The ASPIRE approach for TIA risk stratification.

BACKGROUND: The risk of stroke after transient ischemic attack (TIA) is elevated in the days to weeks after TIA. A variety of prediction rules to predict stroke risk have been suggested. In Alberta a triage algorithm to facilitate urgent access based on risk level was agreed upon for the province. Patients with ABCD2 score ≥ 4, or motor or speech symptoms lasting greater than five minutes, or with atrial fibrillation were considered high risk (the ASPIRE approach). We assessed the ability of the ASPIRE approach to identify patients at risk for stroke. METHODS: We retrospectively reviewed charts from 573 consecutive patients diagnosed with TIA in Foothills Hospital emergency room from 2002 through 2005. We recorded clinical and event details and identified the risk of stroke at three months. RESULTS: Among 573 patients the 90-day risk of stroke was 4.7% (95% CI 3.0%, 6.4%). 78% of the patients were identified as high risk using this approach. In patients defined as high risk on the ASPIRE approach there was a 6.3% (95% CI 4.2%, 8.9%) risk of stroke. In patients defined as low risk using the ASPIRE approach there were no recurrent strokes (100% negative predictive value). In contrast, two patients with low ABCD2 scores (ABCD2 score < 4) suffered recurrent strokes. CONCLUSION: The ASPIRE approach has a perfect negative predictive value in the population in predicting stroke. However, this high sensitivity comes at a cost of identifying most patients as high risk.

Prevention of strokes.

Stroke is a major cause of morbidity and mortality. Risk factors for stroke have been determined through prospective epidemiologic study. Control of risk factors has been demonstrated to reduce stroke incidence, either through controlled trials or inferred from observational studies. In the past few years, new approaches to the treatment of established risk factors have been discovered. These include aggressive control of hypertension in diabetes patients, prevention of type 2 diabetes through lifestyle modification, carotid endarterectomy for moderate symptomatic carotid stenosis, encouragement of a high level of physical activity, and control of abdominal obesity and elevated body mass index. In addition, new strategies for stroke prevention have been identified, including encouragement of a diet high in fruits, vegetables, whole grains, and omega-3 fatty acids, the use of vitamins B12, B6, and folic acid in hyperhomocysteinemia, and moderate alcohol consumption. Clinical trial data support the use of hydroxy-methyl-coenzyme A inhibitors in patients with coronary artery disease, and ramipril in high-risk patients with coronary artery disease and diabetes, for the primary prevention of stroke. New risk factors for stroke are being investigated, including the role of chronic inflammation and infection, and these may provide future strategies for stroke prevention.

A representational vertical bias.

We attempted to determine whether separable components underlie normal subjects' upward bias in bisecting vertical and radial lines under visual guidance. Twelve normal subjects indicated the midpoint of visually presented lines oriented vertically, radially, and horizontally. We placed directional labels ("TOP" and "BOTTOM") at either end of each line. Subjects showed significant bias toward the label TOP in horizontal, vertical, and "radial-down" (below eye level) conditions but not in the "radial-up" (above eye level) position. In the horizontal condition, the misbisections actually changed direction depending on whether TOP was to the left or right of midpoint. There were two biases: one toward an internally represented "top" (as suggested by the verbal labels) and another toward the upper visual field. The latter was stronger when the two were opposed. These findings suggest that normal subjects' upward bias on bisection of vertical and radial lines under visual guidance has both representational- and visual field-based components.