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3.
Artigo em Inglês | MEDLINE | ID: mdl-33600328

RESUMO

Measurement of total-plaque-area (TPA) is important for determining long term risk for stroke and monitoring carotid plaque progression. Since delineation of carotid plaques is required, a deep learning method can provide automatic plaque segmentations and TPA measurements; however, it requires large datasets and manual annotations for training with unknown performance on new datasets. A UNet++ ensemble algorithm was proposed to segment plaques from 2D carotid ultrasound images, trained on three small datasets (n=33, 33, 34 subjects) and tested on 44 subjects from the SPARC dataset (n=144, London, Canada). The ensemble was also trained on the entire SPARC dataset and tested with a different dataset (n=497, Zhongnan Hospital, China). Algorithm and manual segmentations were compared using Dice-similarity-coefficient (DSC) and TPAs were compared using the difference (TPA), Pearson correlation coefficient (r), and Bland-Altman analyses. Segmentation variability was determined using the intra-class correlation coefficient (ICC) and coefficient-of-variation (CoV). For the 44 SPARC subjects, algorithm DSC was 83.3-85.7%, and algorithm TPAs were strongly correlated (r=0.985-0.988; p<0.001) with manual results with marginal biases (0.73-6.75) mm2 using the three training datasets. Algorithm ICC for TPAs (ICC=0.996) was similar to intra- and inter-observer manual results (ICC=0.977, 0.995). Algorithm CoV=6.98% for plaque areas was smaller than the inter-observer manual CoV (7.54%). For the Zhongnan dataset, DSC was 88.6%; algorithm and manual TPAs were strongly correlated (r=0.972, p<0.001) with TPA=-0.444.05 mm2 and ICC=0.985. The proposed algorithm trained on small datasets and segmented a different dataset without retraining with accuracy and precision that may be useful clinically and for research.

4.
5.
J Am Coll Cardiol ; 77(4): 423-436, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33509399

RESUMO

This is an update of the previous 2018 systematic review and meta-analysis of vitamin and mineral supplementation on cardiovascular disease outcomes and all-cause mortality. New randomized controlled trials and meta-analyses were identified by searching the Cochrane library, Medline, and Embase, and data were analyzed using random effects models and classified by the Grading of Recommendations Assessment Development and Evaluation approach. This updated review shows similar findings to the previous report for preventive benefits from both folic acid and B vitamins for stroke and has been graded with moderate quality. No effect was seen for the commonly used multivitamins, vitamin D, calcium, and vitamin C, and an increased risk was seen with niacin (with statin) for all-cause mortality. Conclusive evidence for the benefit of supplements across different dietary backgrounds, when the nutrient is sufficient, has not been demonstrated.

6.
J Stroke Cerebrovasc Dis ; : 105376, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33214054

RESUMO

Patients with renal failure have extremely high cardiovascular risk; in dialysis patients the risk of stroke is increased approximately 10-fold over that in the general population. Reasons include not only a high prevalence of traditional risk factors such as diabetes, hypertension and dyslipidemia, but also the accumulation of toxic substances that are eliminated by the kidneys, so have very high levels in patients with renal failure. These include plasma total homocysteine, asymmetric dimethylarginine, thiocyanate, and toxic products of the intestinal microbiome (Gut-Derived Uremic Toxins; GDUT), which include trimethylamine N- oxide (TMAO), produced from phosphatidylcholine (largely from egg yolk) and carnitine (largely from red meat). Other GDUT are produced from amino acids, largely from meat consumption. Deficiency of vitamin B12 is very common, raises plasma tHcy, and is easily treated. However, cyanocobalamin is toxic in patients with renal failure. To reduce the risk of stroke in renal failure it is important to limit the intake of meat, avoid egg yolk, and use methylcobalamin instead of cyanocobalamin, in addition to folic acid.

7.
Ann Transl Med ; 8(19): 1262, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33178794

RESUMO

Patients with asymptomatic carotid stenosis (ACS) are at very high risk of coronary events, so they should all receive intensive medical therapy. What is often accepted as "best medical therapy" is usually suboptimal. Truly intensive medical therapy includes lifestyle modification, particularly smoking cessation and a Mediterranean diet. All patients with ACS should receive intensive lipid-lowering therapy, should have their blood pressure well controlled, and should receive B vitamins for lowering of plasma total homocysteine (tHcy) if levels are high; a commonly missed cause of elevated tHcy is metabolic B12 deficiency, which should be diagnosed and treated. Most patients with ACS would be better treated with intensive medical therapy than with either carotid endarterectomy (CEA) or stenting (CAS). A process called "treating arteries instead of treating risk factors" markedly reduced the risk of ACS in an observational study; a randomized trial vs. usual care should be carried out. The few patients with ACS who could benefit (~15%, or perhaps more if recent evidence regarding the risk of intraplaque hemorrhage is borne out) can be identified by a number of features. These include microemboli on transcranial Doppler, intraplaque hemorrhage, reduced cerebrovascular reserve, and echolucency of plaques, particularly "juxtaluminal black plaque". No patient should be subjected to CAS or CEA without evidence of high-risk features, because in most cases the 1-year risk of stroke or death with intervention is higher with either CEA (~2%) or CAS (~4%) than with intensive medical therapy (~0.5%). Most patients, particularly the elderly, would be better treated with CEA than CAS. Most strokes can be prevented in patients with ACS, but truly intensive medical therapy is required.

8.
Stroke ; 51(12): 3770-3777, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33121384

RESUMO

The risks of stroke and dementia increase steeply with age, and both are preventable. At present, the best way to preserve cognitive function is to prevent stroke. Therapeutic nihilism based on age is common and unwarranted. We address recent advances in stroke prevention that could contribute greatly to prevention of stroke and dementia at a time when the aging of the population threatens to markedly increase the incidence of both. Issues discussed: (1) old patients benefit even more from lipid-lowering therapy than do younger patients; (2) patients with stiff arteries are at risk from a target systolic blood pressure <120 mm Hg; (3) the interaction of the intestinal microbiome, age, and renal function has important dietary implications for older adults; (4) anticoagulation with direct-acting oral anticoagulants should be prescribed more to old patients with atrial fibrillation; (5) B vitamins to lower homocysteine prevent stroke; and (6) most old patients in whom intervention is warranted for carotid stenosis would benefit more from endarterectomy than from stenting. An 80-year-old person has much to lose from a stroke and should not have effective therapy withheld on account of age. Lipid-lowering therapy, a more plant-based diet, appropriate anticoagulation or antiplatelet therapy, appropriate blood pressure control, B vitamins to lower homocysteine, and judicious intervention for carotid stenosis could do much to reduce the growing burden of stroke and dementia.

11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2043-2046, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018406

RESUMO

Segmentation of carotid vessel wall is required in vessel wall volume (VWV) and local vessel-wall-plus-plaque thickness (VWT) quantification of the carotid artery. Manual segmentation of the vessel wall is time-consuming and prone to interobserver variability. In this paper, we proposed a convolutional neural network (CNN) to segment the common carotid artery (CCA) from 3D carotid ultrasound images. The proposed CNN involves three U-Nets that segmented the 3D ultrasound (3DUS) images in the axial, lateral and frontal orientations. The segmentation maps generated by three U-Nets were consolidated by a novel segmentation average network (SAN) we proposed in this paper. The experimental results show that the proposed CNN improved the segmentation accuracies. Compared to only using U-Net alone, the proposed CNN improved the Dice similarity coefficient (DSC) for vessel wall segmentation from 64.8% to 67.5%, the sensitivity from 63.8% to 70.5%, and the area under receiver operator characteristic curve (AUC) from 0.89 to 0.94.


Assuntos
Artérias Carótidas , Imageamento Tridimensional , Artérias Carótidas/diagnóstico por imagem , Artéria Carótida Primitiva/diagnóstico por imagem , Ultrassonografia , Ultrassonografia Doppler
12.
F1000Res ; 92020.
Artigo em Inglês | MEDLINE | ID: mdl-32864099

RESUMO

Since a 2017 update, there have been important advances in stroke prevention. These include new evidence about nutrition, antiplatelet therapy, anticoagulation, lipid-lowering therapy, hypertension control, pioglitazone, and carotid endarterectomy and stenting. Evidence regarding toxic metabolites produced by the intestinal microbiome from egg yolk and red meat has important dietary implications, particularly for patients with impaired renal function, including the elderly. They should avoid egg yolk and red meat and limit the intake of animal flesh. Higher doses of folic acid may be needed for patients with the T allele of MTHFR, so it may not be sufficient to give vitamin B12 (methylcobalamin) alone, even in countries with folate fortification. There is now good evidence that lipid-lowering therapy is even more beneficial in the elderly than in younger patients; we should be using lipid-lowering therapy more intensively, often/usually combining statins with ezetimibe. There is new evidence that lower systolic blood pressure targets are better for most patients, but a subgroup with stiff arteries, a wide pulse pressure, and a diastolic pressure of <60 would be more likely to be harmed than helped by aiming for a systolic target of <120 mmHg. There is a better understanding of how the pharmacological properties of direct-acting oral anticoagulants and the metabolism of antiplatelet agents should inform decisions about the use of these agents. Pioglitazone markedly reduces the risk of stroke, both in diabetics and prediabetics; it should be used more widely. It is now clear that carotid endarterectomy is safer than stenting and that the difference is strongly affected by age. Most patients, and in particular older patients, would be better served by endarterectomy than stenting.


Assuntos
Prevenção Secundária , Acidente Vascular Cerebral/prevenção & controle , Idoso , Pressão Sanguínea , Dieta , Endarterectomia das Carótidas , Humanos , Hipertensão , Pioglitazona/uso terapêutico , Recidiva
13.
Cardiovasc Diagn Ther ; 10(4): 955-964, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32968653

RESUMO

Ultrasound methods are useful in stroke prevention in several ways. Measurement of carotid plaque burden, as either total plaque area (TPA) or total plaque volume (TPV) are strong predictors of cardiovascular risk: much stronger than intima-media thickness, which does not represent true atherosclerosis, but a biologically and genetically distinct phenotype. Measurement of plaque burden is also useful for the study of genetics, and of new risk factors such as toxic products of the intestinal microbiome. Carotid plaque burden is highly correlated with and as predictive of risk as coronary calcium scores, but is less costly and does not require radiation. Furthermore, because carotid plaques change in time over a period of months, they can be used for a new approach to vascular prevention: "Treating arteries instead of treating risk factors". In high-risk patients with asymptomatic carotid stenosis (ACS), this approach, implemented in 2003 in our clinics, was associated with a >80% reduction of stroke and myocardial infarction over 2 years. "Treating arteries without measuring plaque would be like treating hypertension without measuring blood pressure". Ultrasound methods can also be used to assess plaque vulnerability, by detecting echolucency, ulceration and plaque inhomogeneity on assessment of plaque texture. Transcranial Doppler (TCD) embolus detection is useful for risk stratification in patients with ACS; patients with two or more microemboli in an hour of monitoring have a 1-year risk of 15.6%, vs. 1% without microemboli, so this very clearly distinguishes which patients with ACS could benefit from intervention. TCD saline studies are more sensitive than trans-esophageal echocardiography for detection of patent foramen ovale, and more predictive of recurrent stroke. These methods should be more widely used, to reduce the increasing burden of stroke in our aging populations.

14.
Curr Opin Lipidol ; 31(5): 291-298, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32773468

RESUMO

PURPOSE OF REVIEW: To describe the uses of measurement of carotid plaque burden, as total plaque area (TPA), total plaque volume (TPV), and vessel wall volume (VWV), which includes plaque burden and wall volume. RECENT FINDINGS: Measurement of plaque burden is useful for risk stratification, research into the genetics and biology of atherosclerosis, for measuring effects of new therapies for atherosclerosis, and for treatment of high-risk patients with severe atherosclerosis. SUMMARY: Measurement of plaque burden is far superior to measurement of carotid intima-media thickness (IMT) in many ways, and should replace it. Vessel wall volume can be measured in persons with no plaque as an alternative to IMT.

16.
J Am Coll Cardiol ; 76(7): 885-886, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32792086
17.
Trans Am Clin Climatol Assoc ; 131: 157-177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32675856

RESUMO

Systemic lupus erythematosus (SLE) is an independent risk factor for atherosclerosis. This study was designed to determine the association between atherosclerosis, oxidized LDL immune complexes (oxLDL-IC), and endothelial dysfunction in SLE. SLE patients were recruited, and carotid atherosclerotic total plaque area (TPA) was determined by ultrasound. Levels of oxLDL-IC were measured. In vitro endothelial function was measured by aortic endothelial nitric oxide (NO) production after culture of human aortic endothelial cells (HAEC) with SLE serum. Levels of oxLDL-IC are associated significantly with TPA. In vitro HAEC NO production after culture with SLE serum was positively correlated with serum complement. HAEC NO production was increased with sepiapterin to couple eNOS. To our knowledge, this is the first study to demonstrate an association between subclinical accelerated atherosclerosis and oxLDL-IC in SLE. This is also the first study to demonstrate the effect of sepiapterin on improving in vitro aortic endothelial cell function in SLE.

19.
Age Ageing ; 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32520996

RESUMO

Blood pressure measurement with a cuff in patients with stiff arteries can be misleading, with false elevation of the diastolic pressure. Coronary flow, and most of the cerebral blood flow occur during diastole. There is a marked diastolic J curve in patients with diastolic pressure <60 mmHg and pulse pressure >60 mmHg. Aiming for a systolic target of 120 mmHg is not safe in some frail older patients.

20.
Trials ; 21(1): 515, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32527283

RESUMO

BACKGROUND: This study aimed to test the feasibility and titration methods used to achieve specific blood pressure (BP) control targets in hypertensive patients of rural China. METHODS: A randomized, controlled, open-label trial was conducted in Rongcheng, China. We enrolled 105 hypertensive participants aged over 60 years, and who had no history of stroke or cardiovascular disease. The patients were randomly assigned to one of three systolic-BP target groups: standard: 140 to < 150 mmHg; moderately intensive: 130 to < 140 mmHg; and intensive: < 130 mmHg. The patients were followed for 6 months. DISCUSSION: The optimal target for systolic blood pressure (SBP) lowering is still uncertain worldwide and such information is critically needed, especially in China. However, in China the rates of awareness, treatment and control are only 46.9%, 40.7%, and 15.3%, respectively. It is challenging to achieve BP control in the real world and it is very important to develop population-specific BP-control protocols that fully consider the population's characteristics, such as age, sex, socio-economic status, compliance with medication, education level, and lifestyle. This randomized trial showed the feasibility and safety of the titration protocol to achieve desirable SBP targets (< 150, < 140, and < 130 mmHg) in a sample of rural, Chinese hypertensive patients. The three BP target groups had similar baseline characteristics. After 6 months of treatment, the mean SBP measured at an office visit was 137.2 mmHg, 131.1 mmHg, and 124.2 mmHg, respectively, in the three groups. Home BP and central aortic BP measurements were also obtained. At 6 months, home BP measurements (2 h after drug administration) showed a mean SBP of 130.9 mmHg in the standard group, 124.9 mmHg in the moderately intensive group, and 119.7 mmHg in the intensive group. No serious adverse events were recorded over the 6-month study period. Rates of adverse events, including dry cough, palpitations, and arthralgia, were low and showed no significant differences between the three groups. This trial provided real-world experience and laid the foundation for a future, large-scale, BP target study. TRIAL REGISTRATION: Feasibility Study of the Intensive Systolic Blood Pressure Control; ClinicalTrials.gov, ID: NCT02817503. Registered retrospectively on 29 June 2016.

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