Heart of the matter
Heart of the matter
Around seven women a day in New Zealand die of heart disease – that’s 48 a week. It’s not just New Zealand that is affected. Globally, cardiovascular disease (diseases of the heart and blood vessels, which includes stroke) is the number one killer of women.
This May, around 6000 people are expected at the World Congress of Cardiology in Melbourne, from May 4-7. Topics include innovating for success in cardiovascular health in developing countries and global trends in obesity. There will also be a focus on women, with the fourth International Conference on Women, heart disease and stroke (in conjunction with the World Congress of Cardiology) on May 4.
The goal is to foster action globally about the prevention, identification and treatment of cardiovascular diseases in women. The conference will discuss how different women and men are when it comes to diagnosis and treatment of cardiovascular disease (CVD).
An online survey, conducted for the New Zealand Heart Foundation by Omnijet in 2011, found that approximately 70 per cent of women surveyed did not know that heart disease was the number one killer of women in New Zealand.
Getting the word out
This data has been useful in guiding the New Zealand Heart Foundation’s “Go Red for Women” campaign, which is about empowering women to put themselves first and think about their own risk of heart disease.
“Most assume breast cancer is their biggest risk. It’s very important for women to be aware of their breast health but heart disease kills three times more women so you need to get checked for both,” says Dr Robert Grenfell, Australia’s National Heart Foundation’s resident GP and Director of Cardiovascular Health.
Historically, heart campaigns and research have been male-focused because heart attacks tend to occur earlier in men than women. While these campaigns have been successful in getting men over the “death hump” of 45 to 55, they have helped perpetuate the myth that CVD mostly affects men.
A 1960s American Heart Association conference on women and CVD was titled, “How Can I Help My Husband Cope with Heart Disease?” while the American Heart Association’s public education pamphlet on a prudent diet was called “The Way to a Man’s Heart”. CVD was not seen as relevant to women and there was a corresponding under-representation of women in research into CVD. Statistics have now shown that CVD is not only a male disease, yet CVD research on women is still lagging behind men.
“In particular there remains an under-representation of women in CVD clinical trials,” says medical researcher Dr Natalie Walker, New Zealand Heart Foundation Douglas Senior Fellow in Heart Health (Prevention).
“A recent review of 156 randomised controlled clinical trials, cited in the 2007 American Heart Association guidelines for CVD, demonstrated that women made up only 25 per cent of trial participants yet were responsible for 46 per cent of the population with coronary heart disease.
“Given that it is now clear that CVD is an important cause of morbidity and mortality in both women and men, the question arises as to whether there are substantial differences in CVD patterns between the sexes.”
According to the “European Guidelines on cardiovascular disease prevention in clinical practice (version 2012)” published in the European Heart Journal, “… it is not widely appreciated that CVD is the main cause of premature death in women … responsible for 42 per cent of all deaths under 75 years of age in European women”.
It is thought that the production of the hormone oestrogen may have a protective effect on women, which could explain why a woman’s risk of having a heart attack rises after menopause.
A silent killer
CVD is a “silent killer” in women and the warning signs are hard to pick because they’re often not typical signs of a heart attack.
“Women are often aware of lifestyle factors but don’t see an association with high blood pressure or cholesterol to heart disease. They have a poor understanding of both. With high blood pressure and high cholesterol there are no obvious signs or symptoms to tell you that you have the condition,” says Julie Anne Mitchell, director of Cardiovascular Health Programs, National Heart Foundation Australia NSW Division. “Many women are ticking time bombs because they haven’t had their heart health check with their doctor – which is the only way a woman will truly know what her blood pressure and cholesterol is.
“They can be walking around not knowing. The first sign that anything is wrong is when they have a heart attack. We’re trying to catch women earlier because if their risk factors are treated early it may mean they never have a heart attack at all.”
While chest pain is common, it only occurs in a third of women who have heart attacks. Other symptoms can include an overwhelming sense of fatigue, breathlessness, extreme sense of nausea or clamminess, feeling dizzy, tingly fingers and toes, indigestion pain, excessive burping, pain in the shoulder, jaw pain or back pain, and a sense that something is not right.
“Because of the media depiction of heart attacks, the most common image we have is someone clutching their chest and falling over,” Mitchell says.
“Women delay calling 111 or getting help. They think, ‘I’ll lie down and maybe I will feel better or maybe I’ll go and see my GP tomorrow.’ By the time women present to hospital their symptoms are often much worse and the long-term outcomes can be poorer because they didn’t seek attention as soon as those symptoms started.
“If you think you are having a heart attack get yourself to hospital where they can assess you. It is far better to find out that it was indigestion than delay and then it’s too late to do anything. At the moment, half of those women who have a heart attack will die before they get to hospital because they underestimate their symptoms or have left it too long to get to the hospital,” she says.
Early diagnosis saves lives and can preserve quality of life too. A common misconception is that when you have a heart attack you die instantly, which can be true – although many people survive but with damage to the heart muscle, which is irreversible.
“You can go on to have further small heart attacks and eventually get pump failure, which is heart failure. It’s a dreadful condition to have and totally preventable,” Grenfell says.
“People also see heart disease as an old person’s disease, and it tends to be. But unfortunately we are still losing too many young people from their 30s onwards from something that is basically preventable,” he adds.
“We know from smoking statistics that a lot of younger women are taking up smoking, which is a worry. Add that to a young woman on the contraceptive pill and you are setting someone up for an early stroke.” The effects of stroke, which occurs when there is a blockage to the brain, can cause permanent damage to speech, coordination, walking and muscle paralysis.
Grenfell uses the example of one of his patients as a successful intervention. The patient had come to talk about her husband, who had undergone bypass surgery. She commented that she and her husband used to go for an evening walk but had stopped because he was too tired. She was also finding she was tired and had to stop every now and then to catch her breath.
Noticing that subtle change, Grenfell asked more direct questions about her general health and arranged for some tests to be done. It was discovered that she had a restriction in one of her coronary arteries, which was then fixed.
“She had come to see me about something completely unrelated and it turned out she was brewing a heart attack,” he says.
Risk factors include smoking, high blood cholesterol, physical inactivity, poorly controlled diabetes, high blood pressure, being overweight, harmful use of alcohol, depression, social isolation and lack of social support, as well as increasing age and family history of heart disease. The more factors you have, the greater the risk.
“The key message is, if you are over 45, get your blood pressure and cholesterol checked and ask your doctor ‘what is my heart attack risk?’ If it is higher than it should be, then make changes and you are probably extending your life,” Grenfell says.
“If you are getting aches and pains for months and [have] done nothing about it, what were you thinking? Well, you may be too busy to do anything about it now but how busy are things going to be if you are impaired or dead? There is no less blunt way of putting it.”
New Zealand is a world leader in preventative health checks in part thanks to 2012/13 Health Targets set by the Ministry of Health for ‘More Heart and Diabetes checks’ and ‘Better help for smokers to quit’.
The target was for 90 per cent of the eligible population to have their cardiovascular and diabetes risk assessed in the last five years, to be achieved in stages by July, 2014. To date, around 60 per cent of the eligible population has been screened for heart health and diabetes.
“In Australia we are not anywhere near that. [We’re] only around five to 10 per cent. We’re trying to emulate what has happened in New Zealand,” Grenfell says.
The Framingham Heart Study, which began in the town of Framingham, Massachusetts in 1948, is an ongoing study that has led to the identification of the major CVD risk factors – high blood pressure, high blood cholesterol, smoking, obesity, diabetes and physical inactivity.
The web-based, heart risk prediction system PREDICT is currently used by 40 per cent of New Zealand GPs, mainly in Auckland and Northland. Using epidemiological data from studies like the Framingham Study in the United States, PREDICT is a tool designed to work at an individual level and predict someone’s risk of having a heart attack or stroke over the next five years.
“When we know what someone’s risk is, that helps decide how intensely you should treat them. If high-risk, they would benefit from having drugs. There are now some amazing drugs that if taken over five years can halve people’s risk,” says Rod Jackson, Professor of Epidemiology at the School of Population Health at the University of Auckland and leader of the PREDICT research programme.
This year, data on 400,000 New Zealanders who have been assessed using the PREDICT system will be used to develop new heart attack and stroke risk prediction tools.
“It means we will be able to predict risk more accurately, in particular groups at high risk,” says Jackson. “The Framingham Study seems not too bad as an average but once you start looking at sub groups it’s not so good, so this will be much more accurate because we’re developing charts for Maori and Pacific, older and younger people.”
While heart disease remains the number one killer in women, it’s not all bad news. Overall risk factor levels and management of heart disease has improved significantly. Mortality trend data shows there have been 81 per cent fewer deaths from coronary heart disease in females aged 35-69 in New Zealand since 1955.
“We’re gaining about six hours of life expectancy a day, mostly because of the decline in heart disease and other vascular disease,” says Jackson. Reasons for this include people quitting smoking in greater numbers than they were in the 1960s, more awareness around the risk of consuming saturated fats (animal fats and dairy) and salt, and today there are better drugs and other treatments.
In 1964, a landmark report on Smoking and Health, released by the US Surgeon General, Luther Terry, focused on the negative health effects of cigarette smoking. It had a widespread effect on the worldwide perception of smoking and the flow-on affect has seen the progressive introduction of “smokefree” legislation many years later throughout the world, including
Jackson credits the introduction of smokefree legislation as the most important thing to have happened in health in New Zealand in the last 50 years.
He also praises the dairy industry for its innovation. “The dairy industry has done amazing things in terms of the wide variety of products now available. There was a time when there was only one sort of milk and butter available – full cream.
“Consumption of saturated fat in the meat of animals and dairy products is up there with smoking as one of the biggest causes of vascular disease. The Heart Foundation had to lobby the Government to change the law so that margarine could be sold in New Zealand. Up until 1972 you could only buy margarine on a doctor’s prescription.”
An expanding problem
Obesity and diet are topics Jackson is hot on.
“Salt consumption has gone down and blood pressure levels come down but we’ve got fatter,” he says. “One of the messages in the 1960s, when evidence was becoming clear that we should eat less saturated fat, got simplified to ‘eat less fat’ [which included the good fats]. Three things that make food tasty are fat,
sugar and salt. Because of the emphasis on fat and salt we’ve replaced it with sugar and we eat too much.”
Jackson is one of the driving forces behind the group FIZZ (Fighting Sugar in Soft Drinks), which aims to make New Zealand free of sugar-sweetened soft drinks by 2025.
“The rationale is that one of the main reasons we are getting fatter is we’re consuming too many calories and there are a lot of calories in sugar-sweetened soft drinks,” he says. “There’s nothing good in a sweetened soft drink apart from the taste. To us, one of the easiest ways of reducing calories is to take sugar out of soft drinks.”
More than one million adults in New Zealand are classified as obese. While most New Zealanders are aware that being overweight is bad for their health, many are
in denial and research suggests that almost a third of overweight adults mistakenly think their health is excellent or very good, some of whom may also have high cholesterol and high blood pressure.
It seems that as being overweight becomes more common, people believe carrying extra kilos is not a threat to their health.
“From a public health point of view, certain risk factors are increasing. More and more people are becoming obese and that’s a strong risk factor for heart disease and cancer,” says Professor Rob Doughty of the School of Medicine at the University of Auckland, consultant cardiologist at Auckland Hospital and Chair in Heart Health at the University. “If obesity is increasing we are going to start to see heart disease and other problems starting to increase as that obesity epidemic continues.”
The sedentary nature of modern life in the Western world is another contributing factor to the obesity epidemic. New evidence linking sedentary behaviour to increased risk of cardiovascular disease has led to the suggestion that “sitting is the new smoking”.
“We’ve really engineered increased physical activity out of our lives,” says Mitchell.
“We now spend most of our day sitting. It’s common for office workers to sit for breakfast, sit on the drive to work, sit at a computer for most of the day, sit on the drive home and spend two or three hours sitting in front of the TV or computer. Our lives have become a lot less active.”
Though evidence on the link between extended sitting and health outcomes is still emerging, research shows that adults who sit less throughout the day have a lower risk of early death – particularly from CVD.
“The person who is continuously active throughout the day in small bursts is better off than a person who does one episode [workout] a day and then sits all day,” says Grenfell. “We need to promote incidental physical activity to create a healthy workplace.”
The National Heart Foundation Australia has adopted a “sit less” strategy that encourages people to be more active in the workplace. Its Sydney office has more than 30 full-time users of sit-stand workstations.
They also conduct walking meetings where rather than sitting around a table they walk around the block for 20 minutes.
In 2013, the Heart Foundation Australia, in collaboration with the Prevention Research Collaboration of the University of Sydney, conducted a study titled [email protected], to determine whether providing sit-stand workstations changes sitting time in desk-based offices. When study participants were measured before they trialled the workstation, it was found they typically spent almost 80 per cent of their work day sitting.
The intervention was successful in reducing sitting time by almost 20 per cent during working hours, which equates to around one hour less of sitting.
During the study a number of people initially felt self-conscious standing but for many this feeling lessened over time.
Dr Natalie Walker is the principal investigator of a New Zealand study called Heart Health: Awareness, Preventative Action and Barriers to Cardiovascular Disease, which involves a nationally representative survey of 1100 men and women, and a second survey of 200 Maori men and women in the Western Bay of Plenty.
The goal of the research is to determine the current level of awareness of CVD in New Zealand women and compare these findings to New Zealand men.
“There are a lot of statements made about women’s heart health but when you start digging around you come across a study that’s only included women and doesn’t have any men as a comparison.
“Some of these statements are not backed up by enough evidence,” Walker says.
Walker expects the results of the survey are likely to show a number of key differences from a similar American study of 2000 women.
“One of the findings of the American survey was that many women didn’t take action to improve their heart health because of their belief that God or some higher power ultimately determines your health so you don’t have to do anything about it.
“About 84 per cent of the population in America believe in God or a higher power compared to about 60 per cent of the New Zealand population. Also the American study didn’t include a male comparison, but we have.”
Over the past decade, developments in the stem-cell field provided hope that it may be possible to re-build the heart by replacing lost cells.
Melbourne’s Baker IDI Heart & Health Institute, and other teams, have shown that heart cells have a capacity to divide, potentially replacing lost cells.
The institute is investigating the way in which cells may be encouraged to divide, in order to provide a possible method of cardiac repair.
The exciting thing about cardiovascular disease is we know most of the causes and how to prevent them. The World Health Organization has stated that more than three-quarters of all CVD mortality may be prevented with adequate changes in lifestyle.
There are many ways heart disease can be treated, from lifestyle modification to drugs that lower blood pressure and cholesterol. Innovation in stent technology is improving the management of blockage of arteries around the heart.
“You can reduce the risk and reverse it rapidly, it’s very preventable,” says Jackson.
The key is having a heart health check early so you have the choice to transform your health.
“Having a diagnosis of heart disease doesn’t mean everything is a disaster,” Doughty says.
“It’s about being proactive, it’s about thinking about our health.
“We take our car to the garage and get a warrant and expect to do something about it and we should do the same for our body.”