Hospitalizations Due to Atrial Fibrillation Up Sharply since 2000

Data from 3.9 million medical records show that the rate of hospitalization for atrial fibrillation (AF) increased dramatically from 2000 to 2010, but the number of AF patients dying in hospital decreased.

Researchers, who took their raw data from the Nationwide Inpatient Sample and published their analysis this month in Circulation, found a 23% jump in overall hospitalizations due to atrial fibrillation from 2000 to 2010.

Part of this stemmed from the increase in the total number of Americans (particularly older Americans), and part stemmed from a 14.4% increase (p<0.001) in the atrial fibrillation hospitalization rate, from 1,552 to 1,812 per million per year.

This increase in the hospitalization rate, in turn, likely relates to the increase in co-morbidities among patients with atrial fibrillation. Conditions such as obesity, diabetes and sleep apnea all became increasingly common among the study population during the decade. The percentage of hospitalized AF patients with kidney failure rose the fastest. It quadrupled to 12.3% by 2010.

Overall, the most common co-morbidities were hypertension, which was observed in 60% of hospitalized AF patients, diabetes (21.5%), and chronic pulmonary disease (20%).

“Atrial fibrillation is a disease in itself, but it also serves as a marker for the severity of other illnesses,” said the study’s lead author, Nileshkumar Patel, MD.

Still, despite the surge in total hospitalizations and co-morbid conditions, the total number of AF patients dying in hospital each year declined over the decade, thanks to a 25% drop (p<0.001) in the mortality rate, which fell from 1.2% in 2000 to 0.9% in 2010.

Analysis of patient demographics yielded several interesting findings.

Among patients under 65, some 66% were male. Among patients over 65, however, 61% were women. This sharp difference also shows up in the figures for average patient ages: among men, it was 66 years old; among women, it was 74. Overall, more women were hospitalized for atrial fibrillation than men, but the gender gap shrank over the course of the study.

The average length of hospital stay remained at 3 days throughout the study period, but even after adjusting for inflation, the average cost per hospitalization rose from $6,410 to $8,439.

Total inflation-adjusted costs per year rose from $2.15 billion to $3.46 billion, leaving the study’s authors worried about how high the bills will grow as the population continues to age.

Older patients cause such concern because they drove most of the total hospitalization increase. Indeed, among people over the age of 80, the AF hospitalization rate jumped from 9,361 to 11,045 per million per year.

“These figures are alarming as the number of persons aged >80 years is expected to increase from 11.4 million in 2008 to 19.5 million in 2030; which in turn will lead to an enormous increased burden on the public health system and associated cost of care,” the authors wrote.

They then speculated about some tools for controlling total costs.

“Certain interventions such as emergency room observation units vs. hospital admission, rate control vs. rhythm control and use of low molecular weight heparin vs. unfractionated heparin have been previously described as potential means to reduce the cost associated with the treatment of AF.”