Impact of renal function on mortality and incidence of major adverse cardiovascular events following acute coronary syndromes

BACKGROUND: Renal failure patients have a dismal prognosis in the setting of acute coronary syndromes (ACS). Several studies have shown that this population is undertreated, benefiting less frequently from cardiovascular agents and interventions. The aim of our study was to evaluate patients hospitalized for ACS who also presented renal dysfunction, identifying baseline clinical characteristics, treatment options and prognosis. We also assessed whether renal failure was an independent predictor of mortality and cardiovascular events. METHODS: We performed an observational, longitudinal, prospective and continuous study, including 1039 consecutive patients hospitalized in a single center for ACS. Two groups were compared according to estimated glomerular filtration rate (eGFR): eGFR > or = 60 ml/min (group A) and eGFR < 60 ml/min (group B). The mean follow-up was twelve months after discharge. Multivariate analysis was used to identify predictors of mortality and major adverse cardiovascular events (MACE) in this population. RESULTS: Group B patients were older and more frequently female, and presented a higher prevalence of cardiovascular risk factors and previous cardiovascular disease, and more severe coronary artery disease. Group B also had more cases of non-ST-elevation acute myocardial infarction, as well as higher blood glucose, higher heart rate on admission, and lower left ventricular ejection fraction. Patients in group B were less frequently treated with the main cardiovascular drugs or by an invasive strategy; this group also presented higher in-hospital mortality (9.1 vs. 2.5%, p < 0.001). During clinical follow-up, survival and MACE-free rates were significantly lower in group B patients (86.6 vs. 93.6%, p < 0.001, and 76.2 vs. 86.2%, p < 0.001, respectively). Multivariate analysis showed that eGFR of < 30 ml/min was an independent predictor of in-hospital mortality (OR 6.92; C statistic = 0.87) and that eGFR of < 60 ml/min was an independent predictor of MACE during follow-up (OR 2.19; C statistic = 0.71). CONCLUSION: We found that moderate to severe renal dysfunction is common in ACS patients, and this variable was an independent predictor of mortality and MACE. However, we also found that these patients are undertreated, which may contribute to their poor prognosis. Early identification of these high-risk patients is important so that the procedures recommended in the international guidelines can be more consistently implemented

Can we improve outcomes in patients with previous coronary artery bypass surgery admitted for acute coronary syndrome?

INTRODUCTION AND OBJECTIVES: Prognosis and in-hospital management of patients with acute coronary syndrome (ACS) and a history of coronary artery bypass graft (CABG) surgery are still debated. The objective of this study was to characterize ACS patients with a CABG and to compare their in-hospital and postdischarge outcomes with those of patients without a CABG. METHODS: This ongoing prospective observational study included 1,495 consecutive patients admitted for ACS to a coronary care unit and followed up for a mean of 19 months. There were two groups: group A (n=73), with CABGs; and group B (n=1,223), without CABGs. RESULTS: Group A patients were more often male (86.3% versus 69.1%; P=.002), and more frequently had a history of diabetes, myocardial infarction and heart failure. Group B patients more frequently had ST-elevation myocardial infarction, and had a higher median ejection fraction (53% [interquartile range, 47%-60%] vs. 50% [42%-55%]; P< .01) and peak troponin-I concentration. There was no difference in the use of invasive techniques. Regarding medication, Group B patients were more likely to receive dual antiplatelet therapy at discharge. No significant difference was observed in in-hospital mortality (9.5% versus 5.9%; P=.2) or mortality at 1 month, 6 months or 1 year (9.8% versus 9.1%; log-rank test, P=.87) and the cumulative major adverse cardiac event rate was equally low in both groups. The presence of a CABG was associated with more readmissions for unstable angina (11.3% vs. 3.1%; P< .01). CONCLUSIONS: In our ACS patients, the presence of a CABG had no significant influence on short- or medium-term outcomes, such as all-cause mortality and adverse cardiac events

Drilling delamination study on carbon reinforced laminates - tool and feed rate effects

The characteristics of carbon fibre reinforced plastics had widespread their use. In order to join different components, drilling is often necessary. It is known that a drilling process that reduces the drill thrust force can decrease the risk of delamination. In this work, three combinations of the drilling process are compared: tool diameter and geometry and feed rate. The parameters considered for analysis include: thrust force, delamination extension and mechanical strength. This work shows that a proper combination of the drilling variables can contribute to reduce the delamination damage

Estudo da delaminação associada à furação de compósitos reforçados com fibras de vidro e de sisal

O crescente conhecimento das suas propriedades e o avanço nas técnicas do seu processamento têm permitido uma utilização cada vez mais variada dos materiais compósitos de matriz polimérica. Embora as aplicações mais frequentes estejam relacionadas com o uso de fibras de vidro ou de carbono como material de reforço, a utilização de fibras de reforço naturais tem vindo a merecer maior atenção. A utilização deste tipo de compósitos está limitada pela desconfiança que resulta da inconsistência das suas propriedades mecânicas e susceptibilidade a operações de maquinagem.Neste trabalho são comparadas placas laminadas com dois tipos de reforços: fibra de vidro e fibra de sisal, ambos obtidos por processamento manual. Para caracterização das principais propriedades de resistência, como a tensão de rotura ou o módulo de elasticidade, foram realizados ensaios mecânicos. De seguida, as placas foram furadas com dois tipos de broca helicoidal e Brad e duas velocidades de avanço baixa e alta sendo a velocidade de corte constante. Após furação, as placas foram radiografadas com recurso a radiografia digital com contraste e as imagens obtidas foram sujeitas a técnicas de processamento e análise de imagem através da utilização de uma plataforma computacional que integra uma rede neuronal para segmentar as imagens. Desta forma foi possível obter resultados da extensão de dano associado à operação de furação delaminação que seguidamente foram correlacionados com os resultados dos ensaios mecânicos complementares.As conclusões deste trabalho permitem contribuir para uma melhor compreensão das possíveis utilizações dos compósitos de fibra natural relativamente a compósitos mais tradicionais

Tribological Performance of PTFE-based Coating Modified with Microencapsulated [HMIM][NTf2] Ionic Liquid

In this work, a PTFE-based self-lubricating coating containing microencapsulated [HMIM][NTf2] ionic liquid (IL) lubricant is reported. The microcapsules, made of polysulphone, are prepared by solvent evaporation. In order to allow incorporation in the thin PTFE coating layer, which is applied by spraying, the capsules were produced with small sizes (below 10 mu m). Their physico-chemical characterization is presented in terms of SEM/EDS, TGA, FTIR and particle size distribution analysis. It is shown that both the encapsulant material and the IL lubricant are able to withstand the high-temperature curing conditions necessary for the coating system used (380 degrees C during 30 min). Crossed-cylinders tribological testing of the applied coatings showed that incorporation of IL-containing capsules yields a reduction in coefficient of friction of up to 12 % when compared to the baseline formulation and a reduction of up to 70 % in wear rate under high load and low sliding speed conditions. The tribological behaviour of the modified coating is further assessed in different load and speed (P.V) combinations

Influence of oxidized graphene nanoplatelets and [DMIM][NTf2] ionic liquid on the tribological performance of an epoxy-PTFE coating

This work reports the tribological performance of a self-lubricating epoxy-PTFE coating modified with oxidized graphene nanoplatelets (GNPox) and 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [DMIM][NTf2] ionic liquid, alone and in combination. [DMIM][NTf2] was incorporated without encapsulation, which is shown not to hinder coating adhesion for the tested applications. Crossed cylinders tribological testing of coatings under different load conditions showed synergistic effects from the combination of GNPox and ionic liquid. The ionic liquid introduced a plasticizing effect on the binder, increasing the actual contact area and facilitating boundary-lubrication. The boundary-lubrication regime facilitated GNPox particle orientation and reduction of their abrasive behaviour, contributing to a lowered coefficient of friction

Invasive versus conservative strategy in non-ST elevation acute coronary syndromes: data from a single Portuguese center

Introdução: As recomendações mais recentes reforçam a importância de uma abordagem invasiva no contexto das síndromes coronárias agudas (SCA) sem supradesnivelamento do segmento ST. No entanto, o prognóstico deste tipo de abordagem é ainda objeto de discussão. Objectivo: Comparar o prognóstico intra- -hospitalar e a médio prazo de uma abordagem invasiva versus conservadora nas SCA sem supradesnivelamento do segmento ST. População e métodos: Estudo prospectivo, observacional e longitudinal de 802 doentes consecutivamente admitidos com SCA sem supradesnivelamento do segmento ST numa única unidade de cuidados intensivos coronários. Os doentes foram divididos em dois grupos: Grupo A (n=418) – abordagem invasiva; Grupo B (n348) – abordagem conservadora. Foi realizado um seguimento clínico de um ano para avaliar a mortalidade de qualquer etiologia e o resultado combinado de eventos cardiovasculares significativos. Resultados: Os doentes do grupo B eram mais frequentemente do género feminino, mais idosos [64,0 (27 – 86) versus 73,0 (29 – 93) anos, p<0,001], mais diabéticos (26,0 versus 35,9% p=0,002), tinham maior prevalência de enfarte agudo do miocárdio, insuficiência cardíaca e fibrilhação auricular prévios. Apresentaram valores médios inferiores de creatinina, hemoglobina iniciale mínima, e de fração de ejeção do ventrículo esquerdo [57,0 (50 – 60) versus 53,0 (45-59) %, p<0,001]. Os doentes do grupo A eram mais fumadores, tinham mais antecedentes de intervenção coronária prévia, estavam em classes Killip inferiores na admissão, e apresentavam um score de risco TIMI também inferior. Durante o internamento receberam mais anti-agregantes plaquetares, inibidores das glicoproteínas IIb/IIIa, beta bloqueantes e iECAs. A taxa de mortalidade intra-hospitalar foi significativamente superior no grupo B (1,9% versus 5,7%, p=0,0041). O género feminino (OR ajustado 0,46; 95% CI 0,27 – 0,78), e uma idade superior a 66,5 anos (OR ajustado 0,55; 95% CI 0,31 – 0,99) foram preditores independentes para a opção por uma abordagem conservadora durante o internamento. A sobrevida no final do primeiro ano foi superior para os doentes admitidos numa abordagem invasiva (95,9% versus 86,2%, log rank p <0,001), bem como a sobrevida livre de “MACE” (88,3% versus 75,7%, log rank p <0,001). De acordo com dois modelos de análise multivariada de Cox, a opção por uma abordagem invasiva durante o internamento conferiu uma redução de 57% do risco relativo de morte (HR 0,43; 95% CI 0,20 – 0,94), e de 56% do risco relativo de “MACE” (HR 0,44; 95% CI 0,26 – 0,77) no final do seguimento clínico. Conclusões: Apesar das diferenças entre os grupos, na nossa população foi verificada em análise multivariada o benefício da abordagem invasiva no prognóstico intra-hospitalar e a médio prazo

Long-term effect of bosentan in pulmonary hypertension associated with complex congenital heart disease

Background: Bosentan is recommended for symptomatic patients with Eisenmenger syndrome due to simple congenital lesions such as atrial and ventricular septal defects (VSD). However, its long-term efficacy and safety in patients with pulmonary arterial hypertension (PAH) associated with complex congenital heart disease (CHD) is unknown. Objectives: We examined the short- and long-term effects and safety profile of bosentan in patients with PAH and complex CHD. Methods: We followed 14 patients with PAH and complex CHD for a mean of four years. Demographic parameters, exercise capacity assessed by the six-minute walking test (6MWT) and oxygen saturation were assessed at baseline, six months and at follow-up. Results: Mean age was 37.1±11.7 years; 90% were in WHO class III or IV. The most common diagnosis was pulmonary atresia with VSD (35.7%), followed by truncus arteriosus (28.6%), patent ductus arteriosus (21.4%) and transposition of the great arteries (14.3%). After six months of treatment, six-minute walking distance (6MWD) increased from 371.9 to 428.4 m (p=0.005) and functional class was improved (p=0.005). After four years, one patient discontinued bosentan due to side effects and four patients were started on sildenafil, after a mean 38 months of bosentan treatment. Mean 6MWD for patients on bosentan monotherapy (n=8) was 440.1±103.8 m, whereas for patients on bosentan-sildenafil combination therapy (n=4) it was 428.8±96.9 m, after four years of therapy. Two patients died during follow-up. Conclusions: Bosentan was safe and was associated with improved exercise capacity in patients with PAH and complex CHD. This improvement was sustained for up to four years and the safety profile was similar to simple CHD patients.Introdução: O bosentano é recomendado em doentes com hipertensão arterial pulmonar (HAP) associada a lesões congénitas simples, como comunicações interventriculares (CIV). Contudo, a sua eficácia e segurança a longo prazo em doentes com HAP associada a cardiopatias congénitas complexas (HAP-CCC) é desconhecida. Objectivos: Avaliámos a eficácia e seguranc¸a a curto e longo-prazo do bosentano na HAP-CCC. Métodos: Estudaram-se 14 doentes com HAP-CCC, relativamente a parâmetros demográficos, capacidade funcional avaliada pelo teste de marcha de seis minutos (TM6M) e saturação de oxigénio, antes de iniciar terapêutica, aos seis meses e durante o período de seguimento clínico a longo-prazo (quatro anos). Resultados: Noventa por cento dos doentes encontravam-se em classe OMS III ou IV, com idade média de 37,1 ± 11,7 anos. O diagnóstico mais frequente foi a atrésia pulmonar com CIV (35,7%), seguida de truncus arteriosus (28,6%), canal arterial patente (21,4%) e transposição de grandes vasos (14,3%). Após seis meses de tratamento, o TM6M aumentou de 371,9 para 428,4 metros (p = 0,005) e a classe funcional melhorou (p = 0,005). Após quatro anos, um doente suspendeu bosentano devido a efeitos secundários e quatro doentes iniciaram sildenafil, após uma duração média de monoterapia de 38 meses. Após quatro anos de terapêutica, nos doentes em monoterapia com bosentano (n = 8) o TM6M foi de 440,1 ± 103,8 metros, enquanto que nos doentes com bosentano-sildenafil (n = 4) foi de 428,8 ± 96,9 metros. Dois doentes faleceram durante o período de seguimento clínico. Conclusões: O bosentano foi seguro e esteve associado a melhoria na capacidade funcional em doentes com HAP-CCC até aos quatro anos de seguimento clínico

Invasive strategy in non-ST elevation acute coronary syndromes: risks and benefits in an elderly population

Introdução: A idade é um importante factor prognóstico em contexto de síndromes coronárias agudas (SCA). A estratégia invasiva tem demonstrado benefício em muitas populações com SCA sem supradesnivelamento de ST; contudo, continua a ser um tema controverso em doentes mais susceptíveis a complicações relacionadas com o procedimento, como os idosos, uma população sub-representada nos estudos sobre a matéria. Objectivo: Comparar o prognóstico intra- -hospitalar e a longo prazo de doentes idosos com SCA sem supradesnivelamento do segmento ST submetidos a estratégia invasiva versus estratégia conservadora. Pretendemos ainda caracterizar os doentes seleccionados para uma abordagem inicialmente invasiva. Métodos: Estudo observacional, longitudinal, prospectivo e contínuo, incluindo 307 doentes com idade superior a 75 anos consecutivamente hospitalizados por SCA sem supradesnivelamento de ST. Foram formados dois grupos de acordo com a abordagem adoptada: Grupo A (n=91) – doentes submetidos a uma estratégia invasiva precoce; Grupo B (n=216) – doentes submetidos a uma estratégia conservadora. Procedeu-se a um seguimento clínico mediano de 18 meses. Resultados: Os doentes abordados de forma invasiva eram mais novos (79,8 ± 3,2 versus 81,4 ± 3,9 anos, p<0,001), mais frequentemente do sexo masculino (63,7 versus 50,9%, p=0,04), tinham maior incidência de doença coronária prévia, receberam clopidogrel mais frequentemente e tiveram um internamento mais longo (5,8 ± 3,1 versus 4,9 ± 2,6 dias, p=0,01). Os doentes submetidos a estratégia conservadora apresentaram classes de Killip superiores e foram tratados mais frequentemente com diuréticos durante a hospitalização. O grupo submetido a estratégia invasiva apresentou uma maior incidência de complicações intra- -hospitalares (13,6 versus 4,9%, p=0,009), não tendo havido diferenças significativas nas taxas de mortalidade. A análise multivariada mostrou que a estratégia invasiva foi preditora independente de morbilidade intra-hospitalar (OR=3,55). No seguimento clínico verificou-se que as taxas de MACE (56,3 versus 33,3%, p=0,002) e morte (32,5 versus 13,8%, p=0,007) foram superiores no grupo que foi submetido a estratégia conservadora e a estratégia invasiva foi um dos factores protectores relativamente a incidência de eventos cardíacos adversos major (MACE); o mais potente preditor de mortalidade foi a fracção de ejecção do ventrículo esquerdo <50%. Conclusões: Apesar da estratégia invasiva ter estado associada a um aumento de complicações intra-hospitalares, condicionou um melhor prognóstico a longo prazo. Estes dados mostram que a idade não deve ser um critério isolado na selecção de doentes para o uso de estratégia invasiva e são a favor da sua realização precoce na população idosa.Introduction: Age is an important prognostic factor in acute coronary syndromes (ACS). An invasive strategy has been shown to benefit many non-ST elevation ACS populations; however, there is some controversy regarding patients who are more susceptible to procedure-related complications, such as the elderly, an under-represented population in the studies on this subject. Objective: We aimed to compare the in-hospital and long-term prognosis of elderly patients with non-ST elevation ACS treated with either invasive procedures or a conservative strategy, and to characterize the patients selected for an early invasive approach. Methods: This observational, longitudinal, prospective and continuous study included 307 patients aged over 75 years consecutively admitted for non-ST elevation ACS. They were divided into two groups, according to the approach adopted: Group A (n=91) – patients treated with an early invasive strategy; and Group B (n=216) – patients treated conservatively. The median clinical follow-up was 18 months. Results: The subjects who were treated invasively were younger (79.8±3.2 vs. 81.4±3.9 years, p<0.001) and more often male (63.7 vs. 50.9%, p=0.04), had a higher incidence of previous coronary artery disease, were more often treated with clopidogrel, and had a longer hospital stay (5.8±3.1 vs. 4.9±2.6 days, p=0.01). Patients managed conservatively presented higher Killip class, and were more often treated with diuretics during hospitalization. The group treated by an invasive approach presented a higher incidence of in-hospital complications (13.6 vs. 4.9%, p=0.009), but there were no significant differences in mortality rates. Multivariate analysis showed that an invasive strategy was an independent predictor of in-hospital morbidity (OR=3.55). In follow-up, rates of MACE (56.3 vs. 33.3%, p=0.002) and death (32.5 vs. 13.8%, p=0.007) were higher in the group that received conservative treatment, and an invasive strategy was a protective factor against MACE; the strongest predictor of mortality was left ventricular ejection fraction <50%. Conclusions: Although an invasive strategy was associated with increased in-hospital complications, it was shown to confer a better long-term prognosis. These data show that age should not be the only criterion in selecting patients for an invasive strategy and favor early adoption of this approach in the elderly