Research suggests that atrial fibrillation (AF) is the most common heart rhythm disorder, but the global burden of AF has not been estimated until recently. The World Health Organization (WHO) assesses the global burden of many public health concerns every 20 years through its Global Burden of Disease Project, but AF was not included in 1990 when the project was last conducted. To establish the global and regional prevalence of AF—in addition to its associated incidence and mortality rates—Sumeet S. Chugh, MD, FACC, FHRS, FAHA, and colleagues systematically reviewed nearly 200 population-based studies of AF.
“The most important metric that WHO established for understanding the burden that a disease imposes on society is disability-adjusted life-years (DALYs),” explains Dr. Chugh. He and his colleagues found that the burden associated with AF, measured in DALYs, increased by nearly 19% in both men and women between 1990 and 2010 (Figure 1). An estimated 33.5 million men and women had AF across the globe in 2010. The estimated age-adjusted, global prevalence rates per 100,000 population increased from 569.5 in 1990 to 596.2 in 2010 for men and from 359.9 in 1990 to 373.1 in 2010 for women. In addition, the overall incidence (Figure 2) and associated mortality rates (Figure 3) increased significantly for both genders during the study period. “AF is not a condition that directly leads to death,” notes Dr. Chugh. “However, it keeps company with many heart conditions that do.”
On the Local Level
It is well understood that patients are getting older, not only because of the baby boomer generation but also because survival rates among patients who experience cardiac events are improving, says Dr. Chugh. “Since patients are living longer, clinicians have different problems that must be addressed, including AF,” he says. “We need a better understanding on how to manage these patients and better prevent AF.”
Dr. Chugh adds that providers should recognize the connection between AF and an elevated risk of cardiovascular symptoms and stroke. “It’s important to understand how to address symptoms and minimize the chances of stroke,” he says. “Likewise, it is important to find ways to prevent AF from increasing in incidence and prevalence. This will require greater efforts to educate patients and their families about AF and the importance of treating high blood pressure and maintaining an ideal body weight with diet and exercise.”
The Future of AF
The incidence of AF is expected to increase, and Dr. Chugh says the disorder has already reached epidemic proportions. “With AF becoming increasingly common, clinicians should expect a rise in associated hospitalizations, strokes, and costs,” he says. “The factors that are driving this epidemic—such as obesity and diabetes—aren’t improving. Further complicating matters is that significant associations have been found between pollution-related particulate matter and the development of heart rhythm disorders, according to early data. If these problems aren’t dealt with on a global scale, it’s likely that the burden of AF will be even higher the next time these data are collected and reviewed.”
Although the risk of developing AF increases with age, Dr. Chugh and colleagues note that their findings most likely are not entirely explained by the aging population. “More research is needed to fully understand the continuing worldwide increase,” Dr. Chugh says. “Regional surveillance is required not just in the United States and Europe—from where 70% of the WHO data currently originates—but in all parts of the world. In some places, there may not be enough local resources or funding to finance this research. We must make a concerted effort to accurately monitor AF incidence, prevalence, and other data. Failing to do so means we won’t be able to understand if prevention efforts are working.”
In addition to accumulating more research, Dr. Chugh says it is critical that clinicians recognize the importance of treating AF in the context of stroke. “Patients with AF are often started on warfarin because it’s widely available and relatively inexpensive,” he says. “The problem with that is the drug requires patients to be closely monitored, a practice that doesn’t always occur. While effective substitutes for warfarin have emerged and are easier to use, costs for these medications can be expensive. Our goal, as physicians, is to figure out how to provide appropriate medications to more patients. Overall, the key is to treat related symptoms and address stroke risk in patients with AF. An emphasis on controlling high blood pressure and obesity is also paramount to preventing AF in those at risk.”
Chugh S, Havmoeller R, Narayanan K, et al. Worldwide epidemiology of atrial fibrillation: a global burden of disease 2010 study. Circulation. 2014;129:837-847. Available at http://circ.ahajournals.org/content/early/2013/12/16/CIRCULATIONAHA.113.005119.abstract.
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