Stroke

• Have rheumatic mitral valve stenosis or significant left ventricular dysfunction, which interferes with your heart's ability to pump well.
• Are already taking the anticoagulant warfarin (such as Coumadin). Warfarin prevents clots from forming and greatly reduces your risk of stroke.
• Have had a stroke or transient ischemic attack within 30 days of developing atrial fibrillation. If so, you are already at high risk, and this tool will not work for you.

The values you enter include the most important risk factors for stroke. They are:

• Age and gender. The risk of stroke increases with age. The risk doubles every decade after age 55. Also, among those with atrial fibrillation, women have a higher risk of stroke than men.
• Systolic blood pressure. Systolic blood pressure is the first number of your blood pressure reading. For example, if your reading is 120/80 (120 over 80), your systolic blood pressure is 120 millimeters of mercury (mm Hg).
• Diabetes. Having diabetes increases your risk of stroke. You can decrease this risk by working with your doctor to keep your blood sugar levels at normal or near-normal levels.
• Prior stroke or transient ischemic attack (TIA). If you have had a stroke or a transient ischemic attack (TIA) within 30 days of developing atrial fibrillation, you are already at high risk, and this tool will not work for you. However, if you had a prior stroke or TIA before you developed atrial fibrillation, this tool will work for you.

What does your score mean?

Your score will appear in values from 1% to 99%. If your score is 5%, it means that 5 out of 100 people with this level of risk will have a stroke in the next 5 years. If your score is 10%, it means that 10 out of 100 people with this level of risk will have a stroke in the next 5 years.

These percentages are important because doctors often use them to determine whether a person should take the anticoagulant warfarin (such as Coumadin) to prevent a stroke.

If you are at a 10% risk or lower, you may get enough protection from stroke by taking aspirin. Aspirin may be preferred because the risk of serious bleeding from taking warfarin outweighs the risk of having a stroke.

If you are above a 10% risk, talk to your doctor about taking warfarin. You may benefit from this medication because your risk for having a stroke is greater than the risks from taking warfarin.

What's next?

Talk to your doctor about how to lower your risk of stroke if you have atrial fibrillation.You may be able to take medication or make lifestyle changes, such as quitting smoking or changing your diet, that can reduce your chances of stroke. While warfarin offers the best protection against stroke, it can also cause serious bleeding and other problems. Some people cannot take warfarin because they have ulcers, a high risk of falling, or other conditions that increase the risk of serious bleeding. If you have a moderate to high risk of stroke but cannot take warfarin, your doctor will probably have you take another medication. For more information, see the topic Atrial Fibrillation.