EBSD-data analysis of an additive manufactured maraging 300 steel submitted to different tempering and aging treatments

This research was funded by FAPESP grants (2017/17697-5, 2019/00691-0, and 2020/09079-2) and was supported by LNNano – Brazilian Nanotechnology National Laboratory (CNPEM/MCTI) during the use of the electron microscopy open access facility. F. Conde acknowledges the Ph.D. scholarship CNPq 142440/2019-1. In addition, JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, of the Associate Laboratory Institute of Nanostructures, Nanomodelling, and Nanofabrication – i3N. Finally, Julian A. Avila is a Serra Hunter Fellow and a CNPq fellow. Publisher Copyright: © 2023 The AuthorsMaraging is a high alloy steel sensitive to the precipitation of intermetallics from a supersaturated solid solution during aging heat treatments. The precipitation phenomenon is well described in the literature, which gave rise to the alloy name regarding a martensite matrix with precipitates formed by aging treatment. Many studies have been performed to characterize this material, usually subjected to many sample preparations for transmission microscopy, which is very laborious, and few EBSD analyses. Therefore, in this work, a large study was conducted using electron backscatter diffraction (EBSD) to analyze maraging microstructures through band-contrast, kernel average misorientation (KAM), grain orientation spread (GOS), and misorientation distribution. Our results show that solubilization of the additive manufactured maraging steel resulted in a more homogeneous microstructure with new angle grain boundaries. Furthermore, tempering heat treatments relieve martensite strain, increasing band contrast values. Posterior aging presented a low impact on the results of EBSD analysis.publishersversionpublishe

Impact of Routine Use of Drug-eluting Stents in Contemporary Interventional Cardiology at a Tertiary Center: One-decade Experience of the DESIRE Registry

ABSTRACTBackgroundDrug-eluting stents (DES) have changed contemporary interventional cardiology practice, enabling the approach of increasingly more complex clinical and angiographic scenarios. The objective of this study was to demonstrate the changes observed in the last 10 years in the indication and practice of percutaneous coronary intervention (PCI) at a tertiary private hospital in the State of São Paulo.MethodsDESIRE is a single-center prospective registry aiming at following the acute and late outcomes of consecutive patients treated by DES.ResultsFrom 2002 to 2011, 4,299 patients were included, with mean age of 64.3±11.2years, 23% were female and 30.5 were diabetic. The total number of lesions treated was 6,518 of which 61.5% were type B2/C. During the course of the study, DES were progressively more used, reaching a penetration of 88.4% in 2011. The complexity of PCIs has increased and in the past year 1.76 lesions per patient were treated with an average of 1.89 DES. The SYNTAX score increased from 12.3±4.4 (2002-2006) to 15.7±4.7 (2007-2011). Clinical follow-up was obtained in 98.2% of the patients, with a median of 5.2years, and during this period target-lesion revascularization rate was 5%, myocardial infarction was 6.7% and cardiovascular death was 4.1%. Stent thrombosis was observed in 2.4% of the cases.ConclusionsOur results showed a marked increment in the complexity profile of patients treated in the last 10 years and at the same time confirm the long-term effectiveness of DES, despite the clinical and angiographic profile of patients

Impact of Side Branch Predilation on Percutaneous Coronary Intervention in Complex Coronary Bifurcation Lesions

ABSTRACTBackgroundThe treatment of coronary bifurcation lesions with single stenting in the main vessel and provisional side branch stenting may be limited by the degree of anatomical/morphological complexity. Side branch predilation, a procedural step that is typically avoided, may be required to maintain side branch patency. The impact of side branch predilation on the immediate results of percutaneous coronary intervention in complex coronary bifurcation lesions was investigated.MethodsBetween May, 2008 and August, 2009, 59 patients with single coronary bifurcation lesions and significant involvement of the main and side branches were included in the study. The main exclusion criteria were the involvement of the left main coronary artery, ST-elevation acute myocardial infarction (< 72 hours) and in-stent restenosis.ResultsThe mean age of patients was 61.2±11 years, 25.4% were female, and 30.1% had diabetes mellitus. Lesions were most prevalent in the left anterior descending artery/diagonal branch (86.4%). During the procedure, 8.5% (5/59) of lesions had unsuccessful side branch predilation, and four of these bifurcations were treated with two stents. In the multivariate model, side branch stenosis at baseline was the only significant predictor of unsuccessful side branch predilation (odds ratio 1.15, 95%CI: 1.01–1.30; P=0.04), and side branch stenosis > 87.6% was identified as the most accurate cut-off value to predict failure in the receiver operating characteristic (ROC) curve.ConclusionsSide branch predilation was associated with immediate side branch failure in < 10% of cases, and the only significant predictor in the multivariate model was side branch stenosis severity (> 85%) at baseline

Impact of occlusion duration on the success rate and outcomes of percutaneous coronary intervention in chronic total occlusions

ABSTRACTBackgroundInitial studies have shown that old occlusions or those with indeterminate occlusion duration have been associated with percutaneous coronary intervention (PCI) failure and a worse prognosis. This study aimed to determine the impact of occlusion duration on the success and outcomes of contemporary PCI on chronic total occlusion (CTO).MethodsThe authors analyzed a retrospective cohort of consecutive patients submitted to PCI in CTO, who were compared according to the confirmed occlusion duration (COD) < 12 months, ≥ 12 months, or indeterminate occlusion duration (IOD).ResultsA total of 168 patients were treated, 122 (72.6%) with COD (80 < 12 months, 42 ≥ 12 months) and 46 (24.7%) with an IOD. Lesion extension was 17.0 ± 13.6mm, in 2.90 ± 0.58mm vessels, and the anterograde approach was used in 98.8% of cases. Angiographic success was attained in 79.2% of patients (80.0% vs. 73.8% vs. 82.6%; p = 0.73). The main cause of failure was the inability to cross the lesion with the guidewire (68.6%). Occlusion duration had no impact on in-hospital events (4.8% vs. 7.1% vs. 6.0%; p = 0.73), which were almost entirely explained by periprocedural myocardial infarction, or on late outcomes (18.8% vs. 7.1% vs. 15.3%; p = 0.23). At the multivariate analysis, lesion length ≥ 20mm (odds ratio - OR = 7.27; 95% confidence interval - 95% IC 1.94-29.1; p = 0.003), calcification (OR = 4.72; 95% CI 1.19-19.1; p = 0.02), and tortuosity of the occluded segment (OR = 15.98; 95% CI 2.18-144.7; p = 0.007) were predictors of failure.ConclusionsOcclusion duration was not associated with increased failure rate of the procedure or worse PCI outcomes in CTO

Vascular response after implantation of biolimus A9-eluting stent with bioabsorbable polymer and everolimus-eluting stents with durable polymer. Results of the optical coherence tomography analysis of the BIOACTIVE randomized trial

AbstractBackgroundIn BIOACTIVE study, we evaluated vascular responses after the implant of biolimus A9-eluting stent (BES; BioMatrixTM) and the everolimus-eluting stent (EES; XIENCE VTM). In this study, we present the optical coherence tomography analysis (OCT) 6 months post-intervention.MethodsPatients were randomized to treatment with BES (n = 22) or EES (n = 18). The primary outcome was the frequency of non-covered, poorly positioned struts by OCT.ResultsOCT was performed in 26 patients (BES: n = 15; EES: n = 11) and 749 tomographic images and 7,725 stent struts were analyzed. BES and EES showed similar luminal and stent areas. Neointimal hyperplasia area, neointimal thickness and the percentage of in-stent obstruction (8.44 ± 5.10% vs. 9.21 ± 6.36%; p = 0.74) were similar. The rates of not covered struts (BES: 2.10 ± 3.60% vs. ESS: 2.46 ± 2.15%, p = 0.77) and poorly positioned struts (BES: 0.48 ± 1.48% vs. EES 0.44 ± 1.05%, p = 0.94) were similarly low. The frequency of frames with signs consistent with peri-strut inflammatory infiltrate was low and similar between BES (15.53 ± 20.77%) and EES (11.70 ± 27.51%; p = 0.68).ConclusionsThe second-generation drug-eluting stents BES and EES were equally effective at suppressing the neointimal formation after 6 months, with favorable vascular responses. The frequency of frames with peri-strut infiltrate signals per patient was low, and lower than that observed historically with first-generation drug-eluting stents

Predictors of long-term adverse events after Absorb bioresorbable vascular scaffold implantation: a 1,933-patient pooled analysis from international registries

Aims: The aim of this study was to investigate the predictors of long-term adverse clinical events after implantation of the everolimus-eluting Absorb bioresorbable vascular scaffold (BVS). Methods and results: We pooled patient-level databases derived from the large-scale ABSORB EXTEND study and five high-volume international centres. Between November 2011 and November 2015, 1,933 patients underwent PCI with a total of 2,372 Absorb BVS implanted. The median age was 61.0 (IQR 53.0 to 68.6) years, 24% had diabetes, and 68.2% presented with stable coronary artery disease. At a median follow-up of 616 days, MACE occurred in 93 (4.9%) patients, all-cause death in 36 (1.9%) patients, myocardial infarction in 47 (2.5%) patients, and target vessel revascularisation in 72 (3.8%) patients. Definite or probable scaffold thrombosis occurred in 26 (1.3%) patients. On multivariable logistic regression analysis, acute coronary syndromes (hazard ratio [HR] 2.79, 95% confidence interval [CI]: 1.47 to 5.29; p=0.002), dyslipidaemia (HR 1.43, 95% CI: 1.23 to 1.79; p=0.007), scaffold/reference diameter ratio &gt;1.25 (HR 1.49, 95% CI: 1.18 to 1.88; p=0.001), and residual stenosis &gt;15% (HR 1.67, 95% CI: 1.34 to 2.07; p&lt;0.001) were independent predictors of MACE, whereas the use of intravascular imaging was independently associated with a reduction in MACE (HR 0.13, 95% CI: 0.06 to 0.28; p&lt;0.001). Conclusions: Optimal Absorb BVS implantation and the use of intravascular imaging guidance are associated with lower rates of adverse events at long-term follow-up

POLAR registry (Promus eluting stent registry in Latin America ):1 year follow-up results

BACKGROUND: Drug-eluting stents have been used since 2002 in different patient populations aiming to achieve high success rates with low clinical and angiographic restenosis rates. With the late thrombosis adverse events associated to the first generation sirolimus and paclitaxel-eluting stents, second-generation everolimus and zotarolimus-eluting stents has been recently developed. METHODS: The POLAR registry is a prospective, non-randomized, multicenter study, which included 988 patients, totaling 1,362 lesions treated with the everolimus-eluting stent Promus®. In order to represent the clinical practice, almost all subtypes of patients and lesions were included in this registry. Clinical follow-up was planned to be performed 1, 6, 12 and 24 months after the procedure. RESULTS: Most patients were male (69.8%), with mean age of 64.9 ± 9.4 years, 35.2% were diabetics and 55% had been treated for acute coronary syndrome. Vessel diameter was 2.95 ± 0.43 mm and lesion extension was 20.5 ± 5.6 mm. A total of 1.14 ± 0.38 stent/patient were implanted and the procedural success rate was 96.6%. Major adverse cardiac events occurred in 4.5% of patients, and stent thrombosis was observed in 5 patients (0.5%) after a clinical follow-up of 12 months. CONCLUSIONS: The present registry suggests that everolimus-eluting stents are safe and effective in daily clinical practice patients, with a low rate of major adverse cardiac events at the end of the first year of follow-up.INTRODUÇÃO: Desde 2002, os stents farmacológicos são utilizados em diversas populações de pacientes objetivando alcançar elevados índices de sucesso, com baixas taxas de reestenose angiográfica e clínica. Com os resultados adversos em relação à trombose tardia associados aos stents farmacológicos de primeira geração eluidores de sirolimus e paclitaxel, surgiram recentemente os stents farmacológicos de segunda geração eluidores de zotarolimus e everolimus. MÉTODOS: O registro POLAR é um registro prospectivo, não-randomizado, multicêntrico, que incluiu 988 pacientes totalizando 1.362 lesões tratadas com o stent Promus®. Objetivando representar a prática clínica, praticamente todos os subtipos de pacientes e lesões foram incluídos neste registro. O seguimento clínico foi planejado para ser realizado 1 mês, 6 meses, 12 meses e 24 meses após o procedimento. RESULTADOS: A maioria dos pacientes era do sexo masculino (69,8%), com média de idade de 64,9 ± 9,4 anos, 35,2% eram diabéticos e 55% tinham sido tratados na vigência de síndrome coronária aguda. O diâmetro do vaso foi de 2,95 ± 0,43 mm e a extensão da lesão, de 20,5 ± 5,6 mm. Foi implantado 1,14 ± 0,38 stent/paciente e o sucesso do procedimento foi alcançado em 96,6% dos casos. Eventos cardíacos adversos maiores ocorreram em 4,1% dos pacientes, e trombose de stent esteve presente em 5 pacientes (0,5%) após o seguimento clínico de 12 meses. CONCLUSÕES: O presente registro sugere que os stents farmacológicos eluidores de everolimus são seguros e eficazes em pacientes da prática clínica diária, com baixas taxas de eventos cardíacos adversos maiores ao término do primeiro ano de seguimento.Universidade Federal de São Paulo (UNIFESP)Instituto Dante Pazzanese de CardiologiaStatus CorHospital Israelita Albert EinsteinENCORE Hospital Lúcio RebeloReal e Benemérita Associação Portuguesa de BeneficênciaHospital Cardiológico CostantiniHemodinâmica Meridional Intercath MeridionalInstituto de Cardiologia do Espírito SantoFundação Universitária de Cardiologia Instituto de Cardiologia do Rio Grande do SulUNIFESPSciEL