2) preuve expérimentale de concept, 3) confirmation des bénéfices mécaniques in vivo, et 4) validation clinique. Dans ce travail nous avons donc d’abord expérimentalement démontré la supériorité du résultat mécanique final du rePOT par rapport aux techniques non séquentielles de provisional stenting (manuscrit # 1). Ainsi, le rePOT effondre la malapposition globale du stent, conserve la circularité proximale physiologique et optimise l’obstruction ostiale résiduelle de la branche accessoire. Ces excellents résultats sont confirmés indépendamment du design ou de la composition des stents (manuscrits # 2, 4). Nous avons par ailleurs démontré l’importance de chacune des 3 étapes du rePOT: POT initial (manuscrit # 1), ouverture de SB et POT final (manuscrit # 3). Enfin, fort de ces démonstrations expérimentales, nous avons confirmé in vivo avec mesures OCT itératives à la fois les excellents résultats expérimentaux et la bonne évolution clinique à moyen terme (manuscrit # 5). Ce travail démontre donc étape par étape, de l’expérimentale à la clinique, l’ensemble des bénéfices de cette nouvelle technique séquentielle de stenting provisionnel "rePOT", devenue une référence en Europe dans la revascularisation percutanée des bifurcations coronaires / Coronary bifurcations are a preferential location for atherosclerosis development. Until now, no technic with balloons juxtaposition demonstrated a clinical benefit in percutaneous coronary bifurcation revascularization by provisional stenting (with 1 stent). Successive failures could be explained by the absence of respect of the bifurcations fractal geometry, which need to be systematically followed during all revascularization (correction of the malapposition and optimization of the side branch ostium). Thus, we imagined a new technique, simple and sequential, in 3 steps, named rePOT. It is combining initial Proximal Optimizing Technique (POT), side-branch opening and final POT. We proposed a demonstration in 4 steps : 1) concept, 2) experimental proofs of concept, 3) confirmation of the clinical benefits in vivo, and 4) clinical validation. In this work, we experimentally demonstrated the superiority of the final mechanical results of the rePOT compared to all non-sequential provisional stenting (manuscript # 1). Thus, rePOT decreased stent global malapposition, maintained the initial proximal circularity and optimized the final ostial side branch obstruction. These excellent results were confirmed independently of stent design or material (manuscripts # 2, 4). Moreover, we demonstrated the specific benefits of each steps of the rePOT : initial POT (manuscript # 1), SB opening, and final POT (manuscript # 3). Finally, we confirmed in vivo, with serial OCT analysis, these excellent mechanical results and the good clinical outcome at mid-term. (manuscript # 5). Thank to this step by step demonstration, from experimental to clinic, we confirmed all benefits of this new provisional stenting sequential technique "rePOT". Thereby, before the last step of the demonstration, rePOT became a reference in Europe for the percutaneous revascularization of coronary bifurcations

Complicações vasculares do transplante hepático podem causar alterações de perfusão e drenagem do enxerto com prejuízo à sua função, comprometendo a qualidade de vida e a sobrevida do receptor. A angioplastia transluminal percutânea é uma opção de tratamento para estas complicações. No entanto, pela falta de trabalhos dedicados para população pediátrica, não há consenso sobre sua segurança em longo prazo e qual técnica seria a mais adequada. Este estudo teve como objetivo avaliar a resposta terapêutica do tratamento endovascular percutâneo da estenose de veia porta em crianças submetidas ao transplante de fígado. Entre agosto de 2000 e agosto de 2009, foram realizados 254 transplantes hepáticos no Instituto da Criança Professor Pedro de Alcântara do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Quinze delas (5,9%; 15/254) desenvolveram estenose de veia porta com indicação de tratamento. O diagnóstico da lesão foi confirmado pela ultrassonografia em todos os casos. O tratamento da estenose consistiu inicialmente na angioplastia com balão por acesso transparietohepático ao sistema porta, sendo o implante de stent indicado nos casos de estenose residual maior que 30%, ou na recidiva da estenose. A idade média do grupo tratado foi de 4,5 anos ± 2,9 anos (mediana de 3,6 anos) e o peso médio, de 15,3 kg ± 5,7 kg (mediana de 14,6 kg). Dez pacientes (66,7%; 10/15) foram tratados com sucesso por uma única sessão de angioplastia com balão. Outra criança (1/15; 6,7%) foi tratada com sucesso por implante de stent indicado pela estenose residual > 30% após a tentativa de tratamento com balão numa mesma sessão. Outras quatro, inicialmente tratadas por angioplastia com balão (26,7%; 4/15), evoluíram com recidiva da estenose após 19 dias, 2 meses, 8 meses e 2 anos do tratamento e foram submetidas a nova angioplastia, desta vez com implante de stent. O tempo médio de seguimento foi de 7,4 anos ± 2,6 anos (mediana de 7,9 anos) com taxa de perviedade primária foi de 73,3% (11/15) e taxa de perviedade primária assistida, obtida pela reintervenção precoce da re-estenose da veia porta antes de sua obstrução, de 100%. A angioplastia com balão da estenose de veia porta após transplante hepático em crianças demonstrou ser um método seguro e efetivo neste grupo de pacientes no seguimento avaliado. Os casos tratados com stent apresentaram índices semelhantes de segurança e sucesso terapêutico / Vascular complications of liver transplantation can compromise grafts perfusion and drainage affecting its function and recipients quality of life. Percutaneous transluminal angioplasty is an option for these complications. However, especially in children, there is no consensus about its long-term safety and which technique would be most appropriate. This study has the objective to evaluate the therapeutic response of percutaneous endovascular treatment of portal vein stenosis in children submitted to liver transplantation. Between August 2000 and August 2009, 254 liver transplants were performed at the Instituto da Criança - Professor Pedro de Alcântara do Hospital da Clínicas da Faculdade de Medicina da Universidade de São Paulo. Fifteen of them (5.9%, 15/254) developed portal vein stenosis confirmed by ultrasound in all cases. The treatment of the portal vein stenosis consisted initially in balloon angioplasty. The stent was indicated in residual (greater than 30%) or recurrent stenosis. The mean age of the treated group was 4.5 years ± 2.9 years (median 3.6 years) and the mean weight was 15.3 kg ± 5.7 kg (median 14.6 kg). Ten patients (66.7%, 10/15) were successfully treated by a single session of balloon angioplasty. Another child (1/15, 6.7%) was successfully treated by stent due to residual stenosis after balloon angioplasty. Four other children (26.7%, 4/15) developed recurrent stenosis after 19 days, 2 months, 8 months and 2 years of initial treatment with balloon and underwent to a new angioplasty this time, with stent. The primary patency rate was 73.3% (11/15) and the assisted primary patency rate, determined by early intervention before portal vein occlusion, was 100%. Follow-up time was 7.4 years ± 2.6 years (median 7.9 years). Balloon angioplasty of portal vein stenosis after liver transplantation in children demonstrated to be a safe and effective method in this group of patients during the follow-up period of this research. Cases treated with stent had similar rates of safety and therapeutic successes

INTRODUÇÃO: Historicamente, os procedimentos de revascularização do miocárdio (cirúrgicos ou percutâneos) foram admitidos como opções terapêuticas efetivas para a proteção, em curto e médio prazo, do miocárdio isquêmico em pacientes portadores de doença arterial coronária. Todavia, não está estabelecido se tais procedimentos são essenciais para a preservação da função ventricular, nem se a ausência dos mesmos contribui para sua piora. OBJETIVOS: Avaliar a evolução da fração de ejeção (FEVE) em pacientes portadores de doença multiarterial coronariana crônica estável, e com função ventricular esquerda preservada, dez anos após terem sido submetidos a três diferentes estratégias terapêuticas: revascularização cirúrgica do miocárdio (RM), angioplastia coronária percutânea (ATC) ou tratamento medicamentoso (TM) isoladamente (subestudo do MASS II). MÉTODOS: Realizou-se o ecocardiograma transtorácico com doppler para avaliação da FEVE em pacientes portadores de DAC multiaterial estável no início do estudo e após dez anos das intervenções. O cálculo da FEVE foi realizado pelos métodos de Teichholz ou bidimensional. RESULTADOS: Dos 611 pacientes integrantes do estudo MASS II, 422 pacientes estavam vivos ao término de 10,32 (±1,43) anos de seguimento; destes, 108 pacientes do grupo TM, 111 do RM e 131 do ATC realizaram reavaliação ecocardiográfica da função ventricular. As principais características demográficas, clínicas e angiográficas foram semelhantes nos 3 grupos, bem como a ocorrência de infarto agudo do miocárdico (IAM). A FEVE foi semelhante entre os grupos no início do estudo (0,61 + 0,07, 0,61 + 0,08 e 0,61 + 0,09, respectivamente, para os grupos ATC, RM e TM [p=0,675]) e ao término do seguimento (0,56 + 0,11, 0,55 + 0,11 e 0,55 + 0,12, respectivamente, para os grupos ATC, RM e TM [p=0,675]). Observou-se redução da função ventricular (p<0,001) nos três grupos terapêuticos de forma semelhante (p=0,641). Outras variáveis, como gênero, diabetes, idade, padrão arterial, necessidade de ATC ou RM adicionais, não influenciaram a evolução da FEVE. Porém, a ocorrência de IAM foi responsável por acentuada queda da FEVE (delta de decréscimo de 18,29 + 21,22% e 6,63 + 18,91% para pacientes com e sem IAM, respectivamente [p=0,001]). Além disso, a presença de IAM prévio à randomização e IAM durante o seguimento foram associadas a desenvolvimento de disfunção ventricular, definida como FEVE < 45%. CONCLUSÃO: Pacientes do grupo clínico portadores de DAC multiarterial desprotegida pelas estratégias de revascularização não apresentaram prejuízo adicional na função ventricular em comparação ao observado nos grupos cirúrgico e angioplastia. Além disso, qualquer que tenha sido a estratégia terapêutica aplicada, a função ventricular permaneceu preservada na ausência de infarto agudo do miocárdio / BACKGROUND: Historically, myocardial revascularization procedures, either by coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI), are assumed as effective therapeutic options for the protection of the ischemic myocardium. However, it is not established if those procedures are responsible for left ventricular function preservation, or even if their absence may contribute for the deterioration of left ventricular ejection fraction (LVEF). OBJECTIVES: to evaluate the evolution of LVEF in patients with chronic multivessel coronary heart disease and left ventricular function initially preserved, submitted to CABG, PCI or medical treatment (MT), after ten years of follow-up (MASS II substudy). METHODS: Transthoracic echocardiography was performed in patients with multivessel coronary heart disease, participants of MASS II trial, previously to randomization for one of the three possible therapeutic strategies (CABG, PCI and MT), and after 10 years of follow-up. LVEF was measured by the biplane method (Simpson) or alternatively by the Teichholz method. RESULTS: Of the 611 patients participants of MASS II trial, 422 were alive after a follow-up of 10.32 (±1.43) years. 350 had LVEF reassessed: 108 patients in MT group, 111 in CABG group and 131 in PCI group. Main baseline characteristics were similar among the three groups, including demographic, angiographic and laboratorial findings. The occurrence of acute myocardial infarction (AMI) was also similar among the 3 groups. There was no difference of LVEF either at the beginning (0.61 + 0.07, 0.61 + 0.08 e 0.61 + 0.09 respectively for PCI, CABG and MT, p=0.675) and the end of follow up (0.56 + 0.11, 0.55 + 0.11 e 0.55 + 0.12 respectively for PCI, CABG and MT groups, p=0.675). However, there was a slight, but significant reduction (P<0.001) of LVEF, similar on the three therapeutic groups (p=0.641). The impact of other variables over LVEF evolution, such as gender, age, diabetes, arterial pattern (including, left anterior descending coronary artery commitment) and additional revascularization, were also analyzed, with no influence on the evolution of LVEF. However, the presence of previous AMI (OR 2.50, 95% CI 1.40-4.45; p= 0.0007) and the occurrence of AMI during follow up (OR 2.73, 95% IC 1.25- 5.92; p=0.005) were associated with an increased risk of developing LVEF < 45%. Also, AMI during follow-up was responsible for a greater reduction of LVEF (reduction delta of 18.29 ± 21.22% and 6.63 ± 18.91%, respectively for patients with and without AMI during follow-up, p=0.001). CONCLUSION: Compared with PCI or CABG, the Medical group, with unprotected coronary disease by mechanical revascularization, showed no differences in left ventricular function after 10 years of follow-up. Moreover, regardless of therapeutic strategy applied, ventricular function remained preserved without AMI