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Biomedical subjects

L M Brass

Publications and source records attributed to L M Brass.

At least 19 recordsLinked to original sources
PubMed2005

Do the Brain Attack Coalition's criteria for stroke centers improve care for ischemic stroke?

BACKGROUND: In 2000, the Brain Attack Coalition (BAC) recommended 11 major criteria for the establishment of primary stroke centers. The BAC relied heavily on expert opinion because evidence supporting the criteria was sparse. OBJECTIVE: To assess primary stroke center elements, based on the criteria proposed by the BAC, with a questionnaire at 34 academic medical centers. METHODS: Patient characteristics and outcomes were collected for all patients (n = 16,853) admitted with ischemic stroke to each hospital from 1999 to 2001. Stroke center elements were evaluated as predictors of treatment with tissue plasminogen activator (tPA) and outcomes after adjustment for patient characteristics. RESULTS: The in-hospital mortality rate was 6.3% (n = 1,062), and 2.4% (n = 399) of patients received tPA. None of the 11 major stroke center elements was associated with decreased in-hospital mortality or increased frequency of discharge home. However, four elements predicted increased tPA use, including written care protocols, integrated emergency medical services, organized emergency departments, and continuing medical/public education in stroke (each odds ratio [OR] > 2.0, p < 0.05). Use of tPA also tended to be greater at centers with an acute stroke team, a stroke unit, or rapid neuroimaging (each OR > 2.0, p < 0.10). Institutions with a greater number of major stroke center elements used tPA more frequently. CONCLUSIONS: Of the 11 stroke center elements recommended by the BAC, 7 were associated with increased tPA use. Institutions with a greater number of these seven features used tPA more often, suggesting these key elements may be most important for primary stroke center designation, at least in terms of identifying centers that deliver IV tPA frequently.

Academic Medical Centers↗
PubMed2003

Impaired insulin sensitivity among nondiabetic patients with a recent TIA or ischemic stroke.

OBJECTIVES: To determine the prevalence of impaired insulin sensitivity among nondiabetic patients with a recent TIA or nondisabling ischemic stroke. METHODS: Eligible subjects were nondiabetic men and women over age 45 years who were hospitalized with a TIA or ischemic stroke. To measure insulin sensitivity, subjects underwent an oral glucose tolerance test between 2 and 6 months after their event. Impaired insulin sensitivity was defined by a value of < or =2.5 on the Composite Insulin Sensitivity Index derived from insulin and glucose values during the test. RESULTS: Between July 2000 and June 2001, we identified 177 eligible patients, among whom 105 declined to participate and 72 enrolled. The median age of participants was 71 years and 46 (64%) were men. The baseline event was stroke for 57 subjects (79%). A history of myocardial infarction (MI) was reported by 14 subjects (19%), and 16 (22%) were obese (body mass index > 30). Fasting glucose was normal (<110 mg/dL) for 58 (80%) participants and impaired (110 to 125 mg/dL) for 14 (20%). Among 72 participants, the median insulin sensitivity index value was 2.6 (range 0.9 to 10.2). The prevalence of impaired insulin sensitivity was 36 of 72 (50%, 95% CI 38% to 62%). Impaired insulin sensitivity was more prevalent among younger patients and patients with obesity, lacunar stroke etiology, and disability (Rankin grade >1). CONCLUSION: Impaired insulin sensitivity is highly prevalent among nondiabetic patients with a recent TIA or nondisabling ischemic stroke. This finding has important therapeutic implications if treatment to improve insulin sensitivity is shown to reduce risk for subsequent stroke and heart disease.

Aged↗
PubMed2003

Use of Ephedra-containing products and risk for hemorrhagic stroke.

This case-control study examined the association between Ephedra use and risk for hemorrhagic stroke. For use of Ephedra at any dose during the 3 days before the stroke, the adjusted OR was 1.00 (95% CI 0.32 to 3.11). For daily doses of < or =32 mg/day, the OR was 0.13 (95% CI 0.01 to 1.54), and for >32 mg/day, the OR was 3.59 (95% CI 0.70 to 18.35). Ephedra is not associated with increased risk for hemorrhagic stroke, except possibly at higher doses.

Adolescent↗
PubMed2003

Hyperglycaemia in patients with acute ischaemic stroke: how often do we screen for undiagnosed diabetes?

BACKGROUND: Hyperglycaemia is common among patients with acute ischaemic stroke, and may be due to the physiological stress of the acute stroke event or reflect underlying diabetes mellitus. The under-diagnosis of diabetes in the general population, combined with the association of diabetes and stroke, suggests a rationale for screening for diabetes among hyperglycaemic stroke patients. AIM: To determine how often clinicians screen for diabetes among hyperglycaemic stroke patients without a prior diagnosis of diabetes. DESIGN: Retrospective medical record review. METHODS: We reviewed the records of acute ischaemic stroke patients admitted at any of ten Connecticut hospitals from May 1996 through December 1998. RESULTS: We identified 90 acute stroke patients with no prior history of diabetes. The prevalence of hyperglycaemia varied from 31% down to 6%, depending on the maximum glucose cut-off used to define hyperglycaemia: from > or = 140 mg/dl (7.8 mmol/l) to > or = 200 mg/dl (11.1 mmol/l). Only one of the hyperglycaemic patients (1/90, 1%) had any evidence that a clinician screened or planned to screen for undiagnosed diabetes: one patient had a haemoglobin A1c measured during the hospitalization, none received oral glucose tolerance testing while hospitalized, and no discharge summary included a plan to screen for diabetes as an out-patient. DISCUSSION: Hyperglycaemic stroke patients without a previous diagnosis of diabetes are not routinely screened for diabetes. This situation represents an opportunity, currently unused, to identify an important and modifiable condition.

Adult↗
PubMed2002

Insulin resistance and risk for stroke.

BACKGROUND AND PURPOSE: Resistance to insulin-mediated glucose uptake by peripheral tissues is a cardinal defect in type 2 diabetes mellitus. Insulin resistance is also common among nondiabetic individuals, and may be an important risk factor for stroke in both populations. The authors review the definition, epidemiology, and treatment of insulin resistance. METHODS: The authors searched Medline (1977-2001) and reviewed bibliographies to identify pertinent English-language publications. RESULTS: Insulin resistance is present in most patients with type 2 diabetes. It is also common among elderly persons, certain ethnic groups, and persons with hypertension, obesity, physical deconditioning, and vascular disease. The principal pathophysiologic defect is impaired intracellular signaling in muscle tissue leading to defective glycogen synthesis. Insulin resistance is associated with numerous metabolic, hematologic, and cellular events that promote atherosclerosis and coagulation. The association between insulin resistance and risk for stroke has been examined in four case-control studies and five prospective observational cohort studies. Six of the nine studies are methodologically sound and provide evidence that insulin resistance is associated with risk for stroke. CONCLUSION: Insulin resistance may be a prevalent risk factor for stroke. New drugs can safely reduce insulin resistance and may have a role in stroke prevention.

Animals↗
PubMed2001

A clinical trial of estrogen-replacement therapy after ischemic stroke.

BACKGROUND: Observational studies have suggested that estrogen-replacement therapy may reduce a woman's risk of stroke and death. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of estrogen therapy (1 mg of estradiol-17beta per day) in 664 postmenopausal women (mean age, 71 years) who had recently had an ischemic stroke or transient ischemic attack. Women were recruited from 21 hospitals in the United States and were followed for the occurrence of stroke or death. RESULTS: During a mean follow-up period of 2.8 years, there were 99 strokes or deaths among the women in the estradiol group, and 93 among those in the placebo group (relative risk in the estradiol group, 1.1; 95 percent confidence interval, 0.8 to 1.4). Estrogen therapy did not reduce the risk of death alone (relative risk, 1.2; 95 percent confidence interval, 0.8 to 1.8) or the risk of nonfatal stroke (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.4). The women who were randomly assigned to receive estrogen therapy had a higher risk of fatal stroke (relative risk, 2.9; 95 percent confidence interval, 0.9 to 9.0), and their nonfatal strokes were associated with slightly worse neurologic and functional deficits. CONCLUSIONS: Estradiol does not reduce mortality orthe recurrence of stroke in postmenopausal women with cerebrovascular disease. This therapy should not be prescribed for the secondary prevention of cerebrovascular disease.

Aged↗
PubMed2001

Reduction in stroke with gemfibrozil in men with coronary heart disease and low HDL cholesterol: The Veterans Affairs HDL Intervention Trial (VA-HIT).

BACKGROUND: A low level of HDL cholesterol has been identified as a risk factor for stroke in observational studies. METHODS AND RESULTS: Our objective was to determine whether treatment aimed at raising HDL cholesterol and lowering triglycerides reduces stroke in men with coronary heart disease and low levels of both HDL and LDL cholesterol. The study was a placebo-controlled, randomized trial conducted in 20 Veterans Affairs medical centers. A total of 2531 men with coronary heart disease, with mean HDL cholesterol 0.82 mmol/L (31.5 mg/dL) and mean LDL cholesterol 2.9 mmol/L (111 mg/dL), were randomized to gemfibrozil 1200 mg/d or placebo and were followed up for 5 years. Strokes were confirmed by a blinded adjudication committee. Relative risks were derived from Cox proportional hazards models. There were 134 confirmed strokes, 90% of which were ischemic. Seventy-six occurred in the placebo group (9 fatal) and 58 in the gemfibrozil group (3 fatal), for a relative risk reduction, adjusted for baseline variables, of 31% (95% CI, 2% to 52%, P=0.036). The reduction in risk was evident after 6 to 12 months. Patients with baseline HDL cholesterol below the median may have been more likely to benefit from treatment than those with higher HDL cholesterol. CONCLUSIONS: In men with coronary heart disease, low HDL cholesterol, and low LDL cholesterol, gemfibrozil reduces stroke incidence.

Aged↗
PubMed2001

A quality-of-life instrument for young hemorrhagic stroke patients.

BACKGROUND AND PURPOSE: Hemorrhagic stroke has a high initial mortality rate. While survivors often recover motor function, many experience significant changes in their quality of life (QOL). Available outcome measures assess neurological impairment, disability, or handicap, yet often inadequately characterize the full impact of a stroke on patients' lives. In this study, we develop and validate a QOL instrument specific for young patients with hemorrhagic strokes. METHODS: Methodological guidelines for instrument development were initially established. Based on the content of 40 open-ended patient interviews, a 54-item instrument (HSQuale) was developed. The reliability (test-retest and internal consistency) and validity (content and construct) of HSQuale were assessed in another 71 patients (18 to 49 years of age, 63% women, 77% white), at 1 year after their hemorrhagic stroke. Comparisons were made between HSQuale and other commonly used outcome measures. RESULTS: HSQuale demonstrated reproducibility (test-retest kappa, 0.40 to 0.96) and internal consistency (Cronbach alpha >/=0.80 for 5 of 7 domains). HSQuale scores had broad frequency distributions (</=33% of subjects scored in any single score decile), avoided ceiling effects found for other outcome measures (Barthel Index and Short Form-36), and discriminated among clinically distinct subject groups (eg, intracerebral versus subarachnoid hemorrhage patients). CONCLUSIONS: HSQuale is a reliable and valid QOL instrument. Compared with other outcome measures, it assesses a broader range of deficits and is better able to discriminate among subgroups of hemorrhagic stroke survivors.

Adolescent↗
PubMed2001

Utilization of intravenous tissue-type plasminogen activator for ischemic stroke at academic medical centers: the influence of ethnicity.

BACKGROUND AND PURPOSE: We sought to measure the overall rate of usage of tissue-type plasminogen activator (tPA) for ischemic stroke at academic medical centers, and to determine whether ethnicity was associated with usage. METHODS: Between June and December 1999, 42 academic medical centers in the United States each identified 30 consecutive ischemic stroke cases. Medical records were reviewed and information on demographics, medical history, and treatment were abstracted. Rates of tPA use were compared for African Americans and whites in univariate analysis and after adjustment for age, gender, stroke severity, and type of medical insurance with multivariable logistic regression. RESULTS: Complete information was available for 1195 ischemic stroke patients; 788 were whites and 285 were African Americans: Overall, 49 patients (4.1%) received tPA. In the subgroup of 189 patients without a documented contraindication to therapy, 39 (20.6%) received tPA. Ten (20%) of those receiving tPA had documented contraindication. African Americans were one fifth as likely to receive tPA as whites (1.1% African Americans versus 5.3%; P=0.001), and the difference persisted after adjustment (OR 0.21, 95% CI 0.06 to 0.68; P=0.01). When comparison was restricted to those without a documented contraindication to tPA, the difference remained significant (OR 0.24, 95% CI 0.06 to 0.93; P=0.04). Medical insurance type was independently associated with tPA treatment. After adjustment for ethnicity and other demographic characteristics, those with Medicaid or no insurance were one ninth as likely to receive tPA as those with private medical insurance (OR 0.11, 95% CI 0.02 to 0.17; P=0.003). CONCLUSIONS: tPA is used infrequently for ischemic stroke at US academic medical centers, even among qualifying candidates. African Americans are significantly less likely to receive tPA for ischemic stroke. Contraindications to treatment do not appear to account for the difference.

Academic Medical Centers↗
PubMed2001

Long-term heart disease and stroke mortality among former American prisoners of war of World War II and the Korean Conflict: results of a 50-year follow-up.

For the first 30 years after repatriation, former American prisoners of war (POWs) of World War II and the Korean Conflict had lower death rates for heart disease and stroke than non-POW veteran controls and the U.S. population, but subsequent morbidity data suggested that this survival advantage may have disappeared. We used U.S. federal records to obtain death data through 1996 and used proportional hazards analysis to compare the mortality experience of POWs and controls. POWs aged 75 years and older showed a significantly higher risk of heart disease deaths than controls (hazard ratio = 1.25; 95% confidence interval, 1.01-1.56), and their stroke mortality was also increased, although not significantly (hazard ratio = 1.13; 95% confidence interval, 0.66-1.91). These results suggest that circulatory disease sequelae of serious, acute malnutrition and the stresses associated with imprisonment may not appear until after many decades.

Aged↗
PubMed2000

Phenylpropanolamine and the risk of hemorrhagic stroke.

BACKGROUND: Phenylpropanolamine is commonly found in appetite suppressants and cough or cold remedies. Case reports have linked the use of products containing phenylpropanolamine to hemorrhagic stroke, often after the first use of these products. To study the association, we designed a case-control study. METHODS: Men and women 18 to 49 years of age were recruited from 43 U.S. hospitals. Eligibility criteria included the occurrence of a subarachnoid or intracerebral hemorrhage within 30 days before enrollment and the absence of a previously diagnosed brain lesion. Random-digit dialing identified two matched control subjects per patient. RESULTS: There were 702 patients and 1376 control subjects. For women, the adjusted odds ratio was 16.58 (95 percent confidence interval, 1.51 to 182.21; P=0.02) for the association between the use of appetite suppressants containing phenylpropanolamine and the risk of a hemorrhagic stroke and 3.13 (95 percent confidence interval, 0.86 to 11.46; P=0.08) for the association with the first use of a product containing phenylpropanolamine. All first uses of phenylpropanolamine involved cough or cold remedies. For men and women combined, the adjusted odds ratio was 1.49 (95 percent confidence interval, 0.84 to 2.64; P=0.17) for the association between the use of a product containing phenylpropanolamine and the risk of a hemorrhagic stroke, 1.23 (95 percent confidence interval, 0.68 to 2.24; P=0.49) for the association with the use of cough or cold remedies that contained phenylpropanolamine, and 15.92 (95 percent confidence interval, 1.38 to 184.13; P=0.03) for the association with the use of appetite suppressants that contained phenylpropanolamine. An analysis in men showed no increased risk of a hemorrhagic stroke in association with the use of cough or cold remedies containing phenylpropanolamine. No men reported the use of appetite suppressants. CONCLUSIONS: The results suggest that phenylpropanolamine in appetite suppressants, and possibly in cough and cold remedies, is an independent risk factor for hemorrhagic stroke in women.

Adolescent↗
PubMed2000

HMG-CoA reductase inhibitors (statins): a promising approach to stroke prevention.

Statins represent a promising class of agents to prevent stroke. In randomized trials of middle-aged patients with coronary artery disease, statins reduce the incidence of stroke. The reduction in stroke may not be solely related to cholesterol or low-density lipoprotein reduction but may involve nonsterol mechanisms effects on endothelial cells, macrophages, platelets, and smooth muscle cells. Statins also reduce the size of cerebral infarction in a murine stroke model, suggesting a neuroprotective effect. The best current evidence for stroke prevention is with pravastatin and simvastatin. Pravastatin reduces the risk of stroke in patients with coronary artery disease and average cholesterol levels; simvastatin reduces the risk of the combined endpoint of stroke and transient ischemic attack in hypercholesterolemic patients with coronary artery disease. Future studies of statins are needed in stroke populations, particularly the elderly.

Humans↗
PubMed2000

The impact of cerebrovascular disease.

Stroke may be affected by pathologic conditions such as atherosclerosis, vascular injury, coagulopathy, and increased platelet aggregability. Knowledge of the pathophysiology of stroke is critical in order to effectively prevent or treat this disabling state. Cerebrovascular disease is the third leading cause of death in the USA. It is also associated with significant morbidity, leading to extremely high health care costs and lost productivity. Total estimated costs of stroke are estimated to be more than $45 billion annually. This is an especially important issue for patients with diabetes, who are at higher risk for stroke and have a worse clinical outcome than non-diabetic patients. This review describes the impact of vascular disease, particularly cerebrovascular disease, and describes the pathophysiology of the disease. Interventions that result in reduction of stroke will likely result in decreased health care costs and improved clinical outcomes.

Cerebrovascular Disorders↗
PubMed2000

Quality Enhancement Research Initiative in stroke: prevention, treatment, and rehabilitation.

Stroke is the third leading cause of death and a leading cause of adult disability in the United States. Both within and outside of the Veterans Health Administration (VHA), the lack of a systematic approach to stroke prevention and treatment may have contributed to reduced rates of compliance with recommended practices and increased rates of stroke. Gaps in the knowledge base inhibit a systematic approach to high-quality care within the veteran population. Initial recommendations for closing those gaps are proposed. In some cases (eg, systematic anticoagulation management), the VHA is perceived as a leader in applied research; therefore, a systematic national policy for implementing these clinics may significantly reduce stroke rates. In other areas (eg, carotid endarterectomy), databases exist that would help advance quality and outcomes, but short-term studies are necessary to establish their utility. To promote strategic improvement in prevention, treatment, and rehabilitation for veterans who may be at risk or have had a stroke, specific objectives are proposed to (1) identify best practices for the effective delivery of long-term anticoagulation and enhance veterans' access to these services, (2) develop risk-adjusted models for the surgical preventive procedure carotid endarterectomy to understand facility variation in outcomes so practices can be improved, (3) define a systematic acute stroke management system so that high-quality stroke-related care can be generalizable to a variety of VHA settings, and (4) assess the impact of poststroke rehabilitation on risk adjustment and the location of outcomes so as to facilitate the implementation of best rehabilitation practices.

Adult↗
PubMed2000

Blood pressure exceeding national guidelines among women after stroke.

BACKGROUND AND PURPOSE: After a transient ischemic attack or stroke, the risk for recurrence may be reduced by treatment of hypertension. The purpose of this study was to determine how commonly blood pressure exceeds national guidelines among patients who have had one of these events. METHODS: Subjects were 644 women participating in a randomized trial of estrogen for secondary stroke prevention. We measured blood pressure 1 month after the stroke or TIA while patients were under the care of their personal physicians. Among 536 patients, a second measure was made at an average of 2.9 years after the first. RESULTS: The mean age of participants was 71 years, and 73% reported a history of hypertension. At baseline, only 44% (280/644) of the women had blood pressure values within national guidelines (<140/90 mm Hg). With separate guidelines used for diabetics (<130/85 mm Hg) and nondiabetics (<140/90 mm Hg), the proportions of women within the guidelines were 27% and 44%, respectively. Overall, 39% of patients were within the diabetes-adjusted guidelines. Among patients whose blood pressure exceeded 140/90 mm Hg at first examination, 55% were still in excess at follow-up. Features associated with severe hypertension at first examination (>160/100 mm Hg) were history of hypertension, education less than college, and higher cognitive functioning. CONCLUSIONS: Blood pressure values in excess of national guidelines are common after stroke and TIA, especially among diabetic patients. Efforts to lower blood pressure control may enhance secondary prevention.

Aged↗