Guidelines for the management of transient ischemic attacks. From the Ad Hoc Committee on Guidelines for the Management of Transient Ischemic Attacks of the Stroke Council of the American Heart Association

[Non-taking oral antithrombotic agents in patients with ischemic stroke]

BACKGROUND

In clinical practice, secondary prevention in patients with ischemic stroke (IS) needs to be continued permanently; however, antithrombotic agents are sometimes stopped by clinicians or the patients themselves. The rate of non-taking oral antithrombotic agents was evaluated in IS patients.

METHODS

266 consecutive patients (154 men and 112 women; age, 73.6 +/- 11.5 years) with first-ever acute IS were studied. Patients with transient ischemic attack (TIA) were also included. Emboligenic heart diseases, frequency of past stroke, oral antithrombotic agent use just before IS, and secondary prevention were evaluated.

RESULTS

The number of past strokes was 0 in 182 cases (68.4%), 1 in 66 cases (24.8%), 2 in 14 cases (5.3%), 3 in 3 cases (1.1%), and 9 in 1 case (0.4%; 3 times with stroke, and 6 times with TIA). There were 42 cases (15.8%) with TIA, 47 (17.7%) with lacunar infarction, 69 (25.9%) with atherothrombotic infarction, 62 (23.3%) with cardioembolic infarction, 23 (8.7%) with other types of infarction, and 23 (8.7%) with stroke of unknown etiology. Although 15-26% of patients with their first IS had taken antithrombotic agents just before IS, about 40% of the patients with a previous IS history were not taking antithrombotic agents just before their recurrent IS.

CONCLUSION

About 40% of the patients with recurrent IS were not taking antithrombotic agents at the time of their recurrent IS; had they been taking antithrombotic agents at the time, the recurrent IS might have been prevented. Clinicians must recognize the importance of antithrombotic agents in patients with IS, and patients must continue to take antithrombotic agents permanently.

Lipoprotein-associated phospholipase A2 and risk of stroke

Stroke is the second-leading cause of death worldwide and is a disabling disease of both older and younger adults. Stroke is also among the most highly preventable disorders because there are well-defined risk factors and preventatives. The establishment of new risk markers or factors for stroke risk assessment provides a new avenue for stroke prevention. Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an enzyme that hydrolyzes oxidized phospholipids, releasing lysophosphatidylcholine, which has proinflammatory properties thought to be involved in the development of atherosclerosis and plaque rupture. In 2005, the Lp-PLA(2) blood test was approved by the US Food and Drug Administration (FDA) for assessing the risk of ischemic stroke and coronary artery disease. In epidemiologic studies, low-density lipoprotein cholesterol and other lipid factors have not been shown to be consistent predictors of stroke risk. Lp-PLA(2) measures, on the other hand, have shown a consistent association with stroke risk, conferring about a 2-fold increase in stroke occurrence. This relation has been studied in both first and recurrent stroke and is reviewed in this article. Importantly, a recent study has now shown that Lp-PLA(2) may increase the area under the curve beyond that of traditional cardiovascular risk factors and C-reactive protein. Therefore, Lp-PLA(2) determination may provide a pivotal opportunity to appropriately classify previously misclassified persons who are actually at high risk of stroke and in need of aggressive stroke intervention.

Three presentations of monocular vision loss

BACKGROUND

Carotid artery disease is estimated to affect 30% of persons older than 50. Risk factors include hypertension, cigarette smoking, hyperlipidemia and diabetes mellitus. Symptoms ascribed to carotid artery lesions with stenosis of the artery or plaque formation include monocular vision loss and transient ischemic attacks. Patients can present with transient monocular vision loss as their initial symptom.

CASE REPORTS

Three patients from a geriatric clinic in Wilmington, Delaware presented with different complaints of vision loss with similar overall outcomes. Patient A was an 87-year-old woman who presented with dimming of vision on extreme left head turn. Dilated fundus examination found a retinal arterial emboli in the left eye (O.S.). Carotid duplex examination found 50% to 79% left internal carotid stenosis with no hemodynamic stenosis of the right internal carotid. Patient B was a 78-year-old woman who presented with a right superior altitudinal defect and transient vision loss in the right eye. Dilated fundus examination found retinal arterial emboli in the right eye (O.D.). Carotid duplex examination found 50% to 79% carotid stenosis in both the left and right internal carotids. Patient C was an 84-year-old man who complained of a superior altitudinal visual field defect O.D. Dilated fundus examination found a retinal arterial emboli O.D. Carotid duplex results showed calcified atherosclerotic plaques present at the level of the common carotid artery bifurcations bilaterally, with 50% to 70% narrowing of the right internal carotid artery with no significant narrowing of the left internal carotid artery.

CONCLUSIONS

These 3 presentations show that in patients older than 50 who present with chief complaints of monocular vision loss, a differential diagnosis of carotid artery disease must be considered. Patients who exhibit retinal arterial emboli are at increased risk for stroke and vascular death. Appropriate measures for confirming a diagnosis include duplex ultrasound imaging, magnetic resonance angiography (MRA), and carotid angiography. Surgical techniques such as carotid angioplasty and carotid endarterectomy may be recommended.

Potential Confounding by Intermediate Phenotypes in Studies of the Genetics of Ischaemic Stroke

BACKGROUND

Family history (FHx) of stroke is perceived to be an important risk factor for ischaemic stroke. However, there are several intermediate phenotypes that are often involved in the aetiology of ischaemic stroke and that have a substantial genetic component themselves. We studied FHx of ischaemic heart disease (IHD), hypertension (HTN) and diabetes mellitus (DM) as risk factors for ischaemic stroke.

METHODS

We performed a systematic review of case-control and cohort studies reporting on FHx(IHD), FHx(HTN) or FHx(DM) as risk factors for stroke using bibliographic databases, and by hand searching reference lists and journals. Odds ratios of FHx as a risk factor for stroke were calculated within individual studies. We included unpublished data from two Oxfordshire population-based studies to assess effects on subtypes of ischaemic stroke.

RESULTS

We identified 54 studies that investigated the odds of stroke conferred by a positive FHx, 24 of which reported data on FHx of one or more intermediate phenotypes in addition to FHx of stroke. Most studies reported an increased frequency of FHx(IHD) and FHx(HTN) in stroke patients versus controls. The association was significant in 6 out of 14 studies for FHx(IHD) and 4 out of 11 studies for FHx(HTN). In contrast, FHx(DM) was not associated with stroke. FHx(IHD) was particularly associated with large vessel strokes (OR 1.72, CI 1.3-2.2, p = 0.00004).

CONCLUSIONS

FHx(IHD) and FHx(HTN) are both risk factors for stroke. It is likely that the apparent heritability of stroke is partly accounted for by heritability of HTN and large vessel atherosclerosis. Analyses of heritability of stroke and candidate gene studies should be adjusted accordingly.

Secondary prevention after ischemic stroke

BACKGROUND AND OBJECTIVE

An optimal management of vascular risk factors, associated with antithrombotic drugs and carotid surgery when appropriate, reduces the risk of a new vascular event after stroke. Although secondary prevention is not optimal in many patients in practice, the question of whether there is an improvement over time remains unanswered. The aim of our study was to test the hypothesis that secondary prevention measures after cerebral ischemia improve over time.

METHOD

We included 123 consecutive patients in 1994, and 125 consecutive patients in 2002, who were admitted to a neurological department for any reason and had had an episode of cerebral ischemia less than 6 years earlier. We compared the groups for the management of arterial hypertension, hypercholesterolemia, diabetes mellitus and smoking. We recorded the values of blood pressure, biological parameters, and presence of antithrombotic therapy, lipid-lowering and anti-hypertensive drugs. Whether patients were properly treated or not, was determined by a comparison between their current treatment and guidelines available when recruited.

RESULTS

Prevention was not optimal in 96 of 123 (78%) patients in 1994, and in 77 of 125 (62 %) in 2002. Vascular risk factors were better identified and managed in 2002 than in 1994, especially for hypercholesterolemia. Antithrombotic therapies, statins and antihypertensive drugs, except calcium channel blockers, were more often used in 2002. The proportion of patients in whom arterial hypertension and hypercholesterolemia were identified was higher in 2002, but the proportion of patients identified as diabetics remained stable. However, the proportion of patients with blood pressure >140/90 mmHg, glycemia >or = 126 mg/dl, total cholesterol level > or = 240 mg/dl, or being current smokers, were significantly lower in 2002 than in 1994.

CONCLUSION

Although most of patients with previous cerebral ischemia did not receive an optimal management of their risk factors in 2002, there was an improvement over an 8-year period.

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.

Risk of stroke and recurrent dissection after a cervical artery dissection: A multicenter study

OBJECTIVE

To assess the risk of stroke, TIA, or dissection recurrence after a first event of cervical artery dissection (CAD).

METHODS

The authors undertook a historical cohort study of consecutive patients with a first event of CAD who were admitted in 24 departments of neurology within a period of at least 1 year. Patients were retrospectively selected from a stroke data bank or from the local administrative data bank using the 10th revision of the International Statistical Classification of Diseases. A neurologist and a radiologist reviewed all charts to validate diagnosis and collect data. In 2002, patients were interviewed by phone or during a visit by the local investigators.

RESULTS

Four hundred fifty-nine patients (mean age 44.0 +/- 9.7 years) were included in the study. Among the 457 survivors, 25 (5.5%) could not be contacted in 2002 because they had moved. After a mean follow-up of 31 months, four (0.9%) patients presented a recurrent ischemic stroke attributable to either not yet completely recovered initial CAD (n = 2) or a recurrent CAD (n = 2). Eight (1.8%) patients had a TIA without CAD recurrence. Two TIA occurred at the acute stage of CAD. Of the six remaining TIA, only one was associated with chronic arterial stenosis. In addition, two patients had recurrent CAD without stroke, giving a total of four (0.9%) CAD recurrences.

CONCLUSIONS

Patients with a first event of CAD have a very low risk of ischemic events or dissection recurrences. Ischemic events seem rarely to be in relation with chronic arterial lesions.

Transient ischaemic attacks : new approaches to management

The fact that transient ischaemic attacks are a harbinger for the possible development of ischaemic stroke has been recognised for several decades. However, within the past decade, our concepts regarding transient ischaemic attacks as a distinct entity from stroke and the prognosis for transient ischaemic attack patients have been challenged. In addition, clinical trials have clarified that modern transient ischaemic attack management is more complex than in the past, with the addition of newer pharmacological options to the stroke prevention armamentarium. Recent information regarding newer antiplatelet agents is reviewed in this article, along with results of clinical trials pertaining to warfarin in stroke prevention. The evolving role of statins, ACE inhibitors and estrogen replacement is reviewed. Finally, the appropriate use of surgery following transient ischaemic attacks is outlined. Recent studies have shown that many patients will benefit from a multimodal pharmacological approach following transient cerebral ischaemia, and the potential for combination therapy is highlighted.

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.

The renin-angiotensin-aldosterone system and carotid artery disease in mild-to-moderate primary hypertension

BACKGROUND

The evidence linking activation of the renin-angiotensin system with accelerated cerebro-vascular atherosclerosis remains controversial. We therefore prospectively investigated the relationships of plasma renin activity and aldosterone levels with carotid artery lesions (CAL) in essential hypertension.

METHODS

We evaluated the prevalence and severity of CAL and the intimal-medial thickness (IMT) with a high-resolution echo-Doppler technique in 107 cerebrovascularly asymptomatic consecutive primary hypertensives (55 male, 52 female) and in 70 (42 male, 28 female) normotensive controls. We also measured supine plasma renin activity (PRA) and aldosterone before and 45 min after captopril administration, while daily urinary excretion of sodium was measured.

RESULTS

Both the prevalence (59.4 versus 26.2%) and severity of sex- and age-adjusted and unadjusted CAL and IMT were significantly higher in hypertensives than in controls. Regression analysis showed different predictors of IMT (age and captopril-stimulated-PRA, R2 = 0.27, P < 0.0001), score of CAL (mean blood pressure, R2 = 0.15, F=12.73, P< 0.0001) and maximal stenosis (pulse pressure and known duration of hypertension R2 = 0.29, F = 14.58, P< 0.0001). Sex- and age-adjusted IMT did not differ between quartiles of renin-sodium profile. However, patients in the quartile with the highest PRA had the lowest score of CAL and an inverse relationship between age-adjusted PRA and IMT and CAL was found.

CONCLUSIONS

These results, besides confirming an association of both IMT and CAL with primary hypertension and ageing, demonstrate that CAL and IMT have different correlates. However, they do not support the contention that a high renin-sodium profile carries an excess risk of CAL in primary hypertensives with no clinical evidence of cerebro-vascular disease.

Use of oral anticoagulants in older patients

Recently published American and British guidelines have comprehensively reviewed the indications for long term anticoagulation. The best evidence currently available supports the use of long term oral anticoagulants in patients with nonvalvular atrial fibrillation (NVAF), venous thromboembolic disease, ischaemic heart disease, mural thrombi, and mechanical heart valves. Selected patients with valvular heart disease, cerebral vascular disease, and peripheral arterial disease may also benefit from the use of these drugs. When no specific contraindications are present, elderly patients with either paroxysmal or persistent NVAF should be considered candidates for treatment with anticoagulants. Pooled analyses of the results from 9 randomised trials demonstrate that warfarin significantly reduces the risk of ischaemic stroke in patients with NVAF, particularly those in a 'high risk' category defined by the presence of additional clinical or echocardiographic risk factors. Long term anticoagulation does not appear to be justified in patients with NVAF considered to be at 'low risk' for stroke. Because the prevalence of NVAF and most other cardiovascular conditions increases with advancing age, many elderly patients will be candidates for thromboprophylaxis. The potential benefit of long term anticoagulation must be carefully weighed against the risk of serious haemorrhage in such patients. Bleeding complications with anticoagulant drugs appear to occur more frequently in older patients than in younger individuals. Advanced age (>75 years), intensity of anticoagulation [International Normalised Ratio (INR) >4.0], history of cerebral vascular disease (recent or remote), and concomitant use of drugs that interfere with haemostasis [aspirin (acetylsalicylic acid) or nonsteroidal anti-inflammatory drugs] are among the most important variables in determining an individual's risk for major bleeding with anticoagulants. Older patients often display increased sensitivity to the effects of warfarin, both in the early induction phase and during the long term maintenance phase of therapy. Conditions such as congestive heart failure, malignancy, malnutrition, diarrhoea and unsuspected vitamin K deficiency, enhance the prothrombin time response. The decision to interrupt anticoagulant therapy before elective surgery in elderly patients should evaluate the thrombotic risk of such a manoeuvre versus the risk of bleeding if anticoagulants are continued. In non-surgical patients, excessively elevated INRs without associated haemorrhage can usually be managed by simply witholding one or several doses of warfarin. If more rapid reversal is needed, small doses of phytomenadione (vitamin K1) can be administered safely without overcorrection or the development of vitamin K-induced warfarin resistance.

Cerebral infarction and transient ischemic attacks. Efficient evaluation is essential to beneficial intervention

Rapid but precise evaluation of patients presenting with cerebral infarction is essential to determine immediate intervention. Initial assessment should include history taking, physical examination, routine laboratory testing, electrocardiography, chest radiology, and noncontrast head CT. Localizing the event to the appropriate arterial circulation (anterior versus posterior) and determining topography (subcortical versus cortical) guide sequential testing to ascertain the mechanism of cerebral infarction. Diagnostic testing focuses on selectively identifying potential cardiac, large-vessel, small-vessel, or hematologic causes. Although diagnostic tools are evolving, 15% of cerebral infarctions still have an unknown cause or multiple potential sources.

The role of nursing in the rehabilitation of acute stroke patients: toward a unified theoretical perspective

A review of existing literature indicates an uncertainty about the specific therapeutic role of nurses in the rehabilitation of stroke patients. Two different conceptualizations of the nursing role exist, but neither is related to specific rehabilitation goals and patient outcomes. A beginning theoretical account of the specific role of nursing in stroke recovery is offered as a structure to integrate the therapeutic aspects of the coordinating, maintenance, and training functions of the nurse. Existing research literature is reviewed to substantiate the account. Further research is needed to develop the specific content and focus of nursing in stroke recovery.

Arterial Damage, Triglycerides, Apolipoprotein, and Lp-(a) Values in PVD Patients

The aim of the study was to provide a detailed apolipoproteic profile in stage II peripheral vascular disease (PVD) patients and to ascertain whether lower ankle/ arm pressure index (API) values were associated with a worse profile.

Apolipoproteins of 83 stage II PVD patients (average age 64.7 ± 9.3 years) were selected and compared with those of a group of 44 normal control subjects, similar in terms of age, sex, and smoking and eating habits. Neither PVD patients nor controls had ever received lipid-lowering agents or defined dietary treatment. A diagnosis of PVD was confirmed by an API of <0.85. Arteriopathic patients were also split into two groups, depending on their API values, similar in terms of age, sex and smoking habits: API values of one group (n = 38) were ≥0.6, those of the other group (n = 45) were <0.6. The following biohumoral parameters were considered: fasting glycemia, total cholesterol, triglycerides (TGs); high-density lipoprotein cholesterol (HDL-C); low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), total cholesterol (TC)/HDL-C (TC/ HDL-C), Apoproteins (Apos) AI, AII, B, CII, CIII, and E; and lipoprotein a [Lp(a)].

HDL-C and Apo AI were lower ( p < 0.01), while TC/ HDL-C ratios, Apo B, and Apo CII were higher ( p < 0.01) in PVD patients compared with controls. The comparison between the two PVD groups with different API values showed higher blood TG and VLDL-C values for the patients with lower API values (p < 0.05), indicating a relationship between hypertriglyceridemia and greater arterial damage. Key Words: Peripheral arterial occlusive disease-Triglyceride-Lipoprotein a.

Cooperative stroke management project by a peer-review organization

To improve the care of patients in Mississippi through increased adherence to nationally accepted ischemic stroke management guidelines, patterns for ischemic stroke services were determined from hospital chart review. Hospital-specific education and data feedback were performed to encourage international systems improvements. The Mississippi Foundation for Medical Care, Inc, reviewed records of Medicare beneficiaries discharged with the principal diagnosis of acute ischemic stroke from four hospitals over a 1-year period. Records were analyzed for compliance with stroke management guidelines. Hospital-specific and aggregate data were presented to the staffs of each hospital and the hospitals were encouraged to develop internal quality improvement projects. The Foundation reviewed 427 records of acute stroke patients, of whom 375 (87.8%) had ischemic stroke. Among the 427 stroke patients, there were 76 (17.8%) in-hospital deaths. Notable variances from the ischemic stroke management guidelines included those for emergent hypertension management, deep vein thrombosis prophylaxis, evaluation for cause of ischemic stroke, and use of antithrombotic therapy on discharge of ischemic stroke patients. Thus, the management of acute stroke patients in these four regional hospitals in Mississippi often differed from nationally accepted guidelines. We hope to improve the care of stroke patients by using the expertise of academic stroke physicians and hospital-specific analyses that are personally meaningful but not personally threatening to treating physicians.