Taking a daily aspirin has been showed to help prevent a second stroke for those who have already suffered a stroke, yet fewer than half of people worldwide who have had a stroke take the medication, according to a new study.
Cardiovascular disease, including heart attack and stroke, is the leading cause of death globally. Multiple studies conducted in the 1970s and 1980s established that antiplatelet therapy — including aspirin — can reduce the risk of a second cardiovascular event, such as a second heart attack or stroke.
As a result of these studies, daily aspirin has been recommended for this purpose. Daily aspirin therapy is also generally affordable. In the U.S., a monthly supply of baby aspirin (81 milligrams per dose) can cost from $2 to $8, depending on the retailer and the amount purchased.
This new study was led by researchers at Washington University School of Medicine in St. Louis and the University of Michigan.
Study, first author Sang Gune Yoo, says: “Survivors of heart attacks and stroke often face a high risk of having subsequent events.
“In fact, many people die from having recurring attacks. Aspirin offers one effective and relatively low-cost option for reducing the likelihood of additional events in individuals with established cardiovascular disease, and yet most people who could benefit from a daily aspirin don’t take it.”
According to Yoo, the new study cannot explain why aspirin is so underused, however, it is likely that there are multiple intersecting explanations, including varying accessibility to health care in general, inconsistent messaging surrounding use of the drug, and the fact that aspirin is not always available over-the-counter and instead requiring a prescription in some countries.
Despite the benefits of aspirin, the study showed that in low-income countries, only 16.6 per cent of eligible individuals — those who had experienced a first heart attack or stroke — were taking aspirin to prevent a second heart attack or stroke. In lower-middle-income countries this number was 24.5 per cent. It increased to 51.1 per cent for upper-middle-income countries, and to 65 per cent in high-income countries, including the United States.
Myriad factors contribute to the risk of heart attacks and strokes such as smoking, diabetes, unhealthy diet, genetics, lack of exercise, obesity and even air pollution.
Aspirin works as a blood thinner, preventing small blood cells known as platelets from forming clots. These clots can block arteries and contribute to a reduction in the amount of oxygen-rich blood being delivered to vital organs. Such blockage also can cause other complications, including a heart attack or stroke.
The researchers, including senior author David Flood, MD, an assistant professor in the Division of Hospital Medicine at the University of Michigan, analysed data from nationally representative health surveys that were conducted in 51 low-, middle- and high-income countries.
The surveys included questions about people’s medical history of cardiovascular disease and on aspirin use. The study included 125,505 individuals, with 10,590 self-reporting a history of cardiovascular disease.
An earlier study that was conducted by a different group of researchers, the Prospective Urban Rural Epidemiology cohort study, was published in 2011 and found similarly low aspirin usage. Despite international efforts to improve access to cardiovascular disease medicines, including aspirin, from 2011 through 2023, aspirin remains severely underused. Yoo says this lack of progress underscores the urgent need to continue developing and implementing interventions to promote aspirin use.
Yoo, says: “We might expect that after 10 years there would be more widespread aspirin use, but things haven’t really changed.
“This research deals with a disease process that affects many people, regardless of where you live. We have to remember that this could benefit a tremendous number of people.”
According to Yoo, with interventions you should take a multipronged approach and should consider the contexts in which they’re being implemented. Such approaches could involve repurposing system-level strategies deployed to manage other chronic conditions, such as HIV/AIDS.
Yoo, says: “Particularly in lower-middle-income countries, there is often a good infrastructure for caring for patients living with HIV or other endemic disease.
“We can think about restructuring that so that we can also address comorbidities of heart attack and stroke such as cardiovascular disease as part of those existing systems, instead of having to reinvent the wheel.”
Interventions also could take place where aspirin is easily available, targeting pharmacies or primary care physicians to make the drug more accessible to eligible patients.
Yoo, says: “In order to create interventions, we have to understand what is actually going on, which is what we’re trying to establish in this study.
“Then we can start to think about how to develop strategies to increase evidence-based aspirin use in order to save lives.”
