Cost-effective investigation of patients with suspected transient ischaemic attacks

Validation of the Canadian TIA Score to Predict Subsequent Stroke Risk in Chinese TIA Patients

BACKGROUND AND OBJECTIVES

The Canadian TIA Score has been verified as a good predictive tool for subsequent stroke risk in Caucasian patients; however, it had insufficient external verification of other races. We aimed to validate the Canadian TIA Score in Chinese patients and compared it with ABCD2 for subsequent stroke risk after transient ischemic attack (TIA).

METHODS

The Third China National Stroke Registry (CNSR-III) was a nationwide, multicenter prospective registry recruiting consecutive patients with acute ischemic stroke or TIA within 7 days of the onset from August 2015 to March 2018. The Canadian TIA Score was verified in patients diagnosed with TIA from the CNSR-III (N = 1,184). The outcomes were subsequent stroke at 7 days, 14 days/discharge, 3 months, and 1 year. Outcomes were recorded by face-to-face assessment or telephone interview. The prognostic performance of the scoring system was assessed by the area under the receiver operator characteristic curve (AUC).

RESULTS

Of 1,184 TIA patients (mean [IQR] age, 61.00 [53.00-69.00] years; 413 women [34.88%]), there were 40 patients (3.38%) having subsequent stroke within 7 days, 45 (3·80%) within 14 days/hospitalization, 66 (5·57%) within 3 months, and 100 (8·45%) within 1 year. The Canadian TIA Score (AUC 0 63-0·68) seemed to be a better prognostic score of stroke risk than the ABCD2 score (AUC 0·61-0·62), although no significant differences were noted. In the subgroup of atypical TIA, the Canadian TIA Score showed significantly stronger predictivity than the ABCD2 score within 7 days (0.80 [0.62-0.98] vs. 0.52 [0.30-0.73]; difference in AUC, 0.28 [0.03-0.53]; p, 0.026), and marginal significantly stronger predictivity within 1 year (0.71 [0.61-0.80] vs. 0.58 [0.48-0.68]; difference in AUC, 0.12 [-0.01 to 0.25]; p, 0.06).

CONCLUSION

The Canadian TIA Score might be a better prognostic score than the ABCD2 score for post-TIA stroke risk, especially in patients with atypical TIA.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Atherothrombosis and plaque heterology: different location or a unique disease?

Formation of unstable plaques frequently results in atherothrombosis, the major cause for ischaemic stroke, myocardial infarction and peripheral arterial disease. Patients who have symptomatic thrombosis in one vascular bed are at increased risk of disease in other beds. However, the development of the disease in carotid, coronary and peripheral arteries may have different pathophysiology suggesting that more complex treatment protocols may have to be designed to reduce plaque development at different locations. In this review we describe the known risk factors, compare the developmental features of coronary and carotid plaque development and determine their association with end-point ischaemic events. Differences are also seen in the genetic contribution to plaque development as well as in the deregulation of gene and protein expression and cellular signal transduction activity of active cells in regions susceptible to thrombosis. Differences between carotid and coronary artery plaque development might help to explain the differences in anatomopathological appearance and risk of rupture.

Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack

BACKGROUND

We aimed to validate two similar existing prognostic scores for early risk of stroke after transient ischaemic attack (TIA) and to derive and validate a unified score optimised for prediction of 2-day stroke risk to inform emergency management.

METHODS

The California and ABCD scores were validated in four independent groups of patients (n=2893) diagnosed with TIA in emergency departments and clinics in defined populations in the USA and UK. Prognostic value was quantified with c statistics. The two groups used to derive the original scores (n=1916) were used to derive a new unified score based on logistic regression.

FINDINGS

The two existing scores predicted the risk of stroke similarly in each of the four validation cohorts, for stroke risks at 2 days, 7 days, and 90 days (c statistics 0.60-0.81). In both derivation groups, c statistics were improved for a unified score based on five factors (age >or=60 years [1 point]; blood pressure >or=140/90 mm Hg [1]; clinical features: unilateral weakness [2], speech impairment without weakness [1]; duration >or=60 min [2] or 10-59 min [1]; and diabetes [1]). This score, ABCD(2), validated well (c statistics 0.62-0.83); overall, 1012 (21%) of patients were classified as high risk (score 6-7, 8.1% 2-day risk), 2169 (45%) as moderate risk (score 4-5, 4.1%), and 1628 (34%) as low risk (score 0-3, 1.0%).

IMPLICATIONS

Existing prognostic scores for stroke risk after TIA validate well on multiple independent cohorts, but the unified ABCD(2) score is likely to be most predictive. Patients at high risk need immediate evaluation to optimise stroke prevention.

The use of neurovascular imaging for triaging tia and minor stroke: Implications for therapy

Nondisabling cerebrovascular events (minor stroke or transient ischemic attack) are not benign; a significant proportion of these patients will suffer a new disabling stroke or develop stroke progression in hospital, resulting in dependence or death. With the exception of the modest benefits of aspirin, there are currently no effective acute medical therapies to prevent early progression or recurrence in such patients. Early carotid revascularization appears to be the most efficacious treatment available for patients with symptomatic (> 50%) internal carotid artery stenosis. More acute treatment and acute prevention trials are needed. MRI, CT bolus techniques, and transcranial Doppler emboli detection represent tools for detection of patients at high risk for deterioration and should be incorporated into the development of effective therapies by targeting the most appropriate patients for intervention.

The patient with transient cerebral ischemia: a golden opportunity for stroke prevention

Transient ischemic attack (TIA) provides a golden opportunity for stroke prevention. TIA should be treated as a medical emergency with prompt investigations to determine the mechanism of ischemia and subsequent preventive therapy. The risk of stroke after TIA is estimated to be 10%-20% in the first 90 days. The risk is time-dependent with 50% of the risk accruing in the first 48 hours. In this review, we describe the diagnosis and management of TIA, introduce new concepts in TIA and suggest that all patients with significant TIA should undergo rapid investigation and management to prevent stroke.

Automatic cardiac event recorders reveal paroxysmal atrial fibrillation after unexplained strokes or transient ischemic attacks

BACKGROUND

The etiology of stroke or transitory ischemic attack (TIA) remains frequently unknown. While paroxysmal atrial fibrillation (PAF) is often suspected, its presence remains difficult to establish. Therefore, we investigated the occurrence of PAF episodes in such a population using a long-term automatic cardiac event recorder.

METHODS

We prospectively investigated 60 consecutive subjects admitted in our university hospital for stroke (n=44) or TIA (n=16), adding long-term automatic cardiac event recorders, with a target duration of 4 days, to standard investigations, which included 12-lead ECGs and 24-hour Holter recordings.

RESULTS

In 28 patients no etiology was found for their stroke or TIA. However, one or more than one PAF episode was found in 4 of them (14.3%) using the long-term automatic event recorder. In the 32 remaining patients, 8 presented with PAF, and this was considered as the cause of their stroke. In both groups, AF was paroxysmal. The PAF episodes' duration went from 1 to 96 hours (mean +/- standard deviation, 18 hours and 30 minutes+/-30 hours).

CONCLUSIONS

Patients suffering PAF episodes after ischemic stroke or TIA were statistically less often recognized using the 24-hour Holter ECG recording alone than the R-Test Evolution alone.

Transient ischaemic attacks: desired diagnosis and management by Polish primary care physicians

OBJECTIVE

The aim of this study was to assess the competence of Polish primary care physicians in diagnosing and managing patients with transient ischaemic attacks (TIAs) in the carotid territory.

METHOD

A written questionnaire was distributed to all first-contact physicians (n = 100) in one of the seven health care districts of Warsaw (response rate 89%). The questionnaire included three pairs of TIA cases. In each of the pairs, only the age and type varied. Three cases were characterized by transient monocular blindness and the other three by symptoms of hemispheral ischaemia.

RESULTS

Physicians confronted with TIA cases had difficulties in diagnosing it. In the cases of monocular blindness, only 20-44% of cases were diagnosed correctly, and hemispheral ischaemia was diagnosed correctly in 46-78% of cases. Patients with no history of non-specific symptoms and with the first attack would have a higher percentage of correct diagnoses in comparison with those with recurrent attacks and a history of non-specific symptoms. Patients with hemispheral ischaemia frequently would be referred to neurologists, and about two-thirds of doctors would refer patients with monocular blindness to ophthalmologists, and fewer than half to neurologists. Antiplatelet therapy would be prescribed by <22% of physicians, while peripheral vasodilatators would be prescribed by up to 60% of them.

CONCLUSION

The results of this study indicate that Polish primary care physicians when confronted with TIA cases would have basic difficulties, especially in diagnosis and management. These results underline the need for changes in the vocational training of primary care physicians, with special attention to frequent family medicine problems.

Management of the first-time transient ischaemic attack

The assessment and management of patients with a suspected transient ischaemic attack of the brain or eye is a daily task in busy emergency departments. They are common, affecting about 50 per 100,000 population each year. Conditions which mimic a transient ischaemic attack are even more common (e.g. migraine aura, partial seizures, benign paroxysmal positional vertigo, hysteria). This comprehensive review outlines an approach to the management of this complex and challenging problem.

Use of ambulatory electrocardiography for the detection of paroxysmal atrial fibrillation in patients with stroke. Canadian Task Force on Preventive Health Care

BACKGROUND

Patients with stroke commonly undergo investigations to determine the underlying cause of stroke. These investigations often include ambulatory electrocardiography to detect paroxysmal atrial fibrillation. There is conflicting evidence in the literature regarding whether routine ambulatory electrocardiography should be performed in all or selected stroke patients. This paper reviews the available evidence on (1) the yield of ambulatory electrocardiography in detecting paroxysmal atrial fibrillation in patients with stroke or transient ischemic attack and (2) the effectiveness of anticoagulation in preventing recurrent stroke in patients with paroxysmal atrial fibrillation.

METHODS

A MEDLINE search for primary articles was performed, and the references were reviewed manually. In addition, citations were obtained from experts. The evidence was systematically reviewed using the evidence-based methodology of the Canadian Task Force on Preventive Health Care.

RESULTS

Ambulatory electrocardiography can detect atrial fibrillation not found on initial electrocardiogram in between 1% and 5% of people with stroke. Ambulatory electrocardiography is generally safe. The risk of recurrent stroke in the setting of paroxysmal atrial fibrillation is uncertain, but appears to be similar to that seen with chronic atrial fibrillation (about 12% per year). Therapy with warfarin may reduce this risk by about two-thirds as compared to placebo. The annual risk of major bleeding with warfarin therapy is between 1% and 3% but rates for individual patients depend on various specific risk factors.

INTERPRETATION

There is insufficient evidence to recommend for or against the use of ambulatory electrocardiography for the detection of paroxysmal atrial fibrillation in either selected or unselected patients with stroke (C Recommendation). There is fair evidence to recommend therapy with warfarin for patients with stroke and paroxysmal atrial fibrillation (B Recommendation).

Medical complications associated with carotid endarterectomy. North American Symptomatic Carotid Endarterectomy Trial (NASCET)

BACKGROUND AND PURPOSE

Carotid endarterectomy (CE) has been shown to be beneficial in patients with symptomatic high-grade (70% to 99%) internal carotid artery stenosis. To achieve this benefit, complications must be kept to a minimum. Complications not associated with the procedure itself, but related to medical conditions, have received little attention.

METHODS

Medical complications that occurred within 30 days after CE were recorded in 1415 patients with symptomatic stenosis (30% to 99%) of the internal carotid artery. They were compared with 1433 patients who received medical care alone. All patients were in the North American Symptomatic Carotid Endarterectomy Trial (NASCET).

RESULTS

One hundred fifteen patients (8.1%) had 142 medical complications: 14 (1%) myocardial infarctions, 101 (7.1%) other cardiovascular disorders, 11 (0.8%) respiratory complications, 6 (0.4%) transient confusions, and 10 (0.7%) other complications. Of the 142 complications, 69.7% were of short duration, and only 26.8% prolonged hospitalization. Five patients died: 3 from myocardial infarction and 2 suddenly. Medically treated patients experienced similar complications with one third the frequency. Endarterectomy was approximately 1.5 times more likely to trigger medical complications in patients with a history of myocardial infarction, angina, or hypertension (P<0.05).

CONCLUSIONS

Perioperative medical complications were observed in slightly fewer than 1 of every 10 patients who underwent CE. The majority of these complications completely resolved. Most complications were cardiovascular and occurred in patients with 1 or more cardiovascular risk factors. In this selected population, the occurrence of perioperative myocardial infarction was uncommon.

Diagnosis and management of transient ischaemic attacks in accident and emergency

Stroke is an important cause of morbidity and mortality. Often the first presentation of cerebrovascular disease is a TIA which will present to the A&E department. Patients who have had a TIA are at increased risk of stroke, myocardial infarction, and vascular death. The risk of stroke after a TIA is greatest in the first year (approximately 11.6%) with a risk of approximately 5.9% per year over the first five years. As the risk is highest in the first months following a TIA it is important that the patients are diagnosed accurately, investigated promptly, and referred appropriately for treatment in order that valuable time is not lost. For this reason A&E physicians have a valuable role in the initial assessment and management of the patient. It has been advocated that patients should be seen by a neurologist or physician with an interest in cerebrovascular disease within days of their symptoms and be prepared for surgery within two weeks after a TIA. While it is usually not possible to achieve this ideal, improved cooperation between A&E physicians and these neurologists, general physicians, and geriatricians should lead to the implementation of speedy efficient referral procedures which can only improve patient care. When you next see a patient with a TIA in the A&E department remember what they have to lose. Three questions relating to this article are: (1) How are TIAs subdivided and what clinical features allow this differentation? (2) What are the initial investigations that should be performed in A&E? (3) When are the risks of completed stroke greatest after a TIA? Enumerate these risks. How effective is aspirin at reducting this risks?

Direct costs of transient ischemic attacks: a hospital-based study of resource use during the first year after transient ischemic attacks in Denmark

BACKGROUND AND PURPOSE

Knowledge of costs of health care and social services for patients who have transient ischemic attacks (TIAs) is scarce. This study investigates the resource use and estimates direct costs during the first year after a TIA.

METHODS

All patients admitted to a university hospital in Copenhagen, Denmark, because of TIA during 12 months in 1994-1995 were included in a database. The patients were followed until 1 year after admission, and data on resource use during and after the hospital stay were collected prospectively at interviews.

RESULTS

The cost of the hospital stay had a mean of DKr 10100 (US $1800), and the cost of health care and social services after discharge had a mean of DKr 8800 (US $1600).

CONCLUSIONS

The total cost of health care and social services during the first year after a TIA had a mean of DKr 18800. The hospital stay and the services after discharge each made up half of the total direct cost.

Etiopathogenesis of transient ischemic attacks and minor ischemic strokes: a community-based study in Segovia, Spain

BACKGROUND AND PURPOSE

We sought to analyze the etiology and underlying vascular risk factors of transient ischemic attacks (TIAs) and minor ischemic strokes (MISs).

METHODS

We prospectively studied the vascular risk factors and etiologic categories in 235 patients with TIAs and MISs from a community-based register in a rural area of Spain. Five etiologic categories were considered: (1) cardioembolism, (2) large-artery atherosclerosis, (3) small-artery disease, (4) other etiologies, and (5) undetermined etiology. Systematic investigations included neuroimaging (CT/MRI) and vascular studies (duplex scan/MR angiography and angiography in selected cases).

RESULTS

The two most frequent etiologic categories were small-artery disease (31%) and cardioembolism (26%). Large-artery atherosclerosis was detected in 11% of the patients. Significant carotid stenosis (> or =50%) was present in 13% of patients with carotid territory events. No cause could be found or it was uncertain in almost one third of the patients. The distribution of etiologic categories was similar in TIAs and MISs. The most prevalent vascular risk factors were as follows: arterial hypertension (50%), smoking (26%), atrial fibrillation (20%), hypercholesterolemia (17%), diabetes (15%), ischemic heart disease (12%), and peripheral vascular disease (3%). Carotid bruits were detected in 3% of the patients.

CONCLUSIONS

An etiologic classification of TIAs and MISs is feasible. The two most frequent pathogenetic mechanisms in our study were small-artery disease and cardioembolism. The prevalence of large-artery atherosclerosis was low.

Diagnosis of transient ischemic attack by the nonneurologist. A validation study

BACKGROUND AND PURPOSE

Interobserver reliability of the diagnosis of transient ischemic attack (TIA) is low, and diagnosis of TIA made by nonneurologists is often erroneous. We sought to validate the diagnosis of TIA made by general practitioners (GPs) and by hospital emergency service physicians (emergency MDs).

METHODS

A list of 20 neurological symptoms was distributed to 20 GPs and 22 neurologists who graded the compatibility of each symptom with the TIA diagnosis. At least two neurologists validated TIA diagnoses made by GPs for patients under their care or by emergency MDs.

RESULTS

Compared with neurologists, GPs considered "confusion" and "unexplained fall" more often compatible with TIA and "lower facial palsy" and "monocular blindness" less often compatible with TIA. Validation of diagnosis by GP was confirmed in 10 patients (19%); 26 patients had strokes, and 16 (31%) had a noncerebrovascular disorder. Validation of diagnosis by emergency MD was confirmed in 4 patients (13%); 10 patients had strokes, and 17 (55%) had noncerebrovascular disorders. The most frequent conditions misdiagnosed as TIAs were transient disturbances of consciousness, mental status, and balance.

CONCLUSIONS

The TIA concept is understood differently by neurologists and nonneurologists. GPs and emergency MDs often label minor strokes and several nonvascular transient neurological disturbances as TIAs. Until this misconception of TIA is changed, the term TIA should probably be avoided in the communication between referring physicians and neurologists. If not referred to a neurologist, one third to one half of patients labeled with a diagnosis of TIA will be inappropriately managed.

Imaging blood vessels of the head and neck

ATHEROSCLEROTIC DISEASE: Patients with transient ischaemic attacks or a non-disabling stroke who are surgical candidates should be screened with Doppler ultrasound, or MRA/CT, or both. The choice will depend on local expertise and availability. If DUS is used it is recommended that the equipment is regularly calibrated and a prospective audit of results, particularly of those patients that go on to angiography, is maintained locally. Those patients found to have the DUS equivalent of a 50% stenosis should have angiography only if surgical or balloon angioplasty treatment is contemplated. Angiography should be performed with meticulous technique to minimise risks. ANEURYSM AND ARTERIOVENOUS MALFORMATIONS: Angiography remains the investigation of choice for patients with subarachnoid haemorrhage. Magnetic resonance angiography and CT can demonstrate the larger aneurysm but because even small aneurysms can rupture with devastating effects, these techniques are not the examination of first choice. Angiography is also the only technique that adequately defines the neck of an aneurysm. This information is becoming increasingly important in management decisions-for instance, whether to clip or use a coil. Likewise angiography is the only technique to fully define the vascular anatomy of arteriovenous malformations although the size of the nidus can be monitored by MRA and this is a useful method of follow up after stereotactic radiosurgery, embolisation, or surgery. There are specific uses for MRA such as in patients presenting with a painful 3rd nerve palsy and as a screening test for those patients with a strong family history of aneurysms. VASCULITIS, FIBROMUSCULAR HYPERPLASIA, AND DISSECTION: These rare arterial diseases are best detected by angiography, although there are increasing reports of successful diagnosis by MRA. There are traps for the many unwary and MRA does not give an anatomical depiction of the arteries but a flow map. Slow flow may lead to signal loss and a false positive diagnosis of vasculitis.

False facilitation to repetitive stimulation

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Cost-effective intervention in stroke

A rigorous assessment of current practice in all branches of medicine is necessary to ensure that we are minimising the costs and maximising the effectiveness of management and treatment. This is especially important in cerebrovascular disease which imposes a large burden of death; it is the third commonest cause of death after cancer and heart disease in most developed countries, and the commonest cause of long term disability on society. Stroke consumes up to 5% of healthcare expenditure in developed countries, and costs can be expected to remain static or increase with an increase in the proportion of elderly (who are at high risk of stroke) in the community over coming decades. This article reviews the epidemiology of stroke (risk factors, incidence, prevalence and the burden of disability and handicap), the various studies dealing with the community and individual costs of stroke, and the cost-effectiveness of interventions to prevent stroke such as control of hypertension, reduction in cigarette intake, encouragement of a healthy lifestyle, antiplatelet or anticoagulant therapy, and carotid endarterectomy. Acute treatment of stroke remains an area of major potential therapeutic benefit, but no widely applicable therapy currently exists, although many treatments are being investigated. Rehabilitation after stroke is costly, but may result in significant reduction in disability and handicap with reduced need for long term institutional care. The clinical implications of these studies and the potential for future research are also discussed.