Introdução: Entre pacientes portadores de doença arterial coronária (DAC), o Diabetes mellitus indica um pior prognóstico. A associação com doença renal crônica parece conferir risco cardiovascular adicional a essa população. Há poucos estudos comparando os diferentes tratamentos para DAC na população de diabéticos com insuficiência renal crônica (IRC). Objetivo: Comparar diferentes tratamentos para DAC em uma população portadora de diabetes tipo 2 estratificada por níveis de função renal. Métodos: Estudo observacional, prospectivo do tipo registro, selecionou do Registro Geral do Grupo MASS pacientes portadores de Diabetes tipo 2 com doença coronariana crônica submetidos aos tratamentos medicamentoso exclusivo (TM), cirúrgico (CRM) ou percutâneo (ICP). Todos os pacientes eram portadores de doença coronária multiarterial, função ventricular preservada, sendo a função renal estimada pelo método de Cockroft-Gault e grupada em três estratos: 1) função renal preservada (clearance de creatinina > 90 mL/min), 2) IRC discreta (60-89 mL/min) e 3) IRC moderada (30-59 mL/min). Os desfechos primários foram uma combinação de morte, infarto do miocárdio não fatal ou necessidade de intervenções adicionais. Resultados: Foram selecionados em um período entre 1995 e 2010, 763 pacientes, com seguimento médio de 5,4 anos e alocados em três estratos: estrato 1 (N=270) foi formado por 122 pacientes submetidos à CRM, 72 submetidos à ICP e 76 submetidos ao TM; estrato 2 (N=367), composto por 167 pacientes submetidos à CRM, 92 submetidos à ICP e 108 submetidos ao TM; estrato 3 (N=126), composto por 46 pacientes submetidos à CRM, 40 pacientes submetidos à ICP e 40 pacientes submetidos ao TM. As taxas de sobrevivência livres de eventos foram 80,4%, 75,7% e 67,5% para os estratos 1, 2 e 3 respectivamente (P=0,037). As taxas de sobrevivência entre os pacientes dos estratos 1, 2 e 3 foram 91,1%, 89,6% e 76,2%, respectivamente (P=0,001) (HR:0,69; 0,51-0,95; P=0,024 para estrato 1 versus 3). Comparando-se as estratégias terapêuticas dentro de cada estrato, observou-se similaridade nas taxas de morte ou infarto em todos os estratos. Por outro lado, observou-se uma menor taxa de revascularização adicional em indivíduos submetidos a CRM (P < 0,001, P < 0,001 e P=0,029 para os estratos 1, 2 e 3, respectivamente). Uma maior mortalidade foi encontrada entre os estratos 3 e 2 no grupo CRM (HR: 0,42; 0,18-0,99; P=0,04). Conclusão: Comparados com pacientes com função renal preservada, pacientes portadores de IRC evoluem com maior incidência de mortalidade independente da estratégia terapêutica. Por outro lado, o tratamento medicamentoso alcançou os mesmos índices de eventos cardiovasculares quando comparados com a intervenção cirúrgica ou percutânea. Em contrapartida, a intervenção cirúrgica conferiu menor incidência de reintervenção, independente da condição renal / Introduction: Diabetes Mellitus is a risk factor associated with worse prognosis in patients with croronary artery disease (CAD). Some studies have demonstrated that this prognosis has additional risk when associated with chronic kidney disease. There are few data available comparing different therapies for multivessel CAD among patients with diabetes and CKD in a long-term follow-up. Objective: To compare three different therapeutic strategies for CAD among diabetic patients stratified by renal function. Methods: This is a prospective, registry-based and single center study that enrolled patients from the MASS Group Registry. Type 2 diabetic patients with multivessel CAD were allocated to three different treatment strategies: coronary artery bypass graft (CABG), angioplasty (PCI), and optimized medical therapy alone (MT). Data were analyzed according to estimated glomerular filtration rate in 3 strata: normal (> 90mL/min), mild CKD (60- 89mL/min), and moderate CKD (30-59mL/min). Primary endpoint was combined of overall mortality, acute myocardial infarction (AMI) and need for additional revascularization. Multivariate Cox proportional hazard survival analysis was performed to assess whether the associations of groups with all-cause mortality and other end points considered was independent of potential confounders. Demographic and clinical variables, as well as treatment applied were included in the analysis. Results: From 1995 to 2010, patients enrolled (N=763) were followed for a mean time of 5.4 years. Among normal renal function patients (N=270), 122 underwent CABG, 72 PCI, and 76 MT; among mild CKD patients (N=367), 167 underwent CABG, 92 PCI, an d108 MT; and for moderate CKD patients (N=126), 46 underwent CABG, 40 PCI, and 40 MT. Survival free of events were 80.4%, 75.7% e 67.5% for strata 1, 2 and 3 respectively (P=0.037). Survival rates among patients with no, mild, and moderate CKD are respectively 91.1%, 89.6%, and 76.2% (P=0.001) (HR:0.69; 0.51-0.95; P=0.024 for stratum 1 versus 3). Comparing treatment strategies in patients according to the renal function strata, we found no differences regarding overall mortality or AMI irrespective of strata. On the other hand, the need of additional revascularization was different in all strata, favoring CABG group (P < 0.001, P < 0.001, and P=0.029 for no, mild, and moderate CKD respectively). Comparing different strata of renal function among treatments we found a higher risk of death among moderate CKD subjects compared to mild CKD (HR:0.42; 0.18-0.99; P=0.04) in CABG group. Conclusion: Among diabetic patients with CAD, mortality rates were higher among patients with CKD. Nevertheless, revascularization procedures groups had similar rates of cardiovascular events compared to MT alone, except for less need of additional revascularization in CABG group in all renal function strata

No description available.

Mild cognitive deficits that negatively impact self-management education-related outcomes may be present in a proportion of cardiac rehabilitation patients and the degree of impairment may vary by the type of coronary revascularization procedure. The purpose of this study was to compare cognitive function, as measured by the Montreal Cognitive Assessment (MoCA), between coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) patients, and to determine independent variables of MoCA score. In a cross-sectional study, 78 cardiac rehabilitation patients (CABG n = 38, PCI n = 40) completed the MoCA. Demographics were collected and disease burden was calculated using the age-adjusted Charlson Comorbidity Index (ACCI). Mild cognitive deficits (MoCA ≤26) were present in 55.3% CABG and 30.0% PCI patients. An independent Student’s t test showed that MoCA scores were significantly lower among CABG patients (mean = 24.5, SD = 3.3) compared to PCI patients (M = 26.7, SD = 2.7), t (76) = 3.15, p < 0.01. Descriptive analyses of cognitive domain scores indicated that deficits in short-term memory and language were present among CABG patients. Using a backward regression, coronary revascularization procedure (CABG vs. PCI) (p = 0.006) and disease burden (ACCI) (p = 0.015) remained significant, while heart failure diagnosis became non-significant and was removed from the model (F (2, 75) = 8.382, p < 0.001). The final model explained 16.1% of the total variance in MoCA score (adjusted R2 = 0.161). Results indicate that cognitive deficits were present in cardiac rehabilitation participants and associated with the type of coronary revascularization procedure, suggesting the need for formal cognitive screening and adaptation of education interventions in cardiac rehabilitation. A future prospective cohort study is required to establish temporality, and to measure education-related outcomes, such as health-related quality of life (HRQOL) and self-management. / Thesis / Master of Science (MSc) / Cardiac rehabilitation (CR) is a multifaceted program consisting of exercise and education that is essential to the care of post-coronary revascularization patients. While exercise has shown to improve health outcomes, education has demonstrated inconsistent effects. Since education has imposed cognitive demands, this discrepancy in outcomes may, in part, be due to cognitive deficits present in a proportion of program attendees: the degree of impairment may vary by type of coronary revascularization procedure prior to CR. This study compared cognitive function between two groups of coronary revascularization patients, post-coronary bypass surgery and post-coronary angioplasty, and determined independent variables for cognitive function. Results showed that coronary bypass surgery patients had significantly lower cognitive function than coronary angioplasty patients at program intake. Coronary bypass surgery and accumulated disease burden were weakly associated with decreased cognitive function. Cognitive screening and adapted education for patients with cognitive deficits should be considered to improve CR outcomes.

Mais informações são necessárias para definir se o tratamento percutâneo da coartação da aorta com stents é superior à angioplastia com cateter-balão. De julho de 2000 a maio de 2003, 21 adolescentes e adultos com coartação da aorta focal e média de idade de 24 anos (DP 11 anos) foram submetidos, consecutivamente, a implante de stents (grupo 1). Os resultados foram comparados com os obtidos em um grupo histórico de 15 pacientes com média de idade de 18 anos (DP 10 anos) (p = 0,103) submetidos a angioplastia (grupo 2) nos últimos 18 anos. Após o procedimento, a redução do gradiente sistólico foi maior (99% [DP 2%] versus 87% [DP 17%]; p = 0,015), o gradiente residual foi menor (0,4 mmHg [DP 1,4 mmHg] versus 5,9 mmHg [DP 7,9 mmHg]; p = 0,019), o ganho no local da coartação foi maior (333% [DP 172%] \"versus\" 190% [DP 104%]; p = 0,007) e o diâmetro da coartação foi maior (16,9 mm [DP 2,9 mm] versus 12,9 mm [DP 3,2 mm]; p < 0,001) no grupo 1. Alterações da parede da aorta, incluindo dissecções, abaulamentos e aneurismas, foram observadas em oito pacientes do grupo 2 (53%) e em um do grupo 1 (7%) (p < 0,001). Não houve complicações maiores. Cateterismo (n = 33) ou ressonância magnética (n = 2) de controle foram realizados em seguimento mediano de um ano para o grupo 1 e um ano e meio para o grupo 2 (p = 0,005). A redução do gradiente sistólico persistiu em ambos os grupos; entretanto, gradientes tardios mais altos foram observados no grupo 2 (mediana de 0 mmHg para o grupo 1 versus 3 mmHg para o grupo 2; p = 0,014). Não houve perdas no diâmetro da coartação no grupo 1 e houve ganho tardio no grupo 2 (16,7 mm [DP 2,9 mm] versus 14,6 mm [DP 3,9 mm]; p = 0,075). No grupo 1, dois pacientes necessitaram de novo implante de stent em decorrência da formação de aneurisma ou fratura da malha do stent. No grupo 2, as anormalidades da parede aórtica não progrediram e um paciente necessitou de redilatação em decorrência da recoartação. A pressão arterial sistêmica foi semelhante em ambos os grupos durante o seguimento (sistólica: 126 mmHg [DP 12 mmHg] no grupo 1 versus 120 mmHg [DP 15 mmHg] no grupo 2; diastólica: 81 mmHg [DP 11 mmHg] no grupo 1 versus 80 mmHg [DP 10 mmHg] no grupo 2; p = 0,149 e p = 0,975, respectivamente). Apesar de os desfechos clínicos terem sido satisfatórios e similares com ambas as técnicas, o uso de stents propiciou resultados mais previsíveis e uniformes para alívio da estenose, minimizando também o risco de desenvolvimento de alterações da parede da aorta. / More information is needed to define whether stenting is superior to balloon angioplasty for coarctation of the aorta. From July/2000 to May/2003, 21 adolescents and adults with discrete coarctation underwent consecutive stent implantation at a mean age of 24 years (SD 11 years) (group 1). The results were compared to those achieved by balloon angioplasty performed in the last 18 years in a historical group of 15 patients at a mean age of 18 years (SD 10 years) (p = 0.103) (group 2). After the procedure, systolic gradient reduction was higher (99% [SD 2%] vs. 87% [SD 17%]; p = 0.015), residual gradients lower (0.4 mmHg [SD 1.4 mmHg] vs. 5.9 mmHg [SD 7.9 mmHg); p = 0.019), gain at the coarctation site higher (333% [SD 172%] vs. 190% [SD 104%]; p = 0.007) and coarctation diameter larger (16.9 mm [SD 2.9 mm] vs.12.9 mm [SD 3.2 mm]; p < 0.001) in group 1. Aortic wall abnormalities, including dissections, bulges and aneurysms, were observed in eight patients in group 2 (53%) and in one in group 1 (7%) (p < 0.001). There was no major complication. Repeat catheterization (n = 33) or magnetic resonance imaging (n = 2) was performed at a median follow-up of 1.0 year for group 1 and 1.5 year for group 2 (p = 0.005). Gradient reduction persisted in both groups, although higher late gradients were observed in group 2 (median of 0 mmHg for group 1 vs. 3 mmHg for group 2; p = 0.014). There was no late loss in the coarctation diameter in group 1 and there was a late gain in group 2 (16.7 mm [SD 2.9 mm] for group 1 vs. 14.6 mm [SD 3.9 mm] for group 2; p = 0.075). Two patients required late stenting due to aneurysm formation or stent fracture in group 1. Aortic wall abnormalities did not progress and one patient required redilation due to recoarctation in group 2. Blood pressure was similar in both groups at follow-up (systolic: 126 mmHg [SD 12 mmHg] in group 1 vs. 120 mmHg [SD 15 mmHg] in group 2; diastolic: 81 mmHg [SD 11 mmHg] in group 1 vs. 80 mmHg [SD 10 mmHg] in group 2; p = 0.149 and p = 0.975, respectively). Although satisfactory and similar clinical outcomes were observed with both techniques, the use of stents yielded more predictable and uniform results for stenosis relief, also minimizing the risk of developing aortic wall abnormalities.

No description available.

Mais informações são necessárias para definir se o tratamento percutâneo da coartação da aorta com stents é superior à angioplastia com cateter-balão. De julho de 2000 a maio de 2003, 21 adolescentes e adultos com coartação da aorta focal e média de idade de 24 anos (DP 11 anos) foram submetidos, consecutivamente, a implante de stents (grupo 1). Os resultados foram comparados com os obtidos em um grupo histórico de 15 pacientes com média de idade de 18 anos (DP 10 anos) (p = 0,103) submetidos a angioplastia (grupo 2) nos últimos 18 anos. Após o procedimento, a redução do gradiente sistólico foi maior (99% [DP 2%] versus 87% [DP 17%]; p = 0,015), o gradiente residual foi menor (0,4 mmHg [DP 1,4 mmHg] versus 5,9 mmHg [DP 7,9 mmHg]; p = 0,019), o ganho no local da coartação foi maior (333% [DP 172%] \"versus\" 190% [DP 104%]; p = 0,007) e o diâmetro da coartação foi maior (16,9 mm [DP 2,9 mm] versus 12,9 mm [DP 3,2 mm]; p < 0,001) no grupo 1. Alterações da parede da aorta, incluindo dissecções, abaulamentos e aneurismas, foram observadas em oito pacientes do grupo 2 (53%) e em um do grupo 1 (7%) (p < 0,001). Não houve complicações maiores. Cateterismo (n = 33) ou ressonância magnética (n = 2) de controle foram realizados em seguimento mediano de um ano para o grupo 1 e um ano e meio para o grupo 2 (p = 0,005). A redução do gradiente sistólico persistiu em ambos os grupos; entretanto, gradientes tardios mais altos foram observados no grupo 2 (mediana de 0 mmHg para o grupo 1 versus 3 mmHg para o grupo 2; p = 0,014). Não houve perdas no diâmetro da coartação no grupo 1 e houve ganho tardio no grupo 2 (16,7 mm [DP 2,9 mm] versus 14,6 mm [DP 3,9 mm]; p = 0,075). No grupo 1, dois pacientes necessitaram de novo implante de stent em decorrência da formação de aneurisma ou fratura da malha do stent. No grupo 2, as anormalidades da parede aórtica não progrediram e um paciente necessitou de redilatação em decorrência da recoartação. A pressão arterial sistêmica foi semelhante em ambos os grupos durante o seguimento (sistólica: 126 mmHg [DP 12 mmHg] no grupo 1 versus 120 mmHg [DP 15 mmHg] no grupo 2; diastólica: 81 mmHg [DP 11 mmHg] no grupo 1 versus 80 mmHg [DP 10 mmHg] no grupo 2; p = 0,149 e p = 0,975, respectivamente). Apesar de os desfechos clínicos terem sido satisfatórios e similares com ambas as técnicas, o uso de stents propiciou resultados mais previsíveis e uniformes para alívio da estenose, minimizando também o risco de desenvolvimento de alterações da parede da aorta. / More information is needed to define whether stenting is superior to balloon angioplasty for coarctation of the aorta. From July/2000 to May/2003, 21 adolescents and adults with discrete coarctation underwent consecutive stent implantation at a mean age of 24 years (SD 11 years) (group 1). The results were compared to those achieved by balloon angioplasty performed in the last 18 years in a historical group of 15 patients at a mean age of 18 years (SD 10 years) (p = 0.103) (group 2). After the procedure, systolic gradient reduction was higher (99% [SD 2%] vs. 87% [SD 17%]; p = 0.015), residual gradients lower (0.4 mmHg [SD 1.4 mmHg] vs. 5.9 mmHg [SD 7.9 mmHg); p = 0.019), gain at the coarctation site higher (333% [SD 172%] vs. 190% [SD 104%]; p = 0.007) and coarctation diameter larger (16.9 mm [SD 2.9 mm] vs.12.9 mm [SD 3.2 mm]; p < 0.001) in group 1. Aortic wall abnormalities, including dissections, bulges and aneurysms, were observed in eight patients in group 2 (53%) and in one in group 1 (7%) (p < 0.001). There was no major complication. Repeat catheterization (n = 33) or magnetic resonance imaging (n = 2) was performed at a median follow-up of 1.0 year for group 1 and 1.5 year for group 2 (p = 0.005). Gradient reduction persisted in both groups, although higher late gradients were observed in group 2 (median of 0 mmHg for group 1 vs. 3 mmHg for group 2; p = 0.014). There was no late loss in the coarctation diameter in group 1 and there was a late gain in group 2 (16.7 mm [SD 2.9 mm] for group 1 vs. 14.6 mm [SD 3.9 mm] for group 2; p = 0.075). Two patients required late stenting due to aneurysm formation or stent fracture in group 1. Aortic wall abnormalities did not progress and one patient required redilation due to recoarctation in group 2. Blood pressure was similar in both groups at follow-up (systolic: 126 mmHg [SD 12 mmHg] in group 1 vs. 120 mmHg [SD 15 mmHg] in group 2; diastolic: 81 mmHg [SD 11 mmHg] in group 1 vs. 80 mmHg [SD 10 mmHg] in group 2; p = 0.149 and p = 0.975, respectively). Although satisfactory and similar clinical outcomes were observed with both techniques, the use of stents yielded more predictable and uniform results for stenosis relief, also minimizing the risk of developing aortic wall abnormalities.

<p>Cilj: Kod trećine bolesnika sa akutnim ST-eleviranim infarktom (STEMI) nakon primarne angioplastike (pPCI) razvije se postinfarktno remodelovanje leve komore (LK). Cilj istraživanja je nalaženje ranih prediktora post-infarktnog remodelovanja leve komore nakon akutnog STEMI i pPCI. Metodologija: Uključeno je 210 ispitanika sa prvim akutnim STEMI prednjeg zida, lečenih pPCI. Urađena je ehokardiografija u prva 24h, a zatim nakon 6 meseci, kada su ispitanici podeljeni u 2 grupe: ispitivanu sa remodelovanjem (n=55; 26%) i kontrolnu bez remodelovanja (n=155; 74%). Ispitanici su klinički praćeni godinu dana. Rezultati i dikusija: Multivarijantnom regresionom analizom, kao najsnažniji rani prediktori post-infarktnog remodelovanja izdvojili su se: postojanje &quot;no reflow&quot; fenomena nakon pPCI (OR=30.0 95% CI, p&lt;0.0001), pojava dijastolne disfunkcije u prva 24h (OR=27.7 95% CI, p&lt;0.0001), povećan dijametar leve pretkomore - LA (OR=5.0 95% CI, p=0,044) i srčana slabost na prijemu - Killip klasa 2-4 (OR=3.4 95% CI, p=0.003.). Univarijantnom regresionom analizom, snažni prediktori su neadekvatna rezolucija ST segmenta - STR (OR 2.0 95% CI, p=0.024) i zbirni indeks zidne pokretljivosti &ndash; WMSI &gt;2 (OR 21.6 95% CI, p&lt;0.0001). Totalno ishemijsko vreme nije imalo uticaja na post-infarktno remodelovanje (p=0.546). Tokom jednogodi&scaron;njeg praćenja ispitanici sa post-infarktnim remodelovanjem su imali značajno veću incidencu glavnih neželjenih kardiolo&scaron;kih događaja: rehospitalizacija (61.8% vs 22.6%; p&lt;0.0001) / najvi&scaron;e rehospitalizacija zbog srčane slabosti (40% vs 2.6%; p&lt;0.0001), sa mortalitetom 5.5%/; reinfarkta (20% vs 7.1%; p=0.007); rekoronarografija (45.5% vs 18.1%; p&lt;0.0001); revaskularizacija (30.9% vs 11%; p=0.001). Zaključak: Kod pacijenata sa akutnim STEMI prednjeg zida lečenih pPCI, pojava &quot;no reflow&quot; fenomena, dijastolne disfunkcije, povećana LA i srčana slabosti na prijemu su najjači rani nezavisni prediktivni faktori za nastanak post-infarktnog remodelovanja. Značajni prediktori su i neadekvatna STR i WMSI&gt;2. Pacijenti sa post-infarktnim remodelovanjem imaju veću incidencu glavnih neželjenih kardiolo&scaron;kih događaja i mortaliteta.</p> / <p>Objective: Patients with ST-elevated myocardial infarction (STEMI) treated by primary angioplasty (pPCI) will develop left ventricular (LV) remodeling in one third of the cases. The purpose of this study is to determine early predictors of LV remodeling after acute STEMI and pPCI. Methods: 210 patients with a first acute anterior STEMI treated by pPCI were included. All participants underwent echocardiography in the first 24hrs and again after 6 months, after which they were divided into two groups: remodeling (n=55; 26%) and nonremodeling (n=155; 74%). Results and discussion: The most powerful independent early predictors were: &quot;no reflow&quot; after pPCI (OR=30.0 95% CI, p&lt;0.0001), diastolic dysfunction in the first 24hrs (OR=27.7 95% CI, p&lt;0.0001), increased diameter of the left atrium - LA (OR=5.0 95% CI, p=0.044) and at admission Killip class 2-4 (OR=3.4 95% CI, p=0.003), by multivariant regression analysis. Also, strong predictors were incomplete ST-resolution - STR (OR 2.0 95% CI, p=0.024) and Wall motion score index - WMSI &gt;2 (OR 21.6 95% CI, p&lt;0.0001), by univariant regression analysis. Total ischaemic time had no influence on LV remodeling. The group with remodeling had more frequent major adverse cardiac events (MACE) during one year follow-up: re-hospitalisation (61.8% vs 22.6%; p&lt;0.0001) / mostly re-hospitalisation due to heart failure (40% vs 2.6%; p&lt;0.0001) and mortality 5.5%; reinfarction (20% vs 7.1%; p=0.007); recoronagraphy (45.5% vs 18.1%; p&lt;0.0001); revascularisation (30.9% vs 11%; p=0.001). Conclusion: For the patients with a first acute anterior STEMI, treated by pPCI, development of &quot;no reflow&quot; after pPCI, diastolic dysfunction, increased LA and heart failure on admission are the most powerful early independent predictors for LV remodeling. Incomplete STR and WMSI&gt;2 are strong predictors too. Remodeling patients will have a more frequent incidence of MACE and mortality.</p>

Une fistule artérioveineuse (FAV) est un accès vasculaire permanent créé par voie chirurgicale en connectant une veine et une artère chez le patient en hémodialyse. Cet accès vasculaire permet de mettre en place une circulation extracorporelle partielle afin de remplacer les fonctions exocrines des reins. En France, environ 36000 patients sont atteint d’insuffisance rénale chronique en phase terminale, stade de la maladie le plus grave qui nécessite la mise en place d’un traitement de suppléance des reins : l’hémodialyse. La création et présence de la FAV modifient significativement l’hémodynamique dans les vaisseaux sanguins, au niveau local et systémique ainsi qu’à court et à plus long terme. Ces modifications de l’hémodynamiques peuvent induire différents pathologies vasculaires, comme la formation d’anévrysmes et de sténoses. L’objectif de cette étude est de mieux comprendre le comportement mécanique et l’hémodynamique dans les vaisseaux de la FAV. Nous avons étudié numériquement les interactions fluide-structure (IFS) au sein d’une FAV patient-spécifique, dont la géométrie a été reconstruite à partir d’images médicales acquises lors d’un précédent doctorat. Cette FAV a été créée chez le patient en connectant la veine céphalique du patient à l’artère radiale et présente une sténose artérielle réduisant de 80% la lumière du vaisseau. Nous avons imposé le profil de vitesse mesuré sur le patient comme conditions aux limites en entrée et un modèle de Windkessel au niveau des sorties artérielle et veineuse. Nous avons considéré des propriétés mécaniques différentes pour l’artère et la veine et pris en compte le comportement non-Newtonien du sang. Les simulations IFS permettent de calculer l’évolution temporelle des contraintes hémodynamiques et des contraintes internes à la paroi des vaisseaux. Nous nous sommes demandées aussi si des simulations non couplées des équations fluides et solides permettaient d’obtenir des résultats suffisamment précis tout en réduisant significativement le temps de calcul, afin d’envisager son utilisation par les chirurgiens. Dans la deuxième partie de l’étude, nous nous sommes intéressés à l’effet de la présence d’une sténose artérielle sur l’hémodynamique et en particulier à ses traitements endovasculaires. Nous avons dans un premier temps simulé numériquement le traitement de la sténose par angioplastie. En clinique, les sténoses résiduelles après angioplastie sont considérées comme acceptables si elles obstruent moins de 30% de la lumière du vaisseau. Nous avons donc gonflé le ballonnet pour angioplastie avec différentes pressions de manière à obtenir des degrés de sténoses résiduelles compris entre 0 et 30%. Une autre possibilité pour traiter la sténose est de placer un stent après l’angioplastie. Nous avons donc dans un deuxième temps simulé ce traitement numériquement et résolu le problème d’IFS dans la fistule après la pose du stent. Dans ces simulations, la présence du stent a été prise en compte en imposant les propriétés mécaniques équivalentes du vaisseau après la pose du stent à une portion de l’artère. Dans la dernière partie de l’étude nous avons mis en place un dispositif de mesure par PIV (Particle Image Velocimetry). Un moule rigide et transparent de la géométrie a été obtenu par prototypage rapide. Les résultats expérimentaux ont été validés par comparaison avec les résultats des simulations numériques. / An arteriovenous fistula (AVF) is a permanent vascular access created surgically connecting a vein onto an artery. It enables to circulate blood extra-corporeally in order to clean it from metabolic waste products and excess of water for patients with end-stage renal disease undergoing hemodialysis. The hemodynamics results to be significantly altered within the arteriovenous fistula compared to the physiological situation. Several studies have been carried out in order to better understand the consequences of AVF creation, maturation and frequent use, but many clinical questions still lie unanswered. The aim of the present study is to better understand the hemodynamics within the AVF, when the compliance of the vascularwall is taken into account. We also propose to quantify the effect of a stenosis at the afferent artery, the incidence of which has been underestimated for many years. The fluid-structure interactions (FSI) within a patient-specific radio-cephalic arteriovenous fistula are investigated numerically. The considered AVF presents an 80% stenosis at the afferent artery. The patient-specific velocity profile is imposed at the boundary inlet, and a Windkessel model is set at the arterial and venous outlets. The mechanical properties of the vein and the artery are differentiated. The non-Newtonian blood behavior has been taken into account. The FSI simulation advantageously provides the time-evolution of both the hemodynamic and structural stresses, and guarantees the equilibrium of the solution at the interface between the fluid and solid domains. The FSI results show the presence of large zones of blood flow recirculation within the cephalic vein, which might promote neointima formation. Large internal stresses are also observed at the venous wall, which may lead to wall remodeling. The fully-coupled FSI simulation results to be costly in computational time, which can so far limit its clinical use. We have investigated whether uncoupled fluid and structure simulations can provide accurate results and significantly reduce the computational time. The uncoupled simulations have the advantage to run 5 times faster than the fully-coupled FSI. We show that an uncoupled fluid simulation provides informative qualitative maps of the hemodynamic conditions in the AVF. Quantitatively, the maximum error on the hemodynamic parameters is 20%. The uncoupled structural simulation with non-uniform wall properties along the vasculature provides the accurate distribution of internal wall stresses, but only at one instant of time within the cardiac cycle. Although partially inaccurate or incomplete, the results of the uncoupled simulations could still be informative enough to guide clinicians in their decision-making. In the second part of the study we have investigated the effects of the arterial stenosis on the hemodynamics, and simulated its treatment by balloon-angioplasty. Clinically, balloon-angioplasty rarely corrects the stenosis fully and a degree of stenosis remains after treatment. Residual degrees of stenosis below 30% are considered as successful. We have inflated the balloon with different pressures to simulate residual stenoses ranging from 0 to 30%. The arterial stenosis has little impact on the blood flow distribution: the venous flow rate remains unchanged before and after the treatment and thus permits hemodialysis. But an increase in the pressure difference across the stenosis is observed, which could cause the heart work load to increase. To guarantee a pressure drop below 5 mmHg, which is considered as the threshold stenosis pressure difference clinically, we find that the residual stenosis degree must be 20% maximum.

INTRODUÇÃO: A angioplastia carotídea com stent (ACS) sob proteção cerebral é opção terapêutica em pacientes com estenose carotídea. Existe o risco de embolia apesar da utilização do filtro e as modificações na perfusão cerebral após tratamento da estenose carotídea não são claras. O propósito deste estudo é avaliar, após ACS sob proteção cerebral por filtros, modificações nas seqüências de RM de difusão (DWI) e perfusão (PWI), correlacionando-as com os aspectos técnicos da ACS, com as características da estenose e com dados demográficos dos pacientes. MÉTODO: Trinta e seis pacientes portadores de estenose carotídea com idade média de 72,08 anos foram submetidos a exame de RM um dia antes e até 72 horas após a ACS com filtro de proteção. Todos os pacientes eram assintomáticos após a ACS. Áreas de restrição na DWI após a ACS foram correlacionadas com aspectos demográficos, com aspectos da técnica de angioplastia e com a presença de infartos prévios por RM. Os parâmetros CBV volume sanguíneo cerebral, MTT tempo de trânsito médio e TTP tempo para o pico são empregados para análise por PWI. RESULTADOS: Na DWI, 18 de 36 (50,00%) pacientes apresentaram novos focos (NF) de restrição na DWI após ACS. Todos os NF foram clinicamente silenciosos (100%). Estes NF eram localizados em território cerebral nutrido pela artéria carótida submetida à ACS em 77,19% e menores que 10 mm em 91,53%. Os NF em território cerebral não irrigado pela artéria carótida submetida à angioplastia correspondiam a 22,81% destes. A presença de infartos cerebrais prévios na RM foi o único fator com influência no aparecimento de NF (p=0,037). Fatores demográficos e aspectos relacionados com a técnica de angioplastia não tiveram importância na gênese dos NF. Na PWI foi observada melhora nos parâmetros temporais TTP (p<0,001) e MTT (p=0,019) quando comparados de forma normalizada em relação ao território contralateral. CONCLUSÃO: Os novos focos de restrição na DWI após ACS (NF) foram mais comuns no território ipsilateral (77,19%), no entanto houve NF no território contralateral à ACS (22,81%), possivelmente, associados ao cateterismo diagnóstico. Os NF, na sua maioria, são de pequeno diâmetro (<10 mm em 91,53%). Melhora precoce na PWI, observada nos dados normalizados, foi demonstrada nos parâmetros temporais (TTP e MTT). / INTRODUCTION: Carotid angioplasty with stent (CAS) under cerebral protection is a therapeutic option in patients with carotid stenosis. There is a risk of embolism even with a filter, and changes in cerebral perfusion after treatment are not clearly understood. The purpose of this study was to evaluate changes in diffusion- (DWI) and perfusion- (PWI) weighted magnetic resonance imaging (MRI) sequences correlating them with the technical aspects of CAS, stenosis characteristics and patient demographic data. METHODS: Thirty-six carotid stenosis patients with an mean age of 72.08 years were submitted to MRI exam one day before and up to 72 hours after CAS with filter protection. All patients were asymptomatic after CAS. Areas of restriction on DWI were correlated to demographic aspects, technique of angioplasty as well the presence of previous stroke by MRI. The parameters, CBV - cerebral blood volume; MTT - mean transit time, and TTP- time to peak, are used for PWI analysis. RESULTS: Eighteen of the 36 patients (50.00%) presented new focus (NF) of restriction by DWI after CAS. All new focus were clinically silent. The NF were located in the cerebral area fed by the carotid artery submitted to CAS in 77.19% and smaller than 10mm in 91.53%. NF in cerebral area not irrigated by carotid artery submitted by angioplasty correspond to 22,81 %. The presence of previous ischemic lesion on MRI was the only factor which influenced the appearance of NF (p=0.037). Demographic factors and aspects related to angioplasty technique had no importance on NF genesis. Improvement in PWI timing parameters - TTP (p<0.001) and MTT (p=0.019) were observed in relation to the contralateral territory (normalized data). CONCLUSION: The restriction NF in the DWI after CAS are more common in the ipsilateral territory (77.19%), however there were some NF in the contralateral territory to the CAS (22.81%), possibly associated with diagnostic catheterization. Most of the NF were small in diameter (<10mm in 91.53%). Short-term improvement in PWI were demonstrated by normalized timing parameters (TTP and MTT).

Introdução: Análise da custo-efetividade no tratamento da doença multiarterial coronária têm ganhado importância nos ensaios clínicos, uma vez que as principais opções terapêuticas: cirurgia de revascularização miocárdica (CRM), intervenção coronária percutânea (ICP) e tratamento medicamentoso (TM) apresentam eficácia similar em determinados subgrupos de pacientes. Atualmente os interesses direcionados à análise econômica têm crescido, uma vez que os gastos na saúde aumentaram com o desenvolvimento de novas tecnologias, porém os recursos disponíveis são finitos e merecem ser administrados. Objetivo: Analisar, prospectivamente, o custo comparativo das três formas terapêuticas da doença multiarterial coronária estável, durante dez anos de seguimento. Métodos: Foi computado o custo terapêutico global de 611 pacientes do ensaio clínico The Second Medicine, Angioplasty, or Surgery Study (MASS II), baseado na remuneração fornecida pelo sistema de saúde suplementar do Instituto do Coração do HC/FMUSP, utilizando valores em dólares. Posteriormente, a análise de custoefetividade foi realizada corrigindo o custo cumulativo obtido em cada grupo para o \"tempo livre de eventos clínicos\" e também para a combinação de \"tempo livre de eventos\" acrescido de \"tempo livre de angina\". Resultados: O TM apresentou um custo cumulativo ao final de dez anos de US$6.183; o ICP apresentou um custo de US$14.292; e o grupo CRM apresentou um custo de US$12.316. Os custos corrigidos para sobrevida livre de eventos foram, US$11.136 para TM; US$26.912 para ICP e US$17.883 para CRM. Houve diferença estatisticamente significativa entre os 3 grupos (p < 0,0001) e a análise pareada, mostrou um menor custo para o grupo tratamento clínico tanto comparado com CRM (p < 0,0001) quanto comparado com ICP (p < 0,0001). O tratamento CRM contra ICP, também mostrou menor custo (p < 0,0001). Os custos corrigidos para sobrevida livre de eventos e angina foram, US$25.690 para TM; US$45.989 para ICP e US$27.920 para CRM; com expressiva diferença entre os 3 grupos (p < 0,0001). Na comparação dos grupos, observou-se um menor custo no grupo tratamento clínico comparado com ICP (p < 0,0001), o grupo angioplastia também teve um maior custo quando comparado com o grupo cirúrgico (p < 0,001). Contudo entre o grupo tratamento medicamentoso e tratamento cirúrgico não houve diferença significativa (p=0,5613). Conclusão: A análise econômica comparativa de longa data, revelou que ICP foi o tratamento menos custo-efetivo. O tratamento medicamentoso foi o mais custo-efetivo na prevenção de eventos, porém na prevenção de eventos e angina, teve custo-efetividade semelhante ao tratamento cirúrgico / Introduction: The cost-effectiveness analysis in multivessel coronary artery disease treatment have gained importance in clinical trials, since the main treatment options: coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI) and medical treatment (MT) have similar efficacy in certain subgroups of patient. Currently, the concernment in economic analysis have grown, since Medical Treatment costs have increased with the constant development of new technologies, but the available budget are finite and should be administered. Objective: prospectively analyze the comparative cost of the three medical treatments for stable multivessel coronary artery disease, during ten years follow-up. Methods: It was calculated the overall therapeutic cost of 611 patients in the clinical trial \"The Second Medicine, Angioplasty, or Surgery Study (MASS II) \", considering the remuneration provided by the health insurance system of the Heart Institute of HC/FMUSP converted to dollar currency. Afterward, the costeffectiveness analysis was conducted by adjusting the cumulative cost obtained at each group for the \"time free of clinical events\" and also for the combination of \"time free of events\" and \"time free of angina\". Results: The MT had a cumulative cost, at the end of ten years, of US$ 6,183.00; PCI had a cost of US$ 14,292.00; and the CABG group had a cumulative cost of US$ 12,316.00. The costs adjusted for \"events-free survival\" were US$ 11,136.00 for MT; US$ 26,912.00 for PCI and US$ 17,883.00 for CABG. There was a statistically significant difference between the 3 groups (p < 0.0001) and paired analysis showed lower cost for the medical treatment group compared with CABG (p < 0.0001) and PCI (p < 0.0001). The CABG compared with PCI also showed lower cost (p < 0.0001). The adjusted costs for \"survival free of clinical events and angina\" were US$25,690.00 for MT; US$45,989.00 for PCI and US$27,920.00 for CABG; with a significant difference between the 3 groups (p < 0.0001). Comparing the groups, it can be seen a lower cost in the medical treatment group, compared with CABG (p < 0.0001), and also in comparison with PCI (p < 0.0001). However, the comparison between the medical treatment group and surgical treatment group showed no significant difference (p=0.5613). Conclusion: The long-term comparative economic analysis revealed that PCI showed up to be the least cost-effective treatment. The medical treatment was the most cost-effective in \"events prevention\", but considering \"events and angina prevention\", it had a cost-effectiveness similar to surgical treatment