PubMed Health⌕ Search

Biomedical subjects

Peter M Rothwell

Publications and source records attributed to Peter M Rothwell.

At least 19 recordsLinked to original sources
PubMed2007

Asymptomatic carotid stenosis: what to do.

PURPOSE OF REVIEW: Patients with asymptomatic carotid stenosis are at increased vascular risk but optimal treatment is controversial. We reviewed the current evidence for medical and surgical intervention in these patients. RECENT FINDINGS: Optimal medical treatment is the most important aspect of management of patients with asymptomatic carotid stenosis. On the basis of previous trials, endarterectomy is only of overall benefit in men, and this benefit may now be obviated by improved medical treatment. There is insufficient evidence to advocate the routine use of carotid angioplasty or stenting in patients with asymptomatic stenosis. Inaccuracy in the measurement of carotid stenosis may contribute to conflicting estimates of stroke risk in relation to the degree of asymptomatic stenosis. Advances in noninvasive imaging of plaque morphology and inflammation and the detection of microembolic signals may help to risk stratify patients but data on clinical usefulness are lacking. SUMMARY: Absolute benefit from endarterectomy for asymptomatic carotid stenosis is small, but can sometimes be justified in men. Further research is required to determine long-term benefit in women and to risk stratify patients, particularly in the light of advances in medical treatment.

Anticoagulants↗
PubMed2006

Risk of coronary and other nonstroke vascular death in relation to the presence and extent of atherosclerotic disease at the carotid bifurcation.

BACKGROUND AND PURPOSE: It has been proposed that purely unilateral carotid stenosis is due mainly to local hemodynamic factors, whereas more diffuse disease reflects a systemic as well as a local predisposition and should therefore be associated with higher rates of arterial disease in the other territories. However, few studies have tested this hypothesis. METHODS: We studied angiograms from 2741 patients with a recently symptomatic carotid stenosis from the European Carotid Surgery Trial and categorized them as showing purely unilateral disease (no convincing plaque in the contralateral carotid artery) or bilateral disease. We related the presence and extent of plaque at both bifurcations to the prevalence of past atherothrombotic disease in other arterial territories and the risk of future nonstroke vascular events. RESULTS: The degree of symptomatic carotid stenosis was unrelated to either the prevalence of symptomatic arterial disease in other territories at baseline or to the risk of nonstroke vascular death during follow-up, whereas there were strong associations with the presence of bilateral carotid disease. In multivariate analyses, bilateral carotid disease (n=2076) was associated with previous myocardial infarction (odds ratio [OR]=1.7; 95% CI, 1.2 to 2.4) or peripheral vascular disease (OR=1.5; 95% CI, 1.2 to 2.0) and with subsequent nonstroke vascular death (hazard ratio=2.0; 95% CI, 1.5 to 2.6). The 5-year risk of nonstroke vascular death ranged from 2.7% (95% CI, 1.5% to 4.6%) in patients with no history of coronary or peripheral arterial disease at baseline and purely unilateral carotid disease to 21.4% (95% CI, 17.6% to 26.1%) in those with bilateral carotid disease and a history of either coronary or peripheral arterial disease (P<0.0001). CONCLUSIONS: Bilateral carotid disease is associated with higher rates of symptomatic arterial disease in other territories, suggesting a systemic predisposition to atherosclerosis and hence, the need for more aggressive preventive treatment, whereas purely unilateral carotid disease indicates a mainly local hemodynamic etiology.

Aged↗
PubMed2006

Medium-term variability of blood pressure and potential underdiagnosis of hypertension in patients with previous transient ischemic attack or minor stroke.

BACKGROUND AND PURPOSE: Blood pressure (BP) is a major risk factor for stroke. However, the variability of systolic and diastolic BP (SBP and DBP) means that single measurements do not provide a reliable measure of usual BP. Although 24-hour ambulatory BP monitoring can correct for the effects of short-term variation, there is also important medium-term variability. The extent of medium-term variability in BP is most marked in patients with a previous transient ischemic attack (TIA) or stroke. We studied the potential impact of this variability on the likely recognition of hypertension. METHODS: We analyzed multiple repeated measurements of BP in 3 large cohorts with a TIA or minor stroke: the UK-TIA trial (n=2098), the Dutch TIA trial (n=2953), and the European Carotid Surgery Trial (ECST; n=2646). Regression dilution ratios and coefficients of variation were calculated for SBP and DBP from baseline and repeated measurements during the subsequent 12 months. Categorization based on single baseline measurements was also compared with categorization based on the subsequent "usual" BP. RESULTS: The correlation between measurements of BP at baseline and 3 to 5 months later was poor (R(2) from 0.17 to 0.31 for SBP and from 0.10 to 0.20 for DBP). Categorization of patients by baseline values resulted in substantial misclassification in relation to usual BP. For example, of patients with an SBP <140 mm Hg at baseline, the percentage with a usual SBP >or=140 mm Hg was 31.6% in the UK-TIA trial, 48.2% in the Dutch TIA trial, and 57.7% in the ECST. At least 3 consecutive measurements of SBP <120 mm Hg were required to be >90% certain that subsequent usual SBP would not be >or=140 mm Hg. CONCLUSIONS: Given the greater medium-term variability of BP in patients with a previous TIA or stroke than in the general population, single measurements of "normal" or "low" BP will substantially underestimate the true prevalence of hypertension.

Aged↗
PubMed2006

Population-based study of determinants of initial secondary care costs of acute stroke in the United Kingdom.

BACKGROUND AND PURPOSE: To determine the cost-effectiveness of specific interventions to prevent or treat acute stroke, it is necessary to know the costs of stroke according to patient characteristics and stroke subtype and etiology. However, very few such data are available and none from population-based studies. We determined the predictors of resource use and acute care costs of stroke using data from a population-based study. METHODS: Data were obtained from the Oxford Vascular study, a population-based cohort of all individuals in nine general practices in Oxfordshire, UK, which identified 346 patients with a first or recurrent stroke during April 1, 2002, to March 31, 2004. Univariate and multivariate analyses were performed to identify the main predictors of resource use and costs. RESULTS: Acute care costs ranged from 326 pounds sterling (lower decile) to 19,901 pounds sterling (upper decile). There were multiple important univariate interrelations of patient characteristics, stroke subtype, and stroke etiology with hospital admission, length of stay, and 30-day case-fatality. For example, patients with primary intracerebral hemorrhage were more likely to be admitted than patients with partial anterior circulation ischemic stroke and less likely to survive without disability, but length of stay was reduced as a result of high early case-fatality such that cost was substantially less. However, the majority of univariate predictors of resource use, cost, and outcome were confounded by initial stroke severity as measured by the National Institutes of Health Stroke Scale score, which accounted for approximately half of the predicted variance in cost. Cost increased approximately linearly up to an National Institutes of Health Stroke Scale score of 18 and then fell steeply at higher scores as a result of rising early case-fatality. CONCLUSIONS: Several patient and event-related characteristics explained the wide range of initial secondary care costs of acute stroke, but stroke severity was by far the most important independent predictor.

Acute Disease↗
PubMed2006

Underinvestigation and undertreatment of carotid disease in elderly patients with transient ischaemic attack and stroke: comparative population based study.

OBJECTIVE: To identify any underinvestigation of older patients with transient ischaemic attack (TIA) and stroke. DESIGN: Comparative population based studies. SETTING: Routine clinical practice in all secondary care services in Oxfordshire and a nested population based study of incidence of transient ischaemic attack and stroke (the Oxford vascular study-OXVASC). PARTICIPANTS/POPULATION: All patients undergoing carotid imaging for ischaemic retinal or cerebral transient ischaemic attack or stroke from 1 April 2002 to 31 March 2005 in the Oxford vascular study (n = 91,105) and from 1 April 2002 to 31 March 2003 in routine clinical practice (n = 589,899). MAIN OUTCOME MEASURES: Age specific rates of carotid imaging, diagnosed >or= 50% symptomatic carotid stenosis, and subsequent endarterectomy, in patients with recent transient ischaemic attack or stroke. RESULTS: Of patients with recent carotid territory transient ischaemic attack or ischaemic stroke, 575 in routine clinical practice and 402 in the Oxford vascular study had carotid imaging, with similar rates up to the age of 80. The incidence of >or= 50% symptomatic stenosis increased steeply with age, particularly in those aged >or= 80. Compared with investigations in patients in the Oxford vascular study, the rates of carotid imaging (relative rate 0.36, 95% confidence interval 0.28 to 0.46, P < 0.0001), diagnosis of >or= 50% symptomatic stenosis (0.33, 0.16 to 0.69, P = 0.004), and carotid endarterectomy (0.19, 0.06 to 0.63, P = 0.007) in this age group in routine clinical practice were all substantially lower. CONCLUSIONS: Incidence of symptomatic carotid stenosis increases steeply with age, but, despite good evidence of major benefit from endarterectomy in elderly patients and a willingness to have surgery, there is substantial underinvestigation in routine clinical practice in patients aged >or= 80 with transient ischaemic attack or ischaemic stroke.

Aged↗
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↗
PubMed2006

Lead editorial: trials - using the opportunities of electronic publishing to improve the reporting of randomised trials.

This editorial introduces the new online, open access, peer-reviewed journal Trials. The journal considers manuscripts on any aspect of the design, performance, and findings of randomised controlled trials in any discipline related to health care, and also encourages the publication of protocols. Trialists will be able to provide the necessary detail for a true and complete scientific record. They will be able to communicate not only all outcome measures, as well as varying analyses and interpretations, but also in-depth descriptions of what they did and honest reflections about what they learnt. Trials also encourages articles covering generic issues related to trials, for example focussing on the design, conduct, analysis, interpretation, or reporting.

Editorial↗
PubMed2006

National Stroke Association guidelines for the management of transient ischemic attacks.

OBJECTIVE: Transient ischemic attacks are common and important harbingers of subsequent stroke. Management varies widely, and most published guidelines have not been updated in several years. We sought to create comprehensive, unbiased, evidence-based guidelines for the management of patients with transient ischemic attacks. METHODS: Fifteen expert panelists were selected based on objective criteria, using publication metrics that predicted nomination by practitioners in the field. Prior published guidelines were identified through systematic review, and recommendations derived from them were rated independently for quality by the experts. Highest quality recommendations were selected and subsequently edited by the panelists using a modified Delphi approach with multiple iterations of questionnaires to reach consensus on new changes. Experts were provided systematic reviews of recent clinical studies and were asked to justify wording changes based on new evidence and to rate the final recommendations based on level of evidence and quality. No expert was allowed to contribute to recommendations on a topic for which there could be any perception of a conflict of interest. RESULTS: Of 257 guidelines documents identified by systematic review, 13 documents containing 137 recommendations met all entry criteria. Six iterations of questionnaires were required to reach consensus on wording of 53 final recommendations. Final recommendations covered initial management, evaluation, medical treatment, surgical treatment, and risk factor management. INTERPRETATION: The final recommendations on the care of patients with transient ischemic attacks emphasize the importance of urgent evaluation and treatment. The novel approach used to develop these guidelines is feasible, allows for rapid updating, and may reduce bias.

Health Planning Guidelines↗
PubMed2006

Symptomatic and asymptomatic carotid stenosis: how, when, and who to treat?

Carotid stenosis is an important cause of ischemic stroke. Large randomized trials of endarterectomy have shown that surgery reduces the risk of stroke in patients with recently symptomatic carotid stenosis of 50% or greater, and to a lesser extent in patients with asymptomatic carotid stenosis of 60% or greater. More recent research has gone some way in identifying which patients benefit most and when intervention is most effective. Individual risk modeling has been shown to be useful in selecting patients with the most to gain from endarterectomy for symptomatic stenosis, although timely surgery and optimal medical treatment are of equal importance. Further research is required in order to determine the role of carotid stenting and to identify those individuals with asymptomatic stenosis who have the most to gain from intervention.

Carotid Stenosis↗
PubMed2006

Recent advances in management of transient ischaemic attacks and minor ischaemic strokes.

The risk of recurrent stroke during the first few days after a transient ischaemic attack or minor stroke is much higher than previously estimated. However, there is substantial variation worldwide in how patients with suspected transient ischaemic attack or minor stroke are investigated and treated in the acute phase: some health-care systems provide immediate emergency inpatient care and others provide non-emergency outpatient clinical assessment. This review considers what is known about the early prognosis after transient ischaemic attack and minor ischaemic stroke, what factors identify individuals at particularly high early risk of stroke, and what evidence there is that urgent preventive treatment is likely to be effective in reducing the early risk of stroke.

Humans↗
PubMed2006

Prediction and prevention of stroke after transient ischemic attack in the short and long term.

Over the last 5 years, a number of studies have shown the early risk of stroke following transient ischemic attack (TIA) to be of the order of 5-10% at 1 week and 10-20% at 3 months, considerably higher than previously estimated. Because these studies have been carried out in a variety of different clinical settings, their findings are likely to be generalizable. Various independent prognostic factors for this early risk of stroke have been identified and models, based on clinical features at presentation, have been derived and validated to predict risk of stroke within 7 and 90 days after TIA. At the same time, diffusion-weighted magnetic resonance imaging and carotid imaging provide prognostic information and are likely to refine risk prediction further, although no unified model combining clinical and imaging data currently exists. Uncertainty continues surrounding the most effective secondary prevention in the hyperacute phase after TIA, especially in the choice of antiplatelet agents, although clinical trials to address this question are ongoing. However, the need for carotid endarterectomy in patients with symptomatic carotid stenosis is well established. The risk of vascular disease in the medium term (1-5 years) following TIA has been more widely studied, and predictive models for this are available. Recent data on the long-term (10 years and beyond) vascular risk after TIA demonstrate ongoing mortality from both cerebrovascular and cardiovascular causes, highlighting the need for continued secondary prevention.

Humans↗