Lawrence M. Brass

Aspirin and clopidogrel compared with clopidogrel alone after recent ischaemic stroke or transient ischaemic attack in high-risk patients (MATCH): randomised, double-blind, placebo-controlled trial

BACKGROUND Clopidogrel was superior to aspirin in patients with previous manifestations of atherothrombotic disease in the CAPRIE study and its benefit was amplified in some high-risk subgroups of patients. We aimed to assess whether addition of aspirin to clopidogrel could have a greater benefit than clopidogrel alone in prevention of vascular events with potentially higher bleeding risk. METHODS We did a randomised, double-blind, placebo-controlled trial to compare aspirin (75 mg/day) with placebo in 7599 high-risk patients with recent ischaemic stroke or transient ischaemic attack and at least one additional vascular risk factor who were already receiving clopidogrel 75 mg/day. Duration of treatment and follow-up was 18 months. The primary endpoint was a composite of ischaemic stroke, myocardial infarction, vascular death, or rehospitalisation for acute ischaemia (including rehospitalisation for transient ischaemic attack, angina pectoris, or worsening of peripheral arterial disease). Analysis was by intention to treat, using logrank test and a Coxs proportional-hazards model. FINDINGS 596 (15.7%) patients reached the primary endpoint in the group receiving aspirin and clopidogrel compared with 636 (16.7%) in the clopidogrel alone group (relative risk reduction 6.4%, [95% CI -4.6 to 16.3]; absolute risk reduction 1% [-0.6 to 2.7]). Life-threatening bleedings were higher in the group receiving aspirin and clopidogrel versus clopidogrel alone (96 [2.6%] vs 49 [1.3%]; absolute risk increase 1.3% [95% CI 0.6 to 1.9]). Major bleedings were also increased in the group receiving aspirin and clopidogrel but no difference was recorded in mortality. INTERPRETATION Adding aspirin to clopidogrel in high-risk patients with recent ischaemic stroke or transient ischaemic attack is associated with a non-significant difference in reducing major vascular events. However, the risk of life-threatening or major bleeding is increased by the addition of aspirin.

AHA/ACC Guidelines for Preventing Heart Attack and Death in Patients With Atherosclerotic Cardiovascular Disease: 2001 Update A Statement for Healthcare Professionals From the American Heart Association and the American College of Cardiology

Since the original publication (in 1995) of the American Heart Association (AHA) consensus statement on secondary prevention, which was endorsed by the American College of Cardiology (ACC), important evidence from clinical trials has emerged that further supports the merits of aggressive risk reduction therapies for patients with atherosclerotic cardiovascular disease. As noted in that statement, aggressive risk factor management clearly improves patient survival, reduces recurrent events and the need for interventional procedures, and improves the quality of life for these patients. The compelling evidence from recent clinical trials was the impetus …

GUIDELINES FOR CAROTID ENDARTERECTOMY: A STATEMENT FOR HEALTHCARE PROFESSIONALS FROM A SPECIAL WRITING GROUP OF THE STROKE COUNCIL, AMERICAN HEART ASSOCIATION

Since the 1950s carotid endarterectomy has been performed in patients with symptomatic carotid artery stenosis, based on suggestive but inconclusive evidence for its effectiveness. Only during the last 5 years have randomized studies clarified the indications for surgery. In preparing this report, panel members used the same rules of evidence used in the previous report1 2 (Table⇓). View this table: Table 1. Levels of Evidence and Grading of Recommendations Few studies have analyzed control of risk factors in a randomized, prospective manner following carotid endarterectomy. However, a wealth of data are available regarding the general relationship between risk factor control and stroke risk. These data provide some guidance for the care of endarterectomy patients. ### Hypertension Hypertension is the most powerful, prevalent, and treatable risk factor for stroke.3 Both systolic and diastolic blood pressure are independently related to stroke incidence. Isolated systolic hypertension, which is common in the elderly, also considerably increases risk of stroke. Reduction of elevated blood pressure significantly lowers risk of stroke. Meta-analyses of randomized trials found that an average reduction in diastolic blood pressure of 6 mm Hg produces a 42% reduction in stroke incidence.3 4 Treatment of isolated systolic hypertension in people older than 60 years also reduces stroke incidence by 36% without an excessive number of side effects such as depression or dementia.5 Long-term care of patients after endarterectomy should include careful control of hypertension (Grade A recommendation for treatment of hypertension in general; Grade C recommendation for postendarterectomy care). Perioperative treatment of hypertension after carotid endarterectomy represents a special situation. Poor control of blood pressure after endarterectomy increases risk of cerebral hyperperfusion syndrome.6 7 8 9 This complication is characterized by unilateral headache, seizures, and occasionally altered mental status or focal neurological signs. Neuroimaging may show intracerebral hemorrhages10 11 12 or white …

Recommendations for Comprehensive Stroke Centers: A Consensus Statement From the Brain Attack Coalition

Background and Purpose— To develop recommendations for the establishment of comprehensive stroke centers capable of delivering the full spectrum of care to seriously ill patients with stroke and cerebrovascular disease. Recommendations were developed by members of the Brain Attack Coalition (BAC), which is a multidisciplinary group of members from major professional organizations involved with the care of patients with stroke and cerebrovascular disease. Summary of Review— A comprehensive literature search was conducted from 1966 through December 2004 using Medline and Pub Med. Articles with information about clinical trials, meta-analyses, care guidelines, scientific guidelines, and other relevant clinical and research reports were examined and graded using established evidence-based medicine approaches for therapeutic and diagnostic modalities. Evidence was also obtained from a questionnaire survey sent to leaders in cerebrovascular disease. Members of BAC reviewed literature related to their field and graded the scientific evidence on the various diagnostic and treatment modalities for stroke. Input was obtained from the organizations represented by BAC. BAC met on several occasions to review each specific recommendation and reach a consensus about its importance in light of other medical, logistical, and financial factors. Conclusions— There are a number of key areas supported by evidence-based medicine that are important for a comprehensive stroke center and its ability to deliver the wide variety of specialized care needed by patients with serious cerebrovascular disease. These areas include: (1) health care personnel with specific expertise in a number of disciplines, including neurosurgery and vascular neurology; (2) advanced neuroimaging capabilities such as MRI and various types of cerebral angiography; (3) surgical and endovascular techniques, including clipping and coiling of intracranial aneurysms, carotid endarterectomy, and intra-arterial thrombolytic therapy; and (4) other specific infrastructure and programmatic elements such as an intensive care unit and a stroke registry. Integration of these elements into a coordinated hospital-based program or system is likely to improve outcomes of patients with strokes and complex cerebrovascular disease who require the services of a comprehensive stroke center.

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.

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.

Stratified randomization for clinical trials.

Trialists argue about the usefulness of stratified randomization. For investigators designing trials and readers who use them, the argument has created uncertainty regarding the importance of stratification. In this paper, we review stratified randomization to summarize its purpose, indications, accomplishments, and alternatives. In order to identify research papers, we performed a Medline search for 1966-1997. The search yielded 33 articles that included original research on stratification or included stratification as the major focus. Additional resources included textbooks. Stratified randomization prevents imbalance between treatment groups for known factors that influence prognosis or treatment responsiveness. As a result, stratification may prevent type I error and improve power for small trials (<400 patients), but only when the stratification factors have a large effect on prognosis. Stratification has an important effect on sample size for active control equivalence trials, but not for superiority trials. Theoretical benefits include facilitation of subgroup analysis and interim analysis. The maximum desirable number of strata is unknown, but experts argue for keeping it small. Stratified randomization is important only for small trials in which treatment outcome may be affected by known clinical factors that have a large effect on prognosis, large trials when interim analyses are planned with small numbers of patients, and trials designed to show the equivalence of two therapies. Once the decision to stratify is made, investigators need to chose factors carefully and account for them in the analysis.

A study of twins and stroke.

Although there are strong genetic contributions to coronary artery disease, only a few studies have considered heritable influences on stroke. Methods We investigated the role of genetic factors in stroke using the Twin Registry maintained by the National Academy of Sciences-National Research Council. The registry includes 15,948 male twin pairs born between 1917 and 1927. In 1985, 9,475 twins responded to a mailed questionnaire, which covered vascular risk factors, cardiac events, and stroke. Results Analysis of twin pairs in which both responded to the questionnaire, and a question on stroke, indicated proband concordance rates of 17.7% for monozygotic pairs and 3.6% for dizygotic pairs (relative risk=4.3; χ2 =4.94, df=1;p<0.05). Conclusions This nearly fivefold increase in the prevalence of stroke among the monozygotic compared with the dizygotic twin pairs suggests that genetic factors are involved in the etiology of stroke. The twin study paradigm holds considerable promise for identifying both genetic and environmental influences on stroke.

Development of a Test Battery to Identify Older Drivers at Risk for Self‐Reported Adverse Driving Events

OBJECTIVES: The purposes of this study were (1) to develop a battery of tests that assessed a wide range of functional abilities relevant to driving yet could be performed in a clinicians office and (2) to determine which of these tests were most closely associated with self‐reported adverse driving events.

Proton magnetic resonance spectroscopy of cerebral lactate and other metabolites in stroke patients.

Background and Purpose Proton magnetic resonance spectroscopy can measure in vivo brain lactate and other metabolites noninvasively. We measured the biochemical changes accompanying stroke in 16 human subjects with cortical or deep cerebral infarcts within the first 3 weeks after symptom onset, and performed follow-up studies on six. Methods One-dimensional proton spectroscopic imaging encompassing the infarct region was performed with a 2.1-T whole-body magnet using the stimulated echo pulse sequence and an echo time of 270 msec. Results All but one of the cortical stroke patients had increased lactate within or near the infarct. Persistently elevated cerebral lactate was documented in five of six cases studied serially as long as 251 days after infarction. iV-acetylaspartate levels were decreased in most cortical strokes. Elevated lactate, accompanied by minimal reduction in iV-acetylaspartate, was recorded in two of four patients in the first week following a small subcortical infarct. Conclusions Long-term elevation of lactate commonly occurs after stroke. This lactate may arise from ongoing ischemia or infiltrating leukocytes, or it may be a residual of the lactate formed during the initial insult. The ability to observe stroke-elevated lactate pools at any time after lesion onset provides an approach to distinguishing among these possibilities in the future.