• Posted August 22, 2023

Skipping Aspirin After Heart Attack Raises Odds for Recurrence

If you've had a heart attack, your doctor likely told you to take a low-dose aspirin daily to stave off a second heart attack or stroke, but most people don't follow through with this advice over the long-term.

Those folks who don't take daily low-dose aspirin consistently are more likely to have another heart attack, stroke or die compared with their counterparts who consistently take aspirin, a new study shows. Aspirin keeps platelets from clumping together, which can help prevent or reduce the blood clots that can cause heart attacks and strokes.

"Most people should be on lifelong aspirin after a heart attack,"said Dr. Deepak Bhatt, director of Mount Sinai Heart and professor of cardiovascular medicine at the Icahn School of Medicine in New York City.

"Long-term adherence to medication is a problem worldwide, including in the USA, and this is true even for inexpensive drugs such as aspirin, which can be life saving in heart attack patients,"said Bhatt, who had no role in the research.

The study was led by Dr. Anna Meta Kristensen of Bispebjerg and Frederiksberg Hospital in Frederiksberg, Denmark.

The researchers followed more than 40,100 people aged 40 or older who had a first-time heart attack from 2004 through 2017. The study team checked up on aspirin use two, four, six, and eight years after their heart attacks to see who was still taking daily aspirin regularly. Anyone using other blood thinners was not included in the study.

Denmark keeps a national registry of medication use including aspirin. People on aspirin for 80% or less of the time were considered to be non-adherent or not taking aspirin as prescribed. By contrast, folks who took aspirin more than 80% of the time were considered adherent.

People stopped consistently taking aspirin over time. At two years, 90% of heart attack survivors were still taking daily aspirin consistently, and this fell to 84% at four years, 82% at six years, and 81% at eight years, the study showed. People who didn't take aspirin consistently were more likely to have another heart attack, a stroke or die at all follow-up points. At four years, the risk for nonadherent patients was 40% higher compared to patients who took low-dose aspirin as prescribed.

The research was scheduled for presentation Aug. 25 to 28, at the European Society of Cardiology meeting in Amsterdam. Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.

"This study emphasizes the importance of correctly taking aspirin after experiencing a first cardiovascular event,"said Dr. Silvia Castelletti, a cardiologist in Milan, Italy. "Doing so reduces the chances of having another heart attack, as well as the risks of stroke or death,"said Castelletti, who has no ties to the new research.

The study wasn't designed to say why aspirin use wanes over time, and it cannot prove causation.

However, "patients often forget to take aspirin if they are taking multiple medications,"Castelletti said. "Additionally, some patients may experience gastrointestinal issues related to aspirin and choose to stop taking the medication on their own."

While aspirin can lower the risk of heart attacks and strokes, it can also increase the risk of gastrointestinal (GI) bleeding and stomach ulcers. "To minimize these risks, it is recommended to take aspirin during a main meal and regularly use gastroprotective medications,"she said. Proton pump inhibitors, such as Nexium, Prevacid and Prilosec, can reduce the GI side effects of aspirin.

It's important to note that not every heart attack survivor can or should take aspirin to prevent a second heart attack. "If a patient is allergic to aspirin, it should not be used in their therapy after a heart attack,"Castelletti said.

There are many reasons for not adhering to aspirin recommendations, said Bhatt. "At the time of a heart attack, patients are not feeling well and are focused on doing whatever is necessary to get better,"he said. As the time from the heart attack increases and they feel well, there may be less motivation to continue taking preventive medicines.

Unfortunately, this behavior puts them at an increased risk of another heart attack, he added.

A related study published in the Aug. 22 issue of the Journal of the American Medical Association showed that daily aspirin use after a heart attack is lacking across the globe. Fewer than half of all people worldwide who have had a heart attack or stroke take daily low-dose aspirin.

And there hasn't been much of a dent made in these statistics in the past decade.

"We know aspirin use is low overall so we need to find ways to intervene at the patient-provider-level to increase use,"said study author Dr. Sang Gune K. Yoo. He is a fellow in the cardiovascular division at Washington University School of Medicine in St. Louis. "The solution is likely multi-factorial and will involve improved patient education on the benefits of aspirin therapy after a heart attack and greater access to aspirin."

He agreed with Castelletti that not every heart attack survivor should take aspirin. "It's important to discuss the risks and benefits with your doctor,"Yoo said.

More information

Learn how to recognize the signs of a heart attack.

SOURCES: Silvia Castelletti, MD, cardiologist, Milan, Italy; Deepak Bhatt, MD, director, Mount Sinai Heart, and professor, cardiovascular medicine, Icahn School of Medicine, New York City; Sang Gune Yoo, MD, cardiovascular disease fellow, cardiovascular division, Washington University School of Medicine in St. Louis.; European Society of Cardiology Congress 2023, Amsterdam, Aug. 25-28, 2023; Journal of the American Medical Association, Aug. 23, 2023