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Background and Purpose-This guideline provides an overview of the evidence on various established and potential stroke risk factors and provides recommendations for the reduction of stroke risk. Methods-Writing group members were nominated by the committee chair on the basis of each writer's previous work in relevant topic areas and were approved by the American Heart Association Stroke Council's Scientific Statement Oversight Committee. The writers used systematic literature reviews (covering the time period since the last review published in 2001 up to January 2005), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations based on standard American Heart Association criteria. All members of the writing group had numerous opportunities to comment in writing on the recommendations and approved the final version of this document. The guideline underwent extensive peer review before consideration and approval by the AHA Science Advisory and Coordinating Committee. Results-Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to their potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic factors. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, alcohol abuse, drug abuse, oral contraceptive use, sleep-disordered breathing, migraine headache, hyperhomocysteinemia, elevated lipoprotein(a), elevated lipoprotein-associated phospholipase, hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

Background and Purpose-Enlimomab, a murine monoclonal anti-human intercellular adhesion molecule (ICAM)-1 antibody, had a negative outcome in a multicenter acute-stroke trial. We did a bedside-to-bench study in standardized rat stroke models to explore mechanisms for these untoward results. Methods-After focal brain ischemia in Wistar rats and spontaneously hypertensive rats (SHR), we administered murine anti-rat ICAM-1 antibody (1A29), subclass-matched murine immunoglobulin (IgG1), or vehicle intravenously. To examine whether rat anti-mouse antibodies were generated against the mouse protein and whether these were deleterious, we sensitized Wistar rats with 1A29 or vehicle 7 days before surgery. Infarct volume, tissue myeloperoxidase activity, neutrophil CD11b expression, and microvascular E-selectin, P-selectin, and ICAM-1 expression were examined 48 hours after surgery. Complement activation was serially assessed for 2 hours after a single injection of either 1A29 or vehicle. Results-1A29 treatment did not significantly reduce infarct size in either strain. 1A29 sensitization augmented infarct size and generated rat anti-mouse antibodies. Although 1A29 inhibited neutrophil trafficking shown by reduction in brain myeloperoxidase activity, circulating neutrophils were activated and displayed CD11b upregulation. Complement was activated in 1A29-sensitized Wistar rats and 1A29-treated SHR. E-selectin (SHR), endothelial P-selectin (Wistar and SHR), and ICAM-1 (SHR) were upregulated in animals treated with 1A29. Conclusions-Administration to rats of a murine antibody preparation against ICAM-1, 1A29, elicits the production of host antibodies against the protein, activation of circulating neutrophils, complement activation, and sustained microvascular activation. These observations provide several possible mechanisms for central nervous system-related clinical deterioration that occurred when Enlimomab was given in acute ischemic stroke. (Stroke. 2001;32:2665-2674.)

A growing body of evidence, primarily from animal models of cerebral ischemia and preliminary human studies, indicates that inflammatory mechanisms contribute to secondary neuronal injury after acute cerebral ischemia. Ischemia followed by reperfusion rapidly leads to the expression of inflammatory cytokines, particularly tumor necrosis factor-alpha and interleukin-1beta, which stimulate a complex cascade of events involving local endothelial cells, neurons, astrocytes, and perivascular cells. A secondary response includes the release of other cytokines, an increase in components of the coagulation system, an upregulation of cell adhesion molecule expression, and changes in the expression of components of the immune response. The net effect of these events is transformation of the local endothelium to a prothrombotic/proinflammatory state and induction of leukocyte migration to the site of injury. A number of studies have shown that leukocyte migration occurs within hours of reperfusion. Leukocytes accumulate in the injured region, where they cause tissue injury by several mechanisms, including occlusion of microvasculature, generation of oxygen free radicals, release of cytotoxic enzymes, alteration of vasomotor reactivity, and increase in cytokine and chemoattractant release. Monoclonal antibodies against leukocyte adhesion molecules have been shown to reduce infarct volume in animal models of ischemia-reperfusion. However, this treatment failed to show benefit in the Enlimomab Acute Stroke Trial. A number of factors may complicate the use of antibody directed adhesion molecule blockade in acute stroke and will be discussed in this article. Overall, an increased understanding of inflammatory and immunologic mechanisms still offers great potential for reducing acute stroke injury.

Fabry disease is an X‐linked recessive disorder resulting in the deposition of globotriaosylceramide in numerous cell types including vascular endothelial cells. Because this disease is associated with vascular injury and a high recurrence rate of thrombotic events, measurements of factors regulating endothelium and leukocyte interaction may provide insight into the mechanisms leading to a prothrombotic state. Twenty‐five patients with Fabry disease and 25 control subjects participated in the study. Plasma from all 25 Fabry patients and 15 of the 25 controls were studied for multiple endothelial factors. Leukocyte integrins were measured by flow cytometry in 21 Fabry patients and 10 controls. The concentrations of soluble intercellular adhesion molecule‐1, vascular cell adhesion molecule‐1, P‐selectin, and plasminogen activator inhibitor were significantly higher and thrombomodulin was significantly lower in Fabry patients. Expression of the integrin CD11b on monocytes was also significantly higher in the Fabry patients. This study reveals measurable evidence for endothelium and leukocyte activation that is consistent with a prothrombotic state in Fabry patients compared with controls. Further investigations of these findings may help to understand the mechanism of stroke in Fabry disease and provide indicators (or markers) of efficacy of future therapeutic intervention. Ann Neurol 2000;47:229–233