FRAMINGHAM – One in three people are likely to develop atrial fibrillation – an irregular heartbeat that can lead to blood clots, stroke, heart failure and other complications – if they live long enough, according to recent articles analyzing the data from the Framingham Heart Study.
Social isolation, level of education and income do little to change a person’s lifetime risk of developing the disease, doctors say.
Atrial fibrillation, also known as AFib or AF, is the most commonly treated cardiac arrhythmia, according to the Centers for Disease Control and Prevention. A normal heart beats in a regular and coordinated fashion. But when people develop atrial fibrillation, the upper chambers of the heart don’t beat properly, causing the heart to beat irregularly, beating too quickly or too slowly.
“The Framingham Heart Study has generated a great deal of evidence and guided what we know about cardiovascular disease and risk factors,” said Ludovic Trinquart, a translational statistician from Tufts Medical Center who is one of the authors of papers on the subject, published earlier this spring. “Our work has focused on trying to quantify the burden of disease, atrial fibrillation, and trying to understand how it has changed over time.”
By 2030, the CDC has estimated that more than 12 million people will suffer from arrhythmia. Wearable Technology Companies, like FitBit, have even launched features which can notify users of irregular heart rhythms that could indicate atrial fibrillation.
Thanks to advances in modern medicine, people are living longer and are more likely to develop health problems as they age. Women, for example, are more likely to be diagnosed with atrial fibrillation because they tend to live longer.
The researchers hypothesized that more isolated people and people with less education and lower income would be more likely to develop atrial fibrillation. The researchers couldn’t find this link – but that doesn’t mean they were incorrect.
Mortality is key
“We found no evidence of a difference between groups with lower or higher educational attainment and groups with lower or higher household income. What we found – and this probably explains the finding – was that the mortality was different,” Trinquart said. “We also found that people with less connectivity had higher death rates.”
Basically, people in the study with fewer years of schooling and lower incomes were more likely to die before they could develop atrial fibrillation.
The exception was the socially isolated group: the few people in the socially isolated group actually had low cases of atrial fibrillation, a finding the article pointed out was more likely due to the high rate of early death of socially isolated people, rather than social isolation being the key so as not to develop arrhythmia.
Trinquart and his colleagues’ findings differ from another long-term study, “Risk of Atherosclerosis in Communities” from the National Heart, Lung and Blood Institute, which came as a surprise. The results of this study found a link between level of education, household income and the likelihood of developing atrial fibrillation, he said.
Either way, the findings are important, Trinquart said, because researchers are better able to define risk factors beyond the “clinical profile.” Bodies are complicated, and everything from exercise to midnight snacks contributes to their health and well-being — and there are many factors that researchers have yet to explore.
“If we are able to integrate information about social factors, we are likely to improve our understanding of risk,” Trinquart said. “At the population level, we might be able to better identify people at high risk for atrial fibrillation.”
Even with a diagnosis in hand, people are still at risk of losing years of their life if they develop atrial fibrillation, Trinquart said, adding that establishing that a person can develop the arrhythmia regardless of social factors “justifies , probably, invest more in primary and secondary prevention” such as early detection and targeted prevention.
Because of the long-term, multi-generational nature of the Framingham Heart Study, Trinquart and his colleagues were also able to better define lifetime risk – and how that risk has changed over the past 18 years.
“Before it was about one in four, now it’s closer to one in three. Thus, a third of individuals will develop atrial fibrillation in their lifetime,” Trinquart said. “It’s the same for everyone.”
The Framingham Heart Study, a long-term continuous cardiovascular cohort study of city residents, began in 1948 with around 5,000 volunteers. Since then, the offspring of these original study subjects have also volunteered, up to the third generation. There are currently around 15,000 participants, many of whom come from other parts of the country.
Lillian Eden can be reached at 617-459-6409 or [email protected] Follow her on Twitter @LillianWEden.