Winter 2012
ASK THE EXPERT: Blood Thinners

Craig McPherson, MD

Q: My doctor wants me to take a blood thinning medication for my a-fib but I’m worried about the side effects. What can you tell me about blood thinners?

Director of Cardiac Electrophysiology Craig McPherson, MD, responds:


A: If you have atrial fibrillation (a-fib) the upper chambers of your heart are not beating properly. When this occurs, blood can pool in the heart chambers and form blood clots. Pieces of those clots can break off, travel to the brain and cause a stroke.

Blood thinning medications, called anticoagulants, are usually prescribed to patients who have a-fib to decrease the chance of blood clotting and significantly reduce the risk of stroke.

There are several types of anticoagulants and there have been many recent developments in the field. Coumadin (warfarin) is the most widely known anticoagulant, but there are some well-documented problems with it: Coumadin can interact very seriously with other medications (prescription and over-the-counter) as well as many foods and beverages; dosages may change if a patient’s liver or overall health changes; patients need to take frequent blood tests to measure the effectiveness of the medication; and serious bleeding can occur. However, many studies have shown that, for most people, the risk of having a stroke from a-fib is greater than the risk of serious bleeding caused by Coumadin, so Coumadin has been prescribed for most people who have a-fib.

Recently, several new drugs have emerged that may be better for patients with a-fib. Pradaxa (dabigatran) is the newest FDA-approved alternative to Coumadin. It does not require frequent blood tests, nor does it interact with many foods and medicines. Two other potential alternatives to Coumadin will soon become available. In studies, these drugs, like Pradaxa, demonstrated a lower risk of bleeding in the brain. All are at least as effective (and may be better) than Coumadin, and they do not require frequent blood tests and dosage adjustments. Bridgeport Hospital was one of the investigative centers in trials that tested the safety and effectiveness of two of these new anticoagulants: the RE-LY study, which compared the effectiveness and safety of Pradaxa (dabigatran) to Coumadin (warfarin), and the ARISTOTLE study in which the new drug, apixaban, was compared to warfarin.

If you have been diagnosed with a-fib, the benefits of taking a blood thinning medication generally outweigh the risks. So, if your doctor has recommended an anticoagulant medication, you should take it. Your doctor can discuss the specific risks and benefits of anticoagulant therapy in your particular case and help decide which medication is right for you.