Microstructural Characterization of AlCrCuFeMnNi Complex Concentrated Alloy Prepared by Pressureless Sintering.

A significant and increasing number of studies have been dedicated to complex concentrated alloys (CCAs) due to the improved properties that these metallic materials can exhibit. However, while most of these studies employ melting techniques, only a few explore powder metallurgy and pressureless sintering as production methods. In this work, a microstructural characterization of AlCrCuFeMnNi CCA samples obtained by powder metallurgy and pressureless sintering using mixtures of powders with different compositions was carried out. One batch of samples (B1) was prepared using commercial powders of Al, Cr, Cu, Fe, Mn, and Ni. Another batch (B2) used mixtures of CrFeMn, AlNi, and Cu powders. A third set of samples (B3) was obtained by adding 1% at. of Mg to the B2 powder. The samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, energy dispersive spectroscopy, density measurements, and hardness tests. Thermodynamic calculations were also used to complement the microstructural characterization. All the obtained samples exhibited high relative density and hardness values. However, B3 samples showed a higher hardness, attributed to the finer distribution of oxide particles, which was promoted by the presence of Mg during sintering. These last samples presented a hardness/density ratio of 62 HV/(g cm-3), surpassing that of some martensitic stainless steels and nickel-titanium alloys.

Temporal Trends in Transcatheter Aortic Valve Implantation: 10-Year Analysis of the TAVIDOR Registry. / Tendência Temporal no Implante Percutâneo de Bioprótese Aórtica: Análise de 10 Anos do Registro TAVIDOR.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has established itself as the preferential strategy to approach severe aortic stenosis. Information on procedural improvements and nationwide results obtained with the technique throughout the past decade are unknown. OBJECTIVES: To assess the temporal variation of the demographic profile, procedural characteristics, and in-hospital outcomes of patients undergoing TAVI procedures at the Rede D'Or São Luiz. METHODS: Observational registry comprising 29 national institutions, comparing the characteristics of the TAVI procedures performed from 2012 to 2017 (Group 1) to those performed from 2018 to 2023 (Group 2). The statistical significance level adopted was p < 0.05. RESULTS: This study assessed 661 patients, 95 in Group 1 and 566 in Group 2, with a mean age of 81.1 years. Group 1 patients had a higher prevalence of New York Heart Association functional class III or IV and STS risk score > 8%. In addition, they more often underwent general anesthesia, transesophageal echocardiographic monitoring, and access through femoral dissection. Group 2 patients had a higher success rate of the TAVI procedure (95.4% versus 89.5%; p = 0.018), lower mortality (3.9% versus 11.6%; p = 0.004), and less often needed permanent pacemaker implantation (8.5% versus 17.9%; p = 0.008). CONCLUSIONS: The 10-year temporal trends analysis of the TAVIDOR Registry shows a reduction in patients' clinical complexity over time. Furthermore, the advance to minimalistic implantation techniques, added to the technological evolution of the devices, may have contributed to the favorable outcomes observed among those whose implantation occurred in the last 5 years studied.

FUNDAMENTO: O implante percutâneo de bioprótese valvar aórtica (TAVI) consolidou-se como opção terapêutica da estenose aórtica de grau importante. Dados sobre as características evolutivas dos procedimentos e dos resultados obtidos com a técnica ao longo da última década, em escala nacional, são desconhecidos. OBJETIVOS: Analisar a tendência temporal referente ao perfil demográfico, características dos procedimentos e desfechos hospitalares de pacientes submetidos a TAVI na Rede D'Or São Luiz. MÉTODOS: Registro observacional envolvendo 29 instituições nacionais. Comparou-se características dos procedimentos realizados de 2012 a 2017 (Grupo 1) e de 2018 a 2023 (Grupo 2). Foram considerados significantes os resultados com valor de p < 0,05. RESULTADOS: Foram analisados 661 casos, 95 pertencentes ao Grupo 1 e 566 ao Grupo 2. A média de idade foi 81,1 anos. Observou-se no Grupo 1 maior prevalência de pacientes em classe funcional III ou IV e escore de risco > 8%. Foi mais frequente o emprego de anestesia geral, monitorização ecocardiográfica transesofágica e via de acesso por dissecção. Maior taxa de sucesso do procedimento (95,4% versus 89,5%; p = 0,018) foi aferida em implantes efetivados a partir de 2018, assim como menor mortalidade (3,9% versus 11,6%; p = 0,004) e necessidade de marcapasso definitivo (8,5% versus 17,9%; p = 0,008). CONCLUSÕES: A análise temporal de 10 anos do Registro TAVIDOR demonstra uma queda na complexidade clínica dos pacientes. Além disso, o avanço para técnicas de implante minimalistas, somadas à evolução tecnológica dos dispositivos, podem ter contribuído para desfechos favoráveis dentre aqueles cujo implante ocorreu no último quinquênio.

Long term follow-up of drug eluting versus bare metal stents in the treatment of saphenous vein graft lesions.

INTRODUCTION: The safety and effectiveness of drug-eluting stent (DES) compared with bare metal stents (BMS) for the treatment of saphenous vein graft (SVG) disease is controversial, especially because of the lack of long-term follow-up. The aim of this study was to address the late outcome of DES versus BMS for the treatment of SVG lesions. METHODS: A matched, case-control study included 82 patients in each group. Patients groups were matched by gender, age, clinical presentation, and diabetes. The primary study end point was occurrence of major adverse cardiovascular events (MACE). Secondary end points included death, cardiac death, myocardial infarction (MI), and target vessel revascularization (TVR). RESULTS: Clinical and angiographic characteristics were similar between the groups. At 6 months, TVR (hazard ratio [HR] 6.12, 95% confidence interval [CI] 1.39 to 26.93, P = 0.05), and MACE (HR 2.54, 95% CI 1.08 to 5.98, P = 0.04) were higher in the BMS group. At 4 years the risks of MI (P = 0.21), TVR (P = 0.99), and MACE (P = 0.21) were similar between both groups. However, the rates of death (HR 2.74, 95% CI 1.11 to 6.74, P = 0.04) and cardiac death (HR 4.26, 95% CI 1.59 to 11.35, P = 0.01) were significantly higher in the BMS group. CONCLUSIONS: These results suggest that the use of DES compared with BMS in the treatment of SVG lesions reduces TVR and MACE at 6 months of follow-up, a benefit that was lost over the next 3-4 years.

Analysis of ESAFORM 2021 cup drawing benchmark of an Al alloy, critical factors for accuracy and efficiency of FE simulations.

This article details the ESAFORM Benchmark 2021. The deep drawing cup of a 1 mm thick, AA 6016-T4 sheet with a strong cube texture was simulated by 11 teams relying on phenomenological or crystal plasticity approaches, using commercial or self-developed Finite Element (FE) codes, with solid, continuum or classical shell elements and different contact models. The material characterization (tensile tests, biaxial tensile tests, monotonic and reverse shear tests, EBSD measurements) and the cup forming steps were performed with care (redundancy of measurements). The Benchmark organizers identified some constitutive laws but each team could perform its own identification. The methodology to reach material data is systematically described as well as the final data set. The ability of the constitutive law and of the FE model to predict Lankford and yield stress in different directions is verified. Then, the simulation results such as the earing (number and average height and amplitude), the punch force evolution and thickness in the cup wall are evaluated and analysed. The CPU time, the manpower for each step as well as the required tests versus the final prediction accuracy of more than 20 FE simulations are commented. The article aims to guide students and engineers in their choice of a constitutive law (yield locus, hardening law or plasticity approach) and data set used in the identification, without neglecting the other FE features, such as software, explicit or implicit strategy, element type and contact model.

Quantification of thrombus formation in malapposed coronary stents deployed in vitro through imaging analysis.

Stent thrombosis is a major complication of coronary stent and scaffold intervention. While often unanticipated and lethal, its incidence is low making mechanistic examination difficult through clinical investigation alone. Thus, throughout the technological advancement of these devices, experimental models have been indispensable in furthering our understanding of device safety and efficacy. As we refine model systems to gain deeper insight into adverse events, it is equally important that we continue to refine our measurement methods. We used digital signal processing in an established flow loop model to investigate local flow effects due to geometric stent features and ultimately its relationship to thrombus formation. A new metric of clot distribution on each microCT slice termed normalized clot ratio was defined to quantify this distribution. Three under expanded coronary bare-metal stents were run in a flow loop model to induce clotting. Samples were then scanned in a MicroCT machine and digital signal processing methods applied to analyze geometric stent conformation and spatial clot formation. Results indicated that geometric stent features play a significant role in clotting patterns, specifically at a frequency of 0.6225 Hz corresponding to a geometric distance of 1.606 mm. The magnitude-squared coherence between geometric features and clot distribution was greater than 0.4 in all samples. In stents with poor wall apposition, ranging from 0.27 mm to 0.64 mm maximum malapposition (model of real-world heterogeneity), clots were found to have formed in between stent struts rather than directly adjacent to struts. This early work shows how the combination of tools in the areas of image processing and signal analysis can advance the resolution at which we are able to define thrombotic mechanisms in in vitro models, and ultimately, gain further insight into clinical performance.

Optimized Computer-Aided Segmentation and Three-Dimensional Reconstruction Using Intracoronary Optical Coherence Tomography.

We present a novel and time-efficient method for intracoronary lumen detection, which produces three-dimensional (3-D) coronary arteries using optical coherence tomographic (OCT) images. OCT images are acquired for multiple patients and longitudinal cross-section (LOCS) images are reconstructed using different acquisition angles. The lumen contours for each LOCS image are extracted and translated to 2-D cross-sectional images. Using two angiographic projections, the centerline of the coronary vessel is reconstructed in 3-D, and the detected 2-D contours are transformed to 3-D and placed perpendicular to the centerline. To validate the proposed method, 613 manual annotations from medical experts were used as gold standard. The 2-D detected contours were compared with the annotated contours, and the 3-D reconstructed models produced using the detected contours were compared to the models produced by the annotated contours. Wall shear stress (WSS), as dominant hemodynamics factor, was calculated using computational fluid dynamics and 844 consecutive 2-mm segments of the 3-D models were extracted and compared with each other. High Pearson's correlation coefficients were obtained for the lumen area (r = 0.98) and local WSS (r = 0.97) measurements, while no significant bias with good limits of agreement was shown in the Bland-Altman analysis. The overlapping and nonoverlapping areas ratio between experts' annotations and presented method was 0.92 and 0.14, respectively. The proposed computer-aided lumen extraction and 3-D vessel reconstruction method is fast, accurate, and likely to assist in a number of research and clinical applications.

Vessel centerline reconstruction from non-isocentric and non-orthogonal paired monoplane angiographic images.

PURPOSE: Three-dimensional reconstruction of a vessel centerline from paired planar coronary angiographic images is critical to reconstruct the complex three-dimensional structure of the coronary artery lumen and the relative positioning of implanted devices. In this study, a new vessel centerline reconstruction method that can utilize non-isocentric and non-orthogonal pairs of angiographic images was developed and tested. METHODS: Our new method was developed in in vitro phantom models of bifurcated coronary artery with and without stent, and then tested in in vivo swine models (twelve coronary arteries). This method was also validated using data from six patients. RESULTS: Our new method demonstrated high accuracy (root mean square error = 0.27 mm or 0.76 pixel), and high reproducibility across a broad imaging angle (20°-130°) and between different cardiac cycles in vitro and in vivo. Use of this method demonstrated that the vessel centerline in the stented segment did not deform significantly over a cardiac cycle in vivo. In addition, the total movement of the isocenter in each image could be accurately estimated in vitro and in vivo. The performance of this new method for patient data was similar to that for in vitro phantom models and in vivo animal models. CONCLUSIONS: We developed a vessel centerline reconstruction method for non-isocentric and non-orthogonal angiographic images. It demonstrated high accuracy and good reproducibility in vitro, in vivo, and in clinical setting, suggesting that our new method is clinically applicable despite the small sample size of clinical data.

Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants.

BACKGROUND: Stacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design. METHODS AND RESULTS: Strut positions were extracted from sequential OCT frames. Reconstruction with standard interpolation generated discontinuous stent structures. By computationally constraining interpolation to known stent skeletons fitted to 3D 'clouds' of OCT-Angio-derived struts, implant anatomy was resolved, accurately rendering features from implant diameter and curvature (n = 1 vessels, r2 = 0.91, 0.90, respectively) to individual strut-wall configurations (average displacement error ~15 µm). This framework facilitated hemodynamic simulation (n = 1 vessel), showing the critical importance of accurate anatomic rendering in characterizing both quantitative and basic qualitative flow patterns. Discontinuities with standard approaches systematically introduced noise and bias, poorly capturing regional flow effects. In contrast, the enhanced method preserved multi-scale (local strut to regional stent) flow interactions, demonstrating the impact of regional contexts in defining the hemodynamic consequence of local deployment errors. CONCLUSION: Fusion of planar angiography and knowledge of device design permits enhanced OCT image analysis of in situ tissue-device interactions. Given emerging interests in simulation-derived hemodynamic assessment as surrogate measures of biological risk, such fused modalities offer a new window into patient-specific implant environments.

Vascular Response to Experimental Stent Malapposition and Under-Expansion.

Up to 80% of all endovascular stents have malapposed struts, and while some impose catastrophic events others are inconsequential. Thirteen stents were implanted in coronary arteries of seven healthy Yorkshire pigs, using specially-designed cuffed balloons inducing controlled stent malapposition and under-expansion. Optical coherence tomography (OCT) imaging confirmed that 25% of struts were malapposed (strut-wall distance

A Novel Algorithm to Quantify Coronary Remodeling Using Inferred Normal Dimensions.

BACKGROUND: Vascular remodeling, the dynamic dimensional change in face of stress, can assume different directions as well as magnitudes in atherosclerotic disease. Classical measurements rely on reference to segments at a distance, risking inappropriate comparison between dislike vessel portions. OBJECTIVE: to explore a new method for quantifying vessel remodeling, based on the comparison between a given target segment and its inferred normal dimensions. METHODS: Geometric parameters and plaque composition were determined in 67 patients using three-vessel intravascular ultrasound with virtual histology (IVUS-VH). Coronary vessel remodeling at cross-section (n = 27.639) and lesion (n = 618) levels was assessed using classical metrics and a novel analytic algorithm based on the fractional vessel remodeling index (FVRI), which quantifies the total change in arterial wall dimensions related to the estimated normal dimension of the vessel. A prediction model was built to estimate the normal dimension of the vessel for calculation of FVRI. RESULTS: According to the new algorithm, "Ectatic" remodeling pattern was least common, "Complete compensatory" remodeling was present in approximately half of the instances, and "Negative" and "Incomplete compensatory" remodeling types were detected in the remaining. Compared to a traditional diagnostic scheme, FVRI-based classification seemed to better discriminate plaque composition by IVUS-VH. CONCLUSION: Quantitative assessment of coronary remodeling using target segment dimensions offers a promising approach to evaluate the vessel response to plaque growth/regression.

Four-year clinical follow-up of the first-in-man randomized comparison of a novel sirolimus eluting stent with abluminal biodegradable polymer and ultra-thin strut cobalt-chromium alloy: the INSPIRON-I trial.

BACKGROUND: The Inspiron™ sirolimus-eluting stent (SES) is a low-dose, ultra-thin-strut cobalt-chromium stent abluminally coated with biodegradable polymers (BP). Previous results from the INSPIRON-I trial, a first-in-man study, have proven the efficacy of the novel stent in reducing neointimal proliferation. The present report aims at evaluating the long-term clinical outcomes of patients enrolled into the INSPIRON-I trial (Clinical Trials Gov. identifier: NCT01093391). METHODS: A total of 57 patients (60 lesions) were randomly allocated in a 2:1 ratio to treatment with the Inspiron™ SES vs. its equivalent Cronus™ bare metal stent (BMS, both by Scitech Medical™, Aparecida de Goiânia, Goiás, Brazil), in four tertiary centers. The primary endpoint of the present analysis was the occurrence of major adverse cardiac events (MACE) [death, myocardial infarction (MI), target vessel revascularization (TVR) and/or target lesion revascularization (TLR)] at 4 years. RESULTS: Baseline clinical and angiographic characteristics of both groups were similar. After 4 years, the primary endpoint occurred in 7.9% vs. 23.5% of patients in Inspiron and control groups respectively (P=0.11). The rate of death/MI was similar between the groups, but there was a significant decrease in the risk of repeat revascularization in the Inspiron group compared to the control arm TLR (0.0% vs. 23.5% respectively, P=0.02). There were no stent thromboses in the study population. CONCLUSIONS: The novel Inspiron™ SES showed a sustained safe and effective clinical profile after 4-year of follow-up, with very low adverse events and null stent thrombosis (ST) occurrence.

Finite element analysis of stent implantation in a three-dimensional reconstructed arterial segment.

Endovascular stent deployment is a mechanical procedure used to rehabilitate a diseased arterial segment by restoring blood flow in occluded regions. The success or failure of the stent implantation depends on the stent device and the deployment technique. The optimal stent deployment can be predicted by investigating the factors that influence this minimally invasive procedure. In this study, we propose a methodology which evaluates the alterations in the arterial environment caused by stent deployment. A finite element model of a reconstructed right coronary artery with a stenosis was created based on anatomical information provided by intravascular ultrasound and angiography. The model was used to consider placement and performance after intervention with a commercially available Leader Plus stent. The performance of the stent, within this patient-specific arterial segment is presented, as well as the induced arterial deformation and straightening. The arterial stress distribution is analyzed with respect to possible regions of arterial injury. Our approach can be used to optimize stent deployment and to provide cardiologists with a valuable tool to visually select the position and deploy stents in patient-specific reconstructed arterial segments, thereby enabling new methods for optimal cardiovascular stent positioning.

First-in-man randomised comparison of a novel sirolimus-eluting stent with abluminal biodegradable polymer and thin-strut cobalt-chromium alloy: INSPIRON-I trial.

AIMS: The INSPIRON-I trial is a first-in-man evaluation of the safety and efficacy of the Inspiron drug-eluting stent, a sirolimus-eluting stent with abluminal biodegradable polymer coating and thin cobalt-chromium alloy. METHODS AND RESULTS: This is a randomised, multicentre comparison between Inspiron and a stent with the same metallic structure but without polymer coating or drug elution (Cronus). The primary objective was to evaluate the in-segment late loss (LLL) at six months. Secondary endpoints included percent in-stent obstruction as measured by intravascular ultrasound (IVUS) at six months and major adverse cardiac events (MACE). Fifty-eight patients were enrolled (60 lesions), 39 for Inspiron and 19 for Cronus. Baseline clinical and angiographic characteristics of both groups were similar. At six months, the in-segment LLL was reduced in the Inspiron group compared to the control group (0.19±0.16 mm vs. 0.58±0.4 mm, respectively; p<0.001), as well as the percent neointimal obstruction (7.8±7.1% vs. 26.5±11.4%; p<0.001). At two-year follow-up, incidence of MACE was similar between groups (7.9 vs. 21.1%, respectively; p=0.20), with lower target lesion revascularisation for Inspiron (0 vs. 21.1%, respectively; p=0.01) and no stent thrombosis. CONCLUSIONS: Sirolimus eluted from an abluminal biodegradable polymer on a cobalt-chromium alloy proved effective in reducing restenosis at six months.

Intravascular ultrasound guidance to minimize the use of iodine contrast in percutaneous coronary intervention: the MOZART (Minimizing cOntrast utiliZation With IVUS Guidance in coRonary angioplasTy) randomized controlled trial.

OBJECTIVES: The aim of this study was to evaluate the impact of intravascular ultrasound (IVUS) guidance on the final volume of contrast agent used in patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: To date, few approaches have been described to reduce the final dose of contrast agent in PCIs. We hypothesized that IVUS might serve as an alternative imaging tool to angiography in many steps during PCI, thereby reducing the use of iodine contrast. METHODS: A total of 83 patients were randomized to angiography-guided PCI or IVUS-guided PCI; both groups were treated according to a pre-defined meticulous procedural strategy. The primary endpoint was the total volume contrast agent used during PCI. Patients were followed clinically for an average of 4 months. RESULTS: The median total volume of contrast was 64.5 ml (interquartile range [IQR]: 42.8 to 97.0 ml; minimum, 19 ml; maximum, 170 ml) in the angiography-guided group versus 20.0 ml (IQR: 12.5 to 30.0 ml; minimum, 3 ml; maximum, 54 ml) in the IVUS-guided group (p < 0.001). Similarly, the median volume of contrast/creatinine clearance ratio was significantly lower among patients treated with IVUS-guided PCI (1.0 [IQR: 0.6 to 1.9] vs. 0.4 [IQR: 0.2 to 0.6, respectively; p < 0.001). In-hospital and 4-month outcomes were not different between patients randomized to angiography-guided and IVUS-guided PCI. CONCLUSIONS: Thoughtful and extensive use of IVUS as the primary imaging tool to guide PCI is safe and markedly reduces the volume of iodine contrast compared with angiography-alone guidance. The use of IVUS should be considered for patients at high risk of contrast-induced acute kidney injury or volume overload undergoing coronary angioplasty. (Minimizing cOntrast utiliZation With IVUS Guidance in coRonary angioplasTy [MOZART]; NCT01947335).

A Novel Algorithm to Quantify Coronary Remodeling Using Inferred Normal Dimensions / Novo Algoritmo para Quantificar o Remodelamento Coronário Utilizando Dimensões Normais Preditas

Background:Vascular remodeling, the dynamic dimensional change in face of stress, can assume different directions as well as magnitudes in atherosclerotic disease. Classical measurements rely on reference to segments at a distance, risking inappropriate comparison between dislike vessel portions.Objective:to explore a new method for quantifying vessel remodeling, based on the comparison between a given target segment and its inferred normal dimensions.Methods:Geometric parameters and plaque composition were determined in 67 patients using three-vessel intravascular ultrasound with virtual histology (IVUS-VH). Coronary vessel remodeling at cross-section (n = 27.639) and lesion (n = 618) levels was assessed using classical metrics and a novel analytic algorithm based on the fractional vessel remodeling index (FVRI), which quantifies the total change in arterial wall dimensions related to the estimated normal dimension of the vessel. A prediction model was built to estimate the normal dimension of the vessel for calculation of FVRI.Results:According to the new algorithm, “Ectatic” remodeling pattern was least common, “Complete compensatory” remodeling was present in approximately half of the instances, and “Negative” and “Incomplete compensatory” remodeling types were detected in the remaining. Compared to a traditional diagnostic scheme, FVRI-based classification seemed to better discriminate plaque composition by IVUS-VH.Conclusion:Quantitative assessment of coronary remodeling using target segment dimensions offers a promising approach to evaluate the vessel response to plaque growth/regression.

Fundamento:O remodelamento vascular, alteração dimensional dinâmica frente ao estresse, pode assumir diferentes direções e magnitudes na doença aterosclerótica. As medidas clássicas baseiam-se em referências a distância do segmento-alvo, com risco de comparação inadequada pela seleção de porções vasculares indesejáveis.Objetivo:Explorar um novo método para quantificar remodelamento vascular, baseado na comparação entre um determinado segmento-alvo e suas dimensões normais inferidas.Métodos:Parâmetros geométricos e a composição da placa foram determinados em 67 pacientes usando-se ultrassom intravascular de três vasos com histologia virtual (IVUS-VH). Avaliou-se o remodelamento coronário ao nível da seção transversal (n = 27.639) e da lesão (n = 618) usando-se métrica clássica e um novo algoritmo analítico baseado no índice de remodelamento vascular fracionado (FVRI) que quantifica a alteração total nas dimensões da parede arterial em relação a dimensão normal estimada do vaso. Construiu-se um modelo preditivo para estimar a dimensão normal do vaso para calcular o FVRI.Resultados:De acordo com o novo algoritmo, o padrão de remodelamento “ectásico” foi o menos comum, o remodelamento “completo compensatório” foi observado em metade dos casos, e os tipos “negativo” e “incompleto compensatório” foram detectados nos restantes. Comparada ao esquema tradicional diagnóstico, a classificação baseada no FVRI pareceu melhor discriminar a composição da placa através de IVUS-VH.Conclusão:A análise quantitativa do remodelamento coronário utilizando dimensões do segmento-alvo oferece uma abordagem promissora para avaliar a resposta vascular ao crescimento e à regressão da placa.

Infarto agudo do miocárdio complicado por choque cardiogênico: efeito da circulação colateral nos resultados da intervenção coronária percutânea primária: dados do Registro InCor / Acute myocardial infarction complicated by cardiogenic shock: effect of collateral circulation in primary coronary intervention results: data from the InCor Registry

Introdução: A presença de circulação colateral no contexto do infarto agudo do miocárdio (IAM) pode exercer um fator de proteção, levando a menor área de infarto e melhor função ventricular. Este trabalho procurou examinar as características clínicas dos pacientes com diferentes graus de circulação colateral e a influência desta na evolução do IAM com supra desnivelamento de segmento ST (IAMCSST) complicado com choque cardiogênico à admissão hospitalar e tratados com intervenção coronária percutânea (ICP) primária. Métodos: Registro unicêntrico que realizou seguimento prospectivo no período de 2001 a 2009, incluindo105 pacientes divididos em dois grupos, de acordo com o grau de circulação colateral: grupo 1, circulação colateral graus 0/1 (n = 83); e grupo 2, circulação colateral graus 2/3 (n = 22). As características clínicas e angiográficas e os desfechos hospitalares foram comparados entre os grupos. Resultados: Ambos os grupos foram semelhantes em relação às características clínicas, exceto pela menor média de idade (65,9 anos vs. 57,8 anos; P = 0,015) e maior tendência ao tabagismo atual no grupo com colateral graus 2/3 (15,7% vs. 31,8%; P = 0,08). Quanto às características angiográficas, nos indivíduos com colateral graus 2/3 houve maior frequência de lesões/paciente (1,3 lesão vs. 1,8 lesão; P = 0,02) e maior acometimento de bifurcação coronária (18,5% vs. 36,4%; P = 0,03). Na evolução intra-hospitalar ficou evidenciada menor mortalidade nos pacientes com circulação colateral exuberante (49,4% vs. 27,3%, risco relativo de 0,55; P = 0,05). Conclusões: Em pacientes com IAMCSST e choque cardiogênico tratados com ICP primária a presença de circulação colateral pode favorecer um melhor prognóstico na evolução intra-hospitalar.

Background: The presence of collateral circulation in the context of acute myocardial infarction (AMI) may play aprotective role, leading to smaller infarction areas and improvedventricular function. This study was aimed at assessing the clinical characteristics of patients with different degrees of collateral circulation and the effect on outcomes of ST segment elevation AMI (STEMI) complicated by cardiogenic shock at hospital admission and treated by primary percutaneouscoronary intervention (PCI). Methods: Single center registry with a prospective follow-up from 2001 to 2009, including 105 patients divided into two groups, according to the degree of collateral circulation: Group 1, collateral circulationgrades 0/1 (n = 83); and Group 2, collateral circulation grades 2/3 (n = 22). Clinical and angiographic characteristics and hospital outcomes were compared between groups. Results: The clinical characteristics of both groups were similar, except for a lower mean age (65.9 years vs. 57.8years; P = 0.015) and a trend to current smoking in the grade 2/3 group (15.7% vs. 31.8%; P = 0.08). As to angiographiccharacteristics, individuals with grades 2/3 had a higher rate of lesions per patient (1.3 vs. 1.8; P = 0.02) and more bifurcation lesions (18.5% vs. 36.4%; P = 0.03). In-hospital outcomes showed lower mortality in patients with good collateral circulation (49.4% vs. 27.3%, relative risk 0.55; P = 0.05). Conclusions: In patients with STEMI and cardiogenic shock treated by primary PCI, the presence of collateral circulationmay improve in-hospital prognosis.

Desfechos tardios da intervenção coronária percutânea com stent farmacológico em pontes de veia safena: dados do Registro InCor / Late percutaneous coronary intervention outcomes with drug-eluting stent in saphenous vein grafts: data from the InCor Registry

Introdução: A segurança e a eficácia do uso de stent farmacológico para o tratamento de lesões em ponte de veia safena (PVS) ainda é motivo de controvérsia. Este estudo avaliou a evolução tardia de pacientes com lesões em PVS tratados com stent farmacológico. Métodos: Registro unicêntrico que incluiu todos os pacientes submetidos a intervenção em PVS com stent farmacológico (n = 82), sem restrições clínicas ou angiográficas, no período de 2003 a 2009. Foram avaliadas as taxas de eventos cardíacos adversos maiores (ECAM), óbito, infarto agudo do miocárdio (IAM), revascularização do vaso-alvo (RVA) e trombose de stent. Resultados: A média de idade foi de 67,8 + 10,2 anos, a maioria era do sexo masculino (85,4%), 40,2% eram diabéticos e 52,4% eram portadores de angina estável. Foi utilizado 1,45 + 0,5 stent por paciente, empregando-se ostent CypherTM na maioria (61%) dos casos. O diâmetro dos stents foi de 3,22 + 0,39 mm e o comprimento, de 20,1 +7,3 mm. A taxa de sucesso angiográfico foi de 96,3%. No seguimento de 4,1 anos, a taxa de ECAM foi de 28%, com 6% de óbito, 19,5% de IAM e 18,2% de RVA. Nesse período ocorreram dois casos de trombose de stent definitiva ou provável (2,4%). Conclusões: Os resultados demonstraram, em seguimento muito tardio, altas taxas de ECAM em pacientes com lesões de PVS tratados com stent farmacológico, provavelmente pelo aspecto mais agressivo da doença vascular em enxertos venosos.

Background: The safety and efficacy of drug-eluting stents in the treatment of saphenous vein graft (SVG) lesions remains controversial. This study assessed the late follow-up of patients with SVG lesions treated with drug-eluting stents. Methods: Single center registry including patients undergoingSVG interventions using drug-eluting stents (n = 82), without clinical or angiographic exclusion criteria, from 2003 to 2009. The rates of major adverse cardiac events (MACE), death, acute myocardial infarction (AMI), target vessel revascularization (TVR) and stent thrombosis were evaluated. Results: Mean age was 67.8 + 10.2 years, most of them were male (85.4%), 40.2% were diabetic and 52.4% had stable angina. An average of 1.45 + 0.5 stents per patient were implanted and CypherTM was the stent used in most ofthe cases (61%). Stent diameter was 3.22 + 0.39 mm and stent length was 20.1 + 7.3 mm. Angiographic success rate was 96.3%. In the 4.1-year follow-up, the rate of MACE was 28%, death 6%, AMI 19.5% and TVR 18.2%. Therewere two cases of definitive or probable stent thrombosis (2.4%) within the follow-up period. Conclusions: Longtermfollow-up showed high MACE rates in patients with SVG lesions treated with drug-eluting stents, probably due tothe accelerated atherosclerosis that develops within the grafted vein conduits.

Aloenxerto de pele: um novo substituto dérmico? / Skin allograft: is it a new dermal substitute?

Introdução: a utilização de aloderme processada e armazenada em glicerol como substituto dérmico tem sido aventada na literatura, propiciando um avanço no tratamento de pacientes com grandes defeitos cutâneos. Objetivo: avaliar, através de comprovação histológica, a evolução clínica do aloenxerto de pele como substituto dérmico. Métodos: relatar um caso de avulsão completa de couro cabeludo tratado com aloenxertia de pele do Banco de Pele da Santa Casa de Porto Alegre e posterior autoenxertia. Foi realizada análise histológica do aloenxerto após 21 dias do alotransplante e acompanhamento clínico. Resultados: a paciente evoluiu com melhora do defeito e integração do aloenxerto. A análise histológica evidenciou integração com neovascularização da aloderme, sem sinais de rejeição dérmica.Houveepidermólisenaaloepiderme. A Aloderme permitiu bom substrato para autoenxertia, que em 6 meses teve pouca retração cicatricial e aceitável resultado estético. Discussão: o aloenxerto de pele parece ser um novo método de substituir-se derme, promovendo leito de boa qualidade para autoenxertia, funcionando, possivelmente, como um scaffold para regeneração dérmica. Conclusão: centímetros A análise histológica, após três semanas do aloenxerto, demonstrou integração com neovascularização, sem rejeição, possibilitando a autoenxertia sobre o aloderme. O autoenxerto evoluiu com pouca retração cicatricial e aceitável qualidade estética e funcional.

Background: the use of allografts processed and stored in glycerol as dermal substitute has been researched, propitiating an advance in the treatment of patients with great cutaneous defects. Objective: to evaluate, through histological evidence, the clinical evolution of alloderm of skin as dermal substitute. Methods: to tell a case of traumatic pulled away scalp hair treated with allograft with skin from the Santa Casa de Porto Alegre Skin Bank and posterior autograft. The allograft was histologically analyzed in 21 days, and the patient was clinical accompaniment for 6 months. Result: the patient evolves with improvement of the defect and integration of allograft. The histological analysis evidenced integration with neovascularization of alloderm, without signals of dermic rejection. It had epidermosis in aloepidermis with rejection. The Alloderm allowed good substratum for autograft, that in 6 months had little scar retraction and acceptable aesthetic result. Discussion: Allograft of skin seems to be a new method to dermal substitute, promoting a stream bed of good quality for autograft, functioning, possibly, as one scaffold for dermal regeneration. Conclusion: the histological analysis demonstrated to integration with neovascularization, without rejection, making possible the autograft on alloderm. Autograft evolved with little cicatricial retraction and acceptable aesthetic and functional quality.