Heart attacks in women are often missed in Canadian emergency rooms, in part because the blood test used to confirm them was built around male data, according to a CTV News report published Oct. 4, 2026. Research from Alberta cited in the report suggests about 300 women a year in that province are discharged from an emergency department and return with a heart attack within 30 days.
The report centres on troponin, a protein released when heart muscle is damaged. Doctors use a troponin threshold to decide whether a patient is having a heart attack. According to the report, that threshold was set using mostly male patients, and women tend to have lower troponin levels during a cardiac event. A woman can therefore be told her levels are too low for a heart attack when she is in fact having one.
One B.C. woman interviewed by CTV said she was 47 when she went to hospital with chest squeezing and arm pain. She said doctors pointed to her low troponin and her age. She pushed for an angiogram, which showed a 90 per cent blockage in an artery. Her later diagnosis was spontaneous coronary artery dissection, known as SCAD, a heart attack caused by a tear in an artery wall.
Dr. Beth Abramson, a cardiologist at St. Michael’s Hospital in Toronto, told CTV that clinicians need to “treat women as women,” including by accounting for lower troponin levels. The report also said a task force of four international cardiac societies has updated the definition of a heart attack to address the sex gap. Women also receive less preventive therapy, fewer medications, less angioplasty and less rehabilitation than men, according to the report.
The science is not settled on the fix, and that is the part the original story leaves out. A Canadian-led trial called CODE-MI, announced in March 2020 with a $1.6-million Canadian Institutes of Health Research grant, set out to test whether sex-specific troponin cut-points improve diagnosis. According to Providence Health Care, the trial involved 30 sites across Canada and began using female-specific cut-points at two Vancouver hospitals in February 2020. Its lead investigator, Dr. Karin Humphries, said at the time that women produce lower levels of the biomarker, so it is important to account for that. Providence also noted that women under 55 who have heart attacks have twice the mortality rate of men the same age.
A large 2024 study points in a more complicated direction. Researchers writing in the Journal of the American College of Cardiology looked at 16,792 patients, 46 per cent of them women. They found that a single, very low rule-out threshold of less than 5 ng/L worked safely in both sexes. Under it, 73 per cent of women and 62 per cent of men were classed as low risk, and fewer than five patients (under 0.1 per cent) had a heart attack or cardiac death within 30 days. Sex-specific cut-offs of less than 6 ng/L for women and less than 4 ng/L for men would shift few patients and were “unlikely to result in significant clinical impact,” the authors concluded, according to a summary by the American College of Cardiology. That study used one type of high-sensitivity troponin test, so it may not apply to every hospital’s equipment.
Taken together, the evidence suggests the problem is not only one number on a lab report. Missed heart attacks in women can also come from symptoms that do not match the classic picture. The CTV report notes that nausea, indigestion and shortness of breath are less likely to be recognized as cardiac, and that triggers such as childbirth, exercise and stress are specific to women. Those can lead to delays before testing even begins.
For readers, the practical takeaway is to describe all symptoms, not only chest pain, and to ask directly whether a heart problem has been ruled out if symptoms continue after a visit. Anyone with chest pain, pressure, pain spreading to the arm, jaw or back, or sudden shortness of breath should call 911. This article is general information and not medical advice.
What remains unclear is how widely Canadian hospitals use sex-specific thresholds today, and how many of the roughly 300 Alberta returns involved a missed test result versus an atypical presentation. Those answers will shape whether health systems change the number, the training, or both.
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Via CTV News / CP24: Why heart attacks in women are often missed in Canadian emergency rooms. Additional sources: American College of Cardiology journal scan of Li et al., JACC 2024; Providence Health Care (March 2020). The Alberta 300-women figure and the updated international definition rest on the CTV report alone.
