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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.MethodsâandâResults: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.
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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/metabolismoRESUMO
OPINION STATEMENT: Early detection and treatment of cardiotoxicity from cancer therapies is key to preventing a rise in adverse cardiovascular outcomes in cancer patients. Over-diagnosis of cardiotoxicity in this context is however equally hazardous, leading to patients receiving suboptimal cancer treatment, thereby impacting cancer outcomes. Accurate screening therefore depends on the widespread availability of sensitive and reproducible biomarkers of cardiotoxicity, which can clearly discriminate early disease. Blood biomarkers are limited in cardiovascular disease and clinicians generally still use generic screening with ejection fraction, based on historical local expertise and resources. Recently, however, there has been growing recognition that simple measurement of left ventricular ejection fraction using 2D echocardiography may not be optimal for screening: diagnostic accuracy, reproducibility and feasibility are limited. Modern cancer therapies affect many myocardial pathways: inflammatory, fibrotic, metabolic, vascular and myocyte function, meaning that multiple biomarkers may be needed to track myocardial cardiotoxicity. Advanced imaging modalities including cardiovascular magnetic resonance (CMR), computed tomography (CT) and positron emission tomography (PET) add improved sensitivity and insights into the underlying pathophysiology, as well as the ability to screen for other cardiotoxicities including coronary artery, valve and pericardial diseases resulting from cancer treatment. Delivering screening for cardiotoxicity using advanced imaging modalities will however require a significant change in current clinical pathways, with incorporation of machine learning algorithms into imaging analysis fundamental to improving efficiency and precision. In the future, we should aspire to personalized rather than generic screening, based on a patient's individual risk factors and the pathophysiological mechanisms of the cancer treatment they are receiving. We should aspire that progress in cardiooncology is able to track progress in oncology, and to ensure that the current 'one size fits all' approach to screening be obsolete in the very near future.
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Cardiotoxicidade/diagnóstico por imagem , Cardiotoxicidade/etiologia , Diagnóstico por Imagem , Neoplasias/complicações , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores , Cardiotoxicidade/fisiopatologia , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/etiologia , Diagnóstico por Imagem/efeitos adversos , Diagnóstico por Imagem/métodos , Humanos , Imagem Multimodal/métodos , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/etiologia , Neoplasias/tratamento farmacológico , Disfunção VentricularRESUMO
BACKGROUND: The shear stress distribution assessment can provide useful insights for the hemodynamic performance of the implanted stent/scaffold. Our aim was to investigate the effect of a novel bioresorbable scaffold, Mirage on local hemodynamics in animal models. METHOD: The main epicardial coronary arteries of 7 healthy mini-pigs were implanted with 11 Mirage Microfiber sirolimus-eluting Bioresorbable Scaffolds (MMSES). Optical coherence tomography (OCT) was performed post scaffold implantation and the obtained images were fused with angiographic data to reconstruct the coronary artery anatomy. Blood flow simulation was performed and Endothelial Shear Stress(ESS) distribution was estimated for each of the 11 scaffolds. ESS data were extracted in each circumferential 5-degree subunit of each cross-section in the scaffolded segment. The generalized linear mixed-effect analysis was implemented for the comparison of ESS in two scaffold groups; 150-µm strut thickness MMSES and 125-µm strut thickness MMSES. RESULTS: ESS was significantly higher in MMSES (150 µm) [0.85(0.49-1.40) Pa], compared to MMSES (125 µm) [0.68(0.35-1.18) Pa]. Both MMSES (150 µm) and MMSES (125 µm) revealed low recirculation zone percentages per luminal surface area [3.17% ± 1.97% in MMSES (150 µm), 2.71% ± 1.32% in MMSES (125 µm)]. CONCLUSION: Thinner strut Mirage scaffolds induced lower shear stress due to the small size vessels treated as compared to the thick strut version of the Mirage which was implanted in relatively bigger size vessels. Vessel size should be taken into account in planning BRS implantation. Small vessels may not get benefit from BRS implantation even with a streamlined strut profile. This pilot study warrants comparative assessment with commercially available bioresorbable scaffolds.
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Implantes Absorvíveis , Fármacos Cardiovasculares/administração & dosagem , Materiais Revestidos Biocompatíveis , Vasos Coronários/cirurgia , Hemodinâmica , Intervenção Coronária Percutânea/instrumentação , Sirolimo/administração & dosagem , Animais , Velocidade do Fluxo Sanguíneo , Simulação por Computador , Circulação Coronária , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Modelos Animais , Modelos Cardiovasculares , Desenho de Prótese , Estresse Mecânico , Suínos , Porco Miniatura , Fatores de Tempo , Tomografia de Coerência ÓpticaRESUMO
AIMS: Clinical trials suggest that intracoronary delivery of autologous bone marrow-derived cells (BMCs) 1-7 days post-acute myocardial infarction (AMI) may improve left ventricular (LV) function. Earlier time points have not been evaluated. We sought to determine the effect of intracoronary autologous BMC on LV function when delivered within 24 h of successful reperfusion therapy. METHODS AND RESULTS: A multi-centre phase II randomized, double-blind, and placebo-controlled trial. One hundred patients with anterior AMI and significant regional wall motion abnormality were randomized to receive either intracoronary infusion of BMC or placebo (1:1) within 24 h of successful primary percutaneous intervention (PPCI). The primary endpoint was the change in left ventricular ejection fraction (LVEF) between baseline and 1 year as determined by advanced cardiac imaging. At 1 year, although LVEF increased compared with baseline in both groups, the between-group difference favouring BMC was small (2.2%; 95% confidence interval, CI: -0.5 to 5.0; P = 0.10). However, there was a significantly greater myocardial salvage index in the BMC-treated group compared with placebo (0.1%; 95% CI: 0.0-0.20; P = 0.048). Major adverse events were rare in both treatment groups. CONCLUSION: The early infusion of intracoronary BMC following PPCI for patients with AMI and regional wall motion abnormality leads to a small non-significant improvement in LVEF when compared with placebo; however, it may play an important role in infarct remodelling and myocardial salvage.
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Infarto Miocárdico de Parede Anterior/terapia , Transplante de Medula Óssea/métodos , Infarto Miocárdico de Parede Anterior/patologia , Infarto Miocárdico de Parede Anterior/fisiopatologia , Angiografia por Tomografia Computadorizada , Método Duplo-Cego , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/metabolismo , Fragmentos de Peptídeos/metabolismo , Intervenção Coronária Percutânea/métodos , Qualidade de Vida , Terapia de Salvação/métodos , Volume Sistólico/fisiologia , Transplante Autólogo , Disfunção Ventricular Esquerda/diagnósticoRESUMO
BACKGROUND: The benefit of the coronary collateral circulation (natural bypass network) on survival is well established. However, data derived from smaller studies indicates that coronary collaterals may increase the risk for restenosis after percutaneous coronary interventions. The purpose of this systematic review and meta-analysis of observational studies was to explore the impact of the collateral circulation on the risk for restenosis. METHODS: We searched the MEDLINE, EMBASE and ISI Web of Science databases (2001 to 15 July 2011). Random effects models were used to calculate summary risk ratios (RR) for restenosis. The primary endpoint was angiographic restenosis > 50%. RESULTS: A total of 7 studies enrolling 1,425 subjects were integrated in this analysis. On average across studies, the presence of a good collateralization was predictive for restenosis (risk ratio (RR) 1.40 (95% CI 1.09 to 1.80); P = 0.009). This risk ratio was consistent in the subgroup analyses where collateralization was assessed with intracoronary pressure measurements (RR 1.37 (95% CI 1.03 to 1.83); P = 0.038) versus visual assessment (RR 1.41 (95% CI 1.00 to 1.99); P = 0.049). For the subgroup of patients with stable coronary artery disease (CAD), the RR for restenosis with 'good collaterals' was 1.64 (95% CI 1.14 to 2.35) compared to 'poor collaterals' (P = 0.008). For patients with acute myocardial infarction, however, the RR for restenosis with 'good collateralization' was only 1.23 (95% CI 0.89 to 1.69); P = 0.212. CONCLUSIONS: The risk of restenosis after percutaneous coronary intervention (PCI) is increased in patients with good coronary collateralization. Assessment of the coronary collateral circulation before PCI may be useful for risk stratification and for the choice of antiproliferative measures (drug-eluting stent instead bare-metal stent, cilostazol).
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Ponte de Artéria Coronária/efeitos adversos , Estenose Coronária/cirurgia , Vasos Coronários/fisiologia , Revascularização Miocárdica , Complicações Pós-Operatórias/epidemiologia , Vasos Coronários/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Medição de RiscoRESUMO
AIMS: The long-term outcomes of the intracoronary delivery of autologous bone marrow-derived cells (BMCs) after acute myocardial infarction are not well established. Following the promising 1 year results of the REGENERATE-AMI trial (despite it not achieving its primary endpoint), this paper presents the analysis of the 5 year clinical outcomes of these acute myocardial infarction patients who were treated with an early intracoronary autologous BMC infusion or placebo. METHODS AND RESULTS: A 5 year follow-up of major adverse cardiac events (defined as the composite of all-cause death, recurrent myocardial infarction, and all coronary revascularization) and of rehospitalization for heart failure was completed in 85 patients (BMC n = 46 and placebo n = 39). The incidence of major adverse cardiac events was similar between the BMC-treated patients and the placebo group (26.1% vs. 18.0%, P = 0.41). There were no cases of cardiac death in either group, but an increase in non-cardiac death was seen in the BMC group (6.5% vs. 0%, P = 0.11). The rates of recurrent myocardial infarction and repeat revascularization were similar between the two groups. There were no cases of rehospitalization for heart failure in either group. CONCLUSION: This 5 year follow-up analysis of the REGENERATE-AMI trial did not show an improvement in clinical outcomes for patients treated with cell therapy. This contrasts with the 1 year results which showed improvements in the surrogate outcome measures of ejection fraction and myocardial salvage index.
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Transplante de Medula Óssea , Infarto do Miocárdio , Transplante de Medula Óssea/métodos , Seguimentos , Humanos , Infarto do Miocárdio/terapia , Transplante Autólogo , Resultado do TratamentoRESUMO
Background: Intravascular imaging has been used to assess the morphology of lesions causing an acute coronary syndrome (ACS) in native vessels (NV) and identify differences between plaques that ruptured (PR) and caused an event and those that ruptured without clinical manifestations. However, there is no data about the morphological and physiological characteristics of neoatherosclerotic plaques that ruptured (PR-NA) which constitute a common cause of stent failure. Methods: We retrospectively analyzed data from patients admitted with an acute myocardial infarction that had optical coherence tomography (OCT) imaging of the culprit vessel before balloon pre-dilation. OCT pullbacks showing PR were segmented at every 0.4 mm. The extent of the formed cavity, lipid and calcific tissue, thrombus, and macrophages were measured, and the fibrous cap thickness (FCT) and the incidence of micro-channels and cholesterol crystals were reported. These data were used to reconstruct a representative model of the native and neoatherosclerotic lesion geometry that was processed with computational fluid dynamics (CFD) techniques to estimate the distribution of the endothelial shear stress and plaque structural stress. Result: Eighty patients were included in the present analysis: 56 had PR in NV (PR-NV group) and 24 in NA segments (PR-NA group). The PR-NV group had a larger minimum lumen area (2.93 ± 2.03 vs. 2.00 ± 1.26 mm2, p = 0.015) but similar lesion length and area stenosis compared to PR-NA group. The mean FCT (186 ± 65 vs. 232 ± 80 µm, p = 0.009) and the lipid index was smaller (16.7 ± 13.8 vs. 25.9 ± 14.1, p = 0.008) while the of calcific index (8.3 ± 9.5 vs. 2.2 ± 1.6%, p = 0.002) and the incidence of micro-channels (41.4 vs. 12.5%, p = 0.013) was higher in the PR-NV group. Conversely, there was no difference in the incidence of cholesterol crystals, thrombus burden or the location of the rupture site between groups. CFD analysis revealed higher maximum endothelial shear stress (19.1 vs. 11.0 Pa) and lower maximum plaque structural stress (38.8 vs. 95.1 kPa) in the PR-NA compared to the PR-NV model. Conclusion: We reported significant morphological and physiological differences between culprit ruptured plaques in native and stented segments. Further research is needed to better understand the causes of these differences and the mechanisms regulating neoatherosclerotic lesion destabilization.
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Coronary luminal dimensions change during the cardiac cycle. However, contemporary volumetric intravascular ultrasound (IVUS) analysis is performed in non-gated images as existing methods to acquire gated or to retrospectively gate IVUS images have failed to dominate in research. We developed a novel deep learning (DL)-methodology for end-diastolic frame detection in IVUS and compared its efficacy against expert analysts and a previously established methodology using electrocardiographic (ECG)-estimations as reference standard. Near-infrared spectroscopy-IVUS (NIRS-IVUS) data were prospectively acquired from 20 coronary arteries and co-registered with the concurrent ECG-signal to identify end-diastolic frames. A DL-methodology which takes advantage of changes in intensity of corresponding pixels in consecutive NIRS-IVUS frames and consists of a network model designed in a bidirectional gated-recurrent-unit (Bi-GRU) structure was trained to detect end-diastolic frames. The efficacy of the DL-methodology in identifying end-diastolic frames was compared with two expert analysts and a conventional image-based (CIB)-methodology that relies on detecting vessel movement to estimate phases of the cardiac cycle. A window of ± 100 ms from the ECG estimations was used to define accurate end-diastolic frames detection. The ECG-signal identified 3,167 end-diastolic frames. The mean difference between DL and ECG estimations was 3 ± 112 ms while the mean differences between the 1st-analyst and ECG, 2nd-analyst and ECG and CIB-methodology and ECG were 86 ± 192 ms, 78 ± 183 ms and 59 ± 207 ms, respectively. The DL-methodology was able to accurately detect 80.4%, while the two analysts and the CIB-methodology detected 39.0%, 43.4% and 42.8% of end-diastolic frames, respectively (P < 0.05). The DL-methodology can identify NIRS-IVUS end-diastolic frames accurately and should be preferred over expert analysts and CIB-methodologies, which have limited efficacy.
Assuntos
Aprendizado Profundo , Vasos Coronários/diagnóstico por imagem , Humanos , Valor Preditivo dos Testes , Estudos Retrospectivos , Ultrassonografia , Ultrassonografia de IntervençãoRESUMO
OBJECTIVE: Fractional flow reserve (FFR) is regarded as the gold standard for the physiological assessment of intermediate coronary artery stenoses. However, FFR does not allow assessment of plaque morphology and lesion geometry. Intracoronary imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) can help treatment planning by optimising stent implantation, which can improve patient outcomes. The aim of this meta-analysis is to compare the efficacy of IVUS and OCT-derived metrics in detecting flow limiting stenoses in non-left main stem lesions. METHODS: A systematic review of PubMed, Medline, and Cochrane databases was performed and identified studies examining the diagnostic accuracy of IVUS and OCT in detecting significant stenoses when compared to FFR. RESULTS: A total of 33 (7537 lesions) studies (24 IVUS, 7 OCT and 2 IVUS & OCT studies) were included in the meta-analysis. Pooled analysis showed that IVUS- and OCT-derived minimum lumen area (MLA) had a similar sensitivity in predicting haemodynamically significant lesions (IVUS-MLA: 0.747 vs OCT-MLA 0.732, pâ¯=â¯0.519). However, OCT-MLA had a higher specificity (0.763 vs 0.665, pâ¯<â¯0.001) and diagnostic accuracy in detecting flow-limiting stenoses than IVUS-MLA (AUC 0.810 vs 0.754, pâ¯=â¯0.045). Sub-analysis of the studies with the clinically significant FFR cut-off value of 0.80 yielded similar results demonstrating that OCT-MLA has a better accuracy than IVUS-MLA in detecting haemodynamically significant stenoses (AUC 0.809 vs 0.750, pâ¯=â¯0.034). CONCLUSIONS: OCT with its superior image resolution appears to be the preferable intravascular imaging modality for the detection of haemodynamically significant stenoses in non-left main stem lesions.
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Estenose Coronária/diagnóstico , Vasos Coronários/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Ultrassonografia de Intervenção/métodos , Pesquisa Comparativa da Efetividade , HumanosAssuntos
Aneurisma Cardíaco/psicologia , Transtorno de Pânico/etiologia , Calcificação Vascular/psicologia , Adulto , Aneurisma Cardíaco/diagnóstico por imagem , Parada Cardíaca/etiologia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Radiografia , Recidiva , Calcificação Vascular/diagnóstico por imagem , Fibrilação Ventricular/etiologiaRESUMO
OBJECTIVE: To discover whether applicants regard structures interviews as a fair method of selection for jobs. DESIGN: Audit study of short-listed candidates for postgraduate specialty training programmes in the London Deanery. SETTING: Postgraduate applications for the London Deanery. MAIN OUTCOME MEASURES: Satisfaction or otherwise with the application and selection process for postgraduate specialty training programmes amongst short-listed candidates in the London Deanery. Questions were asked under five categories: the applicant, the advertisement, the application form, the short-listing process, and the interview. RESULTS: 89 of 118 forms were completed and analysed. Candidates thought the advertisement was clear on who to contact (97%), when short-listed candidates would be notified of their interview (66%) and when interviews would occur (93%). The design of the application form and the short-listing process both scored a median of 1 or 2 (strongly agree or agree) on all points. The interview process itself also scored well, with most candidates scoring broadly positively. CONCLUSIONS: As in the previous study, the overall response was broadly a positive one from the candidates' perspective, with the majority of candidates finding the system fair and objective.
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Cardiologia/educação , Educação de Pós-Graduação em Medicina , Entrevistas como Assunto , Corpo Clínico Hospitalar/psicologia , Satisfação Pessoal , Critérios de Admissão Escolar , Humanos , Londres , Auditoria Médica , Faculdades de MedicinaRESUMO
BACKGROUND: In ST-elevation myocardial infarction (STEMI) patients with multivessel (MV) disease, after primary percutaneous coronary intervention (PCI), emerging evidence suggests that significant disease in non-infarct-related coronary arteries (IRAs) should be routinely stented. Whether this procedure should be guided by angiography alone or ischemia testing is unclear. METHODS: All STEMI patients treated with primary PCI between January 1, 2005, and December 31, 2012, at a tertiary cardiology center were reviewed retrospectively. Inclusion criterion is patients with at least 70% stenosis in non-IRAs. There were 3 treatment groups: (1) angiography-guided MV-PCI, (2) ischemia-guided PCI, and (3) medical therapy. Primary endpoint is all-cause mortality, and secondary end point is major adverse cardiovascular events (MACE), including death, acute coronary syndrome, revascularization, or stent thrombosis. Event-free survivals were compared using multivariate Cox proportional-hazards analysis. A propensity score-adjusted analysis was performed. RESULTS: Four hundred forty-seven STEMI patients had >70% stenosis in non-IRAs. For all-cause mortality, the 3 strategies did not differ. For MACE, ischemia-guided PCI was associated with the lowest MACE rate, followed by angiography-guided PCI and medical therapy, which was associated with the highest MACE rate, driven by death and myocardial infarction. Hazard ratios (HRs) for MACE: angiography-guided MV-PCI versus ischemia-guided MV-PCI: HR = 2.23 [95% confidence interval (CI), 1.11-4.48; P = 0.023]; medical therapy versus angiography-guided MV-PCI: HR = 1.58 (95% CI, 0.99-2.63; P = 0.062); medical therapy versus ischemia-guided MV-PCI: HR = 1.72 (95% CI, 1.08-2.74; P = 0.022). Propensity score-adjusted analysis yielded similar results. CONCLUSIONS: After primary PCI, complete revascularization in STEMI multivessel disease is associated with lower MACE rates than medical therapy. However, ischemia-testing-guided rather than angiography-guided revascularization was associated with the lowest MACE. This study provides preliminary data and hypotheses for future randomized controlled studies.
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Doença da Artéria Coronariana/terapia , Intervenção Coronária Percutânea/métodos , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Stents , Síndrome Coronariana Aguda/epidemiologia , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Técnicas de Imagem Cardíaca , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mortalidade , Análise Multivariada , Infarto do Miocárdio/epidemiologia , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/terapia , Imagem de Perfusão do Miocárdio , Revascularização Miocárdica/estatística & dados numéricos , Inibidores da Agregação Plaquetária/uso terapêutico , Intervalo Livre de Progressão , Pontuação de Propensão , Modelos de Riscos Proporcionais , Falha de Prótese , Estudos Retrospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Trombose/epidemiologia , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
PURPOSE OF REVIEW: To understand the variety of conditions in which the pericardium may be affected in cancer patients. RECENT FINDINGS: Cancer may affect the pericardium directly (primary cancer; uncommon) or through metastases (commoner). Cancer treatment (chemotherapy and radiotherapy) may affect the pericardium leading to pericarditis and myopericarditis. Pericardial effusions, tamponade and constrictive pericarditis are complications that can also occur. A variety of techniques (predominantly cardiac imaging related) are used to make the diagnosis with the treatment strategy dependent on whether the pericardial disease is due to cancer or as a result of cancer treatment. A variety of pericardial diseases may be caused by cancer and cancer treatment. Determining the aetiology and providing effective treatment can often be challenging.
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Ageing is related to complex molecular, inflammatory and biochemical changes that affect coronary pathology and often lead to coronary artery disease and cardiovascular events. Intravascular imaging is considered as the ideal technique to study coronary plaque morphology and assess its burden. Over the recent years several studies have been performed that investigated the association between pathophysiological mechanisms that promote vascular ageing and plaque morphology. In addition, several reports have compared plaque pathology in different age groups and a few studies included serial intravascular imaging to assess changes in the atheroma burden and compositional characteristics of the plaque. This review article summarizes the evidence derived from intravascular imaging studies about the implications of vascular ageing on coronary artery morphology and discusses the potential of coronary imaging in assessing atherosclerotic evolution.
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Envelhecimento/fisiologia , Vasos Sanguíneos/diagnóstico por imagem , Vasos Sanguíneos/fisiologia , Coração/fisiologia , Animais , Angiografia por Tomografia Computadorizada , Doença da Artéria Coronariana/etiologia , Humanos , Placa Aterosclerótica/diagnóstico por imagem , Tomografia de Coerência Óptica , Ultrassonografia de IntervençãoRESUMO
AIMS: The aim of this study was to assess neoatherosclerotic plaque morphology in bare metal (BMS) and first- and second-generation drug-eluting stents (DES) in patients presenting with an event attributed to stent failure. METHODS AND RESULTS: Thirty-five patients (11 implanted with BMS, 13 with a first-generation and 11 with a second-generation DES) admitted with an event due to stent failure who had neoatherosclerotic lesions on optical coherence tomography were included in the analysis. The lumen and stent borders were detected and the lipid and calcific tissue were identified in the neointima and their burden was estimated. The neointima attenuation and backscatter indices were computed and compared between the different stent types. Although there were no differences in the neointima burden, the BMS group exhibited thinner fibrous caps (p<0.001), and a numerically increased incidence of lipid-rich plaques (p=0.052) and macrophage accumulation (p=0.012). Neointima discontinuities (p=0.009) and thrombus (p=0.032) were seen more often in first-generation DES. In all stent types, neoatherosclerosis had focal manifestations. In neoatherosclerotic lesions the attenuation and backscatter indices were increased in BMS (p=0.031 and p=0.018, respectively) compared to DES; however, there were no differences between stents in the attenuation indices in subsegments located distally to neoatherosclerotic lesions which had low values in all stent types. CONCLUSIONS: Although there are differences in lipid burden and neointima characteristics in different stent types, in all stents neoatherosclerosis has focal manifestations indicating that, irrespective of the stent type, focal triggers are involved in the generation of vulnerable neolesions.
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Doença da Artéria Coronariana/cirurgia , Reestenose Coronária/diagnóstico por imagem , Vasos Coronários/cirurgia , Stents Farmacológicos , Metais , Neointima , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/instrumentação , Placa Aterosclerótica , Falha de Prótese , Stents , Tomografia de Coerência Óptica , Idoso , China , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/patologia , Reestenose Coronária/etiologia , Reestenose Coronária/metabolismo , Reestenose Coronária/patologia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/metabolismo , Vasos Coronários/patologia , Europa (Continente) , Feminino , Fibrose , Humanos , Metabolismo dos Lipídeos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Desenho de Prótese , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVE: To examine the implications of endothelial shear stress (ESS) distribution in the formation of neoatherosclerotic lesions. METHODS: Thirty six patients with neoatherosclerotic lesions on optical coherence tomography (OCT) were included in this study. The OCT data were used to reconstruct coronary anatomy. Blood flow simulation was performed in the models reconstructed from the stent borders which it was assumed that represented the lumen surface at baseline, immediate after stent implantation, and the estimated ESS was associated with the neointima burden, neoatherosclerotic burden and neointima characteristics. In segments with neointima rupture blood flow simulation was also performed in the model representing the lumen surface before rupture and the ESS was estimated at the ruptured site. RESULTS: An inverse association was noted between baseline ESS and the incidence and the burden of neoatherosclerotic (ßâ¯=â¯-0.60, Pâ¯<â¯0.001, and ßâ¯=â¯-4.05, Pâ¯<â¯0.001, respectively) and lipid-rich neoatherosclerotic tissue (ßâ¯=â¯-0.54, Pâ¯<â¯0.001, and ßâ¯=â¯-3.60, Pâ¯<â¯0.001, respectively). Segments exposed to low ESS (<1â¯Pa) were more likely to exhibit macrophages accumulation (28.2% vs 10.9%, Pâ¯<â¯0.001), thrombus (11.0% vs 2.6%, Pâ¯<â¯0.001) and evidence of neointima discontinuities (8.1% vs 0.9%, Pâ¯<â¯0.001) compared to those exposed to normal or high ESS. In segments with neointima rupture the ESS was high at the rupture site compared to the average ESS over the culprit lesion (4.00⯱â¯3.65â¯Pa vs 3.14⯱â¯2.90â¯Pa, Pâ¯<â¯0.001). CONCLUSIONS: Local EES is associated with neoatherosclerotic lesion characteristics, which suggests involvement of ESS in the formation of vulnerable plaques in stented segments.
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Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/fisiopatologia , Hemodinâmica/fisiologia , Tomografia de Coerência Óptica/tendências , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodosAssuntos
Angina Pectoris/reabilitação , Terapia por Exercício/métodos , Feminino , Humanos , MasculinoRESUMO
BACKGROUND AND AIM: Local hemodynamic changes are one of the main factors that determine the vessel wall biological response after stent/scaffold implantation. Computational fluid dynamic studies provide an opportunity to investigate the rheological effects of implanted stent/scaffold. The aim of this study was to assess the local hemodynamic microenvironment in scaffolded segments in porcine coronary models. METHODS: In six epicardial coronary arteries of healthy mini-pigs, six Absorb bioresorbable vascular scaffolds (Absorb BVS) were implanted. Optical coherence tomography(OCT) was performed after scaffold implantation and the images were fused with the angiographic data to reconstruct the three-dimensional coronary artery anatomy. Blood flow simulations were performed, and endothelial shear stress(ESS) distribution was estimated for each scaffolded segment. In a linear mixed-effect model, the contributing factors for low (<1.0Pa) ESS levels were assessed. At 30-day post-implantation, histopathological assessment was performed at 2 scaffolds. RESULTS: In scaffolded segments, the median ESS was 0.57 (IQR: 0.29-0.99) Pa. In linear mixed-effect analysis, cross-section area was associated with low shear stress levels. In scaffolded segments, the percentage of the recirculation zone per scaffolded luminal surface was 3.26±2.07%. At 30-day histopathological assessment of implanted vessel segments revealed minimal injury score, minimal neointimal inflammation and minimal adventitial inflammation scores with moderate endothelial coverage. Fibrin accumulation was seen at 95.69±2.47% of the struts. CONCLUSION: The thick rectangular strut design of the Absorb BVS incited flow disruptions with low shear stress inducing fibrin accumulation. CFD assessment can be used to guide improvements in the scaffold design for a more "hemo-compatible" geometry.
Assuntos
Implantes Absorvíveis , Vasos Coronários/diagnóstico por imagem , Hemodinâmica/fisiologia , Intervenção Coronária Percutânea/métodos , Alicerces Teciduais , Tomografia de Coerência Óptica , Animais , Implante de Prótese Vascular/métodos , Distribuição de Qui-Quadrado , Circulação Coronária/fisiologia , Vasos Coronários/cirurgia , Modelos Animais de Doenças , Neointima/patologia , Estatísticas não Paramétricas , Estresse Mecânico , Suínos , Porco MiniaturaRESUMO
Coronary artery disease remains the leading cause of death in the developed world. Over recent years, research has been focused on the development of diagnostic intravascular imaging techniques that enable assessment of plaque composition and morphology, and allow identification of vulnerable, high-risk lesions. Nevertheless recent studies of coronary atherosclerosis have shown that invasive modalities have a limited accuracy in detecting lesions that will progress and cause events, whilst histology-based studies also highlighted the limitations of invasive imaging in assessing plaque characteristics. To overcome these drawbacks, multimodality imaging has been proposed. Although it is apparent that coronary imaging with two or three imaging modalities is time consuming and is associated with a risk of complications, evidence from small clinical studies demonstrated that it provides incremental information about plaque pathology and biology and underscored the need to develop dual-probe hybrid imaging catheters that would enable complete and comprehensive assessment of plaque morphology. This paper reviews the current clinical evidence that supports the use of multimodality intravascular imaging in the study of atherosclerosis, summarizes the key findings of the first invasive imaging studies that utilize hybrid dual-probe catheters, and discusses the limitations of combined intravascular imaging that restrict its broad application in both the clinical and research arena.
Assuntos
Técnicas de Imagem Cardíaca/tendências , Doença da Artéria Coronariana/diagnóstico por imagem , Imagem Multimodal/métodos , Placa Aterosclerótica/diagnóstico por imagem , Adulto , Idoso , Cateterismo Cardíaco/métodos , Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Doença da Artéria Coronariana/patologia , Estudos de Viabilidade , Feminino , Angiofluoresceinografia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/patologia , Sensibilidade e Especificidade , Espectroscopia de Luz Próxima ao Infravermelho , Tomografia de Coerência Óptica/tendências , Ultrassonografia de Intervenção/métodosRESUMO
INTRODUCTION: Advances in our understanding about atherosclerotic evolution have enabled us to identify specific plaque characteristics that are associated with coronary plaque vulnerability and cardiovascular events. With constant improvements in signal and image processing an arsenal of invasive and non-invasive imaging modalities have been developed that are capable of identifying these features allowing in vivo assessment of plaque vulnerability. Areas covered: This review article presents the available and emerging imaging modalities introduced to assess plaque morphology and biology, describes the evidence from the first large scale studies that evaluated the efficacy of invasive and non-invasive imaging in detecting lesions that are likely to progress and cause cardiovascular events and discusses the potential implications of the in vivo assessment of coronary artery pathology in the clinical setting. Expert commentary: Invasive imaging, with its high resolution, and in particular hybrid intravascular imaging appears as the ideal approach to study the mechanisms regulating atherosclerotic disease progression; whereas non-invasive imaging is expected to enable complete assessment of coronary tree pathology, detection of high-risk lesions, more accurate risk stratification and thus to allow a personalized treatment of vulnerable patients.