Search for a command to run...
Stroke happens when blood flow to part of the brain is suddenly reduced or blocked. It is a leading cause of disability and death worldwide, and many people who survive one stroke are at risk of having another. Each year, millions of people experience a stroke, and a large proportion of them live with long-term health problems. Preventing repeat (recurrent) strokes is therefore a major goal of medical care. In this study, we will focus on a condition called extracranial vertebral artery stenosis (EVAS). This means narrowing of one of the arteries in the neck that supplies blood to the back part of the brain. Narrowing can reduce blood flow and may increase the chance of another stroke, but the level of risk and the best prevention strategy are still not well understood. We will use information from a large previous study called the PRoFESS trial (Prevention Regimen for Effectively Avoiding Second Strokes). This trial included more than 20,000 people who had already had an ischemic stroke (a stroke caused by a blocked blood vessel) and followed them over time to see who had another stroke. Because this rich set of data has already been collected, we will carry out a secondary analysis, meaning we will reanalyze existing information to answer new questions. Our main goal will be to find out whether people with EVAS are more likely to have another ischemic stroke than people without EVAS. We will also look at whether strokes that affect the back of the brain (called posterior circulation strokes) occur more often than strokes in the front part of the brain (anterior circulation strokes) in people with EVAS. In addition, we will examine whether more severe artery narrowing is linked to a higher risk of another stroke. Another important aim of our research will be to understand how different antiplatelet treatments affect stroke risk in people with EVAS. Antiplatelet medicines reduce the ability of blood cells called platelets to form clots. We will compare two commonly used treatments: aspirin combined with dipyridamole, and clopidogrel. To carry out this research, we will analyze baseline information collected at the start of the PRoFESS trial and follow participants over time to see who had another stroke. We will use established mathematical methods to compare stroke risk between groups while taking into account factors such as age, sex, type of initial stroke, and other artery disease. The study will be observational, meaning we will not change any treatments but will carefully analyze existing data. We expect that our findings will help doctors better understand stroke risk in people with vertebral artery disease and choose the most effective prevention strategies. This could lead to more personalized care and fewer repeat strokes in the future.