A long-term Mayo Clinic study has found that many heart attacks in people under 65 are caused by factors other than clogged arteries, with women affected most.
The research, published in the Journal of the American College of Cardiology, evaluated 15 years of data from the Rochester Epidemiology Project.
Nontraditional causes
The study reported that more than half of heart attacks in women under 65 were linked to nontraditional causes such as spontaneous coronary artery dissection (SCAD), embolism or other conditions unrelated to plaque buildup. While heart attack rates were lower in women than in men, the underlying causes in women were more often missed or misdiagnosed.
Atherosclerosis remained the most common cause in both men and women, but it accounted for only 47% of cases in women, compared with 75% in men. SCAD, which affects younger women who are often otherwise healthy, was also frequently misclassified.
Five-year mortality was highest among patients whose heart attacks were triggered by stressors such as anemia or infection, even though these patients generally showed less heart injury.
“This research shines a spotlight on heart attack causes that have historically been under-recognized, particularly in women,” says Claire Raphael, M.B.B.S., Ph.D., an interventional cardiologist at Mayo Clinic and first author of the study. “When the root cause of a heart attack is misunderstood, it can lead to treatments that are less effective — or even harmful.”
The findings suggest that accurate diagnosis is essential. A misdiagnosed SCAD may be treated with a stent unnecessarily, which can raise the risk of complications.
Key findings
Of 1,474 heart attacks reviewed, 68% were caused by plaque buildup, though nontraditional causes accounted for most cases in women.
SCAD was almost six times more common in women than in men.
Stress-related heart attacks were the second-most common overall and the deadliest, with a five-year mortality rate of 33%.
Fewer than 3% of heart attacks remained unexplained after specialist review.
Call for awareness
“Our research highlights the larger need to rethink how we approach heart attacks in this patient population, and for younger adult women, in particular. 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,” says Rajiv Gulati, M.D., Ph.D., chair of the Division of Interventional Cardiology and Ischemic Heart Disease at Mayo Clinic.
“Understanding why a heart attack happened is just as important as treating it,” says Dr. Raphael. “It can mean the difference between recovery and recurrence.”
