3,920 research outputs found

    Cardiovascular Risk Stratification in Diabetic Retinopathy via Atherosclerotic Pathway in COVID-19/non-COVID-19 Frameworks using Artificial Intelligence Paradigm: A Narrative Review

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    Diabetes is one of the main causes of the rising cases of blindness in adults. This microvascular complication of diabetes is termed diabetic retinopathy (DR) and is associated with an expanding risk of cardiovascular events in diabetes patients. DR, in its various forms, is seen to be a powerful indicator of atherosclerosis. Further, the macrovascular complication of diabetes leads to coronary artery disease (CAD). Thus, the timely identification of cardiovascular disease (CVD) complications in DR patients is of utmost importance. Since CAD risk assessment is expensive for lowincome countries, it is important to look for surrogate biomarkers for risk stratification of CVD in DR patients. Due to the common genetic makeup between the coronary and carotid arteries, lowcost, high-resolution imaging such as carotid B-mode ultrasound (US) can be used for arterial tissue characterization and risk stratification in DR patients. The advent of artificial intelligence (AI) techniques has facilitated the handling of large cohorts in a big data framework to identify atherosclerotic plaque features in arterial ultrasound. This enables timely CVD risk assessment and risk stratification of patients with DR. Thus, this review focuses on understanding the pathophysiology of DR, retinal and CAD imaging, the role of surrogate markers for CVD, and finally, the CVD risk stratification of DR patients. The review shows a step-by-step cyclic activity of how diabetes and atherosclerotic disease cause DR, leading to the worsening of CVD. We propose a solution to how AI can help in the identification of CVD risk. Lastly, we analyze the role of DR/CVD in the COVID-19 framework

    Assessing the consequences of gestational diabetes mellitus on offspring's cardiovascular health: MySweetHeart Cohort study protocol, Switzerland.

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    Gestational diabetes mellitus (GDM) is a state of glucose intolerance with onset during pregnancy. GDM carries prenatal and perinatal risks as well as long-term risks for the mother and her child. GDM may be involved in the foetal programming of long-term cardiovascular health. However, evidence is sparse and the effect of GDM on cardiovascular health is unknown. To address these issues, we will conduct MySweetHeart Cohort study. The objectives are to assess the effect of GDM on offspring's cardiovascular health early in life by using surrogate markers of cardiovascular disease and atherosclerosis. This is a cohort study of 100 offspring of women with GDM and 100 offspring of women without GDM. At inclusion, a baseline assessment of the mothers will be conducted through means of self-report questionnaires, a researcher-administrated interview, blood pressure and anthropometric measurements, and a maternal blood sampling. Between the 30th and 34th weeks of gestation, a foetal echography will be performed to assess the foetal cardiac structure and function, the fetomaternal circulation and the hepatic volume. At birth, maternal and neonatal characteristics will be assessed. An echocardiography will be performed to assess cardiac structure and function 2-7 days after birth; carotid intima-media thickness will be also measured to assess vascular structure. MySweetHeart Cohort is linked to MySweetHeart Trial (clinicaltrials.gov/ct2/show/NCT02890693), a randomised controlled trial assessing the effect of a multidimensional interdisciplinary lifestyle and psychosocial intervention to improve the cardiometabolic and mental health of women with GDM and their offspring. A long-term follow-up of children is planned. Ethical approval has been obtained through the state Human Research Ethics Committee of the Canton de Vaud (study number 2016-00745). We aim to disseminate the findings through regional, national and international conferences and through peer-reviewed journals. ClinicalTrials.gov (clinicaltrials.gov/ct2/show/NCT02872974)

    The determinants of intra-plaque neovascularisation: a study by contrast-enhanced carotid ultrasonography

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    Atherosclerosis is a chronic inflammatory disorder, initiated by arterial wall injury, mediated by well-recognised cardiovascular risk factors and culminating in formation of plaques, the patho-biological substrate that precedes events such as stroke and myocardial infarction. Intraplaque neovascularisation (IPN) is one of several defence mechanisms in response to atherosclerosis. With development of an atherosclerotic plaque within the intima, the distance between the deeper intimal layers and the luminal surface increases, producing hypoxia within the arterial wall. This stimulates release of pro-angiogenic factors that induces neoangiogenesis in an attempt to normalise oxygen tension. However, these neo-vessels are fragile, immature and leaky and thought to be the primary cause of intraplaque haemorrhage, now appreciated to be a key risk factor for plaque rupture. Therefore, the presence of IPN is now widely recognised as a precursor of the “vulnerable plaque”. Contrast-enhanced ultrasound (CEUS) is a non-invasive method of imaging carotid plaques and, as contrast bubbles travel wherever erythrocytes travel, they permit visualization of IPN. Prior research studies have demonstrated that CEUS can detect IPN with a high degree of accuracy (on comparison with histological plaque specimens) and have shown a relationship between extent of plaque neovessels and plaque echogenicity and between plaque neovascularization and prior cardiovascular events. However, CEUS is a relatively recently described imaging technique and there were a number of unanswered questions in this field, some of which formed the basis for study in this research Thesis. In this Thesis, research studies were conducted on human subjects using CEUS imaging to identify IPN and its determinants. The incidence and determinants of IPN in healthy asymptomatic individuals was unknown and was studied in subjects from the London Life Sciences Population (LOLIPOP) study, a large study exploring mechanisms for differences in cardiovascular disease (CVD) between South Asian and European White individuals. The study found that approximately half of all plaques contain IPN. The only variable associated with IPN presence in an adjusted analysis was Asian ethnicity. This finding potentially has significant implications as it may help explain, in part, the greater CVD burden observed in Asian populations. A study comparing visualization of the carotid tree during B-mode and CEUS imaging was also conducted. Both IMT visualization and plaque detection were significantly improved by CEUS, implying that CEUS is superior to B-mode imaging for detection of sub-clinical atherosclerosis. Radiotherapy (RT) damages arterial walls and promotes atherosclerosis. The carotid arteries frequently receive significant incidental doses of radiation during RT treatment of head and neck cancers. The effect of RT on plaque composition – specifically IPN – had not been studied and thus a collaborative cardio-oncological study was conducted to assess the effects of RT upon IPN in cancer survivors who had previously received RT. A significant association between RT and IPN was found which may provide insights into the mechanisms underlying the increased stroke risk amongst cancer survivors treated by RT. Finally, a collaboration with biophysicists was formed to develop and validate a novel algorithm for quantitative analysis of IPN. Patients clinically scheduled to undergo carotid endarterectomy were recruited and underwent CEUS imaging prior to surgery. This study did not achieve its principal aims due to challenges with patient recruitment, challenges in image quality and with the quantification software also. Future directions of study in this promising field have been addressed in the thesis summary.Open Acces

    The use of subclinical vascular markers of atherosclerosis in youth

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    The foundations for cardiovascular disease (CVD) in adults are laid in childhood and accelerated by the presence of comorbid conditions. Early detection of manifestations of cardiovascular pathology is an important clinical objective to identify those at risk for subsequent cardiovascular morbidity and events, and to initiate behavioral and medical interventions to reduce risk. Children were once considered to be at low risk, but with the growing health concerns related to lifestyle, cardiovascular screening may be needed earlier. Several noninvasive procedures are available to assess the cumulative effect of these exposures. These include carotid ultrasound, flow-mediated dilation, pulse wave velocity and measures left ventricular mass. This dissertation analyzes the comorbid conditions that increase cardiovascular risk in youth, namely obesity and low physical fitness, using carotid intima-media thickness to objectively detect early manifestations of cardiovascular pathology. Until recently researchers have not used surrogate markers of subclinical atherosclerosis to examine the role of a single bout of exercise. Utilizing the acute exercise model can be advantageous as it allows for an efficient manipulation of exercise variables and permits greater experimental control of confounding variables. It is possible that the effects of a bout of exercise can predict the effects of chronic exercise. We analyze the physiological factors pertinent to arterial stiffness using arterial distensibility and pulse wave velocity in the context of acute exercise in children and adults. In some instances, those who amend their trajectory by not maintaining risk factors into adulthood experience reductions in subclinical markers to levels associated with never having had the risk factor. Though avoidance of risk factors in youth is ideal, there is still a window for intervention where long-lasting cardiovascular effects might be avoided. In this dissertation we present preliminary findings linking modifiable youth risk factors to subclinical markers of CVD in adulthood.As bases da doença cardiovascular (DCV) em adultos sĂŁo estabelecidas na infĂąncia e aceleradas pela presença de comorbidades. A deteção precoce de manifestaçÔes da patologia cardiovascular Ă© um objetivo clĂ­nico importante na identificação daqueles com risco de subsequente morbidade e eventos cardiovasculares, e no estabelecimento de intervençÔes comportamentais e mĂ©dicas para reduzir o risco. As crianças jĂĄ foram considerados de baixo risco, mas com as crescentes preocupaçÔes de saĂșde associadas ao estilo de vida, o rastreio cardiovascular Ă© cada vez mais precoce. VĂĄrios procedimentos nĂŁo invasivos estĂŁo disponĂ­veis para avaliar o efeito cumulativo dessas exposiçÔes. Estes incluem ultrassom da artĂ©ria carĂłtida, a dilatação fluxo-mediada, velocidade de onda de pulso e medidas da massa ventricular esquerda. Esta dissertação analisa comorbidades conhecidas que aumentam o risco cardiovascular em crianças e adolescentes, como a obesidade, pressĂŁo arterial elevada e baixa aptidĂŁo fĂ­sica, usando a espessura da parede intima-media da carĂłtida para detetar objetivamente as manifestaçÔes precoces de patologia cardiovascular. AtĂ© recentemente, estes marcadores subclĂ­nicos de aterosclerose foram pouco utilizados para examinar os efeitos de uma Ășnica sessĂŁo de exercĂ­cio fĂ­sico. No entanto, a utilização do modelo de exercĂ­cio agudo pode ser vantajoso, pois permite uma manipulação eficiente das variĂĄveis do exercĂ­cio e permite maior controle experimental de variĂĄveis de enviezamento. É possĂ­vel que os efeitos de uma sessĂŁo de exercĂ­cio possam prever os efeitos do exercĂ­cio crĂłnico. Nesta dissertação analisamos os fatores fisiolĂłgicos associados Ă  rigidez arterial usando a distensibilidade arterial e velocidade da onda de pulso no contexto de exercĂ­cio agudo em crianças e adultos. Em alguns casos, aqueles que melhoram o seu perfil de risco de risco para as DCV atĂ© Ă  idade adulta experienciam reduçÔes em marcadores subclĂ­nicos de aterosclerose para nĂ­veis saudĂĄveis. Embora a prevenção de fatores de risco na juventude seja o ideal, existe ainda uma janela para a intervenção em que os efeitos cardiovasculares de longa duração pode ser evitada. Nesta dissertação apresentamos resultados preliminares que ligam fatores de risco modificĂĄveis na juventude com marcadores subclĂ­nicos de DCV na idade adulta

    Carotid artery contrast enhanced ultrasound

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    Carotid artery contrast enhanced ultrasound

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    Computer assisted analysis of contrast enhanced ultrasound images for quantification in vascular diseases

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    Contrast enhanced ultrasound (CEUS) with microbubble contrast agents has shown great potential in imaging microvasculature, quantifying perfusion and hence detecting vascular diseases. However, most existing perfusion quantification methods based on image intensity, and are susceptible to confounding factors such as attenuation artefacts. Improving reproducibility is also a key challenge to clinical translation. Therefore, this thesis aims at developing attenuation correction and quantification techniques in CEUS with applications for detection and quantification of microvascular flow / perfusion. Firstly, a technique for automatic correction of attenuation effects in vascular imaging was developed and validated on a tissue mimicking phantom. The application of this technique to studying contrast enhancement of carotid adventitial vasa vasorum as a biomarker of radiation-induced atherosclerosis was demonstrated. The results showed great potential in reducing attenuation artefact and improve quantification in CEUS of carotid arteries. Furthermore, contrast intensity was shown to significantly increase in irradiated carotid arteries and could be a useful imaging biomarker for radiation-induced atherosclerosis. Secondly, a robust and automated tool for quantification of microbubble identification in CEUS image sequences using a temporal and spatial analysis was developed and validated on a flow phantom. The application of this technique to evaluate human musculoskeletal microcirculation with contrast enhanced ultrasound was demonstrated. The results showed an excellent accuracy and repeatability in quantifying active vascular density. It has great potential for clinical translation in the assessment of lower limb perfusion. Finally, a new bubble activity identification and quantification technique based on differential intensity projection in CEUS was developed and demonstrated with an in-vivo study, and applied to the quantification of intraplaque neovascularisation in an irradiated carotid artery of patients who were previously treated for head and neck cancer. The results showed a significantly more specific identification of bubble signals and had good agreement between the differential intensity-based technique and clinical visual assessment. This technique has potential to assist clinicians to diagnose and monitor intraplque neovascularisation.Open Acces

    Predictors of cardiovascular disease and mortality in patients with advanced chronic kidney disease

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    Cardiovascular disease is the leading cause of high mortality in advanced chronic kidney disease (CKD) patients. Treatment and prevention of cardiovascular disease should be in focus to improve prognosis in this high-risk population. The aim of the study was to assess cardiovascular determinants of mortality, to study the effect of diabetes on arterial endothelial function and structure, to evaluate exercise capacity and abdominal aortic calcification (AAC) in patients with advanced CKD, not on dialysis. 210 participants of the Chronic Arterial Disease, quality of life and mortality in chronic KIDney injury -study underwent maximal bicycle ergometry stress test, echocardiography, lateral lumbar radiograph to study AAC score, ultrasound measures of arterial structure and function, and laboratory measures. Determinants of mortality were stress ergometry performance, AAC score, E/e’ ratio of echocardiography, and cardiac biomarkers and albumin. Diabetes was a significant determinant of AAC but did not associate with endothelial dysfunction or increased carotid intima-media thickness. Maximal stress ergometry performance was associated with troponin T (TnT) and AAC. The progression of AAC was rapid and the increment rate was similar in patients transitioning to different modalities of renal replacement therapy. To conclude, stress ergometry performance, AAC, E/e’ of echocardiography, and cardiac biomarkers and albumin predict mortality, and diabetes is associated with AAC in advanced CKD. TnT and AAC are associated with maximal ergometry stress test and AAC progresses at a comparable rate across the CKD treatment groups.SydĂ€n- ja verisuonitautien ja kuolleisuuden ennustekijĂ€t loppuvaiheen munuaisten vajaatoimintaa sairastavilla Loppuvaiheen munuaisten vajaatoimintapotilailla sydĂ€n- ja verisuonitaudit ovat johtava kuolleisuuden syy. SydĂ€n- ja verisuonitautien hoito ja ennaltaehkĂ€isy tulisi olla keskiössĂ€ tĂ€mĂ€n korkean riskin ryhmĂ€n ennusteen parantumiseksi. Tutkimuksessa arvioitiin kuolleisuuteen vaikuttavia sydĂ€n- ja verisuonitautitekijöitĂ€, diabeteksen vaikutusta verisuonen sisĂ€kalvon toimintaan ja suonirakenteeseen, suorituskykyĂ€, sekĂ€ vatsa-aortan kalkkisuutta ei-dialyysihoitoisessa loppuvaiheen munuaisten vajaatoiminnassa. 210 potilasta osallistui Krooninen valtimotauti, elĂ€mĂ€nlaatu ja mortaliteetti vaikeaa munuaisten vajaatoimintaa sairastavilla -tutkimukseen. Tutkittaville tehtiin polkupyörĂ€rasituskoe, sydĂ€men ultraÀÀnitutkimus, lannerangan röntgenkuvaus aortan kalkkisuuden mÀÀrittĂ€miseksi, verisuoniultraÀÀnitutkimus verisuonen rakenteen ja toiminnan tutkimiseksi sekĂ€ otettiin laboratoriokokeet. Kuolleisuutta mÀÀrittivĂ€t suorituskyky, vatsa-aortan kalkkisuus, sydĂ€men ultraÀÀnitutkimuksen E/e’ suhde, sydĂ€nmerkkiaineet ja albumiini. Diabetes mÀÀritti vatsa-aortan kalkkisuutta merkittĂ€vĂ€sti, mutta ei ollut yhteydessĂ€ verisuonen laajenemiskykyyn eikĂ€ kaulavaltimon seinĂ€mĂ€paksuuteen. Maksimaalinen suorituskyky oli yhteydessĂ€ troponiini T:hen (TnT) ja vatsa-aortan kalkkisuuteen. Vatsaaortan kalkkisuus kehittyi nopeasti ja kehityksen suuruus oli sama eri keinomunuaishoitomuodoissa. Yhteenvetona todetaan, ettĂ€ suorituskyky, vatsa-aortan kalkkisuus, sydĂ€men ultraÀÀnitutkimuksen E/e’ suhde, sydĂ€nmerkkiaineet ja albumiini ennustavat kuolleisuutta, ja diabetes on yhteydessĂ€ vatsa-aortan kalkkisuuteen, mutta ei verisuonen laajenemiskykyyn tai sisĂ€kalvopaksuuteen, loppuvaiheen munuaisten vajaatoiminnassa. TnT ja vatsa-aortan kalkkisuus ovat yhteydessĂ€ maksimaaliseen suorituskykyyn, ja vatsa-aortan kalkkisuus etenee samalla nopeudella eri munuaiskorvaushoitomuodoissa
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