RESUMO
BACKGROUND: Platelet activation has an important role in the progression of atheroclerosis and acute ischemic events. In this study, in order to know the significance of platelet functions in a large artery atherosclerotic infarction, we evaluated the serial changes of platelet aggregability in patients with a large artery atherosclerotic infarction. METHODS: We serially (within 24 hrs, at 72 hrs, and 7 days) measured the extents of platelet aggregation to ADP and collagen in 43 patients with acute ischemic stroke (LAA-22, SVD-21) and compared them with those in patients with asymptomatic carotid stenosis (n=20) and in normal controls (n=24). RESULTS: The extents of platelet aggregation to ADP and collagen were significantly increased in large artery atherosclerotic infarctions compared to small vessel disease. These differences of platelet aggregability between the two groups were maintained for seven days after an ischemic event. However, the platelet aggregability was not different between large artery atherosclerotic infarctions and asymptomatic carotid stenosis. CONCLUSIONS: This data suggests that increased platelet aggregability is important in large artery atherosclerotic infarction and is caused by pre-existing atherosclerotic changes rather than acute ischemic events.