Question: When are blood thinners necessary in treating atrial fibrillation, and what are the risks?
Answer :Perhaps the most important goal in treating atrial fibrillation is to prevent a patient from having a stroke. We mentioned earlier that atrial fibrillation will increase a patient's risk of stroke at about five fold. So this is a very serious issue. And strokes will change a patient's life forever.
Now fortunately we have guidelines that tell us when to recommend systemic anticoagulation with a drug called warfarin. Now warfarin is a medication that will thin your blood and will help lower the risk of stroke fairly dramatically in patients with atrial fibrillation. But warfarin also has risks -- it's inconvenient, you've got to check these blood tests, you've got to monitor the level -- so not everyone should be on warfarin.
Now the guidelines that have been developed are been based on what's called a CHADS2 score -- CHADS. C is for congestive heart failure. H is for hypertension. A is for age over 75. D is for diabetes. And the S is for a prior stroke. Now the score system gives you one point for every aspect of that CHADS score, except for prior stroke, which gives you two points. Now the way this works is if your CHADS score totals up to two or greater, you should be on warfarin. And you should be on warfarin indefinitely if you've been diagnosed with atrial fibrillation because you have a very significant risk of stroke, at least it's typically at least a five percent a year, especially with these individuals.
If your CHADS score is zero, you don't have congestive heart failure, you don't have a history of hypertension, you're less than 75, don't have diabetes, haven't had a prior stroke, then aspirin is sufficient. And then if you have a CHADS score of one, that means you're in a borderline category. Your risk of a stroke every year is about two percent. That's about the same as the risk of bleeding from Coumadin.
So if your CHADS score is one, either Coumadin or aspirin would be acceptable, and that's something you should discuss with your doctor.
Clearly when you're diagnosed with atrial fibrillation, or if you have atrial fibrillation, perhaps the most important thing to discuss with your physician is should you be on warfarin, and if so how long should you be on it. And you should discuss these CHADS risk factors.