Traditionally, most heart attacks have been blamed on clogged arteries causing atherothrombosis – where blood clots block flow to the heart. But new research suggests we may be underestimating the role of other causes, particularly in younger adults.
Scientists from the Mayo Clinic in the US analyzed 1,474 heart attack cases in people aged 65 or younger, recorded between 2003 and 2018 in Olmsted County, Minnesota. By carefully reviewing medical records and imaging, they identified a primary cause behind each case.
Atherothrombosis accounted for 75 percent of heart attacks in men, which wasn’t surprising. In women, it was the cause of 47 percent – less than half. That has major implications for the prevention and treatment of heart attacks.
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“This research shines a spotlight on heart attack causes that have historically been under-recognized, particularly in women,” says cardiologist Claire Raphael.
“When the root cause of a heart attack is misunderstood, it can lead to treatments that are less effective – or even harmful.”
Among the other factors significantly contributing to heart attacks were spontaneous coronary artery dissections (SCADs), where tears in artery walls collect blood, embolisms (blood clots traveling from other areas of the body), and other stressors acting on the body (such as anemia).
The team also found that many SCAD-related heart attacks were initially misattributed to atherothrombosis, especially in women, where SCAD was the cause nearly six times as frequently. If heart attack causes are misdiagnosed, then doctors might take the wrong approach to trying to prevent the next one.
“Our research highlights the larger need to rethink how we approach heart attacks in this patient population, and for younger adult women, in particular,” says cardiologist Rajiv Gulati.
“Clinicians must sharpen their awareness of conditions like SCAD, embolism and stress-related triggers, and patients should advocate for answers when something doesn’t feel right.”
This study didn’t explore the significant difference here between men and women, but it could be the result of heart attack risk factors affecting women differently, or women being less likely to seek medical help.
That’s something that future research can look into, as well as using the same analysis techniques across larger and more diverse groups of people.
In the US, someone experiences a heart attack every 40 seconds, and work continues to try and understand as much as we can about the risk factors – which include city living, diet, and air pollution.
The good news is, as the team notes, we’re getting better at spotting, diagnosing, and preventing heart attacks from recurring. Significant progress has been made in heart imaging technology, for example, over the study period.
The researchers now want to see more done to raise awareness of the alternative causes behind heart attacks, both with health professionals and the public – which could ultimately save lives.
“Understanding why a heart attack happened is just as important as treating it,” says Raphael. “It can mean the difference between recovery and recurrence.”
The research has been published in the Journal of the American College of Cardiology.