Click here if you have atrial fibrillation, are age 55 or older, and want to find out your risk of stroke.

This interactive tool measures the chance of having a stroke in the next 5 years, for people with atrial fibrillation who are age 55 or older. To calculate your score, the tool uses the information you enter. The calculation is based on information from the Framingham Heart Study. During the past 50 years, the Framingham Heart Study has investigated the progression of atrial fibrillation and stroke.

You should be aware, however, that the tool cannot be applied to everyone. This tool does not work for people who:

• Have 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.