Incidence and occurrence of total (first-ever and recurrent) stroke

Pregnancy and delivery after right common carotid artery endarterectomy

BACKGROUND

Carotid artery atherosclerosis and essential hypercholesterolemia can add a predisposing risk factor for coagulation in pregnancy. Careful management of anticoagulation during labor, delivery, and puerperium is called for in such a case.

CASE

A 41-year-old woman, gravida 2, para 1, with a previous endarterectomy at the right common carotid artery because of atherosclerotic plaques, underwent anticoagulation studies and prophylactic antithrombotic therapy. Low-molecular-weight heparin was administrated during pregnancy and puerperium. She successfully delivered by cesarean at 36 weeks of gestation.

CONCLUSION

Low-molecular-weight heparin treatment is an effective and safe therapy in pregnancy. The healthy course of therapy, delivery, and puerperium reported here is a reference that may support women with a similar history.

Influence of formaldehyde impurity in polysorbate 80 and PEG-300 on the stability of a parenteral formulation of BMS-204352: identification and control of the degradation product

The purpose of this study was to identify a degradation product formed in the clinical parenteral formulation of BMS-204352, investigate the role of excipients in its formation, and develop a strategy to minimize/control its formation. The degradant was identified as the hydroxy methyl derivative (formaldehyde adduct, BMS-215842) of the drug substance based upon liquid chromatography/mass spectroscopy (LC/MS), liquid chromatography/mass spectroscopy/mass spectroscopy (LC/MS/MS), nuclear magnetic resonance (NMR), and chromatographic comparison to an authentic sample of hydroxymethyl degradation product, BMS-215842. An assay method for the detection of formaldehyde based on HPLC quantitation of formaldehyde dinitrophenylhydrazone was developed to quantitate its levels in various Polysorbate 80 and PEG 300 excipient lots. A direct relationship between the levels of formaldehyde in the excipients and the formation of the hydroxymethyl degradant was found. To confirm the hypothesis that the formaldehyde impurity in these two excipients contributed to the formation of the hydroxymethyl degradant, several clinical formulation lots were spiked with formaldehyde equivalent to 1, 10, and 100 mg/g of BMS-204352. A correlation was found between the formaldehyde level and the quantity of the hydroxymethyl degradant formed upon storage at 5 and 25 degrees C. From these experiments, a limit test on the formaldehyde content in polysorbate 80 and PEG 300 can be set as part of a strategy to limit the formation of the degradation product.

Function and clustered expression of MaxiK channels in cerebral myocytes remain intact with aging

The incidence of stroke increases significantly in the aging population where stroke related deaths boost at >75 years and survivors are often permanently disabled. Aging is known to decrease cerebral blood flow likely due to an increase in arterial tone. Although MaxiK channels are key regulators of cerebral arterial tone their pattern of expression and function in cerebral blood vessels during aging is unknown. Using specific antibodies against the alpha-subunit of MaxiK channels and current recordings, we now demonstrate that in aging cerebral myocytes, MaxiK channels remain healthy. Furthermore, we show for the first time that in the vasculature, MaxiK channels are expressed in clusters. Clusters have an estimated radius of approximately 200 nm in young rats (3-5 month old Fisher 344 rats) which remains normal in old (25-30 month rats) cerebral myocytes. Consistent with a healthy MaxiK channel expression in old cerebral arteries, MaxiK current density, kinetics and Ca(2+) sensitivity were practically identical in young and old myocytes. Sensitivity to nanomolar concentrations of dehydrosoyasaponin-I that activates channels formed by alpha and beta subunits is also the same in young and old myocytes. These results demonstrate that MaxiK channels maintain normal expression during cerebral aging which is in sharp contrast to our previous finding of loss of expression in aging coronary arteries. It seems therefore, that cerebral myocytes have developed a protective anti-aging mechanism leading to the continued expression of MaxiK channels.

Ximelagatran: Pharmacology, Pharmacokinetics, and Pharmacodynamics

Thromboembolism is the largest cause of morbidity and mortality in the western world, yet oral anticoagulation is currently available only with vitamin K antagonists--most often, warfarin. Warfarin has been used for treatment of thrombotic disease for about 50 years. However, despite its widespread use, it is associated with several limitations, such as varied patient response, a narrow therapeutic window, numerous drug and food interactions, and need for frequent therapeutic monitoring. In addition, its full anticoagulant effect usually takes at least 4-5 days after the start of therapy or any dosage change, and it has a slow offset of therapy. A new oral anticoagulant, ximelagatran, has considerable advantages compared with warfarin. The agent requires no therapeutic monitoring, has a wide therapeutic window, and is not known to interact with food or drugs. The advantages ximelagatran brings to clinical practice should be a welcome addition to the options for management of thrombotic disease.

Carotid endarterectomy at the millennium: what interventional therapy must match

OBJECTIVES

Carotid endarterectomy (CEA) is supported by level 1 evidence as the standard treatment of severe carotid stenosis in both symptomatic and asymptomatic patients. As interventional techniques are emerging for treatment of this disease, this study was undertaken to provide a contemporary surgical standard for comparison to carotid stenting.

PATIENTS AND METHODS

During the interval 1989 to 1999, 2236 isolated CEAs were performed on 1897 patients (62% male, 36% symptomatic, 4.6% reoperative procedures). Study endpoints included perioperative events, patient survival, late incidence of stroke, anatomic durability of CEA, and resource utilization changes during the study. Variables associated with complications, long-term and stroke free survival, restenosis, and resource utilization were analyzed by univariate and multivariate analysis.

RESULTS

Perioperative complications occurred in 5.5% of CEA procedures, including any stroke/death (1.4%), neck hematoma (1.7%), cardiac complications (0.5%), and cranial nerve injury (0.4%). Actuarial survival at 5 and 10 years was 72.4% (95% confidence interval [CI] 69.3-73.5) and 44.7% (95% CI 41.7-47.9) respectively, with coronary artery disease (P < 0.0018), chronic obstructive pulmonary disease (P < 0.00018) and diabetes mellitus (P < 0.0011) correlating with decreased longevity. The age- and sex-adjusted incidence of any stroke during follow-up was reduced by 22% (upper 0.35, lower 0.08) of predicted with the patient classification of hyperlipidemia (P < 0.0045) as the only protective factor. Analysis of CEA anatomic durability during a median follow-up period of 5.9 years identified a 7.7% failure rate (severe restenosis/occlusion, 4.5%; or reoperative CEA, 3.2%) with elevated serum cholesterol (P < 0.017) correlating with early restenosis. Resource utilization diminished (first versus last 2-year interval periods) for average hospital length of stay from 10.3 +/- 1.5 days to 4.3 +/- 0.7 days (P < 0.01) and preoperative contrast angiography from 87% +/- 1.4% to 10.3% +/- 4%.

CONCLUSIONS

These data delineate the safety, durability, and effectiveness in long-term stroke prevention of CEA. They provide a standard to which emerging catheter-based therapies for carotid stenosis should be compared.

Reliability and validity testing of the short self-efficacy and outcome expectation for exercise scales in stroke survivors

Self-efficacy has been noted to have a significant impact on exercise behaviors across several clinical conditions, but the influence of self-efficacy and outcome expectations on exercise behaviors in stroke survivors is unknown. This study investigates the reliability and validity of the Short Self-Efficacy for Exercise (SSEE) and Short Outcome Expectations for Exercise (SOEE) scales in stroke survivors and their relationship to regular exercise. A total of 1200 surveys were mailed to stroke support groups throughout North America, with 211 respondents reporting an average age of 66 years and a mean time from stroke of 5.8 years. There was evidence for internal consistency with alpha coefficients of .86 for the SSEE and .90 for the SOEE. Reliability was also estimated using structural equation modeling, and a squared multiple correlation coefficient (R(2)) was used as the estimate of reliability. R(2) values ranged from .38 to .70 in the SSEE and from .47 to .78 in the SOEE. There was evidence of construct validity based on significant lambda values for all items onto their respective constructs. Likewise, there was evidence of construct validity of the SSEE and the SOEE; self-efficacy expectations significantly influenced exercise and accounted for 13% of the variance in exercise, and outcome expectations explained an additional 2% of the variance in exercise, supporting that the SOEE and the SSEE are reliable and valid scales. Measuring these expectations related to exercise post-stroke can establish their influence on exercise behavior and lead to interventions to strengthen these beliefs and improve exercise behavior.

Life review therapy as an intervention to manage depression and enhance life satisfaction in individuals with right hemisphere cerebral vascular accidents

This pilot study sought to determine if the use of Life Review Therapy would result in lower levels of depression and higher degrees of life satisfaction in individuals with right hemisphere cerebral vascular accidents (CVAs). Fourteen subjects in a southern rehabilitation center were randomly assigned to either an experimental or control group. The experimental group received three one-hour sessions of Life Review Therapy and the control group viewed three one-hour sessions of neutral video with a follow-up discussion. Following the third session of each group, subjects were administered the Zung Scale for Depression and the Life Satisfaction Index--Form Z. A one-way ANOVA revealed a significantly lower level of depression (p <.01) and a significantly higher degree of life satisfaction (p <.01) in the Life Review Therapy group.

Amide N-glucuronidation of MaxiPost catalyzed by UDP-glucuronosyltransferase 2B7 in humans

MaxiPost [(3S)-(+)-(5-chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluoromethyl)-2H-indole-2-one), or BMS-204352)] is a potent and specific maxi-K channel opener for potential use to treat stroke. This article describes structural characterization of a major human N-glucuronide metabolite of BMS-204352 and identification of the enzyme responsible for the N-glucuronidation reaction. After intravenous administrations of [(14)C]BMS-204352 (10 mg, 50 microCi) to eight healthy human subjects, one major metabolite M representing an average of 17% of the radioactive dose was excreted in pooled urine collected over 0 to 336 h after dosing. A major biliary metabolite of dogs dosed with [(14)C]BMS-204352 (5 mg/kg), which represented about 33% of the dose, has the same retention time and the same tandem mass spectrometry fragmentation pattern as the human urinary metabolite M. Four hundred fifty micrograms of the metabolite was isolated from the dog bile and analyzed by NMR. Long-range (1)H-(13)C NMR experimentation indicated that the glucuronic acid moiety was at the nitrogen site. The N-glucuronide of BMS-204352 was stable up to 24 h at 37 degrees C in the incubations at different pH values (3.0, 7.4, and 9.0) and with glucuronidases from Escherichia coli and Helix pomatia. Of the seven human UDP-glucuronosyltransferases (UGT) isozymes (1A1, 1A3, 1A4, 1A6, 1A7, 1A10, and 2B7) tested, only UGT2B7 produced metabolite M. UGT2B7-catalyzed N-glucuronidation of BMS-204352 exhibited Michaelis-Menten kinetics with a K(m) of 14.2 microM and V(max) of 0.29 nmol/min. mg of protein. Collectively, these results suggest that amide N-glucuronidation, a major elimination pathway of MaxiPost, is catalyzed by UGT2B7 in humans. This N-glucuronide represents a fully characterized amide N-glucuronide, and glucuronidation at the nitrogen represents a newly identified conjugation reaction for UGT2B7.

Bioequivalence of ximelagatran, an oral direct thrombin inhibitor, as whole or crushed tablets or dissolved formulation

OBJECTIVE

To investigate whether crushed or dissolved tablets of the oral direct thrombin inhibitor ximelagatran are bioequivalent to whole tablet administration. Ximelagatran is currently under development for the prevention and treatment of thromboembolic disorders.

RESEARCH DESIGN AND METHODS

This was an open-label, randomised, three-period, three-treatment crossover study in which 40 healthy volunteers (aged 20-33 years) received a single 36-mg dose of ximelagatran administered in three different ways: I swallowed whole, II crushed, mixed with applesauce and ingested and III dissolved in water and administered via nasogastric tube.

RESULTS

The plasma concentrations of ximelagatran, its intermediates and the active form melagatran were determined. Ximelagatran was rapidly absorbed and the bioavailability of melagatran was similar after the three different administrations, fulfilling the criteria for bioequivalence. The mean area under the plasma concentration-versus-time curve (AUC) of melagatran was 1.6 micromol.h/L (ratio 1.01 for treatment II/I and 0.97 for treatment III/I), the mean peak concentration (C(max)) was 0.3 micromol/L (ratio 1.04 for treatment II/I and 1.02 for treatment III/I) and the mean half-life (t(1/2)) was 2.8 h for all treatments. The time to C(max) (t(max)) was 2.2h for the whole tablet and approximately 0.5 h earlier when the tablet was crushed or dissolved (1.7-1.8 h), due to a more rapid absorption. The study drug was well tolerated as judged from the low incidence and type of adverse events reported.

CONCLUSION

The present study showed that the pharmacokinetics (AUC and C(max)) of melagatran were not significantly altered whether ximelagatran was given orally as a crushed tablet mixed with applesauce or dissolved in water and given via nasogastric tube.

Poststroke motor dysfunction and spasticity: novel pharmacological and physical treatment strategies

Following stroke, approximately 90% of patients experience persistent neurological motor deficits that lead to disability and handicap. Both pharmacological and physical treatment strategies for motor rehabilitation may be considered. In terms of pharmacological treatment, drugs that may potentially promote motor recovery when added to a regimen of physical therapy include the stimulants amphetamine and methylphenidate, as well as levodopa and fluoxetine. Botulinum toxin A has proven effective and well tolerated in several placebo-controlled trials for the treatment of focal upper and lower limb spasticity, although it has not been shown to improve motor function. The focal injection of botulinum toxin A inhibits the release of acetylcholine into the synaptic cleft, resulting in a reversible paresis of the muscles relevant for the spastic deformity. Other drugs, such as benzodiazepines, antiepileptic drugs and antipsychotics, may have detrimental effects on motor function and should be avoided, if possible. With respect to physical strategies, modern concepts of motor learning favour a task-specific repetitive approach that induces skill-acquisition relevant to the patient's daily life. Constrained-induced movement therapy based on the concept of learned non-use, electromyography-triggered electrical stimulation of the wrist muscles, robot-assisted motor rehabilitation to increase therapy intensity and bilateral practice to facilitate the movement of the paretic extremity are examples in upper limb rehabilitation. Lower limb rehabilitation has been enriched by treadmill training with partial bodyweight support, enabling the practice of up to 1000 steps per session; automated gait rehabilitation to relieve the strenuous effort required of the therapist; and rhythmic auditory stimulation, applying individually adjusted music to improve walking speed and symmetry.

De Novo Neurogenesis and Acute Stroke: Are Exogenous Stem Cells Really Necessary?

RECENT STUDIES DOCUMENTING the phenomenon of de novo neurogenesis within the adult brain have propelled this area of research to the forefront of neuroscience investigations and stroke pathogenesis and treatment. Traditional theories have suggested that the central nervous system is incapable of neural regeneration; hence the emergence of the field of stem cell biology as a discipline devoted to uncovering novel forms of neural repair. However, several recent experimental observations have shown that the adult brain is capable of ongoing neurogenesis in discrete regions of the uninjured brain and additional forms of endogenous neural regeneration in the presence of an inciting event (induction neurogenesis). Induction neurogenesis has the potential for providing new insights into the cause and treatment of acute stroke syndromes.

Understanding stroke recovery and rehabilitation: Current and emerging approaches

Although stroke is the third leading cause of death in the United States, it is the significant disability among survivors that has the greatest impact on healthcare and society. It is currently accepted that comprehensive rehabilitation programs improve outcome following stroke. We are now trying to discern which specific therapeutic approaches work and which do not. Years of animal research have resulted in a better understanding of what occurs in the brain following stroke and how the brain may reorganize in response to treatment. Repetitive use of the involved extremities appears key to optimal behavioral recovery and optimal brain reorganization. The advent of technology such as functional magnetic resonance imaging and transcortical magnetic stimulation has allowed the study of brain reorganization following stroke and rehabilitation in humans. Certain drugs also appear to influence neuroplasticity after stroke. Timing of therapy and drug delivery appears crucial; the optimal "critical period" has not yet been clearly identified. New approaches are slow to reach widespread adoption. Neural transplantation combined with repetitive training approaches produces behavioral recovery in animals and offers hope for the future.

Long-lasting functional disabilities in middle-aged rats with small cerebral infarcts

Recommendations from experts and recently established guidelines on how to improve the face and predictive validity of animal models of stroke have stressed the importance of using older animals and long-term behavioral-functional endpoints rather than relying almost exclusively on acute measures of infarct volume in young animals. The objective of the present study was to determine whether we could produce occlusions in older rats with an acceptable mortality rate and then detect reliable, long-lasting functional deficits. A reversible intraluminar suture middle cerebral artery occlusion (MCAO) procedure was used to produce small infarcts in middle-aged rats. This resulted in an acceptable mortality rate, and robust disabilities were detected in functional assays, although the degree of total tissue loss measured 90 d after MCAO was quite modest. Infarcted animals were functionally impaired relative to sham control animals even 90 d after the occlusions, and when animals were subgrouped based on amount of tissue loss, MCAO animals with only 4% tissue loss exhibited enduring neurological-behavioral impairments relative to sham-operated controls, and the functional impairments in the group with the largest infarcts (20% tissue loss) were more severe than the functional impairments in the rats with 4% tissue loss. These results suggest that this model, using reversible MCAO to produce small infarcts and long-lasting functional-behavioral deficits in older rats, may represent an advance in the relatively higher-throughput modeling of stroke and its recovery in rodents and may be useful in the development and characterization of future stroke therapies.

Stroke

The search for evidence-based treatments has resulted in an exciting new era for neurorehabilitation intervention strategies for stroke. Although stroke rehabilitation research poses many methodologic challenges, evaluation of stroke rehabilitation interventions is clearly moving beyond descriptive and observational studies toward well designed randomized clinical trials. The goals of this article are to summarize issues of trial design for stroke rehabilitation, to discuss promising stroke rehabilitation treatments currently undergoing rigorous evaluation, and to present treatments that may be candidates for randomized clinical trials in the future on the basis of promising preliminary data. Several examples of new developments in neuroscience research that are leading to possible rehabilitation interventions will be discussed. New modalities to evaluate the response of neural networks to rehabilitation interventions are also reviewed.

Relation among stroke knowledge, lifestyle, and stroke-related screening results

Stroke is a leading cause of individual and public health burden in the United States. A better understanding of the relation among stroke knowledge, lifestyle, and stroke-related screening results may be useful for improving prevention efforts. This paper assesses the relation among demographics, lifestyle, stroke awareness, and the presence of stroke risk factors determined by screening tests for a select elderly population. A population of 322 participants in the 1999 World Senior Games received 1 or more free screening tests and completed a stroke awareness questionnaire. Results indicate that stroke education efforts should be targeted at the very elderly, those who have less than a college education, and those who do not have a history of chronic disease. It also may be effectively directed toward those with higher cholesterol.

Reliability of treadmill exercise testing in older patients with chronic hemiparetic stroke11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or any organization with which the authors are associated

OBJECTIVE

To assess the test-retest reliability of cardiopulmonary measurements during peak effort and submaximal treadmill walking tests in older patients with gait-impaired chronic hemiparetic stroke.

DESIGN

Nonrandomized test-retest.

SETTING

Hospital geriatric research stress testing laboratory.

PARTICIPANTS

Fifty-three subjects (44 men, 9 women; mean age, 65+/-8y) with chronic hemiparetic gait after remote (>6mo) ischemic stroke. Patients had mild to moderate chronic hemiparetic gait deficits, making handrail support necessary during treadmill walking.

INTERVENTIONS

Peak effort and submaximal effort treadmill walking tests were conducted and then repeated on a separate day at least a week later. Main outcome measures Reliability coefficients (r) were calculated for heart rate, systolic blood pressure (SBP), oxygen consumption (Vo(2) [L/min]), Vo(2) (mL.kg(-1).min(-1)), respiratory exchange ratio (RER), rate-pressure product (RPP), and oxygen pulse during peak effort testing. The reliability coefficients for all but SBP and RPP data were calculated from the submaximal tests.

RESULTS

Heart rate (r=.87), Vo(2)peak (L/min) (r=.92), Vo(2)peak (mL.kg(-1).min(-1)) (r=.92), and oxygen pulse (r=93) were highly reliable parameters during maximal testing in this population. Submaximal testing produced highly reliable results for V.o(2) (L/min) (r=.89) and oxygen pulse (r=.85). All cardiopulmonary measures except RER had a reliability coefficient greater than.80 during submaximal testing in this population.

CONCLUSION

Our study provides the first evidence that peak effort treadmill testing provides highly reliable oxygen consumption measures in chronic hemiparetic stroke patients using minimal handrail support. The submaximal tests were at or near the threshold level of reliability for the 2 most important measures of V.o(2) (L/min) and V.o(2) (mL.kg(-1).min(-1)) (r=.89, r=.84, respectively), with the remaining measures falling above.70.

Protein covalent binding of maxipost through a cytochrome P450-mediated ortho-quinone methide intermediate in rats

(3S)-(+)-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluoromethyl)-2H-indole-2-one) (MaxiPost, BMS-204352) is a potent and specific opener for maxi-K channels and has potential to prevent and treat ischemic stroke. Following single intravenous doses of [14C]BMS-204352 to rats, only 10 to 12% of radioactivity was extractable from plasma with organic solvents. The unextractable radioactivity remained associated with the proteins (mostly albumin) after SDS-polyacrylamide gel electrophoresis or dialysis. Following acid hydrolysis in 6 M HCl for 24 h at 110 degrees C from plasma proteins collected from nine rats dosed with [14C]BMS-204352, one major radioactive product was isolated and identified as a lysine-adduct of des-fluoro des-O-methyl BMS-204352 by liquid chromatography/mass spectrometry and NMR analyses as well as by comparison with the synthetic analog, lysine-adduct of des-fluoro BMS-204352 (BMS-349821). The covalent binding of BMS-204352 results from the displacement of the ring-fluorine atom of des-O-methyl BMS-204352 with the epsilon-amino group of a lysine residue. Microsomal incubations of [14C]BMS-204352 resulted in low levels of covalent binding of radioactivity to proteins. This in vitro covalent binding required cytochrome P450-reductase cofactor NADPH and was attenuated by glutathione. P4503A inhibitors ketoconazole and troleadomycin selectively prevented the covalent binding in vitro. Based on these observations, a two-step bioactivation process for the protein covalent binding of BMS-204352 was postulated: 1) P4503A-mediated O-demethylation leading to spontaneous release of HF and the formation of an ortho-quinone methide reactive metabolite and 2) nucleophilic addition of the epsilon-amino group of protein lysine residue(s) in protein to form des-fluoro des-O-methyl BMS-204352 lysine adduct.

Influence of age on the pharmacokinetics and pharmacodynamics of ximelagatran, an oral direct thrombin inhibitor

OBJECTIVE

To investigate the influence of age on the pharmacokinetics and pharmacodynamics of ximelagatran.

STUDY DESIGN

This was an open-label, randomised, 3 x 3 crossover study with 4 study days, separated by washout periods of 7 days.

SUBJECTS

Subjects comprised 6 healthy young men (aged 20-27 years) and 12 healthy older men and women (aged 56-70 years).

METHODS

All subjects received a 2mg intravenous infusion of melagatran over 10 minutes followed, in randomised sequence, by a 20 mg immediate-release tablet of ximelagatran with breakfast, a 20 mg immediate-release tablet of ximelagatran while fasting, and a 7.5 mg subcutaneous injection of ximelagatran. The primary variables were the plasma concentration of melagatran, the active form of ximelagatran, and the activated partial thromboplastin time (APTT), an ex vivo coagulation time measurement used to demonstrate inhibition of thrombin.

RESULTS

After oral and subcutaneous administration, ximelagatran was rapidly absorbed and biotransformed to melagatran, its active form and the dominant compound in plasma. The metabolite pattern in plasma and urine was similar in young and older subjects after both oral and subcutaneous administration of ximelagatran clearance of melagatran was correlated with renal function, resulting in about 40% (after intravenous melagatran) to 60% (after oral and subcutaneous ximelagatran) higher melagatran exposure in the older than in the young subjects. Renal clearance of melagatran, was 7.7 L/h and 4.9 L/h in the younger and older subjects, respectively. The interindividual variability inn the area under the melagatran plasma concentration-time curve was low following all regimens (coefficient variation 12-25%). The mean bioavailability of melagatran in young and older subjects was approximately 18 and 12% , respectively, following oral administration of ximalagratan, and 38 and 45%, respectively, following subcutaneous administration of ximelagatran. The bioavailability of melagatran following oral administration of ximelagatran was unaffected by whether subjects were fed or fasting, although the plasma concentration of melagatran peaked about 1 hour later under fed than fasting conditions, due to gastric emptying of the immediate-release tablet formulation used. The APTT as prolonged with increasing melagatran plasma concentration-effect relationship was independent of age.

CONCLUSIONS

There were no age-dependent differences in the absorption and biotransformation of ximelagatran, and the observed differences in exposure to melagatran can be explained by differences in renal function between the young and older subjects.

Synthesis of water-soluble prodrugs of BMS-191011: a maxi-K channel opener targeted for post-stroke neuroprotection

A variety of water-soluble prodrugs of BMS-191011 was synthesized and evaluated for solution state stability and rate of conversion to BMS-191011 in rat and human plasma. The deoxycarnitine ester prodrug (11c) was selected for clinical evaluation based on its superior chemical stability, crystallinity and cleavage to BMS-191011 in human plasma.

Pharmacokinetics and pharmacodynamics of ximelagatran, a novel oral direct thrombin inhibitor, in young healthy male subjects

OBJECTIVES

Ximelagatran is a novel, oral direct thrombin inhibitor designed to overcome the low and variable oral absorption of melagatran, its active form. The pharmacokinetics and pharmacodynamics of ximelagatran following single and repeated oral administration were investigated. The primary objectives were to determine the dose linearity and reproducibility of melagatran exposure and the influence of food intake.

METHODS

Two open-label studies were performed in healthy male subjects. Study I was a dose-escalation study, in which subjects received single oral doses of ximelagatran (1-98 mg). Study II was a randomised, two-way crossover study consisting of two 5-day treatment periods, in which subjects received a 20-mg oral dose of ximelagatran twice daily, either before breakfast and with dinner, or with breakfast and after dinner.

RESULTS

Ximelagatran was rapidly absorbed and converted to melagatran, which was the predominant compound in plasma. The mean (+/- standard deviation) bioavailability of melagatran was 22.2+/-4.3% and 17.4+/-2.8% after single and repeated dosings, respectively. The maximum plasma concentration of melagatran and the area under the melagatran plasma concentration-time curve (AUC) increased linearly with dose. Inter- and intra-subject variability in melagatran AUC was 8% and 12%, respectively, with no relevant food- or time dependence. Anticoagulation, assessed as activated partial thromboplastin time, was correlated with melagatran plasma concentration. There was virtually no increase in capillary bleeding time over the dose range studied, and ximelagatran was well tolerated.

CONCLUSION

After oral administration of ximelagatran to healthy male subjects, the pharmacokinetic and pharmacodynamic profile of melagatran is predictable and reproducible.

Prognostic use of circulating plasma nucleic acid concentrations in patients with acute stroke

BACKGROUND

At present there is no simple, accurate blood test that may be used to determine the severity of stroke or to predict mortality and morbidity in stroke patients presenting to emergency departments.

METHODS

Patients with stroke-like symptoms who presented to an emergency department of a university hospital in Hong Kong were recruited for the study. DNA extracted from patients' plasma was analyzed for the beta-globin gene with a fluorescent-based PCR test. The primary outcome measures were in-hospital and 6-month mortality and morbidity using the post-stroke modified Rankin Score.

RESULTS

Among the 88 consecutive patients recruited to the study, 70 (80%) had ischemic stroke, 11 (13%) had intracerebral hemorrhage, and 7 (8%) had transient ischemic attacks. Median plasma DNA concentrations taken within 3 h of symptom onset were higher in patients who died compared with those who survived at discharge (6205 vs 1334 kilogenome-equivalents/L; P = 0.03). Among patients with NIH Stroke Scale scores >8, median plasma DNA concentrations were higher in patients who died compared with those who survived to 6 months (2273 vs 968 kilogenome-equivalents/L; P = 0.002). Plasma DNA concentrations correlated with the volume of cerebral hematoma (r = 0.66; P = 0.03). Plasma DNA concentrations >1400 kilogenome-equivalents/L had a sensitivity of 100% and a specificity of 74.4% for predicting hospital mortality after stroke, and the area under the ROC curve was 0.89 (95% confidence interval, 0.80-0.94). The adjusted odds ratio for plasma DNA concentrations predicting 6-month mortality was 1.6 (1.1-2.4; P = 0.03) and for predicting 6-month post-Rankin Score >2 was 1.8 (1.0-3.3; P = 0.05).

CONCLUSION

Plasma DNA concentrations correlate with stroke severity and may be used to predict mortality and morbidity in the emergency room.

A single bout of walking exercise enhances endogenous fibrinolysis in stroke patients

PURPOSE

Impaired endogenous fibrinolysis is an important predictor for increased risk of stroke and myocardial infarction. Acute exercise can enhance fibrinolysis, primarily by stimulating short-term increases in plasma tissue plasminogen activator (tPA), which is postulated to protect against atherothrombotic events. No prior studies have examined the fibrinolytic response to exercise in stroke survivors despite their high risk for recurrent stroke and myocardial infarction. The purpose of this study was to assess the fibrinolytic response to acute submaximal exercise in chronic hemiparetic stroke patients.

METHODS

Eighteen (16 men, 2 women) untrained stroke patients with chronic hemiparetic gait deficits volunteered for participation in this single session exercise study. Fasting blood samples for determination of tPA and plasminogen activator inhibitor (PAI-1) enzyme activities were obtained before, immediately after, and 60 min after submaximal treadmill walking. Patients walked at 60% maximal heart rate reserve (low-moderate intensity) for a cumulative total of 20 min.

RESULTS

The exercise bout increased tPA activity by 79% (P < 0.01) and decreased PAI-1 activity by 18% (P < 0.01). At 1 h after completing the walking exercise, plasma tPA activity levels were still significantly elevated (43%,P < 0.01), and PAI-1 activity levels were 25% lower (P < 0.01) than baseline.

CONCLUSIONS

These findings demonstrate that a single bout of aerobic walking exercise can improve fibrinolysis profiles in chronic stroke patients. Significant increases in endogenous tPA and reductions in PAI-1 activity persist for at least 1 h after exercise cessation. The implications are that alterations in physical activity during the day may modify clot lysing potential, thereby affecting atherothrombotic risk.

High-risk carotid endarterectomy: fact or fiction

OBJECTIVE

It has been proposed that patients whose conditions do not meet North American Symptomatic Carotid Endarterectomy Trial inclusion criteria or have anatomic risk factors constitute a "high-risk" group for carotid endarterectomy (CEA) and might be candidates for primary carotid angioplasty stenting. Our objective was to review a consecutive series of isolated CEAs, identify the number of such patients at high risk, and determine whether their operations were associated with increased complication rate.

METHODS

Consecutive isolated CEAs performed between June 1996 and June 2001 were reviewed. High-risk comorbidities included: age 80 years or more (n = 80), New York Heart Association class III/IV angina (n = 16), Canadian class III/IV heart failure (n = 4), myocardial infarct 6 months or less (n = 11), steroid-dependent or oxygen-dependent pulmonary disease (n = 4), and creatinine level of 3 or more (n = 13). Anatomic high risk was defined by: contralateral occlusion (n = 66), lesion above C(2) or requirement of digastric division (n = 53), reoperation (n = 29), and neck radiation (n = 3). Statistical analysis was with chi(2) analysis.

RESULTS

Of 788 patients reviewed, 228 (29%) were classified as high risk by one or more of the previous criteria (63% comorbidity, 28% anatomy, 9% both). Presence of preoperative neurologic symptoms and postoperative results were similar across all patient groups. The total stroke and death rate was 1.1% for all the patients. Six patients had postoperative strokes (0.8%), and three patients died of myocardial infarcts (0.4%). The stroke and death rate was 1.3% in the high-risk group as compared with 1.1% in the normal-risk group (P =.51).

CONCLUSION

The concept of the high-risk CEA must be critically reexamined. Although 29% of patients for CEA were high risk as defined by others, we found no evidence that this influenced the results after CEA. Patients with significant medical comorbidities, contralateral carotid occlusion, and high carotid lesions can undergo operation without increased complications. If a high-risk group exists, it is small and restricted to reoperation or radiated neck (4% in this series). With this possible exception, carotid angioplasty stenting should be restricted to randomized clinical trials.

[Antilipemics and prevention of cerebrovascular accidents. Meta-analysis]

BACKGROUND

Previous overviews have suggested that the HMG-CoA reductase inhibitors (statins), but not other lipid lowering therapies (LLTs), may reduce stroke incidence in coronary patients. Our objective was to investigate the amplitude and sources of heterogeneity of LLT effects on stroke prevention.

METHODS

A literature search was performed from 1966-2001 to identify all English-language published trials testing LLT. We then conducted a meta-analysis including randomised primary and secondary coronary heart disease prevention trials, which tested statins, nonstatins, diet or other interventions, and providing data on stroke incidence.

RESULTS

The overall meta-analysis (38 individual trials, 83,161 patients, mean follow-up of 4.7 years) showed a significant relative risk reduction (RRR) of strokes by LLTs of 17% (p < 0.001), without significant heterogeneity between trials and between subgroups according to either the type of prevention (primary or secondary prevention) or type of LLT. Most demonstrative effects was obtained however with statins (RRR = 26%). Effect model analysis showed that the treatment benefits appeared constant whatever the risk of stroke, suggesting that LLTs may be effective in a population with a higher risk of stroke. Weighted regression showed a significant correlation between the RRR of stroke and total cholesterol levels (baseline, final, and change). Only final cholesterol level allowed a clear separation between benefit (RRR > 0) and no effect (RRR < 0) of LLTs on stroke incidence, with a cut-off for benefit of 6.0 mmol/L.

CONCLUSION

LLTs reduce stroke incidence in coronary patients, especially when total cholesterol is under 6.0 mmol/L, this explains the better results obtained with statins.

Correlating carotid artery stenosis detected by panoramic radiography with clinically relevant carotid artery stenosis determined by duplex ultrasound

OBJECTIVE

We sought to assess the utility of panoramic radiography as an adjunct screening tool for detecting significant asymptomatic carotid artery stenosis. The specific aim was to correlate calcifications seen in the region of the carotid bifurcation with clinically relevant carotid artery stenosis as determined by duplex ultrasound (DUS).

STUDY DESIGN

Routine dental panoramic films of patients 55 and older (n = 778) at the University of Rochester Eastman Dental Center were retrospectively reviewed for calcifications around the carotid bifurcation. Patients with such calcifications were referred for DUS, and raw data were interpreted by a vascular surgeon blinded to the radiographic findings. Groups were compared by using the chi(2) test.

RESULTS

Twenty-seven patients (3.5%) had suggestive radiographic calcifications on one or both sides, 20 of whom consented to DUS. Clinically significant carotid stenoses (>50% lumenal narrowing) were present in 50% of the sides with calcification compared with 21% of the sides without (P =.08, chi(2)). Three patients (15% of those screened with DUS) had stenoses greater than 80% and underwent 4 carotid endarterectomies as a direct result of screening.

CONCLUSIONS

Data suggest that clinically significant stenosis may exist if calcifications are observed on panoramic radiographs. Incidental examination of this area carries a minimal cost and appears beneficial as a screening tool for carotid disease, although definitive testing must follow.

Vitamin intervention for stroke prevention

Vitamin Intervention for Stroke Prevention (VISP) is designed to determine whether the utilization of folic acid, vitamins B(6) and B(12), in addition to other risk factor reducing measures, have a demonstrable effect on prevention of recurrent stroke. The entry criteria are a first-ever nondisabling stroke, the patient signs informed consent with willingness to participate and randomization to a high- or low-dose vitamin intervention regimen. Case acquisition of 3,688 individuals has been completed, half in the high-dose and the other half in the low-dose intervention arm. Follow-up is in progress and the end results are expected within the year. The Vitamins to Prevent Stroke (VITATOPS) is a parallel study based in Australia with similar goals, and, hopefully, the data from the two will be comparable and supportive.

Performance-based gait tests for acute stroke patients

OBJECTIVE

Qualitative measures may not differentiate severity of deficits after an acute or subacute stroke. The aim of this study was to contrast the utility of performance-based gait tests with qualitative measures in a sample of acute stroke patients.

DESIGN

Twenty acute stroke subjects had their performance-based gait measured by gait speed, walking distance, gait energy expenditure, and gait energy cost. They were also qualitatively evaluated for cognition, functional outcomes, motor impairment, and Functional Ambulation Category.

RESULTS

Strong and significant correlations were observed among performance-based gait tests. Qualitative scales indicated moderate to minimal deficits in each domain evaluated, although they were not correlated among themselves, except for Functional Ambulation Category and FIM and FIM and Mini-Mental State Exam. Functional Ambulation Category correlated with performance-based gait tests.

CONCLUSIONS

Performance-based gait tests are feasible to conduct during early recovery after a stroke and allow better discrimination among the patients than qualitative measures.

Aneurysmal subarachnoid hemorrhage in Baltic population: experience from Latvia (1996-2000)

Better knowledge of clinical epidemiology and course of aneurysmal subarachnoid hemorrhage (ASAH) is essential for dedicated planning of the need for services. The aim of the study was to obtain a picture of epidemiology and clinical course of ASAH in Riga City (the capital of Latvia). A retrospective population-based study included residents of Riga City who suffered their first ASAH during a 5-year period from the beginning of 1996 till the end of 2000. The total number of ASAH events in the population during the study period was 292, of which 56 (19%) were fatal before reaching the hospital. There was no significant difference between age-specific incidence rates in men and women. The mean ASAH rates per 100 000 per year were 10.3 for age-adjusted incidence (in the population aged 20-79 years) and 7.2 for crude incidence. The mean age-adjusted case fatality rates were 57% for all ASAH events and 45% for those who survived admission. Our data suggest that incidence of ASAH in Baltic population can be recognized as average compared with other European regions. However, the case fatality rate of ASAH in the study population was higher than those of SAH reported from MONICA Collaborating Centers.

Transient ischemic attacks: an emergency medicine approach

Recent advances in TIA research provide emergency physicians a new understanding of the disease process. Untreated or under-treated patients with TIA are at significant risk. Prompt and thorough evaluation must be undertaken to prevent devastating harm to this group of patients. This is truly a paradigm shift for many physicians, and one area in which emergency physicians lead in education and patient advocacy. The authors wish to acknowledge Dr. Stewart Wright, Dr. Alex Schneider, and Dr. Dawn Kleindorfer for their expert review, and Amy Hess for her assistance in the preparation of this manuscript.

The synthesis and structure-activity relationships of 4-aryl-3-aminoquinolin-2-ones: a new class of calcium-dependent, large conductance, potassium (maxi-K) channel openers targeted for post-stroke neuroprotection

A series of 4-aryl-3-aminoquinoline-2-one derivatives was synthesized and evaluated as activators of the cloned maxi-K channel mSlo (hSlo) expressed in Xenopus laevis oocytes using electrophysiological methods. A brain penetrable activator of maxi-K channels was identified and shown to be significantly active in the MCAO model of stroke.

High performance liquid chromatographic-mass spectrometric assay for the quantitation of BMS-204352 in dog K(3)EDTA plasma

A high performance liquid chromatographic-mass spectrometric (LC/MS) assay was developed and validated for the determination of BMS-204352 in dog K(3)EDTA plasma. A 0.5 mL aliquot of control plasma was spiked with BMS-204352 and internal standard (IS) and buffered with 1 mL of 5 mM ammonium acetate. The mixture was then extracted with 3 mL of toluene. After separation and evaporation of the organic phase to dryness using nitrogen at 40 degrees C, the residue was reconstituted in the mobile phase and 25 microL of the sample were injected onto a Hypersil C(18) column (2 x 50 mm; 3 microm) at a flow rate of 0.5 mL/min. The mobile phase was consisted of two solvent mixtures (A and B). Solvent A was composed of 5 mM ammonium acetate and 0.1% triethylamine in 75:25 v/v water:methanol, pH adjusted to 5.5 with glacial acetic acid, and solvent B was 5 mM ammonium acetate in methanol. A linear gradient system was used to elute the analytes. The mass spectrometer was programmed to admit the de-protonated molecules at m/z 352.7 (IS) and m/z 357.9 (BMS-204352). Standard curves of BMS-204352 were linear (r(2) > or = 0.998) over the concentration range of 0.5-1000 ng/mL. The mean predicted quality control (QC) concentrations deviated less than 5.1% from the corresponding nominal values (ie 4, 80, 400 and 2000 ng/mL); the within- and between-assay precision of the assay were within 5.5% relative standard deviation. Stability of BMS-204352 was confirmed after at least three freeze/thaw cycles and BMS-204532 was stable in dog plasma when stored frozen at or below -20 degrees C for at least 16 weeks in spiked QC samples and for at least 4 1/2 weeks for in vivo study samples. BMS-204352 and IS were stable in the injection solvent at room temperature for at least 24 h. The assay was applied to delineate the pharmacokinetic disposition of BMS-204352 in dogs following a single intravenous dose administration. In conclusion, the assay is accurate, precise, specific, sensitive and reproducible for the pharmacokinetic analysis of BMS-204532 in dog plasma.

The synthesis and characterization of BMS-204352 (MaxiPost) and related 3-fluorooxindoles as openers of maxi-K potassium channels

3-Aryl-3-fluorooxindoles can be efficiently synthesized in two steps by the addition of an aryl Grignard to an isatin, followed by treatment with DAST. Oxindole 1 (BMS-204352; MaxiPost) can be isolated using chiral HPLC or prepared by employing chiral resolution. Cloned maxi-K channels are opened by 1, which demonstrates a brain/plasma ratio >9 in rats.

Differential effects of premorbid physical and emotional health on recovery from acute events

OBJECTIVES

Emotional health may have an important effect on disease onset, but there has been little work evaluating premorbid emotional health on recovery from disability that results from acute medical events. The aim of this study is to determine whether premorbid emotional health is predictive of recovery in functional ability 1 year after reporting a stroke, heart attack, or hip fracture (event).

DESIGN

A prospective cohort study of an older population-based sample from 1986 to 1992.

SETTING

Data are from baseline and six annual follow-ups of the North Carolina Established Population for Epidemiological Study of the Elderly.

PARTICIPANTS

Two hundred forty whites and blacks aged 65 and older who reported a stroke, heart attack, or hip fracture during one of the first five follow-up interviews and had an increased level of disability at that follow-up.

MEASUREMENT

Improvement in disability in activities of daily living (ADLs) 1 year postevent.

RESULTS

High depressive symptoms at baseline showed a significant association with poorer recovery in functional ability 1-year postevent after adjustments were made for sociodemographic characteristics, smoking status, ADLs at time of event, cognitive status, and prior history of disease. Compared with nondepressed subjects, depressed subjects had an odds ratio (OR) of 0.38 (95% confidence interval (CI) = 0.16-0.94) for recovery 1 year after reporting a stroke, heart attack, or hip fracture. Additionally, among subjects who reported low depressive symptoms, high positive affect was significantly associated with increased odds of recovery (OR = 2.70, 95% CI = 1.10-6.68), adjusting for the same variables.

CONCLUSIONS

Emotional health, independent of other baseline measures, is associated with recovery in functional ability 1 year after a major health event. Our findings suggest that reducing premorbid levels of depressive symptoms or increasing positive affect may help the recovery process.

Advanced cardiac life support for the new millennium

The American Heart Association has been the recognized source for Advanced Cardiac Life Support (ACLS) education for the past three decades. Since the first ACLS course, numerous revisions have been made to the management algorithms based on evolving scientific evidence. The last revisions made in August 2000 were the first international guidelines published. These guidelines reflect the intense review and analysis of scientific work and emphasize the importance of evidence-based therapies. This article outlines the major changes to ACLS guidelines for dysrhythmias, acute coronary syndromes, and acute stroke management.

Microprocessor-based ambulatory activity monitoring in stroke patients

PURPOSE

Recovery of ambulatory function after stroke is routinely assessed using standardized subject- or observer-rated instruments that do not directly measure ambulatory activities in the home-community setting. Accuracy of conventional pedometers in stroke patients is not established, limiting their application in mobility outcomes monitoring. This study investigates the accuracy and reliability of a mechanical pedometer versus microprocessor-based step activity monitoring (SAM) in gait-impaired hemiparetic stroke patients.

METHODS

Accuracy and test-retest reliability of ankle-worn SAM and belt-worn pedometer were tested directly against hand tallied stride counts and cadence during a battery of timed walks in 16 chronic hemiparetic stroke patients. Patients performed replicate 1-min floor walks at self-selected and fastest comfortable paces, and two 6-min walks on separate days.

RESULTS

SAM cadence and total stride counts are more accurate than pedometers during 1-min walks at self-selected (99 +/- 1 vs 87 +/- 11.3%, mean +/- SD, P < 0.01); fast pace (98 +/- 2.3% vs 85 +/- 15%, P < 0.01); and repeated 6-min walks performed on separate days (99 +/- 1% vs 89 +/- 12%, P < 0.01). Although SAM is highly reliable (r = 0.97, P < 0.0001) and accurate in all patients under every walking condition tested, the mechanical pedometer demonstrates this high level of accuracy in only half of stroke patients and has poor test-retest reliability (r = 0.64, P < 0.05).

CONCLUSION

SAM, but not the conventional pedometer, provides accurate and reliable measures of cadence and total stride counts in hemiparetic stroke patients. Portable microprocessor-based gait monitoring offers potential to quantitatively measure home-community-based ambulatory activity levels in this population.

Cost-effectiveness of ancrod treatment of acute ischaemic stroke: results from the Stroke Treatment with Ancrod Trial (STAT)

RATIONALE, AIMS AND OBJECTIVES

This paper describes a recent randomized controlled trial in which 42% of patients receiving ancrod attained a favourable outcome in comparison with 34% of controls. Although the above effect size corresponds to a number needed to treat (to achieve a favourable outcome) of approximately 13, intuition does not necessarily suggest what would be the overall impact of a treatment with this level of efficacy.

METHODS

The objective was to evaluate the cost-effectiveness of ancrod. Cost-effectiveness analysis of data from the Stroke Treatment with Ancrod Trial (STAT) trial was carried out. The participants were 495 patients with data on functional status at the conclusion of follow-up. Short-term results were based upon utilization and quality of life observed during the trial; these were merged with expected long-term results obtained through simulation using the Stroke Policy Model. The main outcome measure was incremental cost-effectiveness ratio.

RESULTS

Ancrod treatment resulted in both better quality-adjusted life expectancy and lower medical costs than placebo as supported by sensitivity analysis. The cost differential was primarily attributable to the long-term implications of ancrod's role in reducing disability.

CONCLUSIONS

If ancrod is even modestly effective, it will probably be cost-effective (and, indeed, cost-saving) as well. The net population-level impact of even modestly effective stroke treatments can be substantial.

Management of acute ischaemic stroke in the elderly: tolerability of thrombolytics

Stroke and its consequences are of global concern. Although stroke can affect individuals of any age, it primarily affects the elderly. It is among the leading causes of severe disability and mortality. In recent years, acute stroke has become a medical emergency requiring urgent evaluation and treatment. Effective management of patients with acute stroke starts with organisation of the entire stroke care chain, from the community and prehospital scene, through the emergency department, to a dedicated stroke unit and then to comprehensive rehabilitation. Intravenous thrombolysis with alteplase (recombinant tissue plasminogen activator; rt-PA) 0.9 mg/kg (maximum dose 90 mg) was shown to significantly improve outcome of acute ischaemic stroke, despite an increased rate of symptomatic intracerebral haemorrhage, if treatment is initiated within 3 hours after the onset of symptoms to patients who meet strict eligibility criteria. Post-marketing studies have demonstrated that intravenous alteplase can be administered appropriately in a wide variety of hospital settings. However, strict adherence to the published protocol is mandatory, as failure to comply may be associated with an increased risk of symptomatic intracerebral haemorrhage. Intra-arterial revascularisation may provide more complete restitution of flow than intravenous thrombolytic therapy and improve the clinical outcome if it can be undertaken in patients with occlusion of the middle cerebral artery, and possibly the basilar artery, within the first hours from stroke onset. However, further data are needed. Although intravenous alteplase is recommended for any age beyond 18 years, elderly patients, in particular patients aged > or = 80 years, were often excluded or under-represented in randomised clinical trials of thrombolysis, so that available data on risk/benefit ratio for the very elderly are limited. Small post-marketing series suggest that despite elderly patients over 80 years having greater pre-stroke disability, the use of intravenous alteplase in this patient group does not significantly differ in effectiveness and complications compared with the same treatment in patients aged under age 80 years. Further studies are necessary and elderly patients with acute stroke should be included in future trials of the merits of thrombolytic therapy.

Comparison of two aspirin doses on ischemic stroke in post-myocardial infarction patients in the warfarin (Coumadin) Aspirin Reinfarction Study (CARS)

The Coumadin Aspirin Reinfarction Study demonstrated that combination treatment with fixed dose warfarin (1 or 3 mg) + aspirin 80 mg was not superior to aspirin 160 mg alone after myocardial infarction for reducing nonfatal reinfarction, nonfatal stroke, and cardiovascular death. In this analysis, we examined the importance of aspirin dose in the protection against the secondary end point of ischemic stroke. The comparison arms for this analysis were warfarin 1 mg + aspirin 80 mg versus aspirin 160 mg. In the Coumadin Aspirin Reinfarction Study, 2,028 patients were randomized to aspirin 80 mg plus warfarin 1 mg, and 3,393 were randomized to aspirin 160 mg alone. A predictive model for ischemic stroke was developed using the Cox proportional-hazards model. A reduced Cox proportional-hazards model was developed to test for the effect of aspirin dose on ischemic stroke in predefined subgroups. The incidence of ischemic stroke was lower in patients treated with aspirin 160 mg than in patients treated with aspirin 80 mg + warfarin 1 mg (0.6% vs 1.1%; p = 0.0534). Age, previous stroke or transient ischemic attack, and aspirin dose were independent predictors of ischemic stroke. In addition, the highest risk patients, those with Q-wave myocardial infarction and male patients, appeared to receive greater benefit from aspirin 160 mg than from aspirin 80 mg + warfarin 1 mg. The results of this secondary analysis suggest that aspirin 160 mg is more effective than aspirin 80 mg + warfarin 1 mg in preventing ischemic stroke in post-myocardial infarction patients.

Serial [18F] fluorodeoxyglucose positron emission tomography after human neuronal implantation for stroke

OBJECTIVE

There is no known effective treatment for chronic stroke. In this report, we used positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) to map the metabolic brain response to neuronal cell implantation in the first human neuroimplantation trial for stroke.

METHODS

Twelve patients (nine men, three women; mean age +/- standard deviation, 60.8+/-8.3 yr) with chronic basal ganglia infarction and persistent motor deficit underwent FDG PET within 1 week before and 6 and 12 months after stereotactic implantation of human neuronal cells. Serial neurological evaluations during a 52-week postoperative period included the National Institutes of Health stroke scale and the European stroke scale.

RESULTS

Alterations in glucose metabolic activity in the stroke and surrounding tissue at 6 and 12 months after implantation correlated positively with motor performance measures.

CONCLUSION

FDG PET performed as part of an initial open-label human trial of implanted LBS-Neurons (Layton BioScience, Sunnyvale, CA) for chronic stroke demonstrates a relationship between relative regional metabolic changes and clinical performance measures. These preliminary findings suggest improved local cellular function or engraftment of implanted cells in some patients.