Many patients at risk for stroke get wrong medicine
MORE than a third of patients with a heart rhythm problem that can cause a stroke are incorrectly given aspirin instead of the blood-thinning medications they need to make this complication less likely, a U.S. study suggests.
Most strokes occur when an artery that carries blood to the brain gets blocked by a clot. While aspirin can prevent clots, it doesn’t work well as blood thinners to prevent stroke in these patients, guidelines say.
Researchers analyzed data on more than 500,000 people with atrial fibrillation, an irregular rapid heartbeat that can lead to stroke, heart failure and chronic fatigue.
Roughly 40 percent of these patients got aspirin instead of prescriptions for blood thinners – also called anticoagulants. “By prescribing aspirin, we may be fooling ourselves that the patient may be protected from stroke when this is not the case – blood thinners have been shown to be clearly more effective than aspirin in preventing stroke for atrial fibrillation patients,” lead study author Dr. Jonathan Hsu, a heart specialist at the University of California, San Diego, said by email.
In atrial fibrillation, electrical impulses in the upper chambers of the heart are chaotic, and the atrial walls quiver rather than contracting normally. As a result, blood doesn’t move as well to the heart’s lower chambers. This can lead to the formation of clots that can travel through the arteries. Atrial fibrillation patients have up to seven times the stroke risk of people without the disorder. To see how many atrial fibrillation patients receive blood thinners to avert clots, Hsu and colleagues reviewed medical and prescription data collected from 2008 to 2012 in a national registry of people with cardiovascular disease.
One group of about 210,000 people in the study were at least 75 years old and had other risk factors for stroke such as congestive heart failure, diabetes, or high blood pressure. Roughly 38 percent of these patients were treated with aspirin and nearly 62 percent were prescribed anticoagulants.
A second group of roughly 295,000 people were between 65 and 74 years old. Among this subset of atrial fibrillation patients, 40 percent were treated with aspirin and 60 percent got anticoagulants.
For both groups, patients prescribed aspirin were younger, slightly less overweight, and more likely to be female or have other medical problems such as diabetes, hypertension, high cholesterol, coronary artery disease, a prior heart attack or peripheral artery disease, researchers report in the Journal of the American College of Cardiology. The possibility of side effects may partly explain the limited use of blood thinners.