It is found that one-third of the Americans with atrial fibrillation are wrongly prescribed aspirin instead of being prescribed warfarin or Xarelto. This wrong prescription of blood thinners by doctors to heart patients was recently concluded by the researchers of University of California, San Diego and Columbia St. Mary’s Hospital in Milwaukee.

The study was based on patients from 123 cardiology practices in the US. About 40% of people with atrial fibrillation are at a risk of stroke, the risk may stretch from a moderate to severe. This risk is often associated with aging or co-morbidity with other conditions. The researchers made use of the American College of Cardiology registry and reviewed the medical records of more than 210,000 at-risk AF patients. These records were collected between 2008 and 2012.  Patients in this cohort were aged 75 or above and had other risk factors for stroke including congestive heart failure, high blood pressure or diabetic. Amongst them, about 38% of patients were prescribed aspirin, while 62% were prescribed blood thinners.

In addition to this, a secondary analysis was also carried out for 300,000 patients who were at risk in accordance with the updated guidelines.  The patients of this cohort were between 65 and 74 years old. About 40% of the patients were treated with aspirin, while 60% were treated with anticoagulant.

It was also observed that, for both cohorts, patients who were prescribed aspirin were younger, and mostly females. These patients were also found prone to developing another medicine condition such as diabetes, high blood pressure, history of heart attack or heart bypass surgery or high cholesterol levels.

On the other hand, those patients prescribed with blood thinners were more likely to be male, heavy and had a history of congestive heart failure, stroke or blood clot.

It was surprising to find that, despite women being at a higher risk of stroke, men were being prescribed blood thinners.

The results of this study were recently published in the Journal of the American College of Cardiology.

According to estimates from the Centers of Disease Control and Prevention (CDC), 2.7-6.1 million people in the United States have atrial fibrillation. These statistics are predicted to rise in future with improved life expectancy. Atrial fibrillation often called AFib or AF, is the most common type of irregular heart beating pattern. In AF, the normal beating in the atria, the upper chambers of the heart is irregular, which disrupts the blood flow into the ventricles. As the electric impulses are disrupted, the atrial walls are unable to contract normally. This arrhythmic movement of the walls interrupts the normal blood movement into the ventricles which leads to a risk of blood clotting in the arteries. Often blood clotting takes pace in an artery in the brain which results in a stroke.  People who have AF are said to be at a risk as high as seven times of getting a stroke as compared with people who do not have AF.

The condition of AF can occur in brief episodes or may develop as a permanent condition

Lead researcher of the study, Dr. Jonathan Hsu, Assistant Professor of Medicine, Cardiology and Cardiac Electrophysiology at the University of California, San Diego, said, “Despite clear guideline recommendations that patients at risk for stroke that have atrial fibrillation should be given blood thinners, many of these patients are not prescribed these potentially lifesaving medications.”

Hsu added that aspirin helps prevent the clumping together of platelet molecules but it is not a blood thinner. He said that doctors are unaware of the guidelines that have recommended the use of anticoagulant which slows down the chemical process the leading to blood clotting. It was also discovered that the patients were usually apprehensive about the use of blood thinner and preferred to be prescribed aspirin. For such patients, the use of blood thinner is associated with bleeding. Furthermore, it is highly likely that the patients are unaware of their risk of stroke as well as the potential benefits of using blood thinners

Dr Samuel Wann, a cardiologist at Colmbia St. Mary’s Hospital in Milwaukee and co-author of the study, said that aspirin is not an anticoagulant and it does not help prevent strokes in patients with AF.

 Warfarin is one of the oldest widely-used anticoagulants. Newer drugs include dapigratran, apixaban and edoxaban. The researchers also highlighted that newer anticoagulants are expensive which discourage their regular use amongst AF patients.

This research is significant in knowing more about the association between antiplatelet drugs or anticoagulant prescriptions and the incidence of stroke in AF patients. The clinical practices and patients’ awareness about their prescriptions are also aptly highlighted in the study.

However, this study failed to look at the associated medical reasons behind aspirin prescription. Patients of cancer, kidney problems, high blood pressure and alcohol abuse are at a risk of excessive bleeding due to which recommending blood thinners is discouraged. Additionally, the study based their findings on initial prescriptions, but the use of the drug and medication modifications during follow-ups were not included.