Medical Device Daily

A community study conducted on atrial fibrillation (AF) with Minnesota patients, most of whom had received treatment at the Mayo Clinic (Rochester, Minnesota), indicates that the cases of the condition are increasing rapidly and may reach about 16 million in the U.S. by 2050.

According to the study, published in the American Heart Association 's (AHA; Dallas) journal Circulation, “the projection of AF burden was greater in our study than that by Go and colleagues,“ a study which estimated incidence of 2.3 million in 2000 and 5.6 million in 2050.

“Atrial fibrillation is a major public health problem that needs urgent attention,“ said Teresa Tsang, MD, senior author of the study and associate professor at the Mayo Clinic College of Medicine (also Rochester). “Atrial fibrillation and its associated complications significantly decrease longevity and quality of life. From a public health perspective, it exacts a major toll on our healthcare resources.“

Atrial fibrillation is a rhythm abnormality in which the heart's upper chambers, or atria, irregularly quiver rather than beat regularly and effectively. The condition is associated with an increased risk of stroke, heart failure, cognitive dysfunction and premature death, the AHA said.

The AHA noted that previously, atrial fibrillation had been thought to affect 2.2 million Americans. The new study in Circulation, which spans 21 years of patient treatment of a specific rural population in Olmsted County, Minnesota, suggests that AF currently affects 5.1 million.

The investigators also made a projection of a three-fold increase over the next five decades if the rate of rise continues, the AHA said.

The researchers in the community-based study investigated the trends in age-adjusted incidence of AF in Olmsted County using medical records of the adult residents “who had first AF documented between Jan. 1, 1980, and Dec. 31, 2000,“ the study said.

“Final inclusion in the study population required ECG confirmation of AF and verification that the AF episode was the first AF event for the person,“ the study said. “Patients with atrial flutter alone, without any evidence of AF, were not included.“

A total of 4,618 adults were included, 51% of whom were men with an average age of 73, who developed first-documented AF during the time identified. The unified medical record for each patient containing details of all in-patient and outpatient encounters was reviewed “comprehensively,“ the AHA said.

“We found a significant increase in the number of people who newly developed this rhythm problem over the past two decades in Olmsted County, and this increased was not just because people were living longer,“ Tsang said.

The investigators said they believe that there are multiple factors behind the increase, not the least of which is the rising epidemic of obesity over the same period of the study, which they said could explain the dramatic increase.

Based on trends seen during the 21-year study period and U.S. census projections, the researchers projected that 12.1 million to 15.9 million people in the U.S. will have AF by the year 2050. The investigators in the study estimated a potential increase in the number of AF cases by “three-fold over the next 50 years, with 35%, 43% and 22% of the increase being attributable to an increase in incidence, aging of the population and increase in population size, respectively.“

Perhaps most noteworthy, the study authors wrote that they “suspect that even our projections represent conservative estimates, considering that we simply cannot determine the number of persons who have silent AF that was undetected.“

“Clinically, as cardiologists, we deal with this problem every day. Although atrial fibrillation is treatable, and some of the potential complications are preventable, the overriding goal from the clinical and societal perspective should be one of primary prevention,“ Tsang said “That is, we need to prevent the first episode of AF and the risk factors contributing to its development, if we are to turn the tide of this growing epidemic.“

The study was supported by an American Heart Association National Scientist Development Grant.