You can quit smoking, eat healthier and exercise more to lower your risk of having a heart attack, stroke, heart failure or death.

But avoiding heart disease risk factors is only as important as the quality of healthcare available to you, according to a new international study by McMaster University researchers published Wednesday in the New England Journal of Medicine.

In low-income countries where people have the lowest risk for cardiovascular disease, researchers found the highest number of major cardiovascular events, like stroke or heart failure, and death.

But high-income countries where people have greater risk of cardiovascular disease had a lower rate of death and severe heart problems.

“There is a real paradox,” said Dr. Salim Yusuf, who led the study from the university’s Population Health Research Institute.

“We have found that richer countries with higher risk factors have less heart disease and once people have a heart attack or stroke, the risk of dying is substantially less compared to poor countries,” Yusuf said.

'You can't get the treatment you need'

Research has shown the death rate from cardiovascular disease in some high-income countries has dropped off significantly since the mid-1970s, due to lowered risk factors and improved medications and medical management of the disease.

Meanwhile, cardiovascular disease has been picking up in some low- and middle-income countries. The researchers undertook the study as they tried to figure out why 80 percent of deaths each year from cardiovascular disease happen in low- and middle-income countries.

The problem appears circular in the lower-income countries.

“You can’t get the treatment you need to control the risk factors, and then when you have the heart attack or stroke, you may not make it to hospital or you may not get all the life-saving treatments that might be available in a high-income country,” said Dr. Sonia Anand, one of the McMaster researchers.

Another finding from the study showed difference in disease risk and death depending on whether people in low- and middle-income countries lived in urban or rural areas. As populations move to cities from rural areas, the chances they’re working more sedentary jobs go up, as does their risk for developing heart disease. But they’re also closer to hospitals and health care options.

So even though rural residents in low- and middle-income countries were at lower risk for developing heart disease as their urban counterparts, they were at higher risk for heart attacks and strokes and death.

Work to do no matter the income

Both ends of the income spectrum have work to do, the study suggests. The richer countries should maintain their quality healthcare systems while also encouraging people to avoid risk factors – like smoking, high cholesterol, high blood pressure, stress, obesity, diabetes, not eating enough fresh produce and low levels of exercise.

Poorer countries also should avoid those risks, but it’s not enough to have low risk factors. Those countries need to “substantially improve their health care,” Yusuf said.

The study followed more than 156,000 people, living in both rural and urban areas in 17 countries on five continents. The study focused a four-year period, but researches plan to continue to follow the population. 

The low-income countries studied were Bangladesh, India, Pakistan and Zimbabwe. The 10 middle-income countries were Argentina, Brazil, Chile, China, Colombia, Iran, Malaysia, Poland, South Africa and Turkey. And the three high-income countries were Canada, Sweden and the United Arab Emirates.