The stroke prognosis instrument II (SPI-II) : A clinical prediction instrument for patients with transient ischemia and nondisabling ischemic stroke

Predictive value of the Essen Stroke Risk Score and Ankle Brachial Index in acute ischaemic stroke patients from 85 German stroke units

BACKGROUND

Risk stratification can contribute to individualised optimal secondary prevention in patients with cerebrovascular disease.

OBJECTIVE

To prospectively investigate the prediction of the Essen Stroke Risk Score (ESRS) and a pathological Ankle Brachial Index (ABI) in consecutive patients hospitalised with acute ischaemic stroke or transient ischaemic attack (TIA) in 85 neurological stroke units throughout Germany.

METHODS

852 patients were prospectively documented on standardised case report forms, including assessment of ESRS and ABI. After 17.5 months, recurrent cerebrovascular events, functional outcome or death could be assessed in 729 patients predominantly via central telephone interview.

RESULTS

After discharge from the documenting hospital, recurrent stroke occurred in 41 patients (5.6%) and recurrent TIA in 15 patients (2.1%). 52 patients (7.1%) had died, 33 (4.5%) from cardiovascular causes. Patients with an ESRS > or = 3 (vs <3) had a significantly higher risk of recurrent stroke or cardiovascular death (9.7% vs 5.1%; odds ratio (OR) 2.00, 95% confidence interval (CI) 1.08 to 3.70) and a higher recurrent stroke risk (6.9% vs 3.7%; OR 1.93, 95% CI 0.95 to 3.94). Patients with an ABI < or = 0.9 (vs > 0.9) had a significantly higher risk of recurrent stroke or cardiovascular death (10.4% vs 5.5%; OR 2.00, 95% CI 1.12 to 3.56) and a higher recurrent stroke risk (6.6% vs 4.6%; OR 1.47, 95% CI 0.76 to 2.83).

CONCLUSION

Our prospective follow-up study shows a significantly higher rate of recurrent stroke or cardiovascular death and a clear trend for a higher rate of recurrent stroke in patients with acute cerebrovascular events classified as high risk by an ESRS > or = 3 or a pathological ABI.

Prognostication--the lost skill of medicine

Making a prognosis is one of the primary functions of the medical profession. At the end of the nineteenth century prognostication took up approximately ten percent of medical textbooks, by 1970 this had fallen to nearly zero. Given medical technology's awesome ability to prolong the process and suffering of dying today's patients need to know their prognosis in order to make choices about their treatment options. Whilst precise predictions of the future are obviously not possible, relatively simple mathematical modelling techniques can make reasonable estimates of likely outcomes for individual patients. The life expectancy of a patient of any age with any illness can be estimated provided the disease-specific mortality of the illness is known. Decision analysis or logistic regression models can then be used to determine the risks and benefits of various treatment options. A patient's prognosis does not just depend on their age and primary diagnosis, but also on the severity of their illness, their functional capacity both prior to and during the illness and the number of co-morbidities also suffered from. Several predictive instruments have been developed to help simplify the prediction of the outcome of individual patients. There are conflicting reports on how these models compare with doctors' intuition--whatever their strengths and weaknesses it is unlikely that they worsen clinical judgement. Therefore, all doctors should become familiar with them and use them appropriately.

The price of bouncing back: one-year mortality and payments for acute stroke patients with 30-day bounce-backs

OBJECTIVES

To examine 1-year mortality and healthcare payments of stroke patients experiencing zero, one and two or more bounce-backs within 30 days of discharge.

DESIGN

Retrospective analysis of administrative data.

SETTING

Four hundred twenty-two hospitals in the southern and eastern United States.

PARTICIPANTS

Eleven thousand seven hundred twenty-nine Medicare beneficiaries aged 65 and older surviving at least 30 days with acute ischemic stroke in 2000.

MEASUREMENTS

One-year mortality and predicted total healthcare payments were calculated using log-normal parametric survival analysis and quantile regression, respectively. Models included sociodemographics, prior medical history, stroke severity, length of stay, and discharge site.

RESULTS

Crude survival at 1 year for the zero, one and two or more bounce-back groups was 83%, 67%, and 55%, respectively. The one bounce-back group had 49% shorter (time ratio (TR)=0.51, 95% confidence interval (CI)=0.46-0.56) and the two or more bounce-backs group had 68% shorter (TR=0.32, 95% CI=0.27-0.38) adjusted 1-year survival time than the zero bounce-back group. For high- and low-cost patients, adjusted predicted payments were greater with each additional bounce-back experienced.

CONCLUSION

Acute stroke patients experiencing bounce-backs within 30 days have strikingly poorer survival and higher healthcare payments over the subsequent year than their counterparts with no bounce-backs. Bounce-backs may serve as a simple predictor for identifying stroke patients at extremely high risk for poor outcomes.

Systemic Risk Score Evaluation in Ischemic Stroke Patients (SCALA)

BACKGROUND AND PURPOSE

Stratification of patients with transient ischemic attack (TIA) or ischemic stroke (IS) by risk of recurrent stroke can contribute to optimized secondary prevention. We therefore aimed to assess cardiovascular risk factor profiles of consecutive patients hospitalized with TIA/IS to stratify the risk of recurrent stroke according to the Essen Stroke Risk Score (ESRS) and of future cardiovascular events according to the ankle brachial index (ABI) as a marker of generalized atherosclerosis

METHODS

In this cross-sectional observational study, 85 neurological stroke units throughout Germany documented cardiovascular risk factor profiles of 10 consecutive TIA/IS patients on standardized questionnaires. Screening for PAD was done with Doppler ultrasonography to calculate the ABI.

RESULTS

A total of 852 patients (57% men) with a mean age of 67+/-12.4 years were included of whom 82.9 % had IS. The median National Institutes of Health stroke sum score was 4 (TIA: 1). Arterial hypertension was reported in 71%, diabetes mellitus in 26%, clinical PAD in 10%, and an ABI < or = 0.9 in 51%. An ESRS > or = 3 was observed in 58%, which in two previous retrospective analyses corresponded to a recurrent stroke risk of > or = 4%/year. The correlation between the ESRS and the ABI was low (r = 0.21).

CONCLUSION

A high proportion of patients had asymptomatic atherosclerotic disease and a considerable risk of recurrent stroke according to the ABI and ESRS category. The prognostic accuracy as well as the potential benefit of various risk stratification scores in secondary stroke prevention require validation in a larger prospective study.

Performance of the ABCD and ABCD2 Scores in TIA Patients with Carotid Stenosis and Atrial Fibrillation

BACKGROUND

It has been suggested that scores for risk stratification of TIA patients might not identify patients with carotid stenosis or atrial fibrillation (AF) and that this might undermine the usefulness of such scores.

METHODS

In patients with TIA in the Oxford Vascular Study, we studied the associations between ABCD and ABCD2 scores, the presence of > or =50% ipsilateral carotid stenosis or AF, and the risk of stroke at 7 days.

RESULTS

Among 285 TIA patients (from 559 referrals of possible TIA), 69 (24.2%) had either > or =50% carotid stenosis (n = 29) or AF (n = 42), or both (n = 2). Although the ABCD and ABCD2 scores were highly predictive of stroke at 7 days (p < 0.0001), there was no clear relationship between either score and the prevalence of > or =50% carotid stenosis or AF. However, the scores did predict the 7-day stroke risk in patients with these pathologies: ABCD score (trend-p = 0.05); ABCD2 (trend-p = 0.03). Five of the 6 patients with AF or symptomatic stenosis who had a stroke within 7 days of their TIA had an ABCD score of > or =5 and all 6 had an ABCD2 score of > or =4.

CONCLUSIONS

The ABCD and ABCD2 risk scores appear to identify patients with > or =50% carotid stenosis or AF who are at high risk of stroke. However, these findings should be interpreted with caution due to the small number of outcomes among these subgroups, and further validations are necessary.

Ausencia de utilidad de la escala clínica ABCD en el riesgo de infarto cerebral precoz en pacientes con accidente isquémico transitorio

BACKGROUND AND OBJECTIVE

Recently a clinical score (ABCD) to identify individuals at high seven-day risk of stroke after transient ischemic attack (TIA) was proposed. The aim of this study was to test this clinical model.

PATIENTS AND METHOD

We validated the ABCD score (age > or = 65 years = 1; hypertension = 1; unilateral weakness = 2, speech disturbance without weakness = 1, duration of symptoms in minutes > or = 60 = 2; 10-59 = 1; < 10 = 0) in 325 consecutive TIA patients. Clinical data, symptoms duration, CT scan, and ultrasonographic (carotid and transcranial) findings were collected. Seven-day risk of stroke was recorded.

RESULTS

A total of 16 (4.9%) patients had a stroke recurrence within the first seven days after symptoms onset. Six out of 16 (37.5%) strokes occurred in 115 (35.4%) patients with a score of 5 or greater, while the 7-day risk was 4.8% (95% CI 2.04-7.56) in 210 (63.5%) patients with a score less than 5. In cox proportional hazards multivariate analyses only large-artery occlusive disease remained an independent predictor of stroke recurrence [hazard ratio = 5.66 (95% CI 2.06-15.57; p = 0.001)].

CONCLUSIONS

Clinical data are not enough to identify patients at higher risk. The combination of clinical, radiological and vascular information may improve the predictive accuracy of stroke recurrence risk. The routine use of combined carotid/transcranial ultrasound testing performed early will be useful for identifying high risk individuals in order to plan urgent aggressive prevention therapies.

C-reactive protein predicts further ischemic events in transient ischemic attack patients

BACKGROUND AND PURPOSE

Although patients with transient ischemic attack (TIA) experience cardiovascular events frequently, strong clinical predictors of recurrence are lacking. High-sensitivity C-reactive protein (hs-CRP) has been shown to be a powerful predictor of future first-ever and recurrent coronary and cerebral ischemic events. We aimed to investigate the relationship between hs-CRP and the risk of further ischemic events in TIA patients.

METHODS

High-sensitivity C-reactive protein level was determined <24 h after symptom onset among 135 consecutive TIA patients and stroke recurrence or any new vascular event was recorded during 1 year follow-up period.

RESULTS

A total of 38 (28.1%) patients experienced an end point event: 28 (20.7%) cerebral ischemic events, six (4.4%) heart ischemic events, four (3%) peripheral arterial disease, and nine (6.7%) vascular deaths. Cox proportional hazards multivariate analyses identified age [hazard ratio (HR) 1.07, 95% confidence interval (CI) 1.01-1.12, P = 0.01], large-artery occlusive disease (HR 2.73, 95% CI 1.16 to 6.41, P = 0.02) and hs-CRP> 4.1 mg/l (HR 2.81, 95% CI 1.12-7.10, P = 0.03) as independent predictors of stroke. Moreover, age (HR 1.05, 95% CI 1.01-1.10, P = 0.02), large-artery occlusive disease (HR 3.12, 95% CI 1.48-6.58, P < 0.01), coronary disease (HR 2.39, 95% CI 1.11-5.16, P = 0.03), and hs-CRP> 4.1 mg/l (HR 2.71, 95% CI 1.16-6.30, P = 0.02) were also independent predictors of any vascular event.

CONCLUSIONS

High-sensitivity C-reactive protein serum level predicts further ischemic events following TIA. Routine CRP measurement might be a useful tool for identifying high-risk TIA patients in order to plan aggressive diagnostic protocols and prevention therapies.

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.

Risk stratification and prediction of recurrent stroke

Approximately 30% of patients suffer a recurrent stroke during the 5 years after their first cerebrovascular event. Predictors differ for short- and long-term risk of stroke recurrence. Atherosclerotic disease is the single most important predictor for short-term recurrence, while most classical cardiovascular risk factors, as well as age, are independent predictors for long-term recurrence. Several prognostic models for long-term risk of recurrent stroke have been validated, but the predictive value and applicability of these models remains limited. However, an improved understanding of the risk for recurrent stroke is vital for the design of secondary prevention trials as well as individual treatment decisions, especially if the medication or procedure is expensive or risky. The aim of this article is to elucidate the relationship between stroke risk factors, prognostic scores and their predictive value in recurrent stroke.

A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack

BACKGROUND

Effective early management of patients with transient ischaemic attacks (TIA) is undermined by an inability to predict who is at highest early risk of stroke.

METHODS

We derived a score for 7-day risk of stroke in a population-based cohort of patients (n=209) with a probable or definite TIA (Oxfordshire Community Stroke Project; OCSP), and validated the score in a similar population-based cohort (Oxford Vascular Study; OXVASC, n=190). We assessed likely clinical usefulness to front-line health services by using the score to stratify all patients with suspected TIA referred to OXVASC (n=378, outcome: 7-day risk of stroke) and to a hospital-based weekly TIA clinic (n=210; outcome: risk of stroke before appointment).

RESULTS

A six-point score derived in the OCSP (age [> or =60 years=1], blood pressure [systolic >140 mm Hg and/or diastolic > or =90 mm Hg=1], clinical features [unilateral weakness=2, speech disturbance without weakness=1, other=0], and duration of symptoms in min [> or =60=2, 10-59=1, <10=0]; ABCD) was highly predictive of 7-day risk of stroke in OXVASC patients with probable or definite TIA (p<0.0001), in the OXVASC population-based cohort of all referrals with suspected TIA (p<0.0001), and in the hospital-based weekly TIA clinic-referred cohort (p=0.006). In the OXVASC suspected TIA cohort, 19 of 20 (95%) strokes occurred in 101 (27%) patients with a score of 5 or greater: 7-day risk was 0.4% (95% CI 0-1.1) in 274 (73%) patients with a score less than 5, 12.1% (4.2-20.0) in 66 (18%) with a score of 5, and 31.4% (16.0-46.8) in 35 (9%) with a score of 6. In the hospital-referred clinic cohort, 14 (7.5%) patients had a stroke before their scheduled appointment, all with a score of 4 or greater.

CONCLUSIONS

Risk of stroke during the 7 days after TIA seems to be highly predictable. Although further validations and refinements are needed, the ABCD score can be used in routine clinical practice to identify high-risk individuals who need emergency investigation and treatment.

Type 2 Diabetes Mellitus and Insulin Resistance: Stroke Prevention and Management

Clinically recognized disorders of glucose metabolism include impaired fasting glucose, impaired glucose tolerance (both termed prediabetes), and diabetes mellitus. Type 2 diabetes mellitus affects 6% to 13% of adults in the United States. Among patients with recent stroke, 70% will have known diabetes, occult diabetes (detectable on an oral glucose tolerance test), or prediabetes. Type 2 diabetes mellitus is associated with a two- to six-fold increased risk for first or recurrent ischemic stroke. The mechanisms for the association are myriad and include the effects of hyperglycemia on vascular tissues and coagulation, and aberrations in blood pressure regulation, lipid metabolism, endothelial function, vascular inflammation, lipid metabolism, smooth muscle cell proliferation, and fibrinolysis. The most effective strategies to prevent stroke among people with diabetes include blood pressure control, antiplatelet therapy, and statin therapy. Tight glycemic control is recommended to prevent microvascular disease, but the effect on macrovascular disease, including stroke, has not been proven. Target blood pressure should be less than 130/80. Antiplatelet therapy may be accomplished with 81 to 325 mg of aspirin daily or 75 mg of clopidogrel daily. Statins should be given in dosages effective to reduce low-density lipoprotein cholesterol to less than 100 mg/dL. For glycemic control, first line therapy for most patients is metformin, starting at 500 mg daily. With time, most patients will need two or three oral medications from different classes and many eventually will require insulin therapy. Prevention of diabetes may be best accomplished by identifying those at risk and modifying diet, weight, and exercise habits. Screening for prediabetes and diabetes is appropriate for men and women older than 45 years and all individuals with vascular disease. Insulin resistance and impaired insulin secretion is the major underlying defect in type 2 diabetes mellitus. It also affects 50% of nondiabetic subjects with a recent ischemic stroke. Emerging evidence has linked insulin resistance to the pathophysiologic derangements in type 2 diabetes mellitus that accelerate atherosclerosis. Treatment of insulin resistance with weight loss, exercise, or medication can correct these derangements, and represents a promising approach to stroke prevention.

Long term risks of stroke, myocardial infarction, and vascular death in "low risk" patients with a non-recent transient ischaemic attack

BACKGROUND

Previous studies of prognosis after a transient ischaemic attack (TIA) have recruited patients soon after the event, when the risk of stroke is very high. However, the majority of patients survive for many years after a TIA, and the need for continued preventive treatment to lower vascular risk will need to be reassessed at a later date.

OBJECTIVE

To determine the long term risks of stroke and other vascular events in patients with TIA who survive the initial high risk period.

METHODS

290 patients were studied who had initially been followed up after a TIA in the Oxford community stroke project and in a contemporaneous hospital based cohort study, and who were alive and stroke-free at the end of planned follow up in 1988. All patients were followed for a further 10 years, and the risks of major vascular events (stroke, myocardial infarction, vascular death) were determined. Standardised mortality ratios (SMR) were calculated from the observed numbers of fatal events and the number expected on the basis of age and sex in the general population.

RESULTS

Median time since last TIA was 3.8 years (interquartile range, 2.2 to 5.8 years). The risk of major vascular events was constant through time. The 10 year risk of first stroke was 18.8% (95% confidence interval (CI), 13.6 to 23.7; 45 events). The 10 year risk of myocardial infarction or death from coronary heart disease was 27.8% (95% CI, 21.8 to 33.3; 67 events) and there was a significant excess of fatal coronary events compared with that expected in the general population (SMR = 1.47; 95% CI, 1.10 to 1.93; p = 0.009). A total of 114 patients had at least one major vascular event, with a 10 year risk of any first stroke, myocardial infarction, or vascular death of 42.8% (95% CI, 36.4 to 48.5).

CONCLUSIONS

The overall risk of major vascular events remains high for 10 to 15 years after a TIA. It is important therefore that preventive treatments are continued in the long term, even in apparently "low risk" patients who have already survived free of stroke for several years.

Database Conference January 27-30, 2000, Washington D.C.--Do existing databases answer clinical questions about geriatric cardiovascular disease and stroke?

EXECUTIVE SUMMARY: Most randomized, controlled trials evaluating the effectiveness of pharmaceutical, surgical, and device interventions for the prevention and treatment of cardiovascular disease have excluded patients over 75 years of age. Consequently, the use of these therapies in the older population is based on extrapolation of safety and effectiveness data obtained from younger patients. However, there are many registries and observational databases that contain large amounts of data on patients 75 years of age and older, as well as on younger patients. Although conclusions from such data are limited, it is possible to define the characteristics of patients who did well and those who did poorly. The goal of this conference was to convene the principal investigators of these databases, and others in the field of geriatric cardiology, to address questions relating to the safety and effectiveness of treatment interventions for several cardiovascular conditions in the elderly. Seven committees discussed the following topics: (I) Risk Factor Modification in the Elderly; (II) Chronic Heart Failure; (III) Chronic Coronary Artery Disease: Role of Revascularization; (IV) Acute Myocardial Infarction; (V) Valve Surgery in the Elderly; (VI) Electrophysiology, Pacemaker, and Automatic Internal Cardioverter Defibrillators Databases; (VII) Carotid Endarterectomy in the Elderly. The chairs of these committees were asked to invite principal investigators of key databases in each of these areas to discuss and prepare a written statement concerning the available safety and efficacy data regarding interventions for these conditions and to identify and prioritize areas for future study. The ultimate goal is to stimulate further collaborative outcomes research in the elderly so as to place the treatment of cardiovascular disease on a more scientific basis.