Lubeluzole in acute ischemic stroke treatment: A double-blind study with an 8-hour inclusion window comparing a 10-mg daily dose of lubeluzole with placebo

BACKGROUND AND PURPOSE

This trial was a double-blind, placebo-controlled, phase III trial with an 8-hour inclusion window to assess the efficacy and safety of an intravenous loading dose of 7.5 mg followed by a daily intravenous dose of 10 mg lubeluzole for 5 days in acute ischemic stroke patients.

METHODS

A total of 1786 patients were randomized: 901 to lubeluzole and 885 to placebo. Overall, 212 patients (23.5%) from the lubeluzole group and 213 (24.1%) from the placebo group discontinued the trial prematurely. In the lubeluzole group 201 patients (22.3%) discontinued because of adverse events compared with 193 patients (21.8%) in the placebo group.

RESULTS

The primary population for the efficacy analysis comprised the core stroke patients (exclusion of older patients aged >75 years with severe stroke) in the 0- to 6-hour inclusion time window. The primary efficacy parameter was a 3-category functional status (Barthel Index 70 to 100/0 to 70/vegetative, dead) at week 12. In the lubeluzole group 207 patients (47.8%) were classified as mildly dependent/independent at week 12, 131 (30.3%) were moderately/severely dependent, and 95 (21.9%) were vegetative/dead. In the placebo group these numbers were 221 (54.4%), 112 (27.6%), and 73 (18.0%), respectively. Logistic regression analysis showed no statistically significant difference between the treatment groups (P:=0.162). Additionally, for none of the secondary efficacy parameters (mortality at week 12, modified Rankin score, total Barthel score) was a statistically significant difference between the lubeluzole and placebo groups obtained. There were no statistically significant differences between the 2 treatments for all treated patients, patients included within the 6- to 8-hour window, and patients with severe strokes aged >75 years. Overall, of all treated patients, 401 (22.5%) died: 203 (22.5%) in the lubeluzole group and 198 (22.4%) with placebo. Of all subjects treated, 853 (95%) on lubeluzole and 826 (93%) on placebo reported an adverse event during their treatment period or within the next 2 days after discontinuation of treatment. The most frequently observed adverse events were fever (25.9% lubeluzole; 23.4% placebo), constipation (20.2%; 19.7%), and headache (17.6%; 21.2%). Imbalances were found for atrial fibrillation (1.8% lubeluzole; 1.1% placebo) and QT prolongation (0.9%; 0.2%).

CONCLUSIONS

This study failed to show an efficacy of lubeluzole in the treatment of acute stroke. On the other hand, lubeluzole treatment by the current dosage schedule was not associated with a significant safety problem.

The validity and reliability of signs of early infarction on CT in acute ischaemic stroke

It has been suggested that subtle signs of early cerebral infarction on CT are important indicators of outcome and of the effect of thrombolytic treatment in acute ischaemic stroke. We studied these signs prospectively, in 260 patients with an anterior circulation stroke from a European-Australian randomised trial of lubeluzole in acute ischaemic stroke. Interobserver reliability was assessed by means of the chi statistic. The validity of the early signs was assessed by comparing the assessments of the first CT with another CT at 1 week after the onset of stroke, and with stroke outcome at 12 weeks. Each initial CT study was assessed by two of a group of five reviewers, who were blinded to each other's assessments and to the findings on the follow-up CT. The images were assessed twice, once without clinical information and again after disclosure of the side (left or right hemisphere) of the lesion. All reviewers were experienced clinicians with a special interest and training in vascular neurology and CT. The median time between stroke onset and the first CT was 3.2 h; 59% of the patients were imaged within 3 h and 77% within 6 h. More than half of the patients (52%) had a large middle cerebral artery territory (MCA) infarct on follow-up CT. Chance-adjusted interobserver agreement (chi) for any early infarct was 0.27 (95% confidence interval (CI): 0.15 to 0.39). Agreement (chi) on the extent of a middle cerebral artery (MCA) infarct and on the indication for treatment with recombinant tissue plasminogen activator (rt-PA) was fair: 0.37 and 0.35, respectively. Patients with early signs of an infarct of more than 1/3 of the MCA territory were more likely to have a large MCA infarct on follow-up CT (odds ratio 5.7, 95% confidence interval 2.8-11.5); the positive and negative predictive value of these signs was 81% and 57%, respectively. Chance-adjusted interobserver agreement on early, subtle signs of a large MCA territory infarct on CT by neurologists was thus no more than fair, and the accuracy of prediction of actual infarct size on the basis of these signs only moderate, under circumstances which resemble everyday clinical practice.

A short screening instrument for poststroke dementia : the R-CAMCOG

BACKGROUND AND PURPOSE

The CAMCOG is a feasible cognitive screening instrument for dementia in patients with a recent stroke. A major disadvantage of the CAMCOG, however, is its lengthy and relatively complex administration for screening purposes. We therefore developed the Rotterdam CAMCOG (R-CAMCOG), based on the original version. Our aim was to reduce the estimated administration time to 15 minutes or less and to retain or perhaps even improve its diagnostic accuracy.

METHODS

We analyzed the item scores on the CAMCOG of 300 consecutive stroke patients, after exclusion of patients with a severe aphasia or lowered consciousness level, who were entered in the Rotterdam Stroke Databank. The diagnosis of dementia was made independent of the R-CAMCOG score, on the basis of clinical examination and neuropsychological test results. The R-CAMCOG was constructed in 3 steps. First, items with floor and ceiling effects were removed. Next, subscales with no additional diagnostic value were excluded. Finally, we removed items that did not contribute to the homogeneity of the subscales. The diagnostic accuracy of the R-CAMCOG and the original CAMCOG was determined by means of the area under the receiver operating characteristic (ROC) curve.

RESULTS

In the 3 steps, the number of items was reduced from 59 to 25, divided over the subscales orientation, memory (recent, remote, and learning), perception, and abstraction. The subscale orientation did not reach significance in a logistic regression model but was included in the R-CAMCOG because of its high face validity in dementia screening. Internal validation with ROC analysis suggests that the R-CAMCOG and the CAMCOG are equally accurate in screening for poststroke dementia (area under the curve was 0.95 for both tests).

CONCLUSIONS

The R-CAMCOG has overcome the disadvantages of the original CAMCOG. It is a promising, short, and easy-to-administer screening instrument for poststroke dementia. It seems to be sufficiently accurate for this purpose, but the test has yet to be validated in a separate, independent study.

Interobserver variability of cisternal blood on CT after aneurysmal subarachnoid hemorrhage

Interobserver variability in the prediction of delayed cerebral ischemia by means of blood on CT was investigated in 159 patients with aneurysmal subarachnoid hemorrhage, admitted within 72 hours after the bleed. The authors found considerable interobserver variability in the assessment of the amount of blood in the individual cisterns. A high sum score was an independent predictor for delayed cerebral ischemia only for rater 1 (rater 1: hazard ratio, 3.26; 95% confidence interval [CI], 1.14 to 7.75; rater 2: hazard ratio, 1.72; 95% CI, 0.72 to 4.09). The authors conclude that interobserver variability limits the predictive power of the amount of blood on CT for the occurrence of cerebral ischemia.

Design of the blockade of the glycoprotein IIb/IIIa receptor to avoid vascular occlusion (BRAVO) trial

BACKGROUND

Platelets play a key role in the pathogenesis of atherosclerosis, thrombosis, and acute coronary and cerebrovascular syndromes. Inhibition of platelet function by acetylsalicylic acid (aspirin) has been shown to reduce the incidence atherothrombotic events in patients with coronary, cerebrovascular, or peripheral vascular disease. Thienopyridine agents, however, including ticlopidine and clopidogrel, inhibit the adenosine diphosphate receptor and have modestly superior effects compared with aspirin on reduction of death, myocardial infarction, and stroke among a broad group of patients with vascular disease. More effective antithrombotic agents are still required to treat patients at high risk for recurrent vascular events.

METHODS

Lotrafiban, a selective, nonpeptide antagonist of the human platelet fibrinogen receptor (glycoprotein [GP] IIb/IIIa [alphaIIb/beta3 integrin]), blocks the binding of fibrinogen to the GP IIb/IIIa receptor, which is the final common pathway of platelet aggregation. Lotrafiban at doses of up to 50 mg twice daily was well-tolerated in a 12-week, double-blind, placebo-controlled, dose-ranging study in patients with recent myocardial infarction, unstable angina, transient ischemic attack, or stroke when added to aspirin therapy. On the basis of these results, a dosing regimen was selected for the phase III Blockage of the Glycoprotein IIb/IIIa Receptor to Avoid Vascular Occlusion (BRAVO) trial based on pharmacodynamics and drug tolerability. In the pivotal BRAVO study, lotrafiban therapy is being evaluated in patients who have had a recent myocardial infarction, unstable angina, transient ischemic attack, or ischemic stroke, or who present at any time after a diagnosis of peripheral vascular disease combined with either cardiovascular or cerebrovascular disease.

RESULTS

The efficacy evaluation will be based on a composite end point of clinical events (death by any cause, myocardial infarction, stroke, recurrent ischemia requiring hospitalization, or urgent ischemia-driven revascularization). The target enrollment is 9200 patients worldwide. Approximately 700 centers will participate and will be distributed within 30 countries across North America, Europe, Australia, and Asia.

[Thrombolytic therapy of brain infarct: the end of beginning]

Thrombolysis by intravenous application of thrombolytic drugs may improve the outcome of patients with a brain infarct, but it also entails risks. The effect of recombinant tissue plasminogen activator (rtPA) was compared with placebo in three medium-sized randomized controlled clinical trials. One study, performed in North America, showed a clear benefit of rtPA administered within 3 hours after the onset of symptoms. Two European trials showed a less strong effect, but the number of patients who were independent after 3 months' follow-up was also larger after treatment with rtPA within 6 hours. A meta-analysis of all three trials demonstrates a significant advantage of rtPA over placebo for all the usual outcome measures, without significant excess mortality in the rtPA group. The chance of being able to live independently increases by about 8% after treatment with rtPA. In conclusion there is now sufficient evidence to start with thrombolytic treatment for cerebral infarcts in hospitals with a stroke unit, if a number of additional quality standards for the acute diagnosis and treatment of stroke patients are met.

Cerebral CO2 reactivity, cholesterol, and high-density lipoprotein cholesterol in the elderly

Cholesterol and its subfractions play a role in the development of atherosclerosis. Cerebral CO2 reactivity reflects the compensatory capacity of cerebral arterioles. The authors investigated the relationship between total cholesterol, high-density lipoprotein (HDL), their ratio, and cerebral CO2 reactivity in 826 participants from the Rotterdam Study. Cerebral CO2 reactivity increased significantly with increasing levels of HDL and decreased significantly with an increasing total cholesterol/HDL ratio. This suggests that blood lipids may also affect smaller cerebral blood vessels.

Anticoagulants versus antiplatelet therapy for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischemic attacks

BACKGROUND

People with nonrheumatic atrial fibrillation who have had a transient ischemic attack or minor ischemic stroke are at risk of recurrent stroke.

OBJECTIVES

The objective of this review was to compare the effect of anticoagulants with antiplatelet therapy, for secondary prevention, in people with nonrheumatic atrial fibrillation and previous cerebral ischaemia.

SEARCH STRATEGY

The reviewer searched the Cochrane Stroke Group trials register and contacted trialists.

SELECTION CRITERIA

Randomised trials comparing oral anticoagulants with aspirin in patients with non-rheumatic atrial fibrillation and a previous transient ischaemic attack or minor ischaemic stroke.

DATA COLLECTION AND ANALYSIS

One reviewer extracted the data.

MAIN RESULTS

One trial was included, involving 455 patients. They received either anticoagulants (International Normalised Ratio 2.5 to 4.0), or 300 milligrams of aspirin per day. People joined the trial within three months of transient ischaemic attack or minor stroke. The mean follow-up was 2.3 years. Anticoagulant therapy approximately halved the odds of serious vascular events (odds ratio 0.55, 95% confidence interval 0.36 to 0. 83). This equates to preventing an extra 50 vascular events per year for every 1000 patients treated. Anticoagulant therapy decreased the odds of recurrent stroke by two-thirds (odds ratio 0.35, 95% confidence interval 0.22 to 0.59). This translates to preventing an extra 60 strokes for every 1000 patients treated per year. Major extracranial bleeds occurred more often in patients given anticoagulants (odds ratio 4.65, 95% confidence interval 1.66 to 12.99). The absolute difference was 2.8% versus 0.9% bleeds per year. None of the patients on anticoagulants and one on aspirin had an intracerebral bleed.

REVIEWER'S CONCLUSIONS

The evidence from one trial suggests that anticoagulant therapy can benefit people with nonrheumatic atrial fibrillation and recent cerebral ischaemia. Aspirin may be a useful alternative if there is a contraindication to anticoagulant therapy. The risk of adverse events appears to be higher with anticoagulant therapy than aspirin.

Anticoagulants for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischemic attacks

BACKGROUND

People with nonrheumatic atrial fibrillation who have had a transient ischemic attack or a minor ischemic stroke are at risk of recurrent stroke.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulants for secondary prevention, after a stroke or transient ischaemic attack, in patients with nonrheumatic atrial fibrillation.

SEARCH STRATEGY

The reviewer searched the Cochrane Stroke Group trials register and contacted trialists.

SELECTION CRITERIA

Randomised trials comparing oral anticoagulants (target International Normalised Ratio range 2.5 to 4.0) with control or placebo in people with nonrheumatic atrial fibrillation and a previous transient ischaemic attack or minor ischaemic stroke.

DATA COLLECTION AND ANALYSIS

One reviewer assessed trial quality and extracted data.

MAIN RESULTS

Two trials involving 485 people were included. Anticoagulants reduced the risk of recurrent stroke by two-thirds (odds ratio 0.36, 95% confidence interval 0.22 to 0.58). The risk of all vascular events was shown to be almost halved by treatment (odds ratio 0.55, 95% confidence interval 0.37 to 0.82). No intracranial bleeds were reported among people given anticoagulants.

REVIEWER'S CONCLUSIONS

The evidence suggests that anticoagulants are beneficial, without serious adverse effects, for people with nonrheumatic atrial fibrillation and recent cerebral ischaemia.

Antiplatelet therapy for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischemic attacks

BACKGROUND

People with nonrheumatic atrial fibrillation who have had a transient ischemic attack or minor ischemic stroke are at risk of recurrent stroke.

OBJECTIVES

The objective of this review was to assess the effect of antiplatelet therapy for secondary prevention in people with nonrheumatic atrial fibrillation and a previous transient ischaemic attack or ischaemic stroke.

SEARCH STRATEGY

The reviewer searched the Cochrane Stroke Group trials register and contacted trialists.

SELECTION CRITERIA

Randomised trials comparing an antiplatelet agent with placebo or open control in people with nonrheumatic atrial fibrillation and a previous transient ischaemic attack or minor ischaemic stroke.

DATA COLLECTION AND ANALYSIS

One reviewer extracted the data.

MAIN RESULTS

One trial was included, in which 300 milligrams of aspirin per day was compared with placebo. This review includes 404 aspirin-treated patients and 378 placebo patients in total. The mean follow-up was 2.3 years. No difference was shown between aspirin and placebo in the annual rate of all vascular events, including vascular death, recurrent stroke (ischaemic or haemorrhagic), myocardial infarction, and systemic embolism. The odds ratio was 0.84, 95% confidence interval 0.63 to 1. 14, or 15% of those receiving aspirin versus 19% for those given placebo. Aspirin may prevent 40 vascular events (of all types) per 1000 patients treated for one year. There was a non-significant reduction in the risk of recurrent stroke from 12% to 10% per year (odds ratio 0.89, 95% confidence interval 0.64 to 1.24). The incidence of major bleeding events, requiring hospitalisation, blood transfusion or surgical treatment, was low (0.9% per year for aspirin versus 0.7% for placebo).

REVIEWER'S CONCLUSIONS

Aspirin may reduce the risk of vascular events in people with nonrheumatic atrial fibrillation, but the effect shown in the single trial was not statistically significant.

[Creative mathematics with clopidogrel; exaggeration of the preventive effect by manufacturer]

A number of Dutch medical journals recently carried an advertisement stating that clopidogrel treatment reduced the number of ischaemic complications with 26%, compared with aspirin treatment. This is a miscalculation: the actual reduction is 0.51% in absolute rates, and 8.7% in relative terms. The error by Sanofi-Synthelabo arose by comparison of the event rates for clopidogrel (5.32%) as well as for aspirin (5.83%) with that in an imaginary placebo group (7.77%), yielding a reduction of ischaemic complications of 2.45% and 1.94% respectively; erroneous comparison of these two numbers leads to a difference of 26%.

J-shaped relation between blood pressure and stroke in treated hypertensives

The objective of this study was to investigate the relationship between hypertension and risk of stroke in the elderly. The study was performed within the framework of the Rotterdam Study, a prospective population-based cohort study. The risk of first-ever stroke was associated with hypertension (relative risk, 1.6; 95% CI, 1.2 to 2.0) and with isolated systolic hypertension (relative risk, 1.7; 95% CI, 1.1 to 2.6). We found a continuous increase in stroke incidence with increasing blood pressure in nontreated subjects. In treated subjects, we found a J-shaped relation between blood pressure and the risk of stroke. In the lowest category of diastolic blood pressure, the increase of stroke risk was statistically significant compared with the reference category. Hypertension and isolated systolic hypertension are strong risk factors for stroke in the elderly. The increased stroke risk in the lowest stratum of blood pressure in treated hypertensive patients may indicate that the therapeutic goal of "the lower the better" is not the optimal strategy in the elderly.

Anticoagulant treatment in stroke prevention

This review aims to summarise the value of long-term oral anticoagulant treatment in stroke prevention. Oral anticoagulation is the treatment of first choice in patients with atrial fibrillation (AF) and vascular risk factors and in AF patients with recent cerebral ischemia. The treatment also substantially reduces the risk of stroke in patients after myocardial infarction. The optimal target intensity of anticoagulation in stroke prevention is an International Normalized Ratio (INR) between 2.0 and 3.0. The treatment has been found to be hazardous at INR intensities between 3.0 and 4.5 in patients with transient ischemic attack (TIA) or minor stroke of presumed arterial origin. The value of the treatment in lower intensity in such patients still has to be established.

Stroke prevention: which drugs to use and when?

This review summarizes recent findings from clinical trials regarding the prevention of stroke and translates these into therapeutic guidelines. A distinction is made between patients with previous cerebrovascular disease and those without, and between patients with and those without atrial fibrillation. Although the efficacy of aspirin is disappointingly small, the effects are consistent in all subgroups of patients with confirmed vascular disease, and this treatment remains superior as first choice except in patients with both atrial fibrillation and vascular risk factors, for whom oral anticoagulants are the optimal treatment.

Increased thromboxane biosynthesis is associated with poststroke dementia

BACKGROUND AND PURPOSE

It has been suggested that daily intake of aspirin is associated with a reduction of cognitive decline, both in normal and in demented subjects, but the mechanism is unclear. We have therefore studied the relationship between thromboxane (TX) A(2) biosynthesis, as reflected by the urinary excretion of 11-dehydro-TXB(2), and the presence of dementia in patients after acute stroke.

METHODS

Patients from the Rotterdam Stroke Databank were screened for dementia between 3 and 9 months after stroke. Patients had a full neurological examination, neuropsychological screening, and, if indicated, extensive neuropsychological examination. Criteria used for the diagnosis of dementia were from the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (Revised). Urine samples were taken at the time of screening. Urinary 11-dehydro-TXB(2) was measured by means of a previously validated radioimmunoassay.

RESULTS

Dementia was diagnosed in 71 patients, and urine samples were available for 62. Median value (range) of 11-dehydro-TXB(2) was 399 (89 to 2105) pmol/mmol creatinine for demented patients versus 273 (80 to 1957) for 69 controls with stroke but without dementia (P=0.013). No difference was found between 44 patients with vascular dementia, 404 (89 to 2105) pmol/mmol creatinine, and 18 patients with Alzheimer's disease plus cerebrovascular disease, 399 (96 to 1467) pmol/mmol creatinine (P=0.68). In a stepwise logistic regression analysis, in which possible confounders such as use of antiplatelet medication, cardiovascular risk factors, and type of stroke were taken into account, increased urinary excretion of 11-dehydro-TXB(2) remained independently related to the presence of dementia (OR 1.12, 95% CI 1.03 to 1.22 per 100 pmol/mmol creatinine). The difference in metabolite excretion rates between demented and nondemented patients was most prominent within the subgroup of ischemic stroke patients who received aspirin (P<0.01).

CONCLUSIONS

Increased thromboxane biosynthesis in the chronic phase after stroke is associated with the presence of but not the type of poststroke dementia. It is particularly apparent in patients on aspirin, thereby suggesting the involvement of extraplatelet sources of TXA(2) production in this setting.

Controlled safety study of a hemoglobin-based oxygen carrier, DCLHb, in acute ischemic stroke

BACKGROUND AND PURPOSE

Diaspirin cross-linked hemoglobin (DCLHb) is a purified, cell-free human hemoglobin solution. In animal stroke models its use led to a significant reduction in the extent of brain injury. The primary objective of this study was to evaluate the safety of DCLHb in patients with acute ischemic stroke.

METHODS

DCLHb or saline was administered to 85 patients with acute ischemic stroke in the anterior circulation, within 18 hours of onset of symptoms, in a multicenter, randomized, single-blind, dose-finding, controlled safety trial, consisting of 3 parts: 12 doses of 25, 50, and 100 mg/kg DCLHb over 72 hours.

RESULTS

DCLHb caused a rapid rise in mean arterial blood pressure. The pressor effect was not accompanied by complications or excessive need for antihypertensive treatment. Two patients in the 100 mg/kg group had adverse events that were possibly drug related: one suffered fatal brain and pulmonary edema, the other transient renal and pancreatic insufficiency. Multivariate logistic regression analysis showed that a severe stroke at baseline and treatment with DCLHb (OR, 4.0; CI, 1.4 to 12.0) were independent predictors of a worse outcome (Rankin Scale score of 3 to 6) at 3 months.

CONCLUSIONS

Outcome scale scores were worse in the DCLHb group, and more serious adverse events and deaths occurred in DCLHb-treated patients than in control patients. We recommend that additional safety studies be performed, preferably with a second generation, genetically engineered hemoglobin.

Increased platelet activation in the chronic phase after cerebral ischemia and intracerebral hemorrhage

BACKGROUND AND PURPOSE

Enhanced thromboxane (TX) biosynthesis has previously been reported in the acute phase after ischemic stroke. We investigated whether enhanced urinary excretion of 11-dehydro-TXB2, a noninvasive index of platelet activation, was present in the chronic phase after a transient ischemic attack (TIA) or stroke, including intracerebral hemorrhage.

METHODS

We obtained a single urinary sample from 92 patients between 3 and 9 months after onset of stroke or TIA. The urinary excretion of the major enzymatic metabolite of TXA2, 11-dehydro-TXB2, was measured by a previously validated radioimmunoassay. The excretion rates were compared with those of 20 control patients with nonvascular neurological diseases.

RESULTS

Urinary 11-dehydro-TXB2 averaged 294+/-139, 413+/-419, and 557+/-432 pmol/mmol creatinine for patients with TIA, ischemic stroke, and intracerebral hemorrhage, respectively; the values were higher in all subgroups (P<0.01) than that in control patients (119+/-66 pmol/mmol). Increased 11-dehydro-TXB2 excretion was present in 59% of all patients, in 60% (P<0.001) of patients with TIA, in 56% (P<0.001) of patients with ischemic stroke, and in 73% (P<0.001) of patients with intracerebral hemorrhage. Atrial fibrillation, no aspirin use, and severity of symptoms at follow-up contributed independently to the level of 11-dehydro-TXB2 excretion in a multiple linear regression analysis.

CONCLUSIONS

Platelet activation is often present in patients in the chronic phase after stroke, including those with intracerebral hemorrhage. Persistent platelet activation, which is associated with atrial fibrillation and poor stroke outcome, can be substantially suppressed by aspirin treatment.

Cerebral vasomotor reactivity and cerebral white matter lesions in the elderly

OBJECTIVE

The pathogenesis of white matter lesions is still uncertain, but an ischemic-hypoxic cause has been suggested. Cerebral vasomotor reactivity reflects the compensatory dilatory mechanism of the intracerebral arterioles to a vasodilatory stimulus and provides a more sensitive hemodynamic index than the level of resting flow.

METHODS

The authors determined the association between vasomotor reactivity and white matter lesions in 73 consecutive individuals from the Rotterdam Scan Study who also participated in the Rotterdam Study, a large population-based prospective follow-up study of individuals > or =55 years old. Vasomotor reactivity was measured by means of CO2-enhanced transcranial Doppler, and in all individuals axial T1*-, T2*-, and proton density (PD)-weighted MRI scans (1.5 T) were obtained. White matter lesions were scored according to location, size, and number by two independent readers.

RESULTS

Vasomotor reactivity was inversely associated with the deep subcortical and total periventricular white matter lesions (OR 0.5, 95% CI 0.3 to 1.1; and OR 0.7, 95% CI 0.4 to 1.1, respectively). A strong association was found between impaired vasomotor reactivity and periventricular white matter lesions adjacent to the lateral ventricular wall (OR 0.6, 95% CI 0.4 to 1.0; p = 0.001). No association was found with periventricular white matter lesions near the frontal and occipital horns.

CONCLUSIONS

Our data confirm the association between vasomotor reactivity and white matter lesions and support the hypothesis that some white matter lesions may be associated with hemodynamic ischemic injury to the brain.

Homocysteine and short-term risk of myocardial infarction and stroke in the elderly: the Rotterdam Study

BACKGROUND

Elevated homocysteine level increases vascular disease risk. Most data are based on subjects younger than 60 years; data for the elderly are more limited. We examined the relationship of homocysteine level to incident myocardial infarction and stroke among older subjects in a nested case-control study.

METHODS

Subjects were participants in the Rotterdam Study, a cohort study among 7983 subjects residing in the Ommoord district of Rotterdam, the Netherlands. Baseline examinations were performed from March 1, 1990, to July 31, 1993. The analysis is restricted to myocardial infarction and stroke that occurred before December 31, 1994. One hundred four patients with a myocardial infarction and 120 with a stroke were identified with complete data. Control subjects consisted of a sample of 533 subjects drawn from the study base, free of myocardial infarction and stroke. Nonfasting total homocysteine levels were measured.

RESULTS

Results were adjusted for age and sex. The risk of stroke and myocardial infarction increased directly with total homocysteine. The linear coefficient suggested a risk increase by 6% to 7% for every 1-micromol/L increase in total homocysteine. The risk by quintiles of total homocysteine level was significantly increased only in the group with levels above 18.6 micromol/L (upper quintile): odds ratios were 2.43 (95% confidence interval, 1.11-5.35) for myocardial infarction and 2.53 (95% confidence interval, 1.19-5.35) for stroke. Associations were more pronounced among those with hypertension.

CONCLUSIONS

The present study, based on a relatively short follow-up period, provides evidence that among elderly subjects an elevated homocysteine level is associated with an increased risk of cardiovascular disease.

Secondary stroke prevention in atrial fibrillation: indications, risks, and benefits

Patients with nonrheumatic atrial fibrillation (NRAF) and a recent transient ischemic attack (TIA) or nondisabling ischemic stroke have a high risk of stroke recurrence of about 12% per year. Two randomized clinical trials have shown that oral anticoagulant therapy reduces the risk by two thirds, very similar to the benefit in primary prevention. The optimal intensity is INR 2.0-3.0. In case of a containdication to AC, aspirin and ibuprofen are safe, but less effective, alternatives. During the first 2 weeks following AF-related major stroke, the benefit of subcutaneous heparin is offset by a higher risk of secondary cerebral bleeding, and therefore cannot be recommended, at present, during that period. The risk of stroke recurrence can be predicted by means of easily available clinical information.

The diagnostic value of colour duplex ultrasound for symptomatic carotid stenosis in clinical practice

We assessed the accuracy of colour duplex ultrasound for the detection of severe (70-99%) symptomatic carotid stenosis in a clinical setting, in order to assess whether it could make carotid angiography unnecessary. In 152 patients with a transient ischaemic attack or nondisabling ischaemic stroke in the carotid distribution, we compared the degree of colour duplex ultrasound stenosis with angiographic stenosis by receiver-operating-characteristic analysis. The angiograms were evaluated by blinded observers, and compared with routine reports of the colour duplex examination. We computed the sensitivity and specificity of colour duplex, and the number of angiograms and sonographic studies needed to prevent one stroke within 3 years, taking into account the risks of angiography, and the risks and efficacy of endarterectomy. The estimates were adjusted for nonverification bias. We found 34 patients (22%) with a severe (70-99%) symptomatic carotid stenosis. In 16 patients (11%) the symptomatic artery was occluded. The sensitivity and specificity of duplex ultrasound were 76% and 85%, respectively. The number of patients needed to undergo angiography to prevent one stroke was reduced from almost 200 to 33, when colour duplex was used as a preoperative examination. After adjustment for the effects of nonverification, the sensitivity dropped to 58% and the number of duplex studies needed to prevent one stroke would double. The number of angiograms needed after positive duplex sonography would be virtually unaffected. Were colour duplex sonography to have been the sole preoperative investigation, the number needed to diagnose to prevent one stroke within 3 years would be approximately 350, more than twice as many as with the combined diagnostic strategy. The diagnostic accuracy of colour duplex sonography in clinical practice seems less impressive than previous studies have suggested, but it remains an effective way to select patients for angiography. Its use as a single preoperative assessment cannot be recommended.

Intracranial high-intensity transient signals after homograft or mechanical aortic valve replacement

OBJECTIVE

Comparison of the occurrence, intensity and rate of high-intensity transient signals (HITS), measured in both middle cerebral arteries by transcranial Doppler ultrasound (TCD) after mechanical or homograft aortic valve implantation.

EXPERIMENTAL DESIGN

TCD monitoring was performed by means of a pulsed Doppler ultrasound with two 2 MHz probes, stabilized on the head and directed at the middle cerebral artery.

SETTING

Outdoor patients after aortic valve replacement in a university hospital.

PATIENTS

The study cohort comprised a random transverse sample of patients and included 20 patients with a mechanical aortic valve and 20 with a homograft aortic valve. Comparisons were made with 20 admitted control patients.

INTERVENTIONS

No interventions.

MEASURES

No significant number of HITS were expected in the homograft group and a limited number in the mechanical valve group.

RESULTS

HITS were detected in more patients after implantation of a mechanical aortic valve prosthesis compared with a homograft aortic valve (16 versus 8, p=0.02). Nevertheless, more patients with a homograft aortic valve showed HITS than the control patients (8 versus 1, p=0.02). The mean number of HITS in the mechanical prosthesis group was higher than in the homograft group (3, range 0-18 versus 13, range 0-70, p<0.05). HITS in patients with mechanical prostheses had a higher amplitude than HITS in patients with homograft aortic valves (p<0.0001). Focal neurological deficit (FND) was diagnosed in 9 patients (mechanical prosthesis 6 versus homograft 3, ns).

CONCLUSIONS

HITS commonly occur both in patients with a mechanical aortic valve and in patients with a homograft aortic valve. HITS occur significantly less often, at a lower rate and with a lower intensity in patients with homograft aortic valve compared with patients with a mechanical aortic valve. Future studies should elucidate the nature and prognostic significance of HITS and their relationship with thromboembolic events.