For some cardiac patients with stents, long-term aspirin treatments might be on the way out

For some high-risk cardiovascular patients with stents, the often-recommended practice of prolonged taking of aspirin might be ineffective, and in some cases, even harmful, a new study found.

The report, published in the scientific journal Circulation, looked at more than 7,500 patients with acute coronary syndrome: a term that describes a variety of heart conditions — including heart attacks — caused by a sudden drop in blood flow to the heart.

To treat the condition, each of the patients was undergoing a common procedure called percutaneous coronary intervention, in which doctors thread a small balloon into the body to open the blocked artery. They also insert a metallic mesh tube called a stent into the coronary artery, which props up the blood vessel and keeps blood flowing. To prevent blood clots from forming after putting in the stent, most doctors recommend taking a combination of an antiplatelet medication and aspirin for about a year.

However, the study found that getting rid of aspirin from the regimen after three months was just as effective in avoiding clotting complications — while significantly reducing the risk of severe bleeding that aspirin can cause.

“You often think to yourself, ‘What’s aspirin really doing being next to a very, very potent agent already? ’ ” said Dr. Roxana Mehran, the study’s principal investigator and a cardiologist at the Icahn School of Medicine at Mount Sinai. “What is it doing except to profoundly increase the bleeding risk?”

Potential for new standard of care

Cardiovascular diseases are the leading cause of death worldwide, responsible for nearly 18 million deaths each year, according to the World Health Organization.

For years, medical professionals widely recommended regular aspirin to prevent heart problems, since aspirin can reduce blood clotting to prevent complications like heart attacks or strokes.

However, the medication could also increase the risk of severe bleeding, particularly as people get older.

As a result, in 2019, the American College of Cardiology and the American Heart Association shifted course and no longer recommended daily aspirin as a preventative for older adults who don’t have a high risk or existing heart disease. And in 2022, the United States Preventive Services Task Force recommended against a daily aspirin for people over 60.

 For healthy, younger adults with an increased risk of heart attack or stroke, daily aspirin could have a modest benefit, though experts still recommend weighing it against the risk of bleeding.

Still, many health care professionals still consider aspirin to be beneficial for many patients who have heart problems or have a stent. The new study’s results, however, might challenge that assumption.

Using pooled patient data from two large clinical trials — one that Mehran helped conduct in the United States and a separate trial from collaborators in South Korea — the researchers looked at patients with acute coronary syndrome who were receiving ongoing therapy to prevent clotting after getting stents.

Normally, patients take a combination of aspirin and a potent anti-clotting medication called ticagrelor for up to a year after getting the stent. However, the report found that patients who stopped taking aspirin after three months fared just as well as those on the aspirin-ticagrelor combination therapy: rates of death, heart attacks, and strokes were the same in both groups.

Dropping aspirin also reduced the risk of severe bleeding by nearly 50% compared with patients on the combination therapy, said Mehran — without increasing the risk of cardiac complications.

It’s a finding that experts believe could lead to a new standard of care for high-risk cardiac patients. Given the results of her clinical trial and a growing amount of evidence suggesting that long-term aspirin may not be beneficial for acute coronary syndrome, Mehran prescribes a treatment plan without long-term aspirin for her own patients.

She also believes that aspirin can be removed from the regimen even earlier — potentially after a month. That shortened time frame, she added, is being investigated by several ongoing studies.

“If we have good evidence that aspirin is not doing much of anything except to increase bleeding in that vulnerable period, why not withdraw aspirin after a certain amount of time?” Mehran said.

Aspirin remains ‘an essential therapy’

However, experts agree that aspirin remains a beneficial medication for heart conditions.

“The public should know that aspirin remains an important treatment for a heart attack, and in these studies, it was an essential therapy in the 3 months after receiving the stent,” Dr. Harlan Krumholz, a cardiologist and professor at the Yale School of Medicine, wrote in an email to CNN.

For one, the results do not apply for patients who have other heart problems, such as atrial fibrillation, a condition that requires blood thinners to treat.

“We are not saying that aspirin is terrible and should be stopped in all patients; that is not at all the message,” Mehran added.

The report focused on a select group of high-risk patients recovering from acute coronary syndrome and a stent placement, and eliminating aspirin from their treatment plans is contingent on the patients taking ticagrelor twice a day for at least a year.

Patients in the study also needed to make it through the first three months of combination therapy without any complications before aspirin was removed from their regimen.

Krumholz believes that further research that looks to simplify medication plans could also improve patients’ health.

“We need more studies like these where we are testing the value of withdrawing medications people are on — instead of just assuming that we need to continue them,” he wrote. “This study helps us understand how we can safely simplify the drug regimen for these patients, and by subtracting a drug, we can actually improve outcomes.”