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1.
Nanotechnology ; 35(17)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38253004

RESUMO

Epitaxial growth is a versatile method to prepare two-dimensional van der Waals ferroelectrics like group IV monochalcogenides which have potential for novel electronic devices and sensors. We systematically study SnSe monolayer islands grown by molecular beam epitaxy, especially the effect of annealing temperature on shape and morphology of the edges. Characterization of the samples by scanning tunneling microscopy reveals that the shape of the islands changes from fractal-dendritic after deposition at room temperature to a compact rhombic shape through annealing, but ripening processes are absent up to the desorption temperature. A two-step growth process leads to large, epitaxially aligned rhombic islands bounded by well-defined110-edges (armchair-like), which we claim to be the equilibrium shape of the stoichiometric SnSe monolayer islands. The relaxation of the energetically favorable edges is detected in atomically resolved STM images. The experimental findings are supported by the results of our first-principles calculations, which provide insights into the energetics of the edges, their reconstructions, and yields the equilibrium shapes of the islands which are in good agreement with the experiment.

2.
Clin Radiol ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38880676

RESUMO

AIMS: As the future workload of interventional radiologists in the UK continues to expand, it is imperative that current IR trainees are given maximal opportunities to expand their skill sets. This paper argues that opportunities for involvement in international collaborative fieldwork should be expanded for interventional radiology trainees in the UK, as a means of maximising their future competency and positive contribution to the advancement of global healthcare. The study builds upon first-hand experience of the authors in the field and a review of the relevant literature. MATERIALS AND METHODS: This scoping review aimed to ascertain the current global health opportunities for interventional radiology trainees primarily in Resource Limited Countries (RLCs). This review further contrasted these opportunities with ones provided to trainees within North America and European countries. RESULTS: This review found that the opportunities for international collaborative fieldwork for UK interventional radiology trainees are sparse. The availability of such opportunities in the US is significantly greater as is the awareness and appreciation of the benefits of such international collaborations for trainees. Benefits include greater experience with a variety of pathologies, a potentially larger volume of workload, improved cultural competency and proficiency and greater cost-conscious and more sustainable practices. It is also pertinent that any future global partnership opportunities for UK clinicians are crafted with care to benefit both UK and international healthcare professionals, institutions and patients within RLCs. CONCLUSION: Significant work is needed to expand opportunities for global health for interventional radiology trainees in the UK. It is incumbent upon the major radiology societies and educational bodies within the UK to expand upon such opportunities to develop a robust, world-leading workforce, which would subsequently enhance our global health positionality and reflexivity.

3.
Radiology ; 307(1): e220762, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36511804

RESUMO

Background The effects of regional histopathologic changes on prostate MRI scans have not been accurately quantified in men with an elevated prostate-specific antigen (PSA) level and no previous biopsy. Purpose To assess how Gleason grade, maximum cancer core length (MCCL), inflammation, prostatic intraepithelial neoplasia (PIN), or atypical small acinar proliferation within a Barzell zone affects the odds of MRI visibility. Materials and Methods In this secondary analysis of the Prostate MRI Imaging Study (PROMIS; May 2012 to November 2015), consecutive participants who underwent multiparametric MRI followed by a combined biopsy, including 5-mm transperineal mapping (TPM), were evaluated. TPM pathologic findings were reported at the whole-prostate level and for each of 20 Barzell zones per prostate. An expert panel blinded to the pathologic findings reviewed MRI scans and declared which Barzell areas spanned Likert score 3-5 lesions. The relationship of Gleason grade and MCCL to zonal MRI outcome (visible vs nonvisible) was assessed using generalized linear mixed-effects models with random intercepts for individual participants. Inflammation, PIN, and atypical small acinar proliferation were similarly assessed in men who had negative TPM results. Results Overall, 161 men (median age, 62 years [IQR, 11 years]) were evaluated and 3179 Barzell zones were assigned MRI status. Compared with benign areas, the odds of MRI visibility were higher when a zone contained cancer with a Gleason score of 3+4 (odds ratio [OR], 3.1; 95% CI: 1.9, 4.9; P < .001) or Gleason score greater than or equal to 4+3 (OR, 8.7; 95% CI: 4.5, 17.0; P < .001). MCCL also determined visibility (OR, 1.24 per millimeter increase; 95% CI: 1.15, 1.33; P < .001), but odds were lower with each prostate volume doubling (OR, 0.7; 95% CI: 0.5, 0.9). In men who were TPM-negative, the presence of PIN increased the odds of zonal visibility (OR, 3.7; 95% CI: 1.5, 9.1; P = .004). Conclusion An incremental relationship between cancer burden and prostate MRI visibility was observed. Prostatic intraepithelial neoplasia contributed to false-positive MRI findings. ClinicalTrials.gov registration no. NCT01292291 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Harmath in this issue.


Assuntos
Neoplasia Prostática Intraepitelial , Neoplasias da Próstata , Masculino , Humanos , Pessoa de Meia-Idade , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Neoplasia Prostática Intraepitelial/patologia , Biópsia Guiada por Imagem/métodos , Gradação de Tumores , Imageamento por Ressonância Magnética/métodos , Inflamação/patologia
4.
Med J Malaysia ; 78(1): 46-53, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36715191

RESUMO

INTRODUCTION: Studies are lacking in evaluating brain atrophy patterns in the Malaysian population. This study aimed to compare the patterns of cerebral atrophy and impaired glucose metabolism on 18F-FDG PET/CT imaging in various stages of AD in a Klang Valley population by using voxelbased morphometry in SPM12. MATERIALS AND METHODS: 18F-FDG PET/CT images of 14 healthy control (HC) subjects (MoCA score > 26 (mean+SD~ 26.93+0.92) with no clinical evidence of cognitive deficits or neurological disease) and 16 AD patients (MoCA ≤22 (mean+SD~18.6+9.28)) were pre-processed in SPM12 while using our developed Malaysian healthy control brain template. The AD patients were assessed for disease severity using ADAS-Cog neuropsychological test. KNE96 template was used for registration-induced deformation in comparison with the ICBM templates. All deformation fields were corrected using the Malaysian healthy control template. The images were then nonlinearly modified by DARTEL to segment grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) to produce group-specific templates. Age, intracranial volume, MoCA score, and ADASCog score were used as variables in two sample t test between groups. The inference of our brain analysis was based on a corrected threshold of p<0.001 using Z-score threshold of 2.0, with a positive value above it as hypometabolic. The relationship between regional atrophy in GM and WM atrophy were analysed by comparing the means of cortical thinning between normal control and three AD stages in 15 clusters of ROI based on Z-score less than 2.0 as atrophied. RESULTS: One-way ANOVA indicated that the means were equal for TIV, F(2,11) = 1.310, p=0.309, GMV, F(2,11) = 0.923, p=0.426, WMV, F(2,11) = 0.158, p=0.856 and CSF, F(2,11) = 1.495 p=0.266. Pearson correlations of GM, WM and CSF volume between HC and AD groups indicated the presence of brain atrophy in GM (p=-0.610, p<0.0001), WM (p=-0.178, p=0.034) and TIV (p=-0.374, p=0.042) but showed increased CSF volume (p=0.602, p<0.0001). Voxels analysis of the 18FFDG PET template revealed that GM atrophy differs significantly between healthy control and AD (p<0.0001). Zscore comparisons in the region of GM & WM were shown to distinguish AD patients from healthy controls at the prefrontal cortex and parahippocampal gyrus. The atrophy rate within each ROI is significantly different between groups (c2=35.9021, df=3, p<0.0001), Wilcoxon method test showed statistically significant differences were observed between Moderate vs. Mild AD (p<0.0001), Moderate AD vs. healthy control (p=0.0005), Mild AD vs. HC (p=0.0372) and Severe AD vs. Moderate AD (p<0.0001). The highest atrophy rate within each ROI between the median values ranked as follows severe AD vs. HC (p<0.0001) > mild AD vs. HC (p=0.0091) > severe AD vs. moderate AD (p=0.0143). CONCLUSION: We recommend a reliable method in measuring the brain atrophy and locating the patterns of hypometabolism using a group-specific template registered to a quantitatively validated KNE96 group-specific template. The studied regions together with neuropsychological test approach is an effective method for the determination of AD severity in a Malaysian population.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18/metabolismo , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Atrofia/metabolismo , Atrofia/patologia
5.
Eur J Immunol ; 51(2): 280-291, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33302322

RESUMO

The adaptive immune system is modulated by an important subset of CD4+ T lymphocytes called Treg cells that function in maintaining immune homeostasis by preventing excessive immune activation. Both deficiency and overactivation of Treg cell function can result in disease pathology. While loss of Treg function can lead to autoimmunity, an overabundance of Treg activity can promote tumorigenesis. Blocking and/or depleting Tregs has emerged as a viable strategy to enhance antitumor immunity. A major limitation underlying the limited efficacy observed with Treg therapies in the clinic is lack of selective targeting, often attributed to concurrent depletion of antitumor effector T-cell populations. Novel approaches to improve the specificity of Treg targeting in the context of cancer include the use of T-cell receptor mimic antibodies, bispecific antibodies, and near-infrared photoimmunotherapy. Next-generation technology platforms and transcriptomic/computational-based screening methods have been recently developed to identify preferential Treg targets. Herein, we highlight key advancements and challenges pertaining to the development of novel Treg targeting cancer therapeutics and discuss ongoing clinical trials evaluating next-generation Treg therapies for solid tumors.


Assuntos
Neoplasias/imunologia , Neoplasias/terapia , Linfócitos T Reguladores/imunologia , Animais , Anticorpos/imunologia , Humanos , Imunoterapia/métodos , Transcriptoma/imunologia
6.
Br J Cancer ; 124(6): 1037-1048, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33469153

RESUMO

The development of bispecific antibodies that redirect the cytotoxic activity of CD3+ T cells to tumours is a promising immunotherapeutic strategy for the treatment of haematological malignancies and solid cancers. Since the landmark FDA approval at the end of 2014 of the anti-CD3 × anti-CD19 bispecific antibody blinatumomab (Blincyto®) for the treatment of relapsed/refractory B-cell acute lymphoblastic leukaemia, ~100 clinical trials investigating the safety and efficacy of CD3+ bispecific T-cell redirectors for cancer have been initiated. However, despite early success, numerous challenges pertaining to CD3+ T-cell redirection in the context of cancer exist, including the recruitment of counterproductive CD3+ T-cell subsets, the release of systemic cytokines, the expansion of immune checkpoint molecules, the presence of an immunosuppressive tumour microenvironment, tumour antigen loss/escape, on-target off-tumour toxicity and suboptimal potency. The aim of the present review is to discuss novel approaches to overcome the key challenges associated with CD3+ bispecific T-cell redirection in order to achieve an optimal balance of anti-tumour activity and safety.


Assuntos
Anticorpos Biespecíficos/uso terapêutico , Antígenos CD19/imunologia , Antineoplásicos/uso terapêutico , Complexo CD3/imunologia , Neoplasias/tratamento farmacológico , Microambiente Tumoral/imunologia , Animais , Humanos , Neoplasias/imunologia , Neoplasias/patologia
7.
Catheter Cardiovasc Interv ; 97(4): E552-E559, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32779877

RESUMO

OBJECTIVES: We sought to identify baseline demographics and procedural factors that might independently predict in-hospital stroke following transcatheter aortic valve implantation (TAVI). BACKGROUND: Stroke is a recognized, albeit infrequent, complication of TAVI. Established predictors of procedure-related in-hospital stroke; however, remain poorly defined. METHODS: We conducted an observational cohort analysis of the multicenter UK TAVI registry. The primary outcome measure was the incidence of in-hospital stroke. RESULTS: A total of 8,652 TAVI procedures were performed from 2007 to 2015. There were 205 in-hospital strokes reported by participating centers equivalent to an overall stroke incidence of 2.4%. Univariate analysis showed that the implantation of balloon-expandable valves caused significantly fewer strokes (balloon-expandable 96/4,613 [2.08%] vs. self-expandable 95/3,272 [2.90%]; p = .020). After multivariable analysis, prior cerebrovascular disease (CVD) (odds ratio [OR] 1.51, 95% confidence interval [CI 1.05-2.17]; p = .03), advanced age at time of operation (OR 1.02 [0.10-1.04]; p = .05), bailout coronary stenting (OR 5.94 [2.03-17.39]; p = .008), and earlier year of procedure (OR 0.93 [0.87-1.00]; p = .04) were associated with an increased in-hospital stroke risk. There was a reduced stroke risk in those who had prior cardiac surgery (OR 0.62 [0.41-0.93]; p = .01) and a first-generation balloon-expandable valve implanted (OR 0.72 [0.53-0.97]; p = .03). In-hospital stroke significantly increased 30-day (OR 5.22 [3.49-7.81]; p < .001) and 1-year mortality (OR 3.21 [2.15-4.78]; p < .001). CONCLUSIONS: In-hospital stroke after TAVI is associated with substantially increased early and late mortality. Factors independently associated with in-hospital stroke were previous CVD, advanced age, no prior cardiac surgery, and deployment of a predominantly first-generation self-expandable transcatheter heart valve.


Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Acidente Vascular Cerebral , Substituição da Valva Aórtica Transcateter , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Estudos de Coortes , Hospitais , Humanos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento , Reino Unido/epidemiologia
8.
Catheter Cardiovasc Interv ; 98(3): E444-E452, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33502784

RESUMO

OBJECTIVES: To determine whether a permanent pacemaker (PPM) in situ can enhance survival after transcatheter aortic valve implantation (TAVI), in a predominantly inoperable or high risk cohort. BACKGROUND: New conduction disturbances are the most frequent complication of TAVI, often necessitating PPM implantation before hospital discharge. METHODS: We performed an observational cohort analysis of the UK TAVI registry (2007-2015). Primary and secondary endpoints were 30-day post-discharge all-cause mortality and long-term survival, respectively. RESULTS: Of 8,651 procedures, 6,815 complete datasets were analyzed. A PPM at hospital discharge, irrespective of when implantation occurred (PPM 1.68% [22/1309] vs. no PPM 1.47% [81/5506], odds ratio [OR] 1.14, 95% confidence interval [CI] 0.71-1.84; p = .58), or a PPM implanted peri- or post-TAVI only (PPM 1.44% [11/763] vs. no PPM 1.47% [81/5506], OR 0.98 [0.51-1.85]; p = .95) did not significantly reduce the primary endpoint. Patients with a PPM at discharge were older, male, had right bundle branch block at baseline, were more likely to have received a first-generation self-expandable prosthesis and had experienced more peri- and post-procedural complications including bailout valve-in-valve rescue, bleeding and acute kidney injury. A Cox proportional hazards model demonstrated significantly reduced long-term survival in all those with a PPM, irrespective of implantation timing (hazard ratio [HR] 1.14 [1.02-1.26]; p = .019) and those receiving a PPM only at the time of TAVI (HR 1.15 [1.02-1.31]; p = .032). The reasons underlying this observation warrant further investigation. CONCLUSIONS: A PPM did not confer a survival advantage in the first 30 days after hospital discharge following TAVI.


Assuntos
Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Marca-Passo Artificial , Substituição da Valva Aórtica Transcateter , Assistência ao Convalescente , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Humanos , Masculino , Alta do Paciente , Complicações Pós-Operatórias , Estudos Retrospectivos , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
9.
Catheter Cardiovasc Interv ; 97(3): 516-526, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-32865860

RESUMO

OBJECTIVE: To evaluate the incidence, predictors and outcomes of female patients with patient-prosthesis mismatch (PPM) following transcatheter aortic valve intervention (TAVI) for severe aortic stenosis (AS). BACKGROUND: Female AS TAVI recipients have a significantly lower mortality than surgical aortic valve replacement (SAVR) recipients, which could be attributed to the potentially lower PPM rates. TAVI has been associated with lower rates of PPM compared to SAVR. PPM in females post TAVI has not been investigated to date. METHODS: The WIN-TAVI (Women's INternational Transcatheter Aortic Valve Implantation) registry is a multicenter registry of women undergoing TAVR for severe symptomatic AS. Two hundred and fifty patients with detailed periprocedural and follow-up echocardiographic investigations were included in the WIN-TAVI echocardiographic sub-study. PPM was defined as per European guidelines stratified by the presence of obesity. RESULTS: The incidence of PPM in our population was 32.8%. Patients with PPM had significantly higher BMI (27.4 ± 6.1 vs. 25.2 ± 5.0, p = .002), smaller sized valves implanted (percentage of TAVI ≤23 mm 61% vs. 29.2%, PPM vs. no PPM, p < .001) and were more often treated with balloon expandable valves (48.3 vs. 32.5%, p < .001) rather than self expanding ones (26.3 vs. 52.8%, <.001). BMI (OR = 1.08; 95%CI 1.02-1.14, p = .011) and valve size ≤23 mm (OR = 3.00 95%CI 1.14-7.94, p = .027) were the only independent predictors of PPM. There was no significant interaction between valve size and valve type (p = .203). No significant differences were observed in 1-year mortality or major adverse cardiovascular events. CONCLUSIONS: PPM in females undergoing TAVI occurs in one third of patients. BMI and valve size ≤23 mm are independent predictors. Larger registries are required to determine the impact of PPM on future clinical outcomes.


Assuntos
Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/cirurgia , Feminino , Humanos , Complicações Pós-Operatórias , Prevalência , Sistema de Registros , Fatores de Risco , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
10.
Org Biomol Chem ; 19(13): 2949-2958, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33725086

RESUMO

Electrophilic borylation of indoles with BX3 (X = Cl or Br) using directing groups installed at N1 can proceed at the C2 or the C7 position. The six membered heterocycle directing groups utilised herein, pyridines and pyrimidine, result in indole C2 borylation being the dominant outcome (in the absence of a C2-substituent). In contrast, C7 borylation was achieved using five membered heterocycle directing groups, such as thiazole and benzoxazole. Calculations on the borylation of indole substituted with a five (thiazole) and a six (pyrimidine) membered heterocycle directing group indicated that borylation proceeds via borenium cations with arenium cation formation having the highest barrier in both cases. The C7 borylated isomer was calculated to be the thermodynamically favoured product with both five and six membered heterocycle directing groups, but for pyrimidine directed indole borylation the C2 product was calculated to be the kinetic product. This is in contrast to thiazole directed indole borylation with BCl3 where the C7 borylated isomer is the kinetic product too. Thus, heterocycle ring size is a useful way to control C2 vs. C7 selectivity in N-heterocycle directed indole C-H borylation.

11.
Chem Soc Rev ; 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32495755

RESUMO

The intramolecular C-H borylation of (hetero)arenes and alkenes using electrophilic boranes is a powerful transition metal free methodology for forming C-B bonds. These C-H borylation reactions are preceded by intermolecular bond (both dative and covalent) formation, with examples proceeding via initial C-B and N-B bond formation dominating this field thus both are discussed in depth herein. Less prevalent intramolecular electrophilic C-H borylation reactions that proceed by intermolecular O-B, S-B and P-B bond formation are also summarised. Mechanistic studies are presented that reveal two mechanisms for C-H borylation, (i) electrophilic aromatic substitution (prevalent with B-X electrophiles); (ii) σ-bond metathesis mediated (prevalent with B-H and B-R electrophiles). To date, intramolecular electrophilic C-H borylation is utilised mainly for accessing boron containing conjugated organic materials, however recent developments, summarized herein alongside early studies, have highlighted the applicability of this methodology for forming synthetically versatile organo-boronate esters and boron containing bioactives. The multitude of synthetic procedures reported for intramolecular electrophilic C-H borylation contain many common features and this enables key requirements for successful C-H borylation and the factors effecting regioselectivity and substrate scope to be identified, discussed and summarized.

12.
Cryo Letters ; 42(6): 332-340, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35366299

RESUMO

BACKGROUND: Egg yolk is inevitably associated with risks of microbial contamination and anti-cryoprotectant agents that necessitate the investigation of some synthetic alternatives. OBJECTIVE: To investigate the potential of carboxylated poly-L-lysine (CPLL) as a replacement for egg yolk during the cryosurvivability of Nili-Ravi buffalo sperm. MATERIALS AND METHODS: Semen collected from four Nili-Ravi buffalo bulls (two ejaculates / bull / day; total 40 ejaculates for five replicates) was cryopreserved in different experimental extenders viz: Control (CPLL 0%, egg yolk 20%); E1 (CPLL 5%, egg yolk 15%); E2 (CPLL 10%, egg yolk 10%); E3 (CPLL 15%, egg yolk 5%) and E4 (CPLL 20%, egg yolk 0%). Post-thaw quality was assessed in terms of sperm motility, plasma membrane integrity (PMI), viability, live:dead ratio, lipid peroxidation of sperm and total antioxidant capacity of seminal plasma. RESULTS: Sperm motility improved (P<0.05) in extenders replacing 5%, 10% and 15% egg yolk with CPLL. Sperm PMI, viability and live:dead ratio also improved (P<0.05) in extenders replacing 10%, 15% and whole (20%) egg yolk with CPLL. In contrast, sperm DNA integrity was not different (P>0.05) when CPLL replaced egg yolk at any level. The lipid peroxidation level decreased with a concomitant increase in total antioxidant activity of seminal plasma when CPLL replaced egg yolk at 5%, 10%, 15% and 20%. CONCLUSION: Replacement of 15% egg yolk in the extender with CPLL improves all sperm quality parameters: motility, PMI, viability, live:dead ratio, lipid peroxidation of sperm and total antioxidant activity of seminal plasma.


Assuntos
Búfalos , Preservação do Sêmen , Animais , Criopreservação/veterinária , Gema de Ovo , Masculino , Polilisina/farmacologia , Preservação do Sêmen/veterinária , Motilidade dos Espermatozoides , Espermatozoides
13.
N Engl J Med ; 376(19): 1824-1834, 2017 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-28317458

RESUMO

BACKGROUND: Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR. METHODS: We randomly assigned 2492 patients with coronary artery disease, in a 1:1 ratio, to undergo either iFR-guided or FFR-guided coronary revascularization. The primary end point was the 1-year risk of major adverse cardiac events, which were a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization. The trial was designed to show the noninferiority of iFR to FFR, with a margin of 3.4 percentage points for the difference in risk. RESULTS: At 1 year, the primary end point had occurred in 78 of 1148 patients (6.8%) in the iFR group and in 83 of 1182 patients (7.0%) in the FFR group (difference in risk, -0.2 percentage points; 95% confidence interval [CI], -2.3 to 1.8; P<0.001 for noninferiority; hazard ratio, 0.95; 95% CI, 0.68 to 1.33; P=0.78). The risk of each component of the primary end point and of death from cardiovascular or noncardiovascular causes did not differ significantly between the groups. The number of patients who had adverse procedural symptoms and clinical signs was significantly lower in the iFR group than in the FFR group (39 patients [3.1%] vs. 385 patients [30.8%], P<0.001), and the median procedural time was significantly shorter (40.5 minutes vs. 45.0 minutes, P=0.001). CONCLUSIONS: Coronary revascularization guided by iFR was noninferior to revascularization guided by FFR with respect to the risk of major adverse cardiac events at 1 year. The rate of adverse procedural signs and symptoms was lower and the procedural time was shorter with iFR than with FFR. (Funded by Philips Volcano; DEFINE-FLAIR ClinicalTrials.gov number, NCT02053038 .).


Assuntos
Síndrome Coronariana Aguda/fisiopatologia , Estenose Coronária/fisiopatologia , Estenose Coronária/terapia , Reserva Fracionada de Fluxo Miocárdico , Intervenção Coronária Percutânea/métodos , Síndrome Coronariana Aguda/diagnóstico por imagem , Idoso , Angina Pectoris/diagnóstico por imagem , Angina Pectoris/fisiopatologia , Doenças Cardiovasculares/mortalidade , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Retratamento , Índice de Gravidade de Doença
14.
Catheter Cardiovasc Interv ; 96(7): E747-E754, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-31631520

RESUMO

Trans-Axillary Transcatheter Aortic Valve Replacement (TAVR) has become established as the safest arterial approach when femoral arterial anatomy is unfavorable. Although a left sided axillary approach is generally preferred, patient specific factors may require use of the right axillary artery. In this case series we describe procedural modifications that are required to overcome the challenge of restricted space in the ascending aorta for in situ valve preparation of balloon-expandable valve systems when a right sided trans-Axillary approach is taken. These steps permit implantation of both the Edwards LifeSciences Sapien 3 and Ultra prostheses via the right trans-Axillary approach, allowing patients a greater range of valve options when this arterial route is required for TAVR.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Artéria Axilar , Cateterismo Periférico , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter/instrumentação , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/fisiopatologia , Cateterismo Periférico/efeitos adversos , Feminino , Humanos , Masculino , Desenho de Prótese , Punções , Índice de Gravidade de Doença , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
15.
J Thromb Thrombolysis ; 50(1): 82-89, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31605280

RESUMO

The optimal antithrombotic therapy for patients undergoing TAVI with concomitant indication for oral anticoagulation remains unclear. In this high-risk population group, there is a paucity of data with regards to the use of DOACs. In the present study we compared long-term clinical outcomes of TAVI patients requiring anticoagulation, treated with warfarin versus DOACs. Consecutive patients, who underwent TAVI with indication for oral anticoagulation from the multicenter ATLAS registry were studied and divided in two groups depending on the chosen anticoagulation regimen, warfarin vs. DOACs. 30-day survival, as well as estimated 1 and 2-year all-cause mortality were compared between groups. The secondary endpoint included in-hospital major or life-threatening bleeding. The study group included 217 patients (102 treated with warfarin; 115 treated with DOACs). Kaplan-Meier estimated survival was found to be statistically similar in the warfarin and DOAC groups (90.6% vs. 93.7% for 1-year and 84.5% vs. 88.5%, for 2-year survival, respectively, Plog-rank = 0.984). Adjusted hazard ratio for all cause mortality was similar between the two groups (HRwarfarin vs. DOAC = 1.15; 95% CI 0.33 to 4.04, p = 0.829). Propensity matching revealed similar results. At 30-days, all-cause mortality was found to be comparable between the two groups. With regards to BARC defined bleeding complications, major and life-threatening complications did not differ between the two anticoagulation groups (6% vs. 8% for warfarin and DOACs respectively, p = 0.857). DOACs seem to demonstrate a similar safety and efficacy profile compared to warfarin in TAVI patients with a concomitant indication for oral anticoagulation.


Assuntos
Estenose da Valva Aórtica/cirurgia , Inibidores do Fator Xa , Hemorragia , Efeitos Adversos de Longa Duração , Complicações Pós-Operatórias , Trombose , Substituição da Valva Aórtica Transcateter/efeitos adversos , Varfarina , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Coagulação Sanguínea/efeitos dos fármacos , Inibidores do Fator Xa/administração & dosagem , Inibidores do Fator Xa/efeitos adversos , Feminino , Hemorragia/induzido quimicamente , Hemorragia/diagnóstico , Hemorragia/prevenção & controle , Humanos , Efeitos Adversos de Longa Duração/diagnóstico , Efeitos Adversos de Longa Duração/etiologia , Efeitos Adversos de Longa Duração/mortalidade , Masculino , Seleção de Pacientes , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/prevenção & controle , Prognóstico , Sistema de Registros/estatística & dados numéricos , Análise de Sobrevida , Trombose/sangue , Trombose/etiologia , Trombose/mortalidade , Trombose/prevenção & controle , Substituição da Valva Aórtica Transcateter/métodos , Varfarina/administração & dosagem , Varfarina/efeitos adversos
16.
Eur Heart J ; 40(31): 2620-2629, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31220238

RESUMO

AIMS: The public reporting of healthcare outcomes has a number of potential benefits; however, unintended consequences may limit its effectiveness as a quality improvement process. We aimed to assess whether the introduction of individual operator specific outcome reporting after percutaneous coronary intervention (PCI) in the UK was associated with a change in patient risk factor profiles, procedural management, or 30-day mortality outcomes in a large cohort of consecutive patients. METHODS AND RESULTS: This was an observational cohort study of 123 780 consecutive PCI procedures from the Pan-London (UK) PCI registry, from January 2005 to December 2015. Outcomes were compared pre- (2005-11) and post- (2011-15) public reporting including the use of an interrupted time series analysis. Patients treated after public reporting was introduced were older and had more complex medical problems. Despite this, reported in-hospital major adverse cardiovascular and cerebrovascular events rates were significantly lower after the introduction of public reporting (2.3 vs. 2.7%, P < 0.0001). Interrupted time series analysis demonstrated evidence of a reduction in 30-day mortality rates after the introduction of public reporting, which was over and above the existing trend in mortality before the introduction of public outcome reporting (35% decrease relative risk 0.64, 95% confidence interval 0.55-0.77; P < 0.0001). CONCLUSION: The introduction of public reporting has been associated with an improvement in outcomes after PCI in this data set, without evidence of risk-averse behaviour. However, the lower reported complication rates might suggest a change in operator behaviour and decision-making confirming the need for continued surveillance of the impact of public reporting on outcomes and operator behaviour.


Assuntos
Síndrome Coronariana Aguda/cirurgia , Angina Estável/cirurgia , Cardiologistas/psicologia , Análise de Séries Temporais Interrompida/métodos , Administração dos Cuidados ao Paciente/estatística & dados numéricos , Síndrome Coronariana Aguda/diagnóstico , Idoso , Angina Estável/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/mortalidade , Estudos de Casos e Controles , Transtornos Cerebrovasculares/epidemiologia , Transtornos Cerebrovasculares/mortalidade , Tomada de Decisão Clínica/ética , Feminino , Mortalidade Hospitalar/tendências , Humanos , Masculino , Notificação de Abuso/ética , Pessoa de Meia-Idade , Administração dos Cuidados ao Paciente/ética , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/mortalidade , Intervenção Coronária Percutânea/estatística & dados numéricos , Má Conduta Profissional/estatística & dados numéricos , Estudos Prospectivos , Melhoria de Qualidade/normas , Sistema de Registros , Fatores de Risco , Resultado do Tratamento , Reino Unido/epidemiologia
17.
Circulation ; 138(17): 1780-1792, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-29789302

RESUMO

BACKGROUND: There are no data on how fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are associated with the placebo-controlled efficacy of percutaneous coronary intervention (PCI) in stable single-vessel coronary artery disease. METHODS: We report the association between prerandomization invasive physiology within ORBITA (Objective Randomised Blinded Investigation With Optimal Medical Therapy of Angioplasty in Stable Angina), a placebo-controlled trial of patients who have stable angina with angiographically severe single-vessel coronary disease clinically eligible for PCI. Patients underwent prerandomization research FFR and iFR assessment. The operator was blinded to these values. Assessment of response variables, treadmill exercise time, stress echocardiography score, symptom frequency, and angina severity were performed at prerandomization and blinded follow-up. Effects were calculated by analysis of covariance. The ability of FFR and iFR to predict placebo-controlled changes in response variables was tested by using regression modeling. RESULTS: Invasive physiology data were available in 196 patients (103 PCI and 93 placebo). At prerandomization, the majority had Canadian Cardiovascular Society class II or III symptoms (150/196, 76.5%). Mean FFR and iFR were 0.69±0.16 and 0.76±0.22, respectively; 97% had ≥1 positive ischemia tests. The estimated effect of PCI on between-arm prerandomization-adjusted total exercise time was 20.7 s (95% confidence interval [CI], -4.0 to 45.5; P=0.100) with no interaction of FFR ( Pinteraction=0.318) or iFR ( Pinteraction=0.523). PCI improved stress echocardiography score more than placebo (1.07 segment units; 95% CI, 0.70-1.44; P<0.00001). The placebo-controlled effect of PCI on stress echocardiography score increased progressively with decreasing FFR ( Pinteraction<0.00001) and decreasing iFR ( Pinteraction<0.00001). PCI did not improve angina frequency score significantly more than placebo (odds ratio, 1.64; 95% CI, 0.96-2.80; P=0.072) with no detectable evidence of interaction with FFR ( Pinteraction=0.849) or iFR ( Pinteraction=0.783). However, PCI resulted in more patient-reported freedom from angina than placebo (49.5% versus 31.5%; odds ratio, 2.47; 95% CI, 1.30-4.72; P=0.006) but neither FFR ( Pinteraction=0.693) nor iFR ( Pinteraction=0.761) modified this effect. CONCLUSIONS: In patients with stable angina and severe single-vessel disease, the blinded effect of PCI was more clearly seen by stress echocardiography score and freedom from angina than change in treadmill exercise time. Moreover, the lower the FFR or iFR, the greater the magnitude of stress echocardiographic improvement caused by PCI. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02062593.


Assuntos
Angina Estável/terapia , Cateterismo Cardíaco , Doença da Artéria Coronariana/terapia , Estenose Coronária/terapia , Reserva Fracionada de Fluxo Miocárdico , Intervenção Coronária Percutânea , Agonistas de Receptores Adrenérgicos beta 1/administração & dosagem , Idoso , Angina Estável/diagnóstico , Angina Estável/fisiopatologia , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/diagnóstico , Estenose Coronária/fisiopatologia , Dobutamina/administração & dosagem , Ecocardiografia sob Estresse/métodos , Teste de Esforço , Tolerância ao Exercício , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Valor Preditivo dos Testes , Intervalo Livre de Progressão , Qualidade de Vida , Recuperação de Função Fisiológica , Índice de Gravidade de Doença , Fatores de Tempo , Reino Unido
18.
Lancet ; 391(10115): 31-40, 2018 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-29103656

RESUMO

BACKGROUND: Symptomatic relief is the primary goal of percutaneous coronary intervention (PCI) in stable angina and is commonly observed clinically. However, there is no evidence from blinded, placebo-controlled randomised trials to show its efficacy. METHODS: ORBITA is a blinded, multicentre randomised trial of PCI versus a placebo procedure for angina relief that was done at five study sites in the UK. We enrolled patients with severe (≥70%) single-vessel stenoses. After enrolment, patients received 6 weeks of medication optimisation. Patients then had pre-randomisation assessments with cardiopulmonary exercise testing, symptom questionnaires, and dobutamine stress echocardiography. Patients were randomised 1:1 to undergo PCI or a placebo procedure by use of an automated online randomisation tool. After 6 weeks of follow-up, the assessments done before randomisation were repeated at the final assessment. The primary endpoint was difference in exercise time increment between groups. All analyses were based on the intention-to-treat principle and the study population contained all participants who underwent randomisation. This study is registered with ClinicalTrials.gov, number NCT02062593. FINDINGS: ORBITA enrolled 230 patients with ischaemic symptoms. After the medication optimisation phase and between Jan 6, 2014, and Aug 11, 2017, 200 patients underwent randomisation, with 105 patients assigned PCI and 95 assigned the placebo procedure. Lesions had mean area stenosis of 84·4% (SD 10·2), fractional flow reserve of 0·69 (0·16), and instantaneous wave-free ratio of 0·76 (0·22). There was no significant difference in the primary endpoint of exercise time increment between groups (PCI minus placebo 16·6 s, 95% CI -8·9 to 42·0, p=0·200). There were no deaths. Serious adverse events included four pressure-wire related complications in the placebo group, which required PCI, and five major bleeding events, including two in the PCI group and three in the placebo group. INTERPRETATION: In patients with medically treated angina and severe coronary stenosis, PCI did not increase exercise time by more than the effect of a placebo procedure. The efficacy of invasive procedures can be assessed with a placebo control, as is standard for pharmacotherapy. FUNDING: NIHR Imperial Biomedical Research Centre, Foundation for Circulatory Health, Imperial College Healthcare Charity, Philips Volcano, NIHR Barts Biomedical Research Centre.


Assuntos
Angina Estável/cirurgia , Estenose Coronária/cirurgia , Intervenção Coronária Percutânea , Idoso , Angina Estável/complicações , Angina Estável/diagnóstico por imagem , Angiografia Coronária , Estenose Coronária/complicações , Estenose Coronária/diagnóstico por imagem , Método Duplo-Cego , Tolerância ao Exercício , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Reino Unido
19.
Catheter Cardiovasc Interv ; 93(4): 751-757, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30394657

RESUMO

OBJECTIVES: The UK & Ireland Implanters' registry is a multicenter registry which reports on real-world experience with novel transcatheter heart valves. BACKGROUND: The 34 mm Evolut R transcatheter aortic valve is a self-expanding and fully recapturable transcatheter aortic valve, designed to treat patients with a large aortic annulus. METHODS: Between January 2017 and April 2018, clinical, procedural and 30-day outcome data were prospectively collected from all patients receiving the 34 mm Evolut R valve across 17 participating centers in the United Kingdom and Ireland. The primary efficacy outcome was the Valve Academic Research Consortium-2(VARC-2)-defined endpoint of device success. The primary safety outcome was the VARC-2-defined composite endpoint of early safety at 30 days. RESULTS: A total of 217 patients underwent attempted implant. Mean age was 79.5 ± 8.8 years and Society of Thoracic Surgeons Predicted Risk of Mortality Score 5.2% ± 3.4%. Iliofemoral access was used in 91.2% of patients. Device success was 79.7%. Mean gradient was 7.0 ± 4.6 mmHg and effective orifice area 2.0 ± 0.6 cm2 . Paravalvular regurgitation was more than mild in 7.2%. A new permanent pacemaker was implanted in 15.7%. Early safety was demonstrated in 91.2%. At 30 days, all-cause mortality was 3.2%, stroke 3.7%, and major vascular complication 2.3%. CONCLUSIONS: Real-world experience of the 34 mm Evolut R transcatheter aortic valve demonstrated acceptable procedural success, safety, valve function, and incidence of new permanent pacemaker implantation.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter/instrumentação , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/mortalidade , Estenose da Valva Aórtica/fisiopatologia , Feminino , Hemodinâmica , Humanos , Irlanda , Masculino , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Desenho de Prótese , Sistema de Registros , Medição de Risco , Fatores de Risco , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/mortalidade , Resultado do Tratamento , Reino Unido
20.
Soft Matter ; 15(30): 6237-6246, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31334527

RESUMO

Mechanical testing of connective tissues such as tendons and ligaments can lead to collagen denaturation even in the absence of macroscale damage. The following tensile loading protocols, ramp loading to failure, overloading and release, cyclic overloading and cyclic fatigue loading, all yield molecular damage in rat or bovine tendons. Single collagen fibrils extracted from the positional common digital extensor tendon of the forelimb also show molecular damage after tensile loading to failure. Using fibrils from the same source we assess changes to the molecular and supramolecular structure after tensile stress relaxation at strains between 4 and 22% followed by release. We observe no broken fibril and no significant change in D-band spacing. However, we observe significant binding of a fluorescent collagen hybridizing peptide to the fibrils indicating that collagen denaturation occurs in a strain dependent way for relaxation times between 1 s and 1500 s. We also show that peptide binding is associated with a decrease of the cross-sectional area of the fibrils providing an estimate of the dry volume loss due to molecular denaturation as well as an estimate of the mechanical energy density required, 25-110 MJ m-3. In summary we show that collagen molecular damage can occur in the absence of fibril failure and without visible changes to the supramolecular structure.


Assuntos
Colágeno/química , Estresse Mecânico , Tendões/metabolismo , Animais , Fenômenos Biomecânicos , Bovinos , Membro Anterior/metabolismo , Ratos , Tendões/química
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