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Atrial Fibrillation Health Center

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Atrial Fibrillation Stroke 'Tragedy'

Too Many Strokes in Heart-Rhythm Patients Due to Coumadin Undertreatment


That's not too big a surprise, because not all patients are at high risk of stroke. But Tamariz found that high-risk patients were much less likely to be treated with Coumadin than low-risk patients.

"That is not concordant with the American College of Cardiology recommendations," Tamariz tells WebMD. "The ACC recommends that for low-risk patients you could actually use aspirin, because their lifetime stroke risk is about twice the normal risk. But high-risk patients should be on Coumadin because their stroke risk is 8% to 9%, and Coumadin could reduce it to 4%."

Coumadin: Lifesaver and Nuisance

What's the problem? Why aren't patients who should be on Coumadin getting the drug? And why are so many patients on Coumadin getting too little protection?

Coumadin is a brand name for the drug warfarin. Warfarin was originally invented to kill rodents. Later was it discovered that tiny doses of the drug act as a powerful blood thinner. But the therapeutic window -- the difference between no effect, a helpful effect, and a harmful effect -- is relatively small. And many factors, including other medical conditions or other drugs and dietary supplements, can drastically alter Coumadin's effect.

"Warfarin is known as rat poison for a reason," William O'Neill, MD, professor of medicine and cardiology at the University of Miami Miller School of Medicine, tells WebMD. "I am afraid patients at the highest risk of stroke are also those at highest risk of bleeding complications from Coumadin. It is very hard to maintain patients at the correct level long term. It is a real nuisance."

O'Neill's University of Miami colleague, electrophysiologist Robert Myerburg, MD, agrees with O'Neill that Coumadin is hard to manage.

"It is a nuisance for the patients. But the way I see it is that stroke is a bigger nuisance," Myerberg tells WebMD. "I don't know if Coumadin is underused. I agree with what this and other studies have shown: that atrial fibrillation patients inadequately anticoagulated or not on anticoagulants are at high risk of stroke."

Coumadin is a nuisance for doctors, too. It takes a lot of a doctor's time to manage Coumadin treatment, to assess elderly patients' risk of a fall (Coumadin ups the risk of deadly bleeding in elderly patients who fall) and to help patients go on and off the drug when they need a dental or surgical procedure.

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