Background And Objectives: Whether patent foramen ovale (PFO) closure benefits older patients with PFO and cryptogenic stroke is unknown because randomized controlled trials (RCTs) have predominantly enrolled patients younger than 60 years of age. Our objective was to estimate anticipated effects of PFO closure in older patients to predict the numbers needed to plan an RCT.
Methods: Effectiveness estimates are derived from major observational studies (Risk of Paradoxical Embolism [RoPE] Study and Oxford Vascular Study, together referred to as the "RoPE-Ox" database) and all 6 major RCTs (Systematic, Collaborative, PFO Closure Evaluation [SCOPE] Consortium).
Introduction: Cerebral blood flow (CBF) declines with age and abnormalities in CBF are associated with age-related cerebrovascular disease and neurodegeneration. Women have higher CBF than men, although this sex-difference diminishes to some extent with age in healthy subjects. The physiological drivers of these age/sex differences are uncertain, but might be secondary to age and sex-differences in haemoglobin (Hb) level.
View Article and Find Full Text PDFBackground: Up to 25% of embolic strokes occur in individuals without atrial fibrillation (AF) or other identifiable mechanisms.
Objectives: This study aims to assess whether left atrial (LA) blood flow characteristics are associated with embolic brain infarcts, independently of AF.
Methods: The authors recruited 134 patients: 44 with a history of ischemic stroke and 90 with no history of stroke but CHADSVASc score ≥1.
Objective: Arterial stiffness, cerebral pulsatility, and beat-to-beat blood pressure variability partly mediate the relationship between hypertension and stroke, but it is unknown if these intermediate phenotypes of vascular ageing differ between stroke aetiologies. We therefore aimed to characterize differences in these intermediate cardiovascular phenotypes between patients presenting with strokes of different aetiologies.
Methods: In consecutive patients on best medical management 1 month after TIA or nondisabling stroke (Oxford Vascular Study), arterial stiffness (PWV) was measured by applanation tonometry (Sphygmocor), middle cerebral blood flow velocity, and pulsatility index (MCA-PI) were measured by transcranial ultrasound (TCD, DWL Doppler Box), and beat-to-beat BP variability was measured with a Finometer.
Background Beat-to-beat blood pressure variability (BPV) is associated with an increased risk of stroke but can be driven by both healthy physiological processes and failure of compensatory mechanisms. Blood pressure (BP) complexity measures structured, organized variations in BP, as opposed to random fluctuations, and its reduction may therefore identify pathological beat-to-beat BPV. Methods and Results In the prospective, population-based OXVASC (Oxford Vascular Study) Phenotyped Cohort with transient ischemic attack or minor stroke, patients underwent at least 5 minutes of noninvasive beat-to-beat monitoring of BP (Finometer) and ECG to derive the following: BPV (coefficient of variation) and complexity (modified multiscale entropy) of systolic BP and diastolic BP, heart rate variability (SD of R-R intervals), and baroreflex sensitivity (BRS; Welch's method), in low- (0.
View Article and Find Full Text PDFBackground: Effects of early blood pressure (BP) lowering on cerebral perfusion in patients with moderate/severe occlusive carotid disease after transient ischemic attack (TIA) and non-disabling stroke are uncertain.
Aims: We aimed to evaluate the changes in transcranial Doppler (TCD) indices in patients undergoing blood pressure lowering soon after TIA/non-disabling stroke.
Methods: Consecutive eligible patients (1 November 2011 to 30 October 2018) attending a rapid-access clinic with TIA/non-disabling stroke underwent telemetric home blood pressure monitoring (HBPM) for 1 month and middle cerebral artery velocities measurements ipsilateral to carotid stenosis on TCD ultrasound in the acute setting and at 1 month.
Background: Increased cerebral arterial pulsatility is associated with cerebral small vessel disease, recurrent stroke, and dementia despite the best medical treatment. However, no study has identified the rates and determinants of progression of arterial stiffness and pulsatility.
Methods: In consecutive patients within 6 weeks of transient ischemic attack or nondisabling stroke (OXVASC [Oxford Vascular Study]), arterial stiffness (pulse wave velocity [PWV]) and aortic systolic, aortic diastolic, and aortic pulse pressures (aoPP) were measured by applanation tonometry (Sphygmocor), while middle cerebral artery (MCA) peak (MCA-PSV) and trough (MCA-EDV) flow velocity and Gosling pulsatility index (PI; MCA-PI) were measured by transcranial ultrasound (transcranial Doppler, DWL Doppler Box).
Introduction: There is limited knowledge of the effects of blood pressure (BP) lowering on cerebral haemodynamics after transient ischaemic attack (TIA) and non-disabling stroke, particularly at older ages. We aimed to evaluate changes in transcranial Doppler (TCD) haemodynamic indices in patients undergoing early blood pressure lowering after TIA/non-disabling stroke, irrespective of age.
Patients And Methods: Among consecutive eligible patients attending a rapid-access clinic with suspected TIA/non-disabling stroke and no evidence of extra/intracranial stenosis, hypertensive ones underwent intensive BP-lowering guided by daily home telemetric blood pressure monitoring (HBPM).
Beat-to-beat variability in blood pressure (BP) is associated with recurrent stroke despite good control of hypertension. However, no study has identified rates of progression of beat-to-beat BP variability (BPV), its determinants, or which patient groups are particularly affected, limiting understanding of its potential as a treatment target. In consecutive patients one month after a transient ischaemic attack or nondisabling stroke (Oxford Vascular Study), continuous noninvasive BP was measured beat-to-beat over 5 minutes (Finometer).
View Article and Find Full Text PDFJ Stroke Cerebrovasc Dis
January 2021
Introduction: Increasing blood pressure variability has been reported following acute stroke, but there is uncertainty about how best to measure it and about the impact on prognosis following acute ischaemic stroke and transient ischaemic attack.
Methods: Enhanced casual blood pressure and ambulatory blood pressure monitoring were completed at baseline (≤48 h post symptom onset). Blood pressure variability was defined by standard deviation and coefficient of variation of systolic, diastolic, mean arterial pressure, and pulse pressure.
Background: Beat-to-beat blood pressure variability is associated with increased stroke risk but its importance at different ages is unclear.
Aims: To determine the age-sex distribution of blood pressure variability in patients with transient ischemic stroke or minor stroke.
Methods: In consecutive patients within six weeks of transient ischemic stroke or non-disabling stroke (Oxford Vascular Study), non-invasive blood pressure was measured beat-to-beat over five minutes (Finometer).
Cerebral arterial pulsatility is strongly associated with cerebral small vessel disease and lacunar stroke yet its dependence on central versus local haemodynamic processes is unclear. In a population-based study of patients on best medical managment, 4-6 weeks after a TIA or non-disabling stroke, arterial stiffness and aortic systolic, diastolic and pulse pressures were measured (Sphygmocor). Middle cerebral artery peak and trough flow velocities and Gosling's pulsatility index were measured by transcranial ultrasound.
View Article and Find Full Text PDFImportance: Patent foramen ovale (PFO) closure may prevent recurrent stroke after cryptogenic transient ischemic attack (TIA) or stroke (TIA/stroke) in patients aged 60 years or younger. Patent foramen ovale is associated with cryptogenic stroke in the older population, but risk of recurrence is unknown. Data on prognosis of patients receiving medical treatment at older ages (≥60 years) are essential to justify trials of PFO closure.
View Article and Find Full Text PDFBackground and Purpose- Breath holding (BH) and hyperventilation are used to assess abnormal cerebrovascular reactivity, often in relation to severity of small vessel disease and risk of stroke with carotid stenosis, but responses may be confounded by blood pressure (BP) changes. We compared effects of BP and end-tidal carbon dioxide (etCO) on middle cerebral artery mean flow velocity (MFV) in consecutive transient ischemic attack and minor stroke patients. Methods- In the population-based, prospective OXVASC (Oxford Vascular Study) phenotyped cohort, change in MFV on transcranial Doppler ultrasound (ΔMFV, DWL-DopplerBox), beat-to-beat BP (Finometer), and etCO was measured during 30 seconds of BH or hyperventilation.
View Article and Find Full Text PDFObjective: To investigate if the association between MRI-detectable white matter hyperintensity (WMH) and cognitive status reported in previous studies persists at older ages (>80 years), when some white matter abnormality is almost universally reported in clinical practice.
Methods: Consecutive eligible patients from a population-based cohort of all TIA/nondisabling stroke (Oxford Vascular Study) underwent multimodal MRI, including fluid-attenuated inversion recovery and diffusion-weighted imaging, allowing automated measurement of WMH volume, mean diffusivity (MD), and fractional anisotropy (FA) in normal-appearing white matter using FSL tools. These measures were related to cognitive status (Montreal Cognitive Assessment) at age ≤80 vs >80 years.
Toll-like receptor 4 (TLR4)/prostaglandine synthetase 2 (PTGS2) signaling plays a relevant role in atherosclerotic plaque vulnerability. The purpose of this study was to check the gene expression of 6 genes participating to TLR4/PTGS2 signaling (TLR4, PTGS2, ACSL4, PTGER3, PTGER4, and EPRAP) in carotid plaques and blood samples from the same individual and to evaluate these genes as biomarker of plaque progression. We investigated differential gene expression by qRT-PCR in 62 atherosclerotic patients' carotid plaques and corresponding blood sample.
View Article and Find Full Text PDFCircadian clocks are fundamental physiological regulators of energy homeostasis, but direct transcriptional targets of the muscle clock machinery are unknown. To understand how the muscle clock directs rhythmic metabolism, we determined genome-wide binding of the master clock regulators brain and muscle ARNT-like protein 1 (BMAL1) and REV-ERBα in murine muscles. Integrating occupancy with 24-hr gene expression and metabolomics after muscle-specific loss of BMAL1 and REV-ERBα, here we unravel novel molecular mechanisms connecting muscle clock function to daily cycles of lipid and protein metabolism.
View Article and Find Full Text PDFBackground Although large artery stiffness has been implicated in the pathogenesis of cerebral small vessel disease, whether carotid pulsatility, a convenient surrogate marker of arterial stiffness, is similarly associated with global burden of small vessel disease is unknown. Aims To determine the age and sex-specific associations of carotid pulsatility with global burden of small vessel disease. Methods We studied consecutive patients with transient ischemic attack or non-disabling ischemic stroke from the Oxford Vascular Study who had a brain MRI and carotid duplex ultrasound during 2002-2014.
View Article and Find Full Text PDFInflammation has a key role and translates the effects of many known risk factors for the disease in atherosclerotic vulnerable plaques. Aiming to look into the elements that induce the development of either a vulnerable or stable atherosclerotic plaque, and considering that inflammation has a central role in the progression of lesions, we analyzed the expression of genes involved in the ACE/TLR4/PTGS2 signaling in carotid plaques of symptomatic and asymptomatic patients. Patients with internal carotid artery stenosis undergoing carotid endarterectomy at Verona University Hospital were included in this study.
View Article and Find Full Text PDFBackground: Percutaneous closure of patent foramen ovale (PFO) has been shown to be superior to medical treatment alone for prevention of recurrent stroke after cryptogenic transient ischaemic attack or non-disabling stroke in patients aged 60 years or younger. The justification for trials in older patients with transient ischaemic attack or stroke depends on whether PFO is shown to be associated with cryptogenic events at older ages, for which existing evidence is conflicting, and on the population burden of PFO-associated events. Therefore, we did a population-based screening study using contrast-enhanced transcranial Doppler (bubble-TCD) to detect probable PFO as indicated by a right-to-left shunt (RLS); we also did a systematic review and meta-analysis to compare our results with previous studies.
View Article and Find Full Text PDFBackground And Purpose: Visit-to-visit and day-to-day blood pressure (BP) variability (BPV) predict an increased risk of cardiovascular events but only reflect 1 form of BPV. Beat-to-beat BPV can be rapidly assessed and might also be predictive.
Methods: In consecutive patients within 6 weeks of transient ischemic attack or nondisabling stroke (Oxford Vascular Study), BPV (coefficient of variation) was measured beat-to-beat for 5 minutes (Finometer), day-to-day for 1 week on home monitoring (3 readings, 3× daily), and on awake ambulatory BP monitoring.