Systemic vascular function, measured with forearm flow mediated dilatation, in acute and stable cerebrovascular disease: a case-control study

BACKGROUND Acute ischaemic stroke is associated with alteration in systemic markers of vascular function. We measured forearm vascular function (using forearm flow mediated dilatation) to clarify whether recent acute ischaemic stroke/TIA is associated with impaired systemic vascular function. METHODS Prospective case control study enrolling 17 patients with recent acute ischaemic stroke/TIA and 17 sex matched controls with stroke more than two years previously. Forearm vascular function was measured using flow medicated dilatation (FMD). RESULTS Flow mediated dilatation was 6.0 ± 1.1% in acute stroke/TIA patients and 4.7 ± 1.0% among control subjects (p = 0.18). The mean paired difference in FMD between subjects with recent acute stroke and controls was 1.25% (95% CI -0.65, 3.14; p = 0.18). Endothelium independent dilatation was measured in six pairs of participants and was similar in acute stroke/TIA patients (22.6 ± 4.3%) and control subjects (19.1 ± 2.6%; p = 0.43). CONCLUSIONS Despite the small size of this study, these data indicate that recent acute stroke is not necessarily associated with a clinically important reduction in FMD.This study was funded by the Centre for Training in Clinical Cerebrovascular and Cardiovascular Research, a National Health and Medical Research Council funded Centre of Clinical Research Excellence

Homocysteine, grey matter and cognitive function in adults with cardiovascular disease

Background: Elevated total plasma homocysteine (tHcy) has been associated with cognitive impairment, vascular disease and brain atrophy. Methods: We investigated 150 volunteers to determine if the association between high tHcy and cerebral grey matter volume and cognitive function is independent of cardiovascular disease. Results: Participants with high tHcy (≥15 μmol/L) showed a widespread relative loss of grey matter compared with people with normal tHcy, although differences between the groups were minimal once the analyses were adjusted for age, gender, diabetes, hypertension, smoking and prevalent cardiovascular disease. Individuals with high tHcy had worse cognitive scores across a range of domains and less total grey matter volume, although these differences were not significant in the adjusted models. Conclusions: Our results suggest that the association between high tHcy and loss of cerebral grey matter volume and decline in cognitive function is largely explained by increasing age and cardiovascular diseases and indicate that the relationship is not causal

Ultrasound settings significantly alter arterial lumen and wall thickness measurements

Background. Flow-mediated dilation (FMD) and carotid intima-medial thickness (CIMT), measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods. We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR) and gain set at five decibel (dB) increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results. Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p \u3c 0.001). For a given DR level, a 5 dB increase in gain reduced measured lumen diameter by 0.04 ± 0.004 mm (p \u3c 0.001). A 5 mm increase in distance between the ultrasound probe and the artery reduced measured lumen diameter by 0.04 ± 0.03 mm (p \u3c 0.001). CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p \u3c 0.001). The effects of increasing gain were not consistent and appeared to vary depending on the distance between the artery and the ultrasound probe and the thickness of the artery wall. Conclusion. DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects

Homocysteine, Grey Matter and Cognitive Function in Adults with Cardiovascular Disease

Background: Elevated total plasma homocysteine (tHcy) has been associated with cognitive impairment, vascular disease and brain atrophy. Methods: We investigated 150 volunteers to determine if the association between high tHcy and cerebral grey matter volume and cognitive function is independent of cardiovascular disease. Results: Participants with high tHcy ($15 mmol/L) showed a widespread relative loss of grey matter compared with people with normal tHcy, although differences between the groups were minimal once the analyses were adjusted for age, gender, diabetes, hypertension, smoking and prevalent cardiovascular disease. Individuals with high tHcy had worse cognitive scores across a range of domains and less total grey matter volume, although these differences were not significant in the adjusted models. Conclusions: Our results suggest that the association between high tHcy and loss of cerebral grey matter volume and decline in cognitive function is largely explained by increasing age and cardiovascular diseases and indicate that th

The effect of long-term homocysteine-lowering on carotid intima-media thickness and flow-mediated vasodilation in stroke patients: a randomized controlled trial and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Experimental and epidemiological evidence suggests that homocysteine (tHcy) may be a causal risk factor for atherosclerosis. B-vitamin supplements reduce tHcy and improve endothelial function in short term trials, but the long-term effects of the treatment on vascular structure and function are unknown.</p> <p>Methods</p> <p>We conducted a sub-study of VITATOPS, a randomised, double-blind, placebo-controlled intervention trial designed to test the efficacy of long term B-vitamin supplementation (folic acid 2 mg, vitamin B₆25 mg and vitamin B₁₂0.5 mg) in the prevention of vascular events in patients with a history of stroke. We measured carotid intima-medial thickness (CIMT) and flow-mediated dilation (FMD) at least two years after randomisation in 162 VITATOPS participants. We also conducted a systematic review and meta-analysis of studies designed to test the effect of B-vitamin treatment on CIMT and FMD.</p> <p>Results</p> <p>After a mean treatment period of 3.9 ± 0.9 years, the vitamin-treated group had a significantly lower mean plasma homocysteine concentration than the placebo-treated group (7.9 μmol/L, 95% CI 7.5 to 8.4 versus 11.8 μmol/L, 95% CI 10.9 to 12.8, p < 0.001). Post-treatment CIMT (0.84 ± 0.17 mm vitamins versus 0.83 ± 0.18 mm placebo, p = 0.74) and FMD (median of 4.0%, IQR 0.9 to 7.2 vitamins versus 3.0%, IQR 0.6 to 6.6 placebo, p = 0.48) did not differ significantly between groups. A meta-analysis of published randomised data, including those from the current study, suggested that B-vitamin supplements should reduce CIMT (-0.10 mm, 95% CI -0.20 to -0.01 mm) and increase FMD (1.4%, 95% CI 0.7 to 2.1%). However, the improvement in endothelial function associated with homocysteine-lowering treatment was significant in short-term studies but not in longer trials.</p> <p>Conclusion</p> <p>Although short-term treatment with B-vitamins is associated with increased FMD, long-term homocysteine-lowering did not significantly improve FMD or CIMT in people with a history of stroke.</p> <p>Trial Registration</p> <p>Clinical Trial Registration URL: <url>http://www.actr.org.au/</url></p> <p>Trial Registration number: 12605000005651</p

Carotid intima-medial thickness measured on multiple ultrasound frames: evaluation of a DICOM-based software system

United Kingdo

The quality of care delivered to residents in long-term care in Australia: an indicator-based review of resident records (CareTrack Aged study)

Background: This study estimated the prevalence of evidence-based care received by a population-based sample of Australian residents in long-term care (LTC) aged ≥ 65 years in 2021, measured by adherence to clinical practice guideline (CPG) recommendations. Methods: Sixteen conditions/processes of care amendable to estimating evidence-based care at a population level were identified from prevalence data and CPGs. Candidate recommendations (n = 5609) were extracted from 139 CPGs which were converted to indicators. National experts in each condition rated the indicators via the RAND-UCLA Delphi process. For the 16 conditions, 236 evidence-based care indicators were ratified. A multi-stage sampling of LTC facilities and residents was undertaken. Trained aged-care nurses then undertook manual structured record reviews of care delivered between 1 March and 31 May 2021 (our record review period) to assess adherence with the indicators. Results: Care received by 294 residents with 27,585 care encounters in 25 LTC facilities was evaluated. Residents received care for one to thirteen separate clinical conditions/processes of care (median = 10, mean = 9.7). Adherence to evidence-based care indicators was estimated at 53.2% (95% CI: 48.6, 57.7) ranging from a high of 81.3% (95% CI: 75.6, 86.3) for Bladder and Bowel to a low of 12.2% (95% CI: 1.6, 36.8) for Depression. Six conditions (skin integrity, end-of-life care, infection, sleep, medication, and depression) had less than 50% adherence with indicators. Conclusions: This is the first study of adherence to evidence-based care for people in LTC using multiple conditions and a standardised method. Vulnerable older people are not receiving evidence-based care for many physical problems, nor care to support their mental health nor for end-of-life care. The six conditions in which adherence with indicators was less than 50% could be the focus of improvement efforts

Lowering blood pressure in 2003

The foundation of treatment for patients with hypertension is ongoing use of lifestyle measures such as physical exercise, weight reduction, and salt restriction. There should be emphasis on reduction of total cardiovascular risk, including smoking cessation and achievement of goal blood pressures. There are now five classes of first-line blood-pressure-lowering drugs - diuretics, β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and calcium antagonists. In most patients, the choice of drug will be guided by the clinical situation in the individual patient, including the presence of target organ damage, diabetes, established vascular or kidney disease, or other comorbidities. In the absence of such clinical indications, start drug therapy with a low-dose diuretic. Combination therapy will be needed in around two-thirds of patients, and a diuretic will normally form one element of most combinations, with the second or third drug coming from among the remaining four. Consider the use of fixed-dose combinations to improve adherence to therapy. Use long-acting, once-daily preparations