Doctors could spot twice as many heart attacks in women by using a newer, more sensitive blood test, a study claims.
The test looks for minute traces of a protein that signals that the heart muscle may have been damaged.
Standard tests still used by much of the NHS only detect higher levels of this protein, called troponin.
Research from the Royal Infirmary of Edinburgh shows the standard test misses many cases of heart attack in women with symptoms like chest pain.
A heart attack is a medical emergency and early diagnosis and treatment can mean the difference between life and death.
Doctors rely on blood tests to help them judge if a patient with chest pain might be having an attack, but a normal result can mean the diagnosis is overlooked.
The British Heart Foundation-funded study, reported in the BMJ, included 1,126 men and women who had been admitted with a suspected heart attack.
Using the standard troponin test, almost twice as many men as women were diagnosed as having a heart attack - 117 versus 55.
When the researchers used the more sensitive test, the number of women diagnosed with heart attacks doubled to 111 or 22%.
In comparison, the sensitive test only spotted a handful of extra cases among the men.
And the researchers noticed that the extra men and women picked up by the sensitive test were at higher risk of dying or having another heart attack in the following year.
Researcher Dr Anoop Shah said that while similar numbers of men and women attend A&E with chest pains, women are less likely to be diagnosed with a heart attack.
- A dull pain, ache or "heavy" feeling in the chest
- A mild discomfort in the chest that makes you feel generally unwell
- Pain that spreads to the back, arm or stomach
- Pain that feels like a bad episode of indigestion
- Chest pain accompanied by feeling light-headed or dizzy
"At the moment one in 10 women with chest pains will be diagnosed with a heart attack compared to one in five men.
"Our findings suggest one reason for this difference in diagnosis rates of men and women is that we, as doctors, may have been using a threshold for troponin testing that is too high in women."
He said doctors can rely heavily on blood tests and that faced with a normal result there is the temptation to rule out a heart attack too quickly.
"For some reason, women are less likely to have obvious symptoms and if the test result comes back negative then they might be sent home only to have an event [heart attack] in the next few months because they were not treated appropriately."
Jenni Stevens, 41, from Edinburgh, had dismissed her chest pains, putting them down to stress.
When the pain got much worse her concerned colleagues called an ambulance, which took her to the Royal Infirmary.
"As much as I was frightened, I felt a sense of reassurance when I got to the hospital. They took my blood and did other tests."
Her sensitive troponin test, along with a heart trace called an ECG, alerted doctors that she was having a heart attack.
"I was treated with a stent to save my life. I'm genuinely so grateful that my heart attack was spotted and treated so well and with such compassion."
Not all UK hospitals use the sensitive test, although two different versions of it (troponin I and troponin T) have been approved by regulatory bodies.
Dr Shah and his team say more research is needed to ascertain if using a lower troponin threshold for women will save more lives - they have begun a trial to look at this.
Prof Peter Weissberg of the British Heart Foundation said: "If these results are confirmed in the much larger clinical trial we're funding, using a high sensitivity troponin test, with a threshold specific to each gender, could save many more women's lives by identifying them earlier to take steps to prevent them dying or having another, bigger heart attack."