Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Stroke risk prediction”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2006

Patient behavior immediately after transient ischemic attack according to clinical characteristics, perception of the event, and predicted risk of stroke.

BACKGROUND AND PURPOSE: Little research has been done on patients' behavior after transient ischemic attack (TIA). Recent data on the high early risk of stroke after TIA mean that emergency action after TIA is essential for effective secondary prevention. We therefore studied patients' behavior immediately after TIA according to their perceptions, clinical characteristics, and predicted stroke risk. METHODS: Consecutive patients with TIA participating in the Oxford Vascular Study or attending dedicated hospital clinics in Oxfordshire, UK, were interviewed. Predicted stroke risk was calculated using 2 validated scores. RESULTS: Of 241 patients, 107 (44.4%) sought medical attention within hours of the event, although only 24 of these attended the emergency department. A total of 107 (44.4%) delayed seeking medical attention for > or =1 day. Correct recognition of symptoms (42.2% of patients) was not associated with less delay. However, patients with motor symptoms or duration of symptoms > or =1 hour were more likely to seek emergency attention (hazard ratio, 2.1; 95% CI, 1.4 to 3.2; P=0.00005), as were those at higher predicted stroke risk (P=0.001). The other main correlate with delay was the day of the week on which the TIA occurred (P<0.001), with greater delays at the weekend. Delay was unrelated to age, sex, or other vascular risk factors. CONCLUSIONS: Many patients delay seeking medical attention after a TIA irrespective of correct recognition of symptoms, although patients at higher predicted risk of stroke do act more quickly. Public education about both the urgency and nature of TIA is required.

Aged↗
PubMed2004

Predicting stroke risk in pediatric moyamoya disease with xenon-enhanced computed tomography.

OBJECTIVE: To determine whether estimates of regional cerebral blood flow (rCBF) using xenon computed tomography (XeCT) in children with moyamoya disease can predict stroke risk before and after treatment. METHOD: Seven patients with moyamoya disease underwent 22 serial Xe computed tomographic scans. Estimates of rCBF were obtained at three computed tomographic levels by use of a 5-minute inhalation of 28% Xe. Acetazolamide challenge was performed in eight scans. For comparison of abnormal vessel distribution and areas of infarction, 17 intra-arterial digital subtraction angiograms, 47 computed tomographic scans, and 15 magnetic resonance imaging scans were available. Follow-up exceeded 36 months in all patients. Mean follow-up for the interventional group was 65.2 months (n = 5; range, 37-109 mo) and 38 months for the nonoperative patients (n = 2; 36 and 40 mo). RESULTS: Of six Xe computed tomographic scans obtained at diagnosis, four revealed regions of oligemia, augmented vertebrobasilar flow, and regions of carotid steal after acetazolamide. In the delay between diagnosis and treatment, three patients had strokes in ischemic areas identified by XeCT. Of the 10 posttreatment scans obtained from 4 patients, 2 revealed improved tissue perfusion with angiography confirming successful encephaloduroangiomyosynangiosis. In 2 others, XeCT performed 6 months posttreatment revealed improved perfusion without angiographic change, and angiography at 1 year revealed failed encephaloduroangiomyosynangiosis and new native collaterals. None of the patients with improved rCBF had new strokes. Eleven of 14 Xe computed tomographic scans were obtained within 30 days of angiography. Comparison of these studies demonstrates that regions of oligemia were confined to areas associated with vessel stenosis and little neovascularity or collateral pathways. CONCLUSION: XeCT, particularly with acetazolamide challenge, objectively quantifies rCBF. Our preliminary data suggest that it may permit assessment of stroke risk in children with moyamoya disease and may predict surgical outcome earlier than angiography.

Administration, Inhalation↗
PubMed1996

Ultrasonographic carotid plaque morphology in predicting stroke risk.

A number of new studies have provided evidence which suggests that carotid plaque surface characteristics and internal structure, as seen on ultrasonography, contribute to the development of cerebrovascular endpoints. This review is a critical presentation of the evidence that has emerged so far supporting the hypothesis that the ultrasonographic morphology of the carotid plaque may be an independent variable in predicting the risk of stroke. It is concluded that ultrasonographic plaque morphology should be used together with other local risk factors in prospective natural history studies which aim to identify a subgroup of patients at high risk of stroke.

Carotid Artery Diseases↗
PubMed2005

Asymptomatic embolization detected by Doppler ultrasound predicts stroke risk in symptomatic carotid artery stenosis.

BACKGROUND AND PURPOSE: Asymptomatic cerebral emboli can be detected using transcranial Doppler ultrasound (TCD). These embolic signals have potential as a marker of stroke risk and as a surrogate marker to evaluate antiplatelet agents. Small studies have demonstrated that they predict the combined endpoint of stroke and transient ischemic attack (TIA), but no studies have shown that they predict the more important endpoint of stroke alone. METHODS: TCD was used to record for 1 hour from the ipsilateral middle cerebral artery in 200 patients with >50% symptomatic carotid stenosis. The Doppler audio signal was recorded for later analysis blinded to clinical details. Subjects were followed-up prospectively until surgical intervention, stroke, or study end at 90 days. RESULTS: Embolic signals (ES) were detected in 89 (44.5%). During follow-up, 31 subjects experienced recurrent ipsilateral ischemic events: 7 strokes and 24 TIAs. The presence of ES predicted stroke alone (P=0.001) and the combined endpoint of stroke and TIA (P=0.00001). This remained significant, with an odds ratio of 4.67 (95% CI, 1.99 to 11.01; P<0.0001) after Cox regression to control for age, sex, smoking, hypertension, time from last symptoms, and degree of stenosis. The absence of ES identified a group at low risk for stroke alone and stroke and TIA during follow-up: 0% and 7.5%, respectively, versus 3.5% and 15.5% in all 200 subjects. CONCLUSIONS: Asymptomatic embolization in carotid stenosis predicts short-term ipsilateral stroke risk. This supports use of the technique to identify patients at high-risk for recurrent stroke for therapeutic interventions and as a surrogate marker to evaluate antithrombotic medication.

Aged↗
PubMed1993

Increased stroke risk predicted by compromised cerebral blood flow reactivity.

The authors sought to determine risk for stroke in individuals with symptomatic carotid stenosis or occlusion based upon an assessment of cerebral blood flow (CBF) reserves. Vascular reserve was assessed by two consecutive xenon/computerized tomography (Xe/CT) CBF studies with intravenous acetazolamide introduced 20 minutes prior to the second study. Patients were assigned to one of two vasoreactivity groups. Group 2 included individuals who experienced a CBF reduction of more than 5% in at least one vascular territory and had a baseline flow of 45 cc/100 gm/min or less. Group 1 included all other individuals. Any territory with volume loss on CT of more than 50% was eliminated from analysis. Sixty-eight individuals were followed at 6-month intervals for a mean of 24 months. In Group 1 two strokes were observed contralateral to the side with lowest reserve, for a stroke incidence of 4.4%; in Group 2 eight strokes were observed ipsilateral to the side with lowest reserve, for a stroke incidence of 36%. The latter group had a 12.6 times greater chance of stroke (p = 0.0007). History of stroke, history of transient ischemic attacks, baseline CBF, and degree of stenosis were not associated with an increased stroke rate. In this study, significantly compromised vascular reserves accompanied by relatively low initial flow identified individuals who subsequently demonstrated a significantly increased rate of ipsilateral stroke.

Acetazolamide↗
PubMed2001

Stroke risk predicts verbal fluency decline in healthy older men: evidence from the normative aging study.

Risk factors for stroke cause ischemic changes in the cerebral white matter that may affect frontal lobe functions more than other brain functions. Therefore, stroke risk could specifically affect performance on behavioral indexes traditionally associated with frontal lobe function such as verbal fluency. The authors examined this hypothesis in 235 healthy older men (mean age = 66.41 years) who received concurrent medical and neuropsychological examinations twice at a 3-year interval. Relations between stroke risk and decline in verbal fluency, memory, and visuospatial performance were analyzed through regression, controlling for age and education. Age was associated with decline in all cognitive functions; stroke risk was associated with decline only on verbal fluency. The relation between stroke risk and fluency decline was 80% as large as that between age and fluency decline. These results suggest that stroke risk rivals the effects of aging on verbal fluency performance.

Aged↗
PubMed2006

Carotid artery calcification on CT may independently predict stroke risk.

OBJECTIVE: The purpose of our study was to quantitatively evaluate calcified atherosclerotic burden in the cervical carotid arteries using MDCT to determine the relationship of scores with luminal stenosis and symptomatology. MATERIALS AND METHODS: Calcium plaque volume was measured in 106 cervical carotid arteries (53 patients) using MDCT angiography. The study group included 32 asymptomatic patients (mean age, 70.2 +/- 8.7 [SD] years; 15 women, 17 men) and 21 patients with ischemic neurologic symptoms (69.6 +/- 12.9 years; eight women, 13 men). By vessel, there were 43 high-grade stenotic (> or = 60% by North American Symptomatic Carotid Endarterectomy Trial [NASCET] criteria), 15 moderate-grade stenotic (30-59%), and 44 mild-grade stenotic or normal (0-29%) vessels, with four excluded for prior carotid endarterectomy. Volume scores were calculated by summing the area of calcium in the common and extracranial internal carotid arteries on axial slices and multiplying by the slice increment. RESULTS: Controlling for cardiovascular risk factors and luminal stenosis, we found that scores were significantly related to the occurrence of symptoms (p = 0.003). Even with patient age as a covariant, patients with high-grade stenosis had significantly higher scores than those without high-grade disease (p = 0.004). Moreover, quantitative burden was associated with luminal stenosis on adjusted multivariate analysis (p = 0.034). The specificity and positive predictive value for high-grade luminal narrowing were notably lower on individual vessel analysis than on total score analysis, likely secondary to variability in vascular remodeling. CONCLUSION: Calcium scores in the cervical carotid arteries may represent an independent marker for luminal stenosis and ischemic symptoms. A prospective longitudinal study examining calcium levels and morbidity may be warranted to examine whether burden has a role in risk stratification.

Aged↗
PubMed2002

LPL polymorphism predicts stroke risk in men.

Variation in lipid levels has been associated with atherosclerotic vascular disease, including stroke. Genes contributing to interindividual variation in lipid levels may play a role in the etiology of stroke, either through their effects on lipid synthesis and metabolism or through separate pathways. For this reason, we sought to examine the association between polymorphisms in the lipoprotein lipase (LPL) and apolipoprotein E (APOE) genes and subclinical and clinical stroke in the Atherosclerosis Risk in Communities (ARIC) Study. Subclinical stroke was determined by cerebral magnetic resonance imaging (MRI). Subclinical cerebral infarct cases (n = 197) were compared to a stratified random sample identified from individuals participating in the MRI examination (n = 200). Incidence of clinical ischemic stroke was determined by following the ARIC cohort for an average of 7.5 years for potential cerebrovascular events; 218 validated clinical ischemic strokes were identified. A stratified random sample of the ARIC cohort (CRS, n = 964) was used as the comparison group for clinical cases. The LPL S291-carrying genotypes and APOE epsilon2- and epsilon4-carrying genotypes were not significantly associated with subclinical or clinical stroke. The LPL X447-containing genotypes were significantly associated with subclinical (odds ratio [OR], 4.32; 95% confidence interval [CI], 1.23-15.15; P = 0.020) and clinical stroke (hazard rate ratio [HRR], 2.57; 95% CI, 1.24-5.34; P = 0.01) in men, both by themselves and after adjustment for multiple stroke risk factors. The LPL S447X polymorphism is significantly associated with subclinical cerebral infarction and incident clinical ischemic stroke in men from a middle-aged American population. This association does not appear to be mediated by triglyceride, high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol levels, or additional stroke risk factors.

Apolipoproteins E↗
PubMed1993

Gene polymorphism of apolipoprotein AI, the major protein of high density lipoprotein in predicting stroke risk among white and black subjects.

BACKGROUND AND PURPOSE: Restriction fragment length polymorphism of the apolipoprotein AI gene, which encodes the most prominent apoproteins in high density lipoprotein (HDL), were investigated using the restriction enzymes Sac I and Pst I in white and black subjects to determine the potential role of genetic variations as stroke risks as determined by carotid stenosis and an atherogenic serum profile, such as elevated total cholesterol and low density lipoprotein (LDL) levels or reduced HDL levels. METHODS: Ninety-eight subjects, including normal control subjects with no carotid stenosis and subjects with carotid stenosis, who were believed to be at stroke risk, were the study subjects and included 70 white and 28 black subjects. RESULTS: Sac I polymorphic S2 allele frequency was higher in stroke-risk groups. Significantly higher levels of serum cholesterol, triglycerides, and LDL (P < .05) and significantly lower levels of HDL (P < .05) were present in the stroke-risk group with carotid stenosis. Our study showed the following: Sac I polymorphism frequency was significantly higher in black than white subjects (chi 2 = 3.92, P < .05). Triglyceride level was significantly higher in white subjects compared with black subjects (P < .05). In white subjects, carotid artery stenosis was associated with significantly elevated total cholesterol and LDL levels (P < .01) but not with Sac I polymorphism. In black subjects, the reverse was seen with the Sac I polymorphic S2 allele associated with carotid bifurcation stenosis but did not reach statistical significance because of the small number of subjects. In addition, Sac I polymorphism did not correlate with any lipid profile. Pst I polymorphism was not associated with an abnormal atherogenic lipid profile or carotid artery stenosis abnormalities. CONCLUSIONS: Our study shows that carotid artery stenosis in white subjects is associated with increased plasma total cholesterol and LDL levels and an atherogenic profile but not with Sac I polymorphism for apoprotein AI. In black subjects, Sac I polymorphism appears to identify individuals with significant carotid stenosis, a necessary precursor to atherothrombotic brain infarction, but not those with elevated total cholesterol or LDL and/or reduced HDL levels. These results suggest that Sac I polymorphism may identify black subjects at increased risk for atherothrombotic brain infarctions.

Aged↗
PubMed2005

Family history of stroke does not predict risk of stroke after transient ischemic attack.

BACKGROUND AND PURPOSE: Animal models suggest a genetic contribution to cerebral susceptibility to ischemia. Family history of stroke (FHxstroke) is a risk factor for ischemic stroke, but there is significant confounding by heritability of hypertension and other intermediate phenotypes, and it is uncertain whether genetic factors have a direct independent influence on cerebral susceptibility to ischemia in man. METHODS: We related detailed FHxstroke to baseline characteristics and subsequent risk of stroke in 2 population-based incidence studies and a consecutive hospital-referred series of patients with recent transient ischemic attack (TIA). RESULTS: In none of the cohorts or the pooled data (757 patients; 5515 patient years follow-up; 200 ischemic strokes; 126 myocardial infarctions [MIs]) did FHxstroke predict ischemic stroke (odds ratio [OR], 0.87; 95% CI, 0.57 to 1.32). No associations were revealed by analyses stratified by age or hypertension in the proband, FHx(stroke) in parents versus siblings, number of affected relatives, or their age at stroke. FHxstroke was unrelated to presence of ischemic lesions on baseline computed tomography (OR, 0.96; 0.52 to 1.76) or risk of MI during follow-up. There was no bias attributable to any relationship between FHxstroke and risk factor control or medication. CONCLUSIONS: Family history of stroke does not predict risk of ischemic stroke after TIA.

Aged↗
PubMed2004

How many times should blood pressure be measured at home for better prediction of stroke risk? Ten-year follow-up results from the Ohasama study.

OBJECTIVE: To determine the optimum number of blood pressure self-measurements taken at home (home blood pressure) in relation to their predictive value for stroke risk. METHODS: We obtained more than 14 measurements of home blood pressure from 1491 people aged >or=40 years without a history of stroke in the general population in Japan, and followed them up after a mean period of 10.6 years. The prognostic significance of blood pressure for stroke risk was examined using the Cox proportional hazards regression model, which was adjusted for possible confounding factors. RESULTS: The predictive value of home blood pressure increased progressively with the number of measurements, showing the highest predictive value with the average of whole measurements (mean = 25 measurements, 35% increase in the risk of stroke per 10 mmHg elevation in blood pressure). The initial home blood pressure values (one measurement) showed a significantly greater relation with stroke risk than conventional blood pressure values (mean of two measurements) (19/8% increase in the risk of stroke per 10 mmHg elevation in initial home/conventional systolic blood pressure values, respectively). CONCLUSIONS: There was no threshold for the number of home blood pressure measurements within the range of 1-14 measurements for increasing the predictive power of stroke risk, suggesting that as many measurements as possible, preferably more than 14 measurements, is recommended for better prediction of stroke risk. It should be emphasized that home blood pressure has a stronger predictive power than does conventional blood pressure, even for a lower number of measurements.

Adult↗
PubMed2001

Severely impaired cerebrovascular reactivity predicts stroke and TIA risk in patients with carotid artery stenosis and occlusion.

Cross-sectional studies suggest that impaired cerebral haemodynamics is associated with symptomatic status in patients with carotid stenosis and occlusion, but there is relatively little prospective data confirming this association. Transcranial Doppler ultrasonography was used to determine the reactivity of the middle cerebral artery to 8% carbon dioxide in air in 107 patients with either carotid occlusion (n = 48) or asymptomatic carotid stenosis (n = 59). Subjects were followed prospectively until stroke, transient ischaemic attack (TIA), death or study end. Mean duration of follow-up was 635 days. No patients dropped out due to operation before an end-point was reached, or were lost to follow-up. There were 11 ipsilateral ischaemic events during follow-up (six strokes, five TIAs). Exhausted ipsilateral middle cerebral artery reactivity (>20% increase in ipsilateral middle cerebral flow velocity in response to 8% carbon dioxide) predicted ipsilateral stroke and TIA risk in the whole group (P: < 0.00001) and in the carotid occlusion (P: = 0.019) and carotid stenosis (P: = 0.015) groups alone. It also predicted the risk of ipsilateral stroke alone in all three groups. Cox regression was performed, controlling for age, gender, hypertension, diabetes, smoking, ipsilateral CT infarct, degree of contralateral stenosis and the presence of ipsilateral stenosis versus occlusion. Exhausted reactivity remained an independent predictor of ipsilateral stroke and TIA (odds ratio 14.4, 95% confidence interval 2.63-78.74, P: = 0.0021). In contrast, the pulsatility index of the middle cerebral artery was a poor predictor of the risk of stroke. Reactivity to 6% carbon dioxide also predicted the risk of stroke and TIA, but slightly less effectively than reactivity to 8% carbon dioxide. Severely reduced cerebrovascular reactivity predicts the risk of ipsilateral stroke and TIA in patients with carotid occlusion, and to a lesser extent in asymptomatic carotid stenosis. Particularly in the former group, a study is required to determine whether revascularization reduces the risk of stroke in patients with exhausted reactivity.

Carotid Stenosis↗
PubMed2001

Comparison of PET oxygen extraction fraction methods for the prediction of stroke risk.

UNLABELLED: PET measurement of increased oxygen extraction fraction (OEF) identifies patients at high risk for subsequent stroke. OEF methodology remains controversial. In this study we compare the sensitivity and specificity of absolute OEF measurements with ipsilateral-to-contralateral ratios of absolute OEF and count-based OEF estimates. METHODS: Multivariate analyses of OEF methods were performed using data from patients with symptomatic carotid artery occlusion (n = 68). Outcome and receiver operating characteristic (ROC) curve analyses were performed. RESULTS: All 3 methods were predictive of stroke risk in univariate analysis. Only the count-based method remained significant in multivariate analysis. The area under the ROC curve was greatest for the count-based ratio: 0.815 versus 0.769 (absolute) and 0.737 (ratios of absolute). CONCLUSION: All 3 methods are predictive of stroke risk in patients with unilateral carotid artery occlusion. ROC curve analysis is useful for selecting optimal thresholds for maximal sensitivity and specificity.

Arteriosclerosis↗