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2.
Catheter Cardiovasc Interv ; 101(1): 44-57, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36403271

RESUMO

OBJECTIVES: We investigated the results of T and small protrusion (TAP) versus a novel modification of TAP (mTAP) stenting by multimodality imaging in bench testing and in patients with coronary bifurcation lesions (CBL). BACKGROUND: TAP stenting is a suboptimal technique for bailout side branch (SB) stenting. METHODS: In a bench model, optical coherence tomography (OCT), microscopic examinations (ME), and computational fluid dynamics (CFD) were performed after TAP and mTAP stenting. In 20 patients with CBL, 80 intravascular ultrasound (IVUS) examinations were performed during mTAP stenting in which the SB stent was pulled-back to indent the inflated main vessel (MV) balloon and deployed while deflating it. For TAP stenting, the tip of the SB stent was positioned in the MV and deployed. RESULTS: In bench testing, OCT showed neocarina length (NL) was shorter and minimum stent area (MSA) was larger after mTAP versus TAP stenting (2.84 ± 0.70 vs. 4.80 ± 020 mm; 6.75 ± 1.50 vs. 4.5 ± 2.2 mm2 ; respectively; p < 0.05). By ME, NL was shorter and shear rate trended lower after mTAP versus TAP stenting. In patients, IVUS showed MSA was larger after versus before mTAP stenting (6.32 ± 0.58 vs. 5.21 ± 0.56 mm2 ; p < 0.01); NL was 1.43 ± 0.22 mm with SB ostium coverage. The Seattle Angina questionnaire (SAQ) score was higher at 6 months versus baseline (85 ± 4.0 vs. 48 ± 6.0, respectively; p < 0.001). CONCLUSIONS: This multimodality imaging study showed, for the first time, mTAP stenting resulted in larger stent area and shorter neocarina than TAP stenting in bench testing. In patients with CBL, mTAP stenting led to larger stent area, short neocarina with complete SB ostium coverage, and improved the SAQ score at follow-up.


Assuntos
Angioplastia Coronária com Balão , Doença da Artéria Coronariana , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Angioplastia Coronária com Balão/métodos , Angiografia Coronária , Resultado do Tratamento , Stents , Vasos Coronários/diagnóstico por imagem
3.
Front Cardiovasc Med ; 9: 868635, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35935629

RESUMO

The recent pandemic with SARS-CoV-2 raises questions worldwide regarding telemedicine for housebound patients, including those with cardiovascular conditions. The need for further investigation, monitoring and therapeutic management are advancing practical issues which had not been identified for consideration prior to the pandemic. Using the marketing assessment, we identified the needs of the patients and evaluated the future steps necessary in the short term to meet them. The research found progress made via telemedicine in monitoring and conducting minor decisions (like up-titrating the doses of different medication regimens) in patients with several cardiovascular diseases (heart failure, atrial fibrillation, high blood pressure), as there is a worldwide trend to develop new telemonitoring biosensors and devices based on implantable delivered transcatheter. The worldwide telemedicine trend encourages a switch from small and hesitating steps to a more consistent assessment of the patients, based on high technology and Interventional Cardiology. Cardiovascular telemedicine, although made a sustainable effort in managing patients' health, has many obstacles to overcome before meeting all their needs. Data security, confidentiality and reimbursement are the top priorities in developing remote Cardiology. The regulatory institutions need to play an integrative role in leading the way for defining the framework of future telemedicine activities. The SARS-CoV-2 outbreak with all its tragedy served to reinforce the message that telemedicine services can be life-saving for cardiovascular patients. Once the Covid-19 era will fade away, telemedicine is likely to remain a complementary service of standard care. There is still room to improve the remote identification and investigation of heart disease, provide an accurate diagnosis and therapeutic regimen, and update regulations and guidelines to the new realities of technological progress in the field.

4.
Polymers (Basel) ; 14(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35566886

RESUMO

Currently, the provisional stenting technique is the gold standard in revascularization of lesions located in the left main (LM) bifurcation. The benefit of the routine kissing balloon technique (KBI) in bifurcation lesions is still debated, particularly following the single stent treatment. We compared the latest-generation drug-eluting stent (DES) with no side branch (SB) dilatation "keep it open" technique (KIO) vs. KBI technique vs. bifurcation dedicated drug-eluting stent (BD-DES) implantation. In vitro testing was performed under a static condition in bifurcation silicone vessel models. All the devices were implanted in accordance with the manufacturers' recommendations. As a result, computational fluid dynamics (CFD) analysis demonstrated a statistically higher area of high shear rate in the KIO group when compared to KBI. Likewise, the maximal shear rate was higher in number in the KIO group. Floating strut count based on the OCT imaging was significantly higher in KIO than in KBI and BD-DES. Furthermore, according to OTC analysis, the thrombus area was numerically higher in both KIO and KBI than in the BD-DES. Scanning electron microscopy (SEM) analysis shows the highest degree of strut coating damage in the KBI group. This model demonstrated significant differences in CFD analysis at SB ostia with and without KBI optimization in the LM setting. The adoption of KBI was related to a meaningful reduction of flow disturbances in conventional DES and achieved results similar to BD-DES.

5.
Int J Cardiol ; 353: 43-45, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35143874

RESUMO

BACKGROUND: Currently, there exists differing conclusions on the role of acute stent malapposition and its role in stent thrombosis (ST). The European Association of Percutaneous Cardiovascular Interventions (EAPCI) consensus recommends that acute malapposition <0.4 mm with longitudinal extension <1 mm need not be corrected since there is no clear correlation of malapposition with adverse clinical outcomes. However, malapposition was identified as the main mechanism of ST in the Bern and PESTO registries, and one of the three leading mechanism in the PRESTIGE study. METHODS: In this study, a validated perfused benchtop thrombosis model was deployed to evaluate the role of both stent under-expansion (UE) and acute stent malapposition (MA) on thrombus formation in vitro in a controlled reproducible environment. RESULTS: The results showed that UE alone did not result in acute thrombus formation, but UE together with MA did. The data suggested that a MA distance of 0.25 mm led to significant thrombus formation; and a positive correlation exists between the longitudinal extension of the MA and the thrombus volume formed. CONCLUSION: Experiments in this in vitro model demonstrated that platelets and a thrombosis cascade were activated and developed around large segments of malapposed stent. This was significantly more thrombus formation than in the under-expanded stent region.


Assuntos
Intervenção Coronária Percutânea , Trombose , Plaquetas , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Stents/efeitos adversos , Trombose/diagnóstico por imagem , Trombose/etiologia , Tomografia de Coerência Óptica/métodos , Resultado do Tratamento
6.
Am Heart J ; 240: 28-45, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34077744

RESUMO

Advances in image processing and computer hardware have enabled the development of user-friendly software which operate in real-time and can be used in the catheterization laboratory to facilitate percutaneous coronary intervention (PCI). The two dimensional-(2D) quantitative coronary angiography (QCA) systems that have traditionally been used to assess lesion severity have been replaced by 3D-QCA systems, enabling more reliable evaluation of vessel geometry and lesion dimensions. This also allows 3D reconstruction of coronary bifurcation anatomy and generation of models that can be processed by computational fluid dynamic techniques to reliably detect flow-limiting lesions. More recently, software has been introduced that has the capability of generating a digital silhouette of the coronary arteries superimposed onto X-ray angiography to facilitate wire crossing and stent placement, and potentially reduce contrast use. In parallel, methodologies have been developed that operate with an accessible interface and can process intravascular imaging data, reliably quantify lesion severity and co-register intravascular and X-ray angiographic data to comprehensively assess plaque distribution and guide PCI. The above advances are used in daily practice to improve procedural results and outcomes. This review aims to provide an overview of the developments in the field - it presents the computer-based technologies that have been designed to accurately assess lesion severity, summarizes the advantages and limitations of the systems introduced to co-register imaging data and discusses the potential value of the existing and emerging software in the catheterization laboratory.


Assuntos
Cateterismo Cardíaco/métodos , Vasos Coronários/diagnóstico por imagem , Imageamento Tridimensional , Intervenção Coronária Percutânea/métodos , Software , Angiografia Coronária/métodos , Fluoroscopia/métodos , Humanos , Stents , Tomografia de Coerência Óptica/métodos , Ultrassonografia de Intervenção/métodos
7.
J Cardiovasc Transl Res ; 14(4): 595-597, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33409964

RESUMO

Provisional stenting is considered the gold standard approach for most bifurcation lesions, but the benefit of routine side branch (SB) strut dilatation has not been fully elucidated. A benchtop model was used to determine the benefits of routine side branch (SB) dilatation techniques on strut apposition, acute thrombogenicity, and flow disruption. Three different provisional bifurcation techniques were compared: no SB dilatation "keep it open" method (KIO), sequential balloon dilatation (SBD), and kissing balloon inflation (KBI). Stents were deployed in a silicon bifurcation model and perfused with blood at a flow rate of 200 ml/min for 60 min. Optical coherence tomography (OCT) pullbacks were obtained before and after flow perfusion to conduct strut analysis and acute thrombus measurement respectively. Computational fluid dynamics (CFD) models were created using OCT pullbacks and simulated based on experimental conditions to analyze flow disruption. The strut analysis showed that KBI had the lowest percentage of floating (10.6 ± 2.3%) (p = 0.0004) and malapposed (41.2 ± 8.5%) struts (p = 0.59), followed by SBD and then KIO. This correlated to KBI having the lowest amount of thrombus formed at the SB, followed by SBD, with KIO being the most thrombogenic (KBI: 0.84 ± 0.22mm2, SBD: 1.17 ± 0.25mm2, KIO: 1.31 ± 0.36mm2, p = 0.18). CFD models also predicted a similar trend, with KBI having the lowest amount of area of high shear rate as well as flow recirculation. Based on this benchtop model, SB intervention strategies demonstrated a reduction in number of struts and resulting thrombogenicity at the bifurcation ostia. Graphical abstract.


Assuntos
Angioplastia Coronária com Balão/instrumentação , Doença da Artéria Coronariana/terapia , Vasos Coronários/fisiopatologia , Stents Farmacológicos , Angioplastia Coronária com Balão/efeitos adversos , Simulação por Computador , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Trombose Coronária/etiologia , Trombose Coronária/fisiopatologia , Hemodinâmica , Humanos , Hidrodinâmica , Modelos Anatômicos , Modelos Cardiovasculares , Estresse Mecânico , Tomografia de Coerência Óptica
8.
Cardiovasc Revasc Med ; 24: 11-17, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32972876

RESUMO

BACKGROUND: Percutaneous coronary interventions on complex bifurcation lesions may require implantation of two stents to appropriately treat diffuse side-branch (SB) disease. Comparisons among different bifurcation stenting techniques are continuously attempted by various study designs (bench tests, computer simulations, clinical studies). Among different techniques, double kissing crush (DKC) represents the last evolution for "crushing" while T and small Protrusion (TAP) represents the evolution of "T stenting". Both techniques are actually gaining popularity, but head-to-head comparisons are lacking. METHODS AND RESULTS: Two last generation drug-eluting stents (Synergy™, Boston Scientific, MA, USA and Ultimaster™,Terumo Corp., Japan) were implanted in left main bifurcation bench models using TAP (n = 6 sets) and DKC (n = 6 sets) techniques. A peristaltic pump with fresh porcine blood was used to perfuse the blood through the silicone model at a flow rate of 200 ml/min for 4 min. Optical coherence tomography (OCT) was used to assess stent struts geometry and thrombus formation. SB cross sectional area as well as SB obstruction did not significantly differ between the two techniques. Numerical (but not statistically significant) differences were found in terms of malapposed struts (fewer with TAP) and floating struts (fewer with DKC). Thrombus formation after blood perfusion was similar between TAP and DKC technique (1.53 ± 1.12 vs. 1.20 ± 1.01 mm2, p = 0.6). CONCLUSION: The result of the present in-vitro study shows the absence of significant difference between TAP and DKC in terms of stent struts apposition and acute thrombus formation potential. Despite the completely different technical steps required, both techniques have similar performance according to such articulated pre-clinical evaluation. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT?: Due to its limited complexity, T and Protrusion (TAP) technique is considered the to-go technique for bifurcation lesions with good long-term results. Recently, double kissing crush (DKC) technique has been gaining popularity and demonstrated promising results in randomized clinical trials. WHAT DOES THIS STUDY ADD?: This in-vitro bench test study provides a unique detailed OCT comparison and local hemodynamic environment analysis of the two techniques. HOW MIGHT THIS IMPACT ON CLINICAL PRACTICE?: New insights of acute thrombogenicity and computational flow model simulation may guide percutaneous therapeutic strategies of bifurcation lesions.


Assuntos
Angioplastia Coronária com Balão , Stents Farmacológicos , Intervenção Coronária Percutânea , Angioplastia Coronária com Balão/efeitos adversos , Intervenção Coronária Percutânea/efeitos adversos , Stents , Tomografia de Coerência Óptica
9.
Sci Rep ; 10(1): 20791, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247219

RESUMO

Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. Overhanging struts in front of the side branch (SB) ostium are thought to act as a focal point for thrombi formation and consequently possible stent thrombosis. This study aimed to evaluate the overexpansion capabilities and thrombogenicity at the SB ostia after implantation of four latest generation drug-eluting stents (DES) in an in-vitro bifurcation model. Four clinically available modern DES were utilized: one bifurcation dedicated DES (Bioss LIM C) and three conventional DES (Ultimaster, Xience Sierra, Biomime). All devices were implanted in bifurcation models with proximal optimization ensuring expansion before perfusing with porcine blood. Optical coherence tomography (OCT), immunofluorescence (IF) and scanning electron microscope analysis were done to determine thrombogenicity and polymer coating integrity at the over-expanded part of the stents. Computational fluid dynamics (CFD) was performed to study the flow disruption. OCT (p = 0.113) and IF analysis (p = 0.007) demonstrated lowest thrombus area at SB ostia in bifurcation dedicated DES with favorable biomechanical properties compared to conventional DES. The bifurcated DES also resulted in reduced area of high shear rate and maximum shear rate in the CFD analysis. This study demonstrated numerical differences in terms of mechanical properties and acute thrombogenicity at SB ostia between tested devices.


Assuntos
Stents Farmacológicos/efeitos adversos , Stents Metálicos Autoexpansíveis/efeitos adversos , Trombose/etiologia , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/instrumentação , Animais , Fenômenos Biomecânicos , Estenose Coronária/patologia , Estenose Coronária/cirurgia , Trombose Coronária/etiologia , Vasos Coronários/patologia , Vasos Coronários/cirurgia , Imunofluorescência , Hemodinâmica , Humanos , Hidrodinâmica , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Modelos Cardiovasculares , Desenho de Prótese , Suínos , Tomografia de Coerência Óptica
10.
Vasc Med ; 25(6): 577-587, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32634046

RESUMO

The advancement of drug-coated balloons (DCB) presents an alternative nonstent method in the percutaneous treatment of atherosclerotic lesions. While the current generation of drug-eluting stents (DES) are the device of choice, especially in coronary artery disease (CAD), DCB has potential applications in the treatment of de novo lesions, in-stent restenosis (ISR), bifurcations, and in peripheral artery disease (PAD). In terms of coronary clinical experience, DCB is used most in ISR scenarios and more data are collected to support the use of DCB in de novo lesions compared to best-in-class DES. The use of DCB in bifurcation side branch treatment has demonstrated safety, and with good angiographic and clinical outcomes, but more data from randomized trials will be required to assess its clinical value. For PAD, the clinical outcomes of DCB with and without debulking devices in diseased femoropopliteal arteries and treatment of below-the-knee (BTK) vessels with DCB are discussed. Current data demonstrated conflicting long-term safety outcomes in the use of paclitaxel devices in the femoral and/or popliteal arteries, while the role of DCB in BTK disease remains uncertain due to a lack of randomized controlled trial data. In summary, this review provides an overall view of current DCB technologies and progress, followed by an update on DCB clinical data in the treatment of CAD and PAD.


Assuntos
Angioplastia com Balão/instrumentação , Fármacos Cardiovasculares/uso terapêutico , Materiais Revestidos Biocompatíveis , Doença da Artéria Coronariana/terapia , Doença Arterial Periférica/terapia , Dispositivos de Acesso Vascular , Angioplastia com Balão/efeitos adversos , Angioplastia Coronária com Balão/instrumentação , Cateteres Cardíacos , Fármacos Cardiovasculares/efeitos adversos , Doença da Artéria Coronariana/diagnóstico por imagem , Desenho de Equipamento , Humanos , Doença Arterial Periférica/diagnóstico por imagem , Resultado do Tratamento
11.
Platelets ; 31(2): 167-173, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30973035

RESUMO

Stent thrombosis remains an infrequent but significant complication following percutaneous coronary intervention. Preclinical models to rapidly screen and validate therapeutic compounds for efficacy are lacking. Herein, we describe a reproducible, high throughput and cost-effective method to evaluate candidate therapeutics and devices for either treatment or propensity to develop stent thrombosis in an in vitro bench-top model. Increasing degree of stent malapposition (0.00 mm, 0.10 mm, 0.25 mm and 0.50 mm) was associated with increasing thrombosis and luminal area occlusion (4.1 ± 0.5%, 6.3 ± 0.5%, 19.7 ± 4.5%, and 92.6 ± 7.4%, p < 0.0001, respectively). Differences in stent design in the form of bare-metal, drug-eluting, and bioresorbable vascular scaffolds demonstrated differences in stent thrombus burden (14.7 ± 3.8% vs. 20.5 ± 3.1% vs. 86.8 ± 5.3%, p < 0.01, respectively). Finally, thrombus burden was significantly reduced when healthy blood samples were incubated with Heparin, ASA/Ticagrelor (DAPT), and Heparin+DAPT compared to control (DMSO) at 4.1 ± 0.6%, 6.9 ± 1.7%, 4.5 ± 1.2%, and 12.1 ± 1.8%, respectively (p < 0.01). The reported model produces high throughput reproducible thrombosis results across a spectrum of antithrombotic agents, stent design, and degrees of apposition. Importantly, performance recapitulates clinical observations of antiplatelet/antithrombotic regimens as well as device and deployment characteristics. Accordingly, this model may serve as a screening tool for candidate therapies in preclinical evaluation.


Assuntos
Trombose Coronária/etiologia , Stents/efeitos adversos , Fenômenos Fisiológicos Sanguíneos/efeitos dos fármacos , Trombose Coronária/complicações , Trombose Coronária/diagnóstico por imagem , Trombose Coronária/enzimologia , Stents Farmacológicos/efeitos adversos , Enzimas/sangue , Humanos , Técnicas In Vitro , Modelos Biológicos , Intervenção Coronária Percutânea/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Trombose/sangue , Trombose/complicações , Trombose/enzimologia , Tomografia de Coerência Óptica
12.
Circ J ; 84(1): 91-100, 2019 12 25.
Artigo em Inglês | MEDLINE | ID: mdl-31735729

RESUMO

BACKGROUND: Attenuation-compensated (AC) technique was recently introduced to improve the plaque characterization of optical coherence tomography (OCT). Histological validation demonstrated promising results but the efficacy and reproducibility of this technique for assessing in-vivo tissue composition remains unclear.Methods and Results:OCT images portraying native (n=200) and stented (n=200) segments and 31 histological cross-sections were analyzed. AC-OCT appeared superior to conventional (C)-OCT in detecting the external elastic lamina (EEM) borders (76% vs. 65.5%); AC-OCT enabled larger EEM arc detection compared with C-OCT (174.2±58.7° vs. 137.5±57.9°; P<0.001). There was poor agreement between the 2 techniques for detection of lipid in native and lipid and calcific tissue in stented segments (κ range: 0.164-0.466) but the agreement of C-OCT and AC-OCT was high for calcific tissue in native segments (κ=0.825). Intra and interobserver agreement of the 2 analysts was moderate to excellent with C-OCT (κ range: 0.681-0.979) and AC-OCT (κ range: 0.733-0.892) for all tissue types in both native and stented segments. Ex-vivoanalysis demonstrated that C-OCT was superior to AC-OCT (κ=0.545 vs. κ=0.296) for the detection of the lipid component in native segments. CONCLUSIONS: The AC technique allows better delineation of the EEM but it remains inferior for lipid pool detection and neointima characterization. Combined AC- and C-OCT imaging may provide additional value for complete assessment of plaque and neointima characteristics.


Assuntos
Doença da Artéria Coronariana , Vasos Coronários , Placa Aterosclerótica , Tomografia de Coerência Óptica , Idoso , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/metabolismo , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/metabolismo
13.
Sci Rep ; 9(1): 10072, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296912

RESUMO

We aimed to identify independent predictors of cardiac mortality and hospitalization for heart failure (HHF) from a real-world, multi-ethnic Asian registry [the Singapore Myocardial Infarction Registry] of ST-segment elevation myocardial infarction (STEMI) patients treated by primary percutaneous coronary intervention. 11,546 eligible STEMI patients between 2008 and 2015 were identified. In-hospital, 30-day and 1-year cardiac mortality and 1-year HHF rates were 6.4%, 6.8%, 8.3% and 5.2%, respectively. From the derivation cohort (70% of patients), age, Killip class and cardiac arrest, creatinine, hemoglobin and troponin on admission and left ventricular ejection fraction (LVEF) during hospitalization were predictors of in-hospital, 30-day and 1-year cardiac mortality. Previous ischemic heart disease (IHD) was a predictor of in-hospital and 30-day cardiac mortality only, whereas diabetes was a predictor of 1-year cardiac mortality only. Age, previous IHD and diabetes, Killip class, creatinine, hemoglobin and troponin on admission, symptom-to-balloon-time and LVEF were predictors of 1-year HHF. The c-statistics were 0.921, 0.901, 0.881, 0.869, respectively. Applying these models to the validation cohort (30% of patients) showed good fit and discrimination (c-statistic 0.922, 0.913, 0.903 and 0.855 respectively; misclassification rate 14.0%, 14.7%, 16.2% and 24.0% respectively). These predictors could be incorporated into specific risk scores to stratify reperfused STEMI patients by their risk level for targeted intervention.


Assuntos
Fatores Etários , Povo Asiático , Insuficiência Cardíaca/diagnóstico , Infarto do Miocárdio/diagnóstico , Intervenção Coronária Percutânea , Idoso , Estudos de Coortes , Eletrocardiografia , Feminino , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/cirurgia , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/cirurgia , Prognóstico , Fatores de Risco , Singapura , Análise de Sobrevida , Resultado do Tratamento
14.
Sci Rep ; 8(1): 17409, 2018 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-30479353

RESUMO

Bioresorbable scaffolds (BRS) were introduced to overcome limitations of current metallic drug-eluting stents and poly-L-lactide (PLLA) has been used in the fabrication of BRS due to its biodegradability and biocompatibility. However, such polymers have weaker mechanical properties as compared to metals, limiting their use in BRS. We hypothesized that nanofillers can be used to enhance the mechanical properties considerably in PLLA. To this end, polymer-matrix composites consisting of PLLA reinforced with 5-20 wt% barium sulfate (BaSO4) nanofillers as a potential BRS material was evaluated. Stearic-acid (SA) modified BaSO4 nanofillers were used to examine the effect of functionalization. Rigid nanofillers improved the tensile modulus and strength of PLLA (60% and 110% respectively), while the use of SA-BaSO4 caused a significant increase (~110%) in the elongation at break. Enhancement in mechanical properties is attributed to functionalization which decreased the agglomeration of the nanofillers and improved dispersion. The nanocomposites were also radiopaque. Finite element analysis (FEA) showed that scaffold fabricated from the novel nanocomposite material has improved scaffolding ability, specifically that the strut thickness could be decreased compared to the conventional PLLA scaffold. In conclusion, BaSO4/PLLA-based nanocomposites could potentially be used as materials for BRS with improved mechanical and radiopaque properties.


Assuntos
Materiais Biocompatíveis/química , Stents Farmacológicos , Nanocompostos/química , Sulfato de Bário/química , Meios de Contraste/química , Análise de Elementos Finitos , Poliésteres/química , Resistência à Tração
15.
Acta Physiol (Oxf) ; 224(4): e13109, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29935058

RESUMO

AIM: Severe aortic stenosis frequently involves the development of left ventricular hypertrophy (LVH) creating a dichotomous haemodynamic state within the coronary circulation. Whilst the increased force of ventricular contraction enhances its resultant relaxation and thus increases the distal diastolic coronary "suction" force, the presence of LVH has a potentially opposing effect on ventricular-coronary interplay. The aim of this study was to use non-invasive coronary wave intensity analysis (WIA) to separate and measure the sequential effects of outflow tract obstruction relief and then LVH regression following intervention for aortic stenosis. METHODS: Fifteen patients with unobstructed coronary arteries undergoing aortic valve intervention (11 surgical aortic valve replacement [SAVR], 4 TAVI) were successfully assessed before and after intervention, and at 6 and 12 months post-procedure. Coronary WIA was constructed from simultaneously acquired coronary flow from transthoracic echo and pressure from an oscillometric brachial cuff system. RESULTS: Immediately following intervention, a decline in the backward decompression wave (BDW) was noted (9.7 ± 5.7 vs 5.1 ± 3.6 × 103  W/m2 /s, P < 0.01). Over 12 months, LV mass index fell from 114 ± 19 to 82 ± 17 kg/m2 . Accompanying this, the BDW fraction increased to 32.8 ± 7.2% at 6 months (P = 0.01 vs post-procedure) and 34.7 ± 6.7% at 12 months (P < 0.001 vs post-procedure). CONCLUSION: In aortic stenosis, both the outflow tract gradient and the presence of LVH impact significantly on coronary haemodynamics that cannot be appreciated by examining resting coronary flow rates alone. An immediate change in coronary wave intensity occurs following intervention with further effects appreciable with hypertrophy regression. The improvement in prognosis with treatment is likely to be attributable to both features.


Assuntos
Estenose da Valva Aórtica/cirurgia , Circulação Coronária , Implante de Prótese de Valva Cardíaca , Hipertrofia Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda , Obstrução do Fluxo Ventricular Externo/fisiopatologia , Remodelação Ventricular , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/fisiopatologia , Ecocardiografia Doppler , Feminino , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Masculino , Recuperação de Função Fisiológica , Indução de Remissão , Índice de Gravidade de Doença , Fatores de Tempo , Substituição da Valva Aórtica Transcateter , Resultado do Tratamento , Obstrução do Fluxo Ventricular Externo/diagnóstico por imagem
17.
Catheter Cardiovasc Interv ; 92(6): 1021-1027, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-29508518

RESUMO

OBJECTIVES: To date, experience with bioresorbable scaffolds (BRS) that elute agents other than everolimus is limited. Thus, a post-marketing clinical follow-up study was conducted to evaluate the continued safety and effectiveness of the DESolve® NOVOLIMUS™ Eluting BRS as treatment for patients with stable coronary artery disease. BACKGROUND: The DESolve BRS combines a poly-l-lactide-based backbone with a biodegradable polylactide-based polymer and Novolimus, a macrocyclic lactone mTOR inhibitor. METHODS: One hundred and two patients (mean age 62 years, 77.5% male) were enrolled at 10 European sites. Comparison of baseline and post-procedural angiographic assessment was performed, and a device-oriented composite endpoint (comprising cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization) and rate of scaffold thrombosis at 12 months were examined. RESULTS: The device was successfully delivered and deployed in 98.2% (107/109) of the lesions, with two failures to cross the lesion. A total of 100 patients (109 lesions) were treated with a DESolve BRS. Post-procedural angiographic assessment indicated an in-scaffold acute gain of 1.54 ± 0.44 mm, with a reduction in % diameter stenosis from 61.00 ± 11.29 to 12.69 ± 0.44. At 12 months, the device-oriented composite endpoint had occurred in 3.0% (3/100) of patients, with 1.0% (1/100) experiencing scaffold thrombosis and myocardial infarction and 3.0% (3/100) undergoing target lesion revascularization. There were no cardiac deaths. CONCLUSIONS: Results through 12 months indicate that the DESolve BRS is a safe and effective treatment for coronary lesions, though larger, long-term prospective studies are needed.


Assuntos
Implantes Absorvíveis , Fármacos Cardiovasculares/administração & dosagem , Doença da Artéria Coronariana/cirurgia , Macrolídeos/administração & dosagem , Intervenção Coronária Percutânea/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Fármacos Cardiovasculares/efeitos adversos , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Trombose Coronária/etiologia , Feminino , Alemanha , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/mortalidade , Vigilância de Produtos Comercializados , Estudos Prospectivos , Desenho de Prótese , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
19.
Catheter Cardiovasc Interv ; 92(5): 907-914, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29368394

RESUMO

OBJECTIVES: We assess the mid-term outcomes of ultrathin biodegradable polymer double stenting using a very minimal crushing (Nano-Crush) technique in large complex coronary bifurcation. BACKGROUND: Complex bifurcations have been suggested to be better approached by a planned double stent technique. METHODS: Two hundred and five consecutive patients (107 males and 98 females) referred for large complex coronary bifurcation percutaneous coronary interventions were enrolled. The technique was also evaluated by both a bench test with a silicon tubes phantom resembling a coronary bifurcation and a computed fluid dynamic (CFD) analysis. RESULTS: Left main bifurcation accounted for 40.9% of cases (84 patients). Mean angles between main branch (MB) and side branch (SB) were 63.6 ± 21.3°. SB intravascular ultrasound-calculated MSA was 5.6 ± 1.5 mm2 . Clinical follow-up was available for 100% of patients and at a mean follow-up of 16.2 ± 6.7 months 8 deaths, all due to cardiovascular reason, (3.9%, 4 patients for stroke, two for heart failure, one after surgical aortic valve substitution, and one after acute massive pulmonary embolism) and no presumptive stent thrombosis or target vessel induced ischemia were observed. Angiographic follow-up was available in 108 patients (52.7%) and showed a very low significant restenosis (5 patients, 4.6%). Bench study and CFD evaluation suggested a complete coverage of the SB ostium with a very high strut-free area at the SB. CONCLUSIONS: The revascularization of complex large coronary bifurcation disease using the Nano-crush technique appeared promising thanks to the favorable fluid dynamic profile, complete coverage of the SD ostium, and very small metal amount at the carina.


Assuntos
Implantes Absorvíveis , Angioplastia Coronária com Balão/instrumentação , Doença da Artéria Coronariana/terapia , Stents , Idoso , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/mortalidade , Simulação por Computador , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Feminino , Humanos , Hidrodinâmica , Masculino , Teste de Materiais , Modelos Anatômicos , Modelos Cardiovasculares , Desenho de Prótese , Sistema de Registros , Fatores de Tempo , Resultado do Tratamento
20.
Curr Pharm Des ; 24(4): 381-396, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29283056

RESUMO

The progress and development of drug-coated balloons (DCBs) represents an emerging alternative treatment in peripheral and coronary artery diseases, particularly when a non-stent approach is necessary. Several studies and meta-analyses have evaluated the clinical outcomes of DCBs in different lesions and this review aims to compile the progress and updated clinical data of DCB strategy in both peripheral artery diseases (PAD) and coronary artery diseases (CAD). The review highlights that clinical data has encouraged the use of DCB for applications in PAD and in the treatment of coronary in-stent restenosis (ISR). The employment of DCB in side branch treatment of bifurcation lesions has been reported to be feasible and safe, with good angiographic and clinical outcome. The use of DCB for arteriovenous fistula and grafts stenoses is a promising strategy, but more clinical data is required to draw reliable conclusions. The limitations and impact of the current generation of DCBs will be discussed and the clinical development of newer generation of the device is also covered in this review.


Assuntos
Doença da Artéria Coronariana/terapia , Stents Farmacológicos , Doença Arterial Periférica/terapia , Humanos
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