Too many women are dying from heart attacks after warning signs are not recognised.
When women have heart attacks, they don't always experience them in the same way that men do.
Rather than the classic symptom of crushing chest pain, they may have less obvious signs – feeling a bit off colour or dizzy, tired, breathless, sweaty or nauseous. It can be easy for women and their doctors to miss what is happening.
"Women are also less likely to ask for help," says Gisborne cardiologist Gerry Devlin, medical director of the Heart Foundation. "They're busy and often looking after others, so they tend to ignore their symptoms."
Devlin has found that when you talk to people in coronary care units after a major cardiac event, often they will say they hadn't been feeling right for a while and probably should have seen a doctor earlier.
"One of the messages we'd really like to get across is, if you're feeling off colour, very fatigued, things are harder to do than before or you're experiencing a little chest discomfort, please don't ignore it, as these could be early warning signs.
"Although we've seen a dramatic reduction in deaths from heart attack over the past 50 years, many people who have a heart attack still don't make it to hospital."
With those non-specific symptoms, Devlin says it's about looking at the constellation of things happening, and whether they're normal for you, before you take a better-safe-than-sorry approach and head to a doctor.
Medical scientists don't fully understand why women are more likely to have non-typical symptoms. What is known is that post-menopause, the risk of cardiovascular disease rises steeply for them.
With women, the hormone oestrogen has a protective effect on the heart. Once the ovaries have ceased production, their metabolism changes, body fat increases, particularly around the torso, and blood pressure and low-density lipids (the "bad" cholesterol) rise.
"The benefit of oestrogen is there for about 10-15 years after menopause," says Devlin. "Then, women tend to catch up and have the same risks as men."
More than 50 New Zealand women die each week of heart disease, making it the single biggest cause of death for women in this country.
Those without any known risk factors are advised to get a heart check from the age of 55. Women with known heart-disease risks should be checked at 45; Māori, Pasifika and South Asian women are advised to go from age 40; and those with severe mental illness as early as 25 (their mortality rate is 2-3 times higher and cardiovascular disease is a major contributor to that).
"A heart check will include having your blood pressure and cholesterol checked, getting an HbA1c test to check if you have diabetes, and going through your family history and discussing smoking," says Devlin.
All that information is put into a calculator – the PREDICT tool developed by University of Auckland epidemiologist Rod Jackson – which estimates the risk of a heart attack or stroke over the next five years.
You can then think about doing something about that risk, whether it involves improving diet, stepping up exercise, losing weight, giving up smoking or taking medication to control blood pressure or cholesterol.
Devlin says one of the areas where preventive care could be improved is the management of high blood pressure.
"We recognise that it's a risk factor for stroke. But it's also a risk factor for coronary artery disease, heart attacks and heart failure. There are a lot of New Zealanders living with heart failure, and much of that is because of high blood pressure that's not been treated as well as it should be."
Smoking for women poses an extra risk, possibly because nicotine in their bodies is metabolised faster. Experiencing gestational diabetes or pre-eclampsia during pregnancy, or suffering from polycystic ovary syndrome, may also increase risk later in life.
In the past, many medical studies excluded women, but Devlin says researchers are now focused across all population groups. In this country, they are fortunate to have access to ANZACS-QI, a registry of New Zealanders who have needed cardiac treatment, which holds data that can be used to improve prevention and care.
As well as better understanding the differences with women, there is now a focus on identifying why Māori and Pasifika have higher rates of heart attacks than Pākehā, and whether there is a genetic signal.
"We're trying to answer some of those harder questions," says Devlin.