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Stroke prevention begins in the ER says Canadian study

Blood thinners are a proven medication to prevent strokes in patients who have irregular heartbeats. Emergency physicians may be in the best position to make sure patients start taking their medicine.
The finding that 75 per cent of patients who received an emergency department prescription for blood thinners filled it within two days of discharge suggests that what happened in the ER is highly influential with patients. (Sofia Rodriguez/CBC)

Atrial fibrillation is a common heart rhythm disturbance that can lead to strokes. These can be prevented by taking blood thinners. The challenge is to get patients to take their medicine. A study published Monday in the Canadian Medical Association Journal offers one solution.

The Heart and Stroke Foundation says roughly 200,000 Canadians have atrial fibrillation. The risk increases with age, diabetes, high blood pressure and heart disease.

Atrial fibrillation increases the risk of stroke fivefold by causing turbulent blood flow which triggers the formation of blood clots that cause strokes. The older you are, the greater the risk.

Blood thinner pills reduce the risk of stroke by 60 per cent. Guidelines for managing atrial fibrillation recommend systemic anticoagulation for almost all patients age 65 and older.

The study, by Dr. Clare Aztema and colleagues at ICES looked at 2,100 patients 65 years of age and up who visited the emergency department for atrial fibrillation at 15 Ontario hospitals. Guidelines say these patients should be taking blood thinners on a long-term basis. The researchers wanted to see which patients were still taking them six months after visiting the ER.

About 68 per cent of the patients who got their first prescription for a blood thinner from an ER physician were still taking it six months later. Just 37 per cent of the patients told instead to get it from their family doctor were still taking blood thinners a half year on.

That's a huge difference, and it suggests that ER physicians are essential to preventing strokes from atrial fibrillation.

The older you are, the greater the risk of atrial fibrillation. (ECG Rhythms, Flickr cc)

The study's finding that 75 per cent of patients who received an emergency department prescription for blood thinners filled it within two days of discharge suggests that what happened in the ER is highly influential with patients.

I'm biased because I work there, but ER visits are fear-inducing enough to get the attention of patients.The prescription for a blood thinner offers an effective way to avoid a return visit.

By contrast, patients who need to followup with their GP to obtain their first prescription for a blood thinner might wait a week or even a month. During that interval, if nothing bad happens, the patient might begin to think twice about the need to take blood thinners.

Strokes a terrible complication

It's important to keep in mind that blood thinners carry risks, and abnormal bleeding is the main drawback. Risk factors for bleeding include older age, high blood pressure and prior stroke. People who have a head injury while taking blood thinners have an increased risk of a brain bleed.

Up to 50 per cent of older patients with atrial fibrillation who should receive blood thinners do not because their physicians believe the patient is at high risk of falling and having associated bleeding. Experts in stroke prevention say doctors and patients should fear strokes much more than they fear the risk of bleeding from blood thinners. 

The bottom line is that emergency physicians should start patients with atrial fibrillation on blood thinners. That way, they'll be more likely to take them both in the short run and for the duration.

The authors of the study said a safe approach that balances the need for the medication with the risk of bleeding might be for ER physicians to prescribe short-term blood thinners by default for every patient and leaving it to the family doctor or specialist to decide on renewing the prescription. If for any reason the patient does not get follow-up care, the prescription ends, as does the risk of bleeding.

For patients, the key message is that strokes are a terrible complication of atrial fibrillation. Anything that helps prevent them should be paramount.


Dr. Brian Goldman is a veteran ER physician and an award-winning medical reporter. As host of CBC Radio’s White Coat, Black Art, he uses his proven knack for making sense of medical bafflegab to show listeners what really goes on at hospitals and clinics. He is the author of The Night Shift and The Power of Kindness: Why Empathy is Essential in Everyday Life.


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