What's your risk of a heart attack?by Donna Chisholm
As death rates from coronary heart disease plummet, Donna Chisholm looks at who is most at risk of a life-threatening heart attack or stroke, and how long it takes for poor lifestyle choices to catch up with us.
Severyn-Parrish, an overweight, heavy smoker, had her first attack at just 46. Dave, a non-smoker, thought he was “bulletproof”, and even though he was in a high-stress job and carrying too much weight, his coronary at the age of 69 shocked him.
The pair typifies two of the biggest groups of heart patients in 2018: young, obese Māori and Pasifika with diabetes becoming ill or dying in their 40s and 50s; and older white men having coronaries in their late 60s and 70s after decades of exposure to probably only mildly increased cholesterol levels and blood pressure.
It wasn’t always this way. To see how much has changed, let’s put Chess, now 48, and Dave, 70, in the back seat of our modified DeLorean and take them Back to the Future. We’ll drop them off half a century ago in 1968 – probably outside a milk bar – where both good news and bad news awaits them.
Dave finds an ‘in memoriam’ notice for himself in the local paper and discovers he died three years before, aged 67, having never really recovered from that first heart attack he had at just 55. In those days, mid-50s men were the equivalent of today’s mid-70s blokes – and they were dropping in record numbers. Around half of non-Māori males who died in the late 1960s didn’t reach the age of 70, so his family thought he’d had a pretty good innings.
Chess’s 1960s diet is high in salt and animal and dairy fat, but it helps that she doesn’t take short-cuts on family meals with all those fast-food joints that will spring up later; the first McDonald’s is still eight years in the future.
She’s just taken up smoking, along with many other young women celebrating the early days of feminism. Although she’s felt some pressure in her chest from time to time, she reckons it’s probably a muscle strain and doesn’t think of going to the doctor about it. The 1968 Chess won’t get treated at all. She will die before she sees a hospital ward. The more savvy, present-day Chess gets to the GP, who finds she’s had a heart attack. She is admitted to hospital to have her blocked coronary artery stented.
If our 1968 Chess and Dave visit the local hospital, they’ll find medical beds filling with middle-aged Pākehā men with heart attacks. The men smoke, they are highly stressed and they work long hours. They eat meat every day, and it’s cooked in butter or lard – margarine won’t be legal for the public to buy until 1974 – but they aren’t particularly overweight. There’s not a lot to be done for them in 1968 – pain relief, a bit of oxygen and a couple of weeks’ bed rest before they return home, sometimes a much-diminished version of their former selves.
This is the year we’ve just scaled the peak of our heart disease epidemic. Doctors facing a tsunami of cases here and abroad don’t know it yet, but it will mark the beginning of a precipitous decline that continues to this day. Despite an ageing population, the death rate of about 50 per 100,000 people now is just 20% of what it was then.
Auckland University epidemiologist Professor Rod Jackson is convinced the 60s reversal in deaths was mainly the result of the dietary message hammered since early in the decade by Mediterranean diet proponent Ancel Keys, an American nutritionist who led the 25-year-long Seven Countries Study, which confirmed the first links between diet, blood cholesterol levels and heart disease.
Yes, smoking rates among men were falling and that was having an impact. But smoking among women was on the rise, and their rates of coronary disease were falling exponentially as well. Coronary artery bypass surgery, then angioplasty and more aggressive treatment in general, further accelerated the drop, as did the widespread introduction of lipid-lowering statin drugs at the start of the 2000s.
And yet, until recent years, the US-based algorithms that doctors use to estimate the percentage risk of their patients being hospitalised with a heart attack or stroke in the next five years have been more closely aligned to death and prevalence rates in the 1960s and 70s than today’s.
Doctors calculate risk based on a combination of factors including age, gender, blood pressure, cholesterol level, smoking and diabetes. Now, 30 years after beginning his research, Jackson has led a worldwide revolution to update prediction models to decide who needs preventive treatment for heart disease. Based on his work involving the medication and hospitalisation records of more than 500,000 New Zealanders, he’s discovered the old models overestimate risk by 50-100% in many people.
This is a good news story, says Jackson. It shows how population-based advice can make dramatic differences in our health. “We smoke less, we eat less saturated fat, we have better treatments.”
But what of grim forecasts that we are about to see another turning point in heart disease – this time, for the worse – as obesity rates climb, on the back of a move away from fatty foods to ones high in sugar? “Yes,” Jackson concedes, “the advances might reverse, and being fat is not good for you. But we’ve been getting fatter since 1980 – we’ve had 40 years of getting fatter and it hasn’t happened yet. So there are things far worse for you than being fat, and that’s smoking and eating a diet high in fat and salt.
“[Lack of] exercise and obesity aren’t the main drivers of heart attack and stroke risk. They can’t be, because we do far less exercise than we did 50 years ago, and we are fatter, but our heart disease and stroke rates are plummeting so there’s no way. Of course, for an individual, it’s better to exercise than not to exercise and it’s better to be normal weight. But they are second-level risk factors.
“We don’t want people to take their foot off the accelerator. Most people continue to take the right advice about the sort of food they should be eating, and smoking rates keep declining. So they are doing really well at reducing their risk, but they are eating too much.”
Reducing your risk
Another but – and it’s a big one – is that although prevalence and death rates are falling in all groups at a similar rate, they remain approximately twice as high in Māori and Pasifika people as in Europeans.
Severyn-Parrish, now 48, ticked most of the “what not to do” boxes before her heart attack in 2015: she smoked 20 cigarettes a day, was considerably overweight at 108kg, ate too much of the wrong sort of food and exercised little. A type 2 diabetic, she had blood pressure that hovered in the mid-150s. She’s now given up smoking, is trying to reduce her portion sizes and has a gym membership through work. She’s given up drinking and reduced her coffee consumption, and is taking several different drugs, including lipid- and blood pressure-lowering medication.
But lifestyle change is hard work. A retail administration manager in Napier, she’s still around 104kg and says sticking to her exercise and dietary regime is tough in winter: it’s too cold and dark to get up early to exercise, and she craves comfort food. “When you do start being naughty, or put off going to the gym, I think it’s because you forget the fear. And that happens over time. It’s fear that motivates the change.”
Dave Thomson attributes his June 2016 heart attack and angioplasty to decades of job-related stress, from 30 years in the police, to later roles in work health and safety management, and domestic violence prevention. But at 113kg after nearly 20 years in sedentary work, he was also overweight, thanks to a lack of exercise and a liking for sugary food and eating between meals.
Now 17kg lighter, Thomson has significantly cut back on sugar and, since retirement, has returned to his former sporty and outdoors lifestyle; he walks regularly, works on his Timaru lifestyle block and goes to the gym.
He says his wife Carleen, the practice manager of a medical centre, repeatedly warned him he was “a heart attack waiting to happen”, but he’d taken no heed. “She was on my back all the time. But mortality is something you don’t worry about, until it happens. And then all of a sudden you realise, ‘I’ve only got one life; I’ve only got one heart. I want to live a bit longer.’”
Watch: 5 ways to make exercising in winter easier
One of the most encouraging messages from the analysis of changes in our heart health is how quickly the course of coronary disease can be altered or reversed. For example, someone who changed to, say, a Mediterranean diet could start reducing their risk in a year or less. In randomised trials of statins, which lower cholesterol, the outcomes for those on placebos versus those on the drug start to diverge at six months. It’s simpler to reduce your cholesterol with a drug than with diet, but the effect is the same. “Changing your diet, particularly if you change it radically, can improve your outlook amazingly quickly,” says Jackson.
Statistics show how we’ve heeded that message. Mutton and lamb consumption began to decline from the early 1960s and beef sales peaked in the 1970s. Chicken has now overtaken lamb and beef and is our number one meat. The consumption of butter, which provides about 20% of all saturated fat in our diet, fell dramatically from the mid-1960s but has been on the rise since the late 1990s as the “sugar is bad, fat is better” movement gained traction.
“In the 1960s, the food industry had very little problem with the ‘eat less saturated fat’ message, because they could just replace it with another fat,” says Jackson. “But when the message in the 1980s became ‘eat less fat’ because of concern about obesity causing cancer and diabetes, they had a lot more trouble, because they had to replace fat with sugar.” Salt was already a no-no because of its hypertensive effects. The decline of death rates from stroke, which began in the 1950s, has been attributed in large part to the introduction of domestic refrigerators, which ended the need to preserve meat with salt.
Calculating the risk for a group of readers
The prediction algorithms include a deprivation index score of where the volunteers live (from one being the highest socio-economic status to five being the lowest). That tends to capture factors the other risks don’t – but doesn’t include the height, weight and BMI measures we have added below. Jackson says those will be included in the future, but on the evidence so far, they don’t appear to be highly significant. “If you get fat, your blood pressure and your lipids go up and you get diabetes, so three of the consequences of obesity are already in the equation, buried in other statistics.”
Risk prediction is an evolving field. For example, calcium scores – which use X-rays to measure the amount of calcium in the coronary arteries – are not yet included, but are likely to become increasingly important as radiation doses, and costs, reduce. The scores could be a more valuable assessment tool than blood pressure or cholesterol levels. “It’s more significant, because it’s closer to the disease process. Blood pressure affects the disease process, but a calcium score shows you how much disease you’ve got.”
We’re also not great yet at measuring other crucial factors. While we’re good at getting an accurate idea of our so-called “good” HDL cholesterol, measuring the more important levels of triglycerides is still an inexact science. Triglycerides are a type of fat (lipid), and high levels are associated with increased risk of heart disease, lower HDL and higher LDL.
Jackson won’t be drawn on how the various risk factors are weighted in the algorithms. “The more important message is you want to be a non-smoker, have good lipids, a good blood pressure, and a good weight. It’s not to focus on changing one thing a lot, but to change everything a bit,” he says.
“What kills you or causes disease is the amount of exposure. You can either be exposed to a lot for a short time or a little for a long time. So if you have a blood pressure slightly above the ideal, but you’ve been exposed to it for 50 years, your quantum of risk is the same as someone who’s been exposed to a very high level for a short time. We need to realise just how damn easy it is to reduce cardiovascular risk.”
Here’s how our volunteers fared.
Risk of suffering a heart attack or stroke in next five years: 6%
Risk at age 75: 9%
Rod Jackson: I think Erin should consider taking blood pressure-lowering and lipid-lowering drugs. Those lipids [fats] are far from ideal, and she’s been exposed to that for a long time, so it’s a cumulative thing. If her lipids were brought down to a ratio of 3, her risk would be 4.4%. With both statins and blood pressure pills, that could be further reduced to 3%.
With her current blood pressure at 155, if I were her doctor I’d have a conversation with her about doing something about it. Otherwise, she could consider dietary and lifestyle changes: increasing her exercise, reducing salt intake, switching to margarine from butter, for example. She could lower her blood pressure to around 130 without drugs. At 6%, the risk is still quite low – it’s not a medical emergency, but I’d rather have a lower risk than that.
Erin Morgan says it’s probably little wonder her blood pressure is up a bit. The test was taken just before she had a cataract operation, and she was in the midst of an unpleasant work dispute; she subsequently resigned and is now retired. Her life is still stressful – she is the main caregiver for her husband, who is terminally ill with a rare brain disease. She says she has been told her blood pressure is sometimes a bit high, and hypertension runs in her family.
Because of her commitments at home, and until recently at work, Morgan says she hasn’t had time to spare for much exercise. She did a Jenny Craig diet a few years ago and lost about 10kg, and she says the experience taught her better eating habits, including portion control.
“I’m open to considering medication, so I’ll discuss it with my GP,” she says. “My doctor did suggest medication for the cholesterol, but said I could probably just manage it with diet. So I just walked away and completely forgot about it. If at my age it was going to enhance my life, yes I’d consider it. I do want a long life.”
Risk at 75: 12.4%
Rod Jackson: David’s risk is higher than Erin, although she is the same age and her blood pressure and cholesterol levels are worse, because of gender: even after menopause, women enjoy some cardiovascular protection from oestrogen, and develop heart disease later.
Dietary changes alone could probably bring David’s current risk down to about 6%, and drugs could lower it further and faster. It’s a choice for him. Some people don’t mind taking drugs every day – I know some people who are taking statins at the age of 30 and don’t mind, because they’re lowering their risk from 2% to 1%, whereas others wouldn’t consider drugs at a 15% risk. You’d probably go for a blood pressure pill first with David, because his blood pressure is higher in relative terms than his lipid ratio.
David North says before he’d turn to medication, he’d get his blood pressure checked weekly. In the six years since he retired and moved to Riverton, he’s never been to the doctor, because he hasn’t been sick. He has, however, had a free heart check offered by the local practice when he turned 65. He says he has “white coat syndrome”, which could have raised his blood pressure during the check. “I’m one of those people who don’t like needles or getting my blood pressure taken.” He cycles two or three times a week for between 30 minutes and an hour, and says his family history may look worse than it actually is. His brother who was hospitalised at a young age was a heavy smoker and drinker at the time, but has since recovered and changed his lifestyle.
Risk at 75: 7%
Rod Jackson: Judy has a pretty perfect set of risk factors, except for her weight. If she lost a few kilos, she would probably get her blood pressure and cholesterol closer to the ideal of 120 and 3, but she doesn’t need to have another risk assessment for 10 years. Chinese people and those of other Asian ethnicities have a 25% lower risk than Europeans with the same risk measurements.
Judy Chan was pleasantly surprised by her risk assessment, saying she’s done little exercise for the past four years, although before that she did regular sets of sit-ups, crunches and steps. But that’s hardly a realistic view of her lifestyle. As a cleaner, she’s constantly on the go at work – a colleague estimated they walk around 11,000 steps in a single night shift. She says she rarely eats meat and has a mostly vegan diet; tofu is her main source of protein.
Risk at 75: 15%
Rod Jackson: He’s been a type 2 diabetic but it looks like he’s perfectly treated – his blood sugar level [using an HbA1c measure], at 38, wouldn’t qualify him as a diabetic now. You diagnose diabetes at a level of 50. His cholesterol ratio of 3 is perfect, even though his total cholesterol, at 7, is quite high. His “good” HDL is 2.32 so he’s probably running, which is associated with increased levels of HDL. His blood pressure is pretty good for a guy of 48. He stopped smoking 18 years ago, so that’s no longer relevant. He’s doing all the right things – he’s on blood pressure and statin medication and he’s motivated. Essentially he’s reversed his risk. For a diabetic ex-smoker, he’s doing great. His doctor must love him.
Andy Hammond has worked hard to bring down his heart risk. He was diagnosed with diabetes four years ago, when his total cholesterol was 7, his HDL cholesterol just 1.44 and his LDL 2.5 (ratio 4.3). Today, his HDL cholesterol is up, significantly improving the all-important ratio, and he’s dropped 24kg since October. That’s when he resumed running after a hip injury earlier in 2017 curtailed his exercise regime, and he began a low-carb diet, which he’s having no trouble sticking to.
Today, he runs between 15 and 20km a week, and his doctor recently halved the dosage of his blood pressure medication when his reading fell to 102/60. He became determined to improve his health last year when his glucose level spiked. “I thought, ‘I’m going to die if I don’t do this.’ I wasn’t looking after myself – eating too much and not doing anything, just generally being a bit of a slob.”
Because his father had a heart attack when Hammond was just 14, he’s always been conscious of his cardiovascular health – although he started smoking as a teen, he stopped at age 30. He’s surprised at how much he’s been able to reduce his risk. “The changes I’ve made have added years to my life, I think. I didn’t know my grandparents, and my parents didn’t meet their parents. I have two daughters aged 10 and 12 and I really want to meet my grandchildren.”
Risk at 75: 5%
Rod Jackson: Zena has fantastic lipids, fantastic blood pressure, is a non-smoker and has no diabetes. She won’t need another risk assessment for 10 years. If your risk is between 3 and 5, you’d measure it again in five years. If it goes over 5, you might want to have a conversation about going onto drugs, or increasing the dose of the drugs you’re on. Everyone’s risk does increase with age – you can modify that if you have modifiable factors, but it doesn’t look as if Zena can do more than what she’s already doing.
Zena Taylor says she might simply have good genes, but she’s also walking the walk as well – or running it. She jogs about 5.5km daily, practises yoga most days and eats “pretty sensibly”. “If I feel like cake, I’ll have it, but I’m not a big eater – I never have breakfast and have fruit for lunch. I’ve tried to up the ante with salad greens as I’ve got older.” She says her blood pressure has always been low, “but I’ve no idea why”.
Risk at 75: 16%
Rod Jackson: Steve’s mother probably had a subarachnoid haemorrhage, which means she had a weakness in one of her brain arteries. It’s more common in women, probably not hereditary and therefore irrelevant to his cardiovascular health. If she had dropped dead with a coronary, that would be important. Steve’s risk at the age of 75 will be pretty high. His blood pressure is reasonably well controlled, but dietary changes could get the cholesterol level down.
Steve Philp says he started on blood pressure medication about five years ago when his readings began tracking up. “I’d been through a marriage split, which didn’t help my blood pressure.” He’s lost nearly 15kg since his peak weight of about 135kg three years ago. Since then, he’s left his sedentary job to freelance – and is doing more exercise. He’s joined a tennis club, cycles and practises yoga. “I started playing tennis for the social aspect of it, but I started to build fitness and I’m feeling much better for it.” He’s switched to a low-carb diet, and has cut out highly processed foods and those high in sugar. “I know I don’t eat enough green vegetables, and I’m trying to eat more.”
50, HR worker, Auckland central
Blood pressure: 120
- No family history
- Taking blood pressure medication daily
- Taking lipid-lowering medication daily
- Not taking aspirin or equivalent
- Never smoked
- Type 2 diabetic, on insulin, Metformin, Gliclazide
- Never had atrial fibrillation
Risk at 75: 14%
Rod Jackson: Glancing at Rosaria’s risk factors, she looks to be quite high risk, so I was quite surprised to find it was only 4% – partly because youth is on her side. She has been well treated, and lives in a high socio-economic area. The “local” is [health store] Huckleberry Farm, not Carl’s Jnr, so you’d have to travel further to get rubbishy food. Her blood pressure is ideal but her lipids are too high. As a Pasifika person, she’s at around 20% higher risk of having a cardiovascular event than a European with identical risk factors. If you’re a Māori woman, you’re at 50% higher risk. So being Māori or Pasifika increases your risk in and of itself, but we don’t know if the increased risk is a proxy for some aspect of diet, for example; we can’t say it’s genetic. It’s less important what individual factors go into the assessment – what’s important is what comes out.
Rosaria – not her real name, because she prefers to be anonymous – says she knows she needs to exercise more, but health issues, including brain surgeries in recent years, have not helped. She sees a doctor every three months for check-ups, and to monitor blood pressure and cholesterol. “I have reduced my sugar intake. I’ve returned to my three-times-a-week walks to tone up, lose weight and combat depression. I’ve been referred to a “green prescription programme” created specifically for people with diabetes, and I’m looking at re-joining the YMCA gym programme. I need to concentrate on my health now, and with the information provided by Dr Jackson and my recent blood tests, I’ll be working to improve. No more excuses! I want to be in the best of health now and to reach my 70s.”
Risk at 75: 16.5%
Rod Jackson: All of Dean’s risk factors are slightly raised, but he doesn’t have to freak out and I wouldn’t suggest he start taking drugs. We suggest considering drugs once your risk is over 5%, because then, we know drugs do more good than harm. Losing a bit of weight and changing his diet away from saturated fats and red meat would likely make a real difference. He’s probably just eating a bit too much of the wrong things.
Dean Teiho says he tries to walk every other morning, from 3 or 4km up to 8km some days, and he’s been doing that for a couple of years. He’s about 7kg above the weight at which he feels fittest, although he tries to watch “my carbs”. He eats a lot of meat, which is probably why his cholesterol ratio is higher than ideal.
Risk at 75: 10%
Rod Jackson: Tim has a significant family history with his father, and, because he started cholesterol-lowering medication at a young age, he must have also had abnormal lipids. He’s on a good dose of a very effective statin and his cholesterol ratio now is perfect.
If you’ve got a first-degree relative who’s had a heart attack in their early 40s and a triple bypass, it’s almost always because of a genetic lipid disorder. His blood pressure is a bit high and we usually suggest people try to lose some weight, exercise more, eat less salt and reduce alcohol consumption. As Tim has the ideal weight, I’d suggest he considers reducing his salt intake and, if he drinks regularly, to consider reducing the amount.
Tim Peters accidentally discovered his high cholesterol – his total was 9 or higher – when he had a blood test for another illness when he was only 29. “I’m needle-phobic; I don’t like going to the doctor. That changed when I found I had high cholesterol. Now, I have a yearly blood test.” He was first put on a low drug dose, which had to be increased before it was effective.
Already active before the diagnosis, regularly running 80-100km a week, he’s done five marathons, the last in 2011. He no longer runs as far (30-40km a week), but supplements that with several days of gym work. He put himself on a low-dose aspirin around the time of his diagnosis but stopped because it didn’t seem to make a difference. “I was always sporty and I enjoy exercise anyway, but I’m aware keeping fit is important for my long-term health.” Based on Jackson’s review, he’ll try to reduce both his alcohol and salt intake.
Our participants were all relatively low risk, but what do those at the other end of the spectrum look like? Jackson created these two patient profiles to show how quickly risk can escalate.
72, retired, New Lynn, Auckland
Blood pressure: 140
• No family history
• Not taking blood pressure-lowering medication
• Not taking lipid-lowering drugs
• Never smoked
• Type 2 diabetic
• Never had atrial fibrillation
Risk at 75: 15%
Rod Jackson: Geetha’s risk factors are all moderately raised, and over many years, this leads to a fairly substantially increased chance of a heart attack or stroke in the next five years. And as an ethnic group, Indian people are at nearly 30% more risk than Europeans with the same risk factors.
45, labourer, Porirua, Wellington
Blood pressure: 150
• Father died of a coronary before the age of 50
• Not taking blood pressure medication
• Not taking lipid-lowering medication
• Type 2 diabetic
• Never had atrial fibrillation
Risk at 75: 49%
Rod Jackson: Mike has been exposed for a relatively short time to very high risk factors. If he stopped smoking, his risk would drop to about 15%, and if we treated his high lipid levels with statins, we could drop that to 10%. If he also reduced his blood pressure, his risk would come down to just 7.5%. So, a change in lifestyle and treatment could make a dramatic difference.
I'm sorry Rod Jackson...
Professor Rod Jackson has been warning about the perils of saturated fat – particularly butter – so often, and for so long, that one of his medical students turned his professional obsession into entertainment. Here’s the video the students produced in 2010, I’m Sorry Rod Jackson. It’s had 35,000 views so far, but given its medical subject matter, doesn’t it really deserve to go viral?
This article was first published in the August 2018 issue of North & South.
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