O expressivo número de brasileiros que necessitam correção anatômica da estenose valvar aórtica acentuada e que não realizam cirurgia de substituição valvar devido ao risco proibitivo justifica a necessidade de investigação, tanto da efetividade no cenário clínico real quanto dos custos impostos ao Sistema Único de Saúde e aos planos de saúde suplementar brasileiros pela incorporação do implante transcateter de valva aórtica, que tem se demonstrado efetivo mas oneroso, internacionalmente. No primeiro artigo da tese, avaliaram-se os desfechos intra-hospitalares, a sobrevida e o reembolso pela internação hospitalar de 41 pacientes com idade média de 78,7 ± 6,3 anos, estenose valvar aórtica acentuada, com recusa cirúrgica e decisão multidisciplinar por tratamento transcateter entre outubro de 2010 e outubro de 2015. Os sujeitos foram seguidos prospectivamente por um período mediano de 15,2 (4,5 – 25,6) meses e a sobrevida estimada em 1 e 2 anos foi de 73,2% e 64,1%, respectivamente. Identificou-se que hipertensão pulmonar e revascularização miocárdica cirúrgica prévia estavam independentemente associadas à menor sobrevida. O valor mediano reembolsado pelos pacientes atendidos pelo Sistema Único de Saúde foi R$ 108.634,34 (101.051,05 – 127.255,27) e R$ 115.126,77 (94.603,21 – 132.603,01) para aqueles internados por planos de saúde suplementar ou particulares, sendo o respectivo valor mediano reembolsado pela prótese valvar de R$ 82.000,00 (82.000,00 – 95.450,00) e 84.050,00 (75.000,00 – 92.400,00) Em um grupo de 585 procedimentos de troca valvar aórtica cirúrgica em indivíduos com idade ≥ 60 anos, realizados entre janeiro de 2010 e dezembro de 2015 na mesma instituição, a mortalidade intra-hospitalar estava associada à idade e foi de 5,9% naqueles com idade entre 60 e 70 anos, 10,8% entre 70 e 80 anos e de 22,2% ≥ 80 anos. O reembolso mediano foi de R$ 14.035,96 (11.956,11 – 16.644,90) para os internados pelo Sistema único de Saúde e R$ 20.273,97 (15.358.03 – 32.815,49) pelos planos de saúde suplementar ou particulares. No segundo artigo da tese, identificou-se que do total de 819 pacientes consecutivamente incluídos no Registro Brasileiro de Implante de Bioprótese Aórtica por Cateter entre janeiro de 2008 e outubro de 2015, 15 (1,8%) sofreram perfuração do ventrículo esquerdo. Os pacientes que apresentaram perfuração eram mais idosos (85,4 ± 6,3 vs. 81,5 ± 7,3 anos, p=0,038), predominantemente mulheres (80,0% vs. 50,5%, p=0,024), apresentavam maior fração de ejeção (67,3 ± 7,8% vs. 58,6 ± 15,0%, p=0,001), menor massa ventricular esquerda (203,9 ± 47,1g vs. 247,6 ± 78,7g, p=0,039) e menor altura do tronco da coronária esquerda (11,2 ± 5,4mm vs. 14,0 ± 3,3mm, p=0,034). Os preditores independentes de perfuração do ventrículo esquerdo foram idade e fração de ejeção. No terceiro artigo, descreve-se um caso de ablação septal para tratamento de miocardiopatia hipertrófica obstrutiva assimétrica para posterior implante transcateter de valva aórtica, sugerindo que esta seja uma estratégia factível quando da concomitância dessas duas condições Em conclusão, os desfechos do tratamento transcateter da estenose valvar aórtica acentuada em pacientes inoperáveis são compatíveis com aqueles do cenário idealizado dos ensaios clínicos randomizados, apesar de estarem associados a custos maiores que os anteriormente estimados por painéis de especialistas. O tratamento cirúrgico, por sua vez, apresentou mortalidade maior que aquela idealizada ou relatada como usual. A hipercinesia do ventrículo esquerdo pode favorecer o trauma determinado pelo guia metálico, posicionado em seu interior para realização do procedimento, estando a fração de ejeção independentemente associada à chance de perfuração. Ainda, a ablação septal por álcool eletiva, anterior ao implante transcateter da valva aórtica, é uma abordagem factível para pacientes com hipertrofia ventricular esquerda assimétrica obstrutiva associada à estenose valvar aórtica. / The expressive number of Brazilians who require an anatomic correction for severe aortic valve stenosis and who do not undergo valvar replacement surgery due to prohibitive risk justifies the need to investigate both the effectiveness in the real clinical scenario and the costs imposed to the Public Health System and the Supplementary Health System for the incorporation of the transcatheter aortic valve implantation, which has been shown to be effective but onerous, internationally. In the first article of the thesis, the in-hospital outcomes, long-term survival and reimbursement for 41 patients, with a mean age of 78.7 ± 6.3 years, sever aortic valve stenosis, with surgical refusal and multidisciplinary decision for transcatheter treatment, between October 2010 and October 2015 are described. Subjects were prospectively followed for a median period of 15.2 (4.5 - 25.6) months and the estimated survival at 1 and 2 years was 73.2% and 64.1%, respectively. It was identified that pulmonary hypertension and previous coronary artery bypass grafting were independently associated with lower survival. Median reimbursed values by the Public Health System was R$ 108,634.34 (101,051.05 - 127,255.27) and by supplementary health plans was R$ 115,126.77 (94,603.21 - 132,603.01). The respective median values reimbursed for the valve prosthesis was R$ 82,000.00 (82,000.00 - 95,450.00) and 84,050.00 (75,000.00 - 92,400.00) In a group of 585 surgical aortic valve replacement procedures in subjects aged ≥ 60 years, performed between January 2010 and December 2015 in the same institution, in-hospital mortality was associated with age and was 5.9% in those with age between 60 and 70 years, 10.8% between 70 and 80 years and 22.2% in ≥ 80 years. The median reimbursement was R$ 14,035.96 (11,956.11 - 16,644.90) for those hospitalized by the Public Health System and R$ 20,273.97 (15,358.03 - 32,815.49) by supplementary or private health plans. In the second article of the thesis, it was identified that of the total of 819 patients consecutively included in the Brazilian Registry of Aortic Bioprosthesis Implantation by Catheter (RIBAC) between January 2008 and October 2015, 15 (1.8%) suffered perforation of the left ventricle. Patients with perforation were older (85.4 ± 6.3 vs. 81.5 ± 7.3 years, p=0.038), predominantly women (80.0% vs. 50.5%, p=0.024), had a higher ejection fraction (67.3 ± 7.8% vs. 58.6 ± 15.0%, p=0.001), lower left ventricular mass (203.9 ± 47.1g vs. 247.6 ± 78, 7g, p=0.039) and shorter distance between the aortic annulus and the left main coronary artery ostium (11.2 ± 5.4mm vs. 14.0 ± 3.3mm, p=0.034). The independent predictors of left ventricular perforation were age and ejection fraction. In the third article, a case of septal ablation was described for the treatment of asymmetric obstructive hypertrophic cardiomyopathy for posterior transcatheter aortic valve implantation, suggesting that this is a feasible strategy when these two conditions are concomitant In conclusion, the outcomes of transcatheter treatment of severe aortic stenosis in inoperable patients are compatible with those in the ideal scenario of randomized clinical trials, although they are associated with higher costs than previously estimated by expert panels. Surgical treatment, on the other hand, presented higher mortality than that idealized or reported as usual. The left ventricle hyperkinesia may favor the trauma determined by the metallic guide, positioned inside it to perform the procedure, the ejection fraction being independently associated with the chance of perforation. Furthermore, elective alcohol septal ablation, prior to transcatheter aortic valve implantation, is a feasible approach for patients with obstructive asymmetric left ventricular hypertrophy associated with aortic valve stenosis.

Abstract Type I collagen is the main connective tissue protein in vertebrates. The cross-linking and correct organisation of the molecules is crucial for the proper function of the tissue. Traditionally collagen cross-linking has been studied using chemical cross-link analyses. However, this does not distinguish between the collagen types or the location of the cross-link within the molecule. The focus in this work was to study the carboxyterminal telopeptide domain of type I collagen for the differently cross-linked forms. An immunochemical approach was used and a new immunoassay, SP4, was developed for the detection of immaturely cross-linked peptide forms. The differently cross-linked structures were purified and characterised from human bone by using SP4 together with the earlier developed ICTP assay for trivalently cross-linked C-terminal telopeptide form. It was found that the majority of the trivalent cross-links in the C-terminal telopeptide were presently unknown structures, other than pyridinoline. A non-cross-linked form of C-terminal telopeptide of α1-chain of type I collagen was also discovered in bone. The epitope of the ICTP assay was characterised and found to reside in the phenylalanine rich region of the ICTP peptide. MMP-9, but not cathepsin K, mediated breakdown of the collagenous matrix was found to produce a peptide detectable by the ICTP assay. Healthy human Achilles tendon comprises mainly of type I collagen. In ruptured Achilles tendons, an increased type III collagen content was found. Since the synthesis of type III collagen was not increased, it is postulated that the type III collagen must have accumulated over a long period of time indicative of a long-lasting microtraumatic process in the tendon before the total rupture occurred. The ICTP content was increased and the ratio of SP4 to ICTP decreased in calcified stenotic aortic valves suggesting a change in the molecular organisation and cross-linking towards the type found in human bone. The total collagen content was dramatically decreased in the calcified valves. Both in the Achilles tendons and in the aortic valves, the ICTP content was found to decrease with age with a concomitant increase in the variants of the C-terminal telopeptide structures detectable with the SP4 assay, pointing to a change in the molecular organisation of the collagenous matrix in these tissues.

INTRODUÇÃO: A estenose aórtica, doença valvar de grande prevalência, tem na avaliação clínica e ecocardiográfica as principais ferramentas para avaliação dos pacientes. Ferramentas auxiliares de avaliação são desejáveis e neste contexto surgem os peptídeos natriuréticos. Os peptídeos natriuréticos BNP e NT-proBNP podem ser usados como marcadores diagnósticos e prognósticos em diversas situações clínicas. Postulamos que os peptídeos pudessem ter papel diagnóstico, mas principalmente valor prognóstico em pacientes com estenose aórtica grave. OBJETIVO: primariamente, definir o papel prognóstico de sobrevida dos peptídeos natriuréticos BNP e NT-proBNP no acompanhamento prospectivo de uma população de pacientes com estenose aórtica grave. Secundariamente, comparar os níveis séricos de BNP e NT-proBNP entre pacientes com EAo grave assintomáticos e sintomáticos. MÉTODOS: Foram incluídos de forma consecutiva 66 pacientes com estenose aórtica grave, definida pela presença de gradiente médio de pressão transvalvar aórtica maior que 40 mmHg. Os critérios de exclusão foram fibrilação atrial, outra valvopatia, cardiopatia associada, infecções ativas, neoplasias, doenças auto-imunes ou inflamatórias, insuficiência renal e obesidade. Dos 66 pacientes incluídos, 76% eram sintomáticos (50/66). Os sintomas foram definidos como dispnéia aos esforços, síncope ou angina. Na inclusão, todos os pacientes foram submetidos à avaliação clínica inicial, realização de ecocardiograma e dosagem de BNP e NT-proBNP. Os pacientes sintomáticos recebiam a indicação de tratamento cirúrgico e os pacientes assintomáticos eram conduzidos clinicamente. Os pacientes foram acompanhados prospectivamente. O desfecho clínico avaliado foi óbito cardiovascular, definido por morte súbita, morte por insuficiência cardíaca e óbito peri-operatório. RESULTADOS: Os pacientes foram acompanhados por 869 + 397 dias. Houve 11 óbitos durante o acompanhamento. Na inclusão, os níveis de BNP e NT-proBNP foram similares em assintomáticos e sintomáticos: BNP 72 (41-175) pg/mL versus 104 (46-270) pg/mL; p = 0,275 e NT-proBNP 676 (235-1356) pg/mL vs. 871 (310-2230) pg/mL; p = 0,226. Houve diferença entre os níveis de BNP e NT-proBNP e classe funcional (p < 0,001 e p < 0,001, respectivamente). Através da curva ROC foi determinado um valor de corte de BNP (105 pg/mL) e NT-proBNP (1500 pg/mL) capazes de predizer classe funcional III e IV (New York Heart Association), com área sob a curva de 0,806 e 0,786 respectivamente. BNP e NT-proBNP foram preditores de mortalidade (p=0,007 e p=0,001 respectivamente). BNP > 105 pg/mL aumentou o risco de óbito cardiovascular de forma independente [OR= 6,3 (IC95%: 1,36 - 29,25)]. NT-proBNP > 1500 pg/mL aumentou o risco de óbito cardiovascular de forma independente [OR = 6,5 (IC95%: 1,73 - 24,63)]. CONCLUSÃO: O BNP e o NTproBNP foram preditores independentes de mortalidade em pacientes com estenose aórtica grave em um acompanhamento de quatro anos. O BNP e o NT-proBNP foram preditores de classe funcional III e IV (New York Heart Association) em pacientes com estenose aórtica grave. O BNP e o NT-proBNP não permitiram diferenciar pacientes sintomáticos de assintomáticos / BACKGROUND: Aortic valve stenosis is a high prevalent cardiac valve disease, in which clinical and echocardiographic parameters are the most common approach of diagnosis and risk evaluation. Complementary methods are desirable and the natriuretic peptides BNP and NT-proBNP, both diagnostic and prognostic markers in multiple clinical situations, could improve patient assessment. We postulate that these peptides may have diagnostic purpose, but mainly a prognostic value in patients with severe aortic stenosis. OBJECTIVE: primarily, define the survival prognostic role of natriuretic peptides BNP and NT-proBNP in monitoring a population of patients with severe aortic stenosis prospectively. Secondarily, compare the serum levels of BNP and NT-proBNP among patients with symptomatic and asymptomatic severe aortic stenosis. METHODS: 66 consecutive patients with severe aortic stenosis, defined by the presence of gradient mean transvalvular aortic pressure greater than 40 mmHg were included. Exclusion criteria were concomitant atrial fibrillation, other valve disease, other myocardiopathies, active infections, autoimmunity diseases, inflammatory diseases, neoplasia, renal failure or obesity. 76% of patients were symptomatic (50/66), defined as dyspnea on exertion, syncope or angina. All patients underwent initial clinical evaluation, echocardiography and BNP and NT-proBNP measurement. Symptomatic patients were referred for surgical treatment and asymptomatic patients were clinically managed. (Patients were followed up prospectively). The clinical outcome was cardiovascular death, defined by sudden death, death from heart failure and peri-operative death. RESULTS: Patients were followed up for 869 + 397 days. There were 11 deaths during followup. On admission, levels of BNP and NT-proBNP were similar in asymptomatic and symptomatic individuals: BNP 72 (41-175) pg / mL vs. 104 (46-270) pg / mL, p = 0.275 and NT-proBNP 676 (235-1356) pg / mL vs. 871 (310-2230) pg / ml, p = 0.226. There were differences between the levels of BNP and NT-proBNP and functional class (p <0.001 p <0.001, respectively). ROC-curve analysis demonstrated a cut-off value of BNP (105 pg / mL) and NT-proBNP (1500 pg / mL) capable of predicting NYHA functional class III and IV, with an area under the curve of 0.806 and 0.786 respectively. BNP and NT-proBNP could predict mortality (p = 0.007 and p = 0.001 respectively). BNP > 105 pg/mL independently increased the risk of cardiovascular death [OR = 6.3 (95% CI: 1.36 to 29.25)]. NT-proBNP > 1500 pg/mL independently increased the risk of cardiovascular death [OR = 6.5 (95% CI: 1.73 to 24.63)]. CONCLUSION: BNP and NT-proBNP were independent predictors of mortality in patients with severe aortic stenosis after a follow up of 4 years. BNP and NT-proBNP were predictors of NYHA functional class III and IV in patients with severe aortic stenosis. BNP and NT-proBNP alone did not distinguish symptomatic from asymptomatic patients

<p><i>Chlamydophila pneumoniae</i> (<i>C. pneumoniae</i>) has been suggested as a stimulator of chronic inflammation in atherosclerosis. <i>C. pneumoniae</i> DNA was demonstrated in aortic biopsies in 50% of patients with stable angina pectoris or acute coronary syndrome undergoing coronary artery bypass grafting. <i>C. pneumoniae</i> mRNA, a marker of replicating bacteria, was demonstrated in 18% of the aortic biopsies. </p><p>Inflammation may have a role in the pathogenesis of thoracic aortic aneurysm, aortic dissection and aortic valve stenosis. <i>C. pneumoniae </i>DNA was demonstrated in aortic biopsies in 26% of thoracic aortic aneurysm patients and in 11% of aortic dissection patients undergoing thoracic surgery and in 22% of stenotic aortic heart valves from patients undergoing aortic valve replacement. No bacterial mRNA was demonstrated in these aortic biopsies, nor in the valves, suggesting that the infection has passed into a persistent state. <i>C. pneumoniae</i> DNA was demonstrated in peripheral blood mononuclear cells in only 5% of aortic valve stenosis patients and not in thoracic aortic aneurysm or aortic dissection patients, suggesting that the bacterium disseminated to the cardiovascular tissue long before the patient required surgery. The copper/zinc ratio in serum, a marker of infection/inflammation, was significantly elevated in thoracic aortic aneurysm patients, supporting an inflammatory pathogenesis. Patients positive for <i>C. pneumoniae</i> in the aortic valve had more advanced coronary atherosclerosis, further supporting a possible role for <i>C. pneumoniae</i> in atherosclerosis. </p><p>Mice were infected with <i>C. pneumoniae</i> that disseminated to all organs investigated (i.e. lungs, heart, aorta, liver and spleen). Trace element concentrations were altered in infected animals with an increased copper/zinc ratio in serum, a progressively increased iron concentration in the liver and a progressively decreased iron concentration in serum. Iron is important for <i>C. pneumoniae</i> metabolism, and a changed iron homeostasis was noted in infected mice by alterations in iron-regulating proteins, such as DMT1 and hepcidin.</p>

Para investigar se estresse oxidativo contribui para a progressão da calcificação/estenose valvar aórtica (VA), avaliamos a produção de espécies reativas de oxigênio (ERO) e efeitos dos antioxidantes tempol e ác. lipóico em modelo de calcificação VA em coelhos. Superóxido, H2O2 e 3-nitrotirosina aumentaram em células inflamatórias e principalmente nos núcleos de calcificação, juntamente com as subunidades p22phox, Nox2 da NADPH oxidase e da proteína dissulfeto isomerase, que co-localizam. PCR mostrou aumento da Nox4 em relação a Nox1. A calcificação foi menor com ác.lipóico e maior com tempol, coicidindo com resultados de modelo in vitro em células musculares lisas. VA humanas estenóticas tiveram aumento semelhante de ERO e da expressão protéica em torno da calcificação. Estresse oxidativo pode contribuir para a progressão da estenose aórtica. / To invetigate whether oxidative stress contributes to aortic valve (AV) calcification/stenosis progression, we assessed reactive oxygen species (ROS) production and effects of antioxidants tempol and lipoic acid in a rabbit AV calcification model. Superoxide, H2O2 and 3-nitrotyrosine increased in inflammatory cells and mainly in calcifying nuclei, coincident with NADPH oxidase subunits p22phox, Nox2 and protein disulfide isomerase, which co-localized. PCR showed switch from Nox1 to Nox4. Calcification was smaller with lipoic acid and greater with tempol, similar to an in vitro smooth muscle cell calcification model results. Human stenotic AV had analogous increase in ROS and protein expression around calcifying nuclei. Oxidative stress can contribute to AV stenosis progression.

Introdução: A deposição de cálcio junto aos folhetos valvares esta intimamente relacionada à fisiopatologia da estenose valvar aórtica degenerativa (EAD). A tomografia computadorizada com multidetectores (TCMD), além de possibilitar o delineamento tridimensional das estruturas cardíacas, permite a quantificação da intensidade da calcificação valvar. Atualmente, a relação entre a localização dos depósitos valvares de cálcio e a gravidade hemodinâmica na estenose aórtica permanece incerta. Objetivo: Avaliar se a topografia da calcificação valvar influencia a repercussão hemodinâmica na EAD. Métodos: Trata-se de estudo prospectivo, unicêntrico, incluindo 97 pacientes com EAD moderada ou importante. O escore de cálcio da valva aórtica foi calculado a partir da TCMD sem contraste. A topografia da calcificação valvar foi avaliada através de análise tomográfica específica com infusão de baixa dose de contraste endovenoso, objetivando uma detalhada segmentação anatômica dos planos valvares. A medida da atenuação, expressa em unidades Hounsfield (UH), foi utilizada para quantificar o conteúdo de cálcio na região central e periférica do plano valvar aórtico. Resultados: Pacientes com EAD importante apresentaram escore de cálcio valvar aórtico superior ao dos portadores de EAD moderada (3131 ± 1828 unidades Agatston [UA] e 1302 ± 846 UA, respectivamente; p < 0,001). Quanto à topografia da calcificação, pacientes com EAD importante exibiram atenuações significativamente maiores no centro do plano valvar do que em sua periferia (507,4 ± 181,7 UH vs. 449,8 ± 114,5 UH; p = 0,001). Inversamente, pacientes com EAD moderada apresentaram menor atenuação na região central do que na periferia valvar (308,7 ± 92,9 UH vs. 347,6 ± 84,2 UH, p < 0,001). A razão da atenuação centro/periferia também foi significativamente maior nos pacientes com EAD importante (1,14 ± 0,32 vs. 0,89 ± 0,13; p < 0,001), permanecendo significativamente associada à presença de EAD importante mesmo após ajuste para o grau subjacente de calcificação Resumo valvar. Conclusão: A gravidade da EAD parece resultar não apenas do grau de calcificação, mas também da localização dos depósitos valvares de cálcio / Introduction: The pathophysiology of degenerative aortic valve stenosis (AS) is intimately related to the development of calcific deposits in the valve structure. Multidetector computed tomography (MDCT), a reliable method to delineate the tridimensional heart geometry, has been shown to accurately quantify the global aortic valve calcium content. Currently, the relationship between calcium location and hemodynamic disease severity is poorly understood. Objective: The present prospective study was conducted to test the hypothesis of whether the location of valve calcification influences the functional severity of AS. Methods: Prospective, single-arm study including 97 patients with diagnosed moderate or severe AS. Aortic valve calcium score was calculated from nocontrast multidetector computed tomography (MDCT). \"Low-contrast- os \" MDCT images were acquired for segmentation of the cardiac anatomy, with the attenuation, expressed in Hounsfield units (HU), used to quantify the calcium content at the central and peripheral regions of the aortic valve zone. Results: The calcium score was higher among patients with severe AS compared to patients without severe AS (3131±1828 Agatston units [AU] vs. 1302±846 AU respectively; p < 0.001). Patients with severe AS had significantly higher attenuations at the center of the valve than at its periphery (507.4±181.7 HU vs. 449.8±114.5 HU; p=0.001). Conversely, patients without severe AS had lower attenuation at the center than at the periphery of the valve (308.7 ± 92.9 HU vs. 347.6±84.2 HU; p < 0.001). The center/periphery attenuation ratio was significantly higher for patients with severe AS than for those without severe disease (1.14±0.32 vs. 0.89 ± 0.13; p < 0.001), and remained significantly associated with the presence of severe AS even after adjusting for the underlying degree of valve calcification. Conclusion: The severity of degenerative aortic valve stenosis appears to result not only from the degree of calcification but also from the localization of the calcific deposits within the valve

Chlamydophila pneumoniae (C. pneumoniae) has been suggested as a stimulator of chronic inflammation in atherosclerosis. C. pneumoniae DNA was demonstrated in aortic biopsies in 50% of patients with stable angina pectoris or acute coronary syndrome undergoing coronary artery bypass grafting. C. pneumoniae mRNA, a marker of replicating bacteria, was demonstrated in 18% of the aortic biopsies. Inflammation may have a role in the pathogenesis of thoracic aortic aneurysm, aortic dissection and aortic valve stenosis. C. pneumoniae DNA was demonstrated in aortic biopsies in 26% of thoracic aortic aneurysm patients and in 11% of aortic dissection patients undergoing thoracic surgery and in 22% of stenotic aortic heart valves from patients undergoing aortic valve replacement. No bacterial mRNA was demonstrated in these aortic biopsies, nor in the valves, suggesting that the infection has passed into a persistent state. C. pneumoniae DNA was demonstrated in peripheral blood mononuclear cells in only 5% of aortic valve stenosis patients and not in thoracic aortic aneurysm or aortic dissection patients, suggesting that the bacterium disseminated to the cardiovascular tissue long before the patient required surgery. The copper/zinc ratio in serum, a marker of infection/inflammation, was significantly elevated in thoracic aortic aneurysm patients, supporting an inflammatory pathogenesis. Patients positive for C. pneumoniae in the aortic valve had more advanced coronary atherosclerosis, further supporting a possible role for C. pneumoniae in atherosclerosis. Mice were infected with C. pneumoniae that disseminated to all organs investigated (i.e. lungs, heart, aorta, liver and spleen). Trace element concentrations were altered in infected animals with an increased copper/zinc ratio in serum, a progressively increased iron concentration in the liver and a progressively decreased iron concentration in serum. Iron is important for C. pneumoniae metabolism, and a changed iron homeostasis was noted in infected mice by alterations in iron-regulating proteins, such as DMT1 and hepcidin.

Aortic valve (AV) disease is a major cause of cardiovascular-linked deaths globally. In addition, AV disease is a strong risk factor for additional cardiovascular events; however, the mechanism by which it initiates and progresses is not well-understood. We hypothesize that low and oscillatory flow is present on the fibrosa side of the AV and stimulates ECs to differentially regulate microRNA (miRNA) and mRNAs and influence AV disease progression. This hypothesis was tested employing both in vitro and in vivo approaches, high throughput microarray and pathway analyses, as well as a variety of functional assays. First, we isolated and characterized side-dependent, human aortic valvular endothelial cells (HAVECs). We found that HAVECs express both endothelial cell markers (VE-Cadherin, vWF, and PECAM) as well as smooth muscle cell markers (SMA and basic calponin). Using microarray analysis on sheared, side-specific HAVECs, we identified side- and shear-induced changes in miRNA and mRNA expression profiles. More specifically, we identified over 1000 shear-responsive mRNAs which showed robust validation (93% of those tested). We then used Ingenuity Pathway Analysis to identify key miRNAs, including those with many relationships to other genes (for example, thrombospondin and I&B) and those that are members of over-represented pathways and processes (for example, sulfur metabolism). Furthermore, we validated five shear-sensitive miRNAs: miR-139-3p, miR-148a, miR-187, miR-192, and miR-486-5p and one side-dependent miRNA, miR-370. To prioritize these miRNAs, we performed in silico analysis to group these key miRNAs by cellular functions related to AV disease (including tissue remodeling, inflammation, and calcification). Next, to compare our in vitro HAVEC results in vivo, we developed a method to isolate endothelial-enriched, side-dependent total RNA and identify and validate side-dependent (fibrosa vs. ventricularis) miRNAs in porcine aortic valvular endothelium. From this analysis, we discovered and validated eight side-dependent miRNAs in porcine endothelial-enriched AV RNA, including one miRNA previously identified in vitro, miR-486-5p. Lastly, we determined the relationship between important miRNAs (specifically miR-187 and miR-486-5p) and AV disease by modulating levels of miRNAs and performing functional assays. Preliminary studies overexpressing miR-187 in HAVECs have shown a reduction in inflammatory state through monocyte adhesion (p<0.05). Further, miR-486-5p overexpression reveals an increase in migration (p<0.05) and a trend for a decrease in early apoptosis, linking miR-486-5p to tissue remodeling in the AV. Better understanding of AV biology and disease in terms of gene-regulation under different hemodynamic conditions will facilitate the design of a tissue-engineered valve and provide alternative treatment options.

Die transfemorale Aortenklappenimplantation stellt für ältere Patienten mit einer symptomatischen, hochgradigen Aortenklappenstenose und einem erhöhten perioperativen Letalitätsrisiko eine Alternative zum konventionell-chirurgischen Aortenklappenersatz dar. In der vorliegenden Arbeit wurden die beiden aktuell in Europa zugelassenen transfemoralen Systeme in Bezug auf deren prozedurale Sicherheit, den klinischen Nutzen, die 1-Jahres-Letalitätsrate und die langfristige Klappenfunktionalität unter Anwendung der Kriterien zur standardisierten Komplikationsanalyse des Valve Academic Research Consortiums (VARC) verglichen. Jeweils 100 konsekutive Patienten, bei denen eine transfemorale Aortenklappenimplantation mit den Edwards SAPIEN™/SAPIEN XT™ Transcatheter Heart Valves bzw. dem Medtronic CoreValve ReValving™ System durchgeführt wurde, wurden in die Analyse eingeschlossen. Dies stellt das größte bisher publizierte Patientenkollektiv für den Vergleich der beiden Aortenklappenimplantationssysteme in einem Zentrum über den femoralen Zugangsweg dar. Es wurden mit beiden Systemen ähnlich gute postinterventionelle hämodynamische und klinische Ergebnisse erreicht. Ein signifikanter Unterschied bezüglich der prozeduralen Sicherheit und der 1-Jahres-Letalitätsrate zwischen den beiden Systemen konnte trotz signifikanter Unterschiede in Bezug auf bestimmte periinterventionelle Risiken nicht nachgewiesen werden. Die langfristige Klappenfunktion beider Systeme war exzellent.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 6 uppsatser.