Why is the outcome of transient ischaemic attacks different in different groups of patients?

Anticoagulants for preventing recurrence following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack

BACKGROUND

After a first ischaemic stroke, further vascular events due to thromboembolism are common and often fatal. Anticoagulants could potentially reduce the risk of such events, but any benefits could be offset by an increased risk of fatal or disabling haemorrhages.

OBJECTIVES

To assess the effect of prolonged anticoagulant therapy compared with placebo or open control following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register in May 2008. In June 2008 we searched three online trial registers, used Web of Science Cited Reference Search to identify new citations of previously included studies, contacted a pharmaceutical company, and also contacted authors for additional information on included trials.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing at least one month of anticoagulant therapy with control in people with previous, presumed non-cardioembolic, ischaemic stroke or transient ischaemic attack.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Eleven trials involving 2487 participants were included. The quality of the nine trials which predated routine computerised tomography (CT) scanning and the use of the International Normalised Ratio to monitor anticoagulation was poor. There was no evidence of an effect of anticoagulant therapy on either the odds of death or dependency (two trials, odds ratio (OR) 0.83, 95% confidence interval (CI) 0.52 to 1.34) or of 'non-fatal stroke, myocardial infarction, or vascular death' (four trials, OR 0.96, 95% CI 0.68 to 1.37). Death from any cause (OR 0.95, 95% CI 0.73 to 1.24) and death from vascular causes (OR 0.86, 95% CI 0.66 to 1.13) were not significantly different between treatment and control. The inclusion of two recently completed trials did not alter these conclusions. There was no evidence of an effect of anticoagulant therapy on the risk of recurrent ischaemic stroke (OR 0.85, 95% CI 0.66 to 1.09). However, anticoagulants increased fatal intracranial haemorrhage (OR 2.54, 95% CI 1.19 to 5.45), and major extracranial haemorrhage (OR 3.43, 95% CI 1.94 to 6.08). This is equivalent to anticoagulant therapy causing about 11 additional fatal intracranial haemorrhages and 25 additional major extracranial haemorrhages per year for every 1000 patients given anticoagulant therapy.

AUTHORS' CONCLUSIONS

Compared with control, there was no evidence of benefit from long-term anticoagulant therapy in people with presumed non-cardioembolic ischaemic stroke or transient ischaemic attack, but there was a significant bleeding risk.

Current perspectives in assessment: the assessment of performance at work

BACKGROUND

Traditional assessment has improved significantly over the past 50 years. A number of new testing methods are now in place, the computer is improving both the fidelity and efficiency of examinations, and the psychometric principles on which assessment rests are more sophisticated than ever.

AIM

There is growing interest in quality improvement and there are increasing demands for public accountability. This has shifted the focus of testing from education to work. The purpose of this paper is to describe the assessment of work.

DISCUSSION

In contrast to traditional assessment, there are no 'methods' for the evaluation of work because the content and difficulty of the examination are not controlled in any fashion. Instead it is a matter of identifying the basis for the judgements (outcomes, process, or volume), deciding how the data will be gathered (practice records, administrative databases, diaries/logs, or observation), and avoiding threats to validity and reliability (patient mix, patient complexity, attribution, and numbers of patients).

FUTURE DIRECTIONS

Overall, the assessment of doctors' performance at work is in its infancy and much research and development is needed. Nonetheless, it is being used increasingly in programmes of continuous quality improvement and accountability. It is critical that refinements occur quickly to ensure that patients receive the highest quality of care and that doctors are treated fairly and provided with the information they need to guide their professional development.

Transient Ischemic Attacks Are More Than “Ministrokes”

BACKGROUND AND PURPOSE

Transient ischemic attacks (TIAs) are warning signs of stroke. Recently, the hypothesis was raised that TIA bears a significant risk for death and dependence and requires the same complex diagnostic workup as a complete stroke.

METHODS

We prospectively collected pre- and in-hospital procedures, symptoms, outcome, complications, and therapies from a representative sample of all stroke-treating hospitals (n=82) in southwest Germany. Follow-up was attempted 6 months after discharge. End points were death or dependence in activities of daily living (Barthel Index <95, modified Rankin Scale (mRS) of 3 to 6, or institutionalization in a nursing home).

RESULTS

1380 TIA patients and 3855 stroke patients entered the database. During hospital stay, stroke incidence was 8% for TIA patients and another 5% within the first half-year. Similarly, for ischemic stroke (IS) patients these figures were 7% and 6% (P>0.05), respectively. Two percent of TIA patients died in hospital (5% afterward) compared with 9% of stroke patients (10% afterward, P<0.001). Seventeen percent TIA compared with 38% IS patients (P<0.05) were dependent at follow-up. Whereas an estimated preexisting deficit (mRS >2) was the strongest predictor for death or disability (baseline mRS odds ratio, 4.1; 95% CI, 2.3 to 7.2), admission to a stroke unit was a valid predictor for survival and independence (odds ratio, 0.4; 95% CI, 0.2 to 0.9).

CONCLUSIONS

These data from a large, multicenter, nonselected, observational study underscore the "not so benign" prognosis for TIA patients. There is a relevant individual risk of early stroke, death, or disability in TIA patients. Management and treatment strategies are similar for both TIA and acute stroke.

Population based study of early risk of stroke after transient ischaemic attack or minor stroke: implications for public education and organisation of services

OBJECTIVE

To estimate the very early stroke risk after a transient ischaemic attack (TIA) or minor stroke and thereby inform the planning of effective stroke prevention services.

DESIGN

Population based prospective cohort study of patients with TIA or stroke.

SETTING

Nine general practices in Oxfordshire, England, from April 2002 to April 2003.

PARTICIPANTS

All patients who had a TIA (n = 87) or minor stroke (n = 87) during the study period and who presented to medical attention.

MAIN OUTCOME MEASURES

Risk of recurrent stroke at seven days, one month, and three months after TIAs and minor strokes.

RESULTS

The estimated risk of recurrent stroke was 8.0% (95% confidence interval 2.3% to 13.7%) at seven days, 11.5% (4.8% to 18.2%) at one month, and 17.3% (9.3% to 25.3%) at three months after a TIA. The risks at these three time periods after a minor stroke were 11.5% (4.8% to 11.2%), 15.0% (7.5% to 22.5%), and 18.5% (10.3% to 26.7%).

CONCLUSIONS

The early risks of stroke after a TIA or minor stroke are much higher than commonly quoted. More research is needed to determine whether these risks can be reduced by more rapid instigation of preventive treatment.

Anticoagulants for preventing recurrence following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack

BACKGROUND

After a first ischaemic stroke, further vascular events due to thromboembolism (especially myocardial infarction and recurrent stroke) are common and often fatal. Anticoagulants could potentially reduce the risk of such events, but any benefits could be offset by an increased risk of fatal or disabling haemorrhages.

OBJECTIVES

The objective of this review was to assess the effect of prolonged anticoagulant therapy (compared with placebo or open control) following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register. We contacted companies marketing anticoagulant agents. The most recent search for this review was carried out in August 2002.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing at least one month of anticoagulant therapy with control in people with previous presumed non-cardioembolic ischaemic stroke or transient ischaemic attack.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Eleven trials involving 2487 patients were included. The quality of the 9 trials which predated routine computerised tomography scanning and the use of the International Normalised Ratio to monitor anticoagulation was poor. There was no evidence of an effect of anticoagulant therapy on either the odds of death or dependency (two trials, odds ratio 0.83, 95% confidence interval [CI] 0.52 to 1.34) or of 'non-fatal stroke, myocardial infarction, or vascular death' (four trials, odds ratio 0.96, 95% CI 0.68-1.37). Death from any cause (odds ratio 0.95, 95% CI 0.73 to 1.24) and death from vascular causes (odds ratio 0.86, 95% CI 0.66 to 1.13) were not significantly different between treatment and control. The inclusion of two recent completed trials did not alter these conclusions. There was no evidence of an effect of anticoagulant therapy on the risk of recurrent ischaemic stroke (odds ratio 0.85, 95% CI 0.66 to 1.09). However, anticoagulants increased fatal intracranial haemorrhage (odds ratio 2.54, 95% CI 1.19 to 5.45), and major extracranial haemorrhage (odds ratio 3.43, 95% CI 1.94 to 6.08). This is equivalent to anticoagulant therapy causing about 11 additional fatal intracranial haemorrhages and 25 additional major extracranial haemorrhages per year for every 1000 patients given anticoagulant therapy.

REVIEWER'S CONCLUSIONS

Compared with control, there was no evidence of benefit from long-term anticoagulant therapy in people with presumed non-cardioembolic ischaemic stroke or transient ischaemic attack, but there was a significant bleeding risk.

Stroke care: how do we measure quality?

The purpose of this paper is to review the methods used to measure quality of stroke care. Relevant articles were searched for on Medline using the following key words: stroke, quality, outcome of care, process of care, structure of care. Articles that examined how to measure the quality of stroke care and that examined difficulties in the measurement of care outcomes, processes, and structures were selected. Selected articles were reviewed to summarise methods used to measure quality of stroke care and the primary outcome measures of the studies were extracted. Conclusions were drawn about the best ways to measure the quality of stroke care. Practical problems in using outcome measures to monitor quality of care include the consequences of case mix and difficulties in risk adjustment. Clinicians may use process measures to understand differences in outcome. Once a process of care has been linked to an outcome measure, this care process should be measured. The national sentinel audit for stroke is an audit tool used to examine the quality of the processes of stroke care.

Predictors of major vascular events in patients with a transient ischemic attack or minor ischemic stroke and with nonrheumatic atrial fibrillation. European Atrial Fibrillation Trial (EAFT) Study Group

BACKGROUND AND PURPOSE

The risk of major vascular events after an initial episode of cerebral ischemia in patients with nonrheumatic atrial fibrillation (NRAF) varies from 2% to 15% in the first year and is approximately 5% yearly thereafter. Few studies have reported on risk factors that can be used to identify high-risk subgroups within this patient population.

METHODS

We studied the predictive value of several easily obtainable clinical characteristics in a group of 375 placebo-treated patients with NRAF and a recent episode of transient or nondisabling cerebral ischemia who were entered in a multicenter clinical trial. The mean follow-up was 1.6 years.

RESULTS

By means of multivariate modeling, six independent variables were identified: history of previous thromboembolism, ischemic heart disease, enlarged cardiothoracic ratio on chest roentgenogram, systolic blood pressure greater than 160 mm Hg at study entry, NRAF for more than 1 year, and presence of an ischemic lesion on CT scan. These variables could also be used to stratify patients in low-, medium-, and high-risk subgroups for the other two arms of the trial, those treated with anticoagulation and aspirin. Patients older than 75 years with three or more risk factors seemingly benefited less from both aspirin and anticoagulant treatment.

CONCLUSIONS

Easily obtainable patient characteristics are helpful in estimating the potential effect of adequate secondary prevention in patients with NRAF who recently suffered a transient ischemic attack or minor ischemic stroke.