Aspirin may increase the risk of heart failure in individuals with at least one underlying health factor that predisposes them to such conditions, a new study finds.

Aspirin is a commonly-used drug prescribed, among other uses, as a blood-thinning agent. Blood thinners are anticoagulants, substances that prevent blood from clotting, or that slow down its clotting speed. They’re prescribed to individuals at risk of heart attacks and strokes in order to reduce the chances of such events taking place, as they are caused by blood clotting inside our arteries and veins (where it shouldn’t).

However, this study calls into question the wisdom of prescribing aspirin for such purposes. According to the findings, aspirin may actually increase the risk of heart failure for patients with at least one predisposing factor.

Lesspirin

“This is the first study to report that among individuals with at least one risk factor for heart failure, those taking aspirin were more likely to subsequently develop the condition than those not using the medication,” said study author Dr. Blerim Mujaj of the University of Freiburg, Germany.

“While the findings require confirmation, they do indicate that the potential link between aspirin and heart failure needs to be clarified.”

Despite its use as a preventive treatment for heart failure, aspirin’s effects on this condition remain controversial. The team wanted to provide a better look at the interaction between the two, both in patients with and without heart disease, and whether its use can promote the emergence of heart disease in patients who are already at risk of developing it.

According to the findings, aspirin use is associated with a 26% higher risk of heart failure in patients with at least one predisposing factor. These include smoking, obesity, high blood pressure, high cholesterol, diabetes, and cardiovascular disease.

The study worked with 30,827 participants enrolled from Western Europe and the US into the HOMAGE (Heart OMics in AGEing) study; all were flagged as being ‘at risk’ for developing heart failure due to one of the factors listed above. All participants were aged 40 and above (average age 67) and had not experienced any incidents of heart failure at the start of the study. Roughly 34% of the participants were women.

Their aspirin use was recorded at the start of the study, based on which they were classified as ‘users’ or ‘non-users’. Follow-up investigations were performed at the first fatal or non-fatal heart failure event that required the participant’s hospitalisation.

At baseline, a total of 7,698 participants (25%) were taking aspirin. Over the 5.3-year duration of the study, 1,330 developed heart failure.

The 26% increased risk figure was obtained after adjusting for a whole host of factors including but not limited to sex, age, body mass index, smoking, alcohol use, blood pressure, and hypertension. This means that the increase in risk observed in the study comes down to the use of aspirin exclusively.

In order to verify the results, the team repeated the analysis after matching users and non-users based on risk factors. In this step, aspirin was associated with a 26% increased risk of a new heart failure diagnosis. The authors then excluded patients with a history of cardiovascular disease from the data pool and performed the analysis yet again. Among the 22,690 participants (74% of the initial number) free of cardiovascular disease, aspirin use was associated with a 27% increased risk of developing heart failure.

“This was the first large study to investigate the relationship between aspirin use and incident heart failure in individuals with and without heart disease and at least one risk factor,” Dr. Mujaj explains. “Aspirin is commonly used — in our study one in four participants were taking the medication. In this population, aspirin use was associated with incident heart failure, independent of other risk factors.”

“Large multinational randomised trials in adults at risk for heart failure are needed to verify these results. Until then, our observations suggest that aspirin should be prescribed with caution in those with heart failure or with risk factors for the condition.”

The paper “Aspirin use is associated with increased risk for incident heart failure: a patient‐level pooled analysis” has been published in the journal ESC Heart Failure.