U.S. healthcare expenditures for the most common cardiac arrhythmia--atrial fibrillation (AF)—reach $26 billion per year, according to a study published in the May 3 issue of Circulation: Cardiovascular Quality and Outcomes.

“Atrial fibrillation (AF) is the most common manifestation of cardiac arrhythmia, and, as the population ages, the prevalence of the disease is expected to increase substantially,” Michael H. Kim, MD, of the Northwestern University, Feinberg School of Medicine in Chicago, and colleagues wrote. “Currently there are an estimated three million adults with AF in the U.S., and this figure is projected to at least double in the next 25 years.”

Because data regarding the cost burden of this common arrhythmia is incomplete, Kim et al conducted a retrospective, observational cohort study using administrative claims from the MarketScan Commercial and Medicare Supplemental research data bases between 2004 and 2006 to estimate the nation’s cost of AF.

The researchers reported inpatient and outpatient medical services and pharmacy prescriptions for each patient.

Kim et al matched 89,066 AF patients to an identical number of control patients without AF. Of these AF patients, 19.5 percent had newly diagnosed AF, 80.5 percent had pre-existing AF and 5 percent had coexisting atrial flutter. Of these AF patients, 73.5 percent of patients were administered rate-control therapy, 22 percent were on rhythm-control therapy and 57.2 percent were taking warfarin.

The researchers reported that after 12-months, two times as many AF patients were hospitalized for any reason compared to control patients, 37.5 percent vs. 17.5 percent. Additionally, three times as many AF patients had multiple hospitalizations compared to control patients, 11.1 percent vs. 3.3 percent.

Patients with AF were also four times as likely to undergo cardiovascular hospitalization compared with control patients, 21.3 percent vs. 5.4 percent, and eight times more likely to have multiple cardiovascular hospitalizations, 4.1 percent vs. 0.5 percent.

As for costs, the researchers reported that the total direct per patient costs over the 12-month post index period were $20,670 in the AF group compared with $11,965 in the control group, an incremental cost of $8,705. The total outpatient costs and pharmaceutical costs for both AF patients and control patients were $9,225 vs. $5,629 and $3,605 vs. $3,714, respectively.

The researchers attributed the large cost variations to inpatient services that were $7,841 for AF patients vs. $2,622 for control subjects. These costs were followed by office visits ($966 vs. $655) and $371 vs. $168 for emergency room services.

The researchers estimated that the annual medical costs for AF patients were 73 percent higher than the control group, a net incremental AF cost of $8,705 per patient.

“This study indicates that direct medical costs are substantially higher in AF patients than in medically matched non-AF control subjects—primarily because of higher inpatient costs (due to more frequent hospitalization/mortality) and outpatient medical costs associated with AF,” the authors wrote.

In addition, they said that less than one-quarter of total AF incremental costs were related to AF care. Based on current U.S. data, the national incremental costs of AF can range from $6 billion to a lofty $26 billion, which includes both cardiovascular and non-cardiovascular related costs.

“Atrial fibrillation is a significant issue and it is clearly causing primary hospitalizations, but we are likely underestimating its costs,” Kim concluded.