Patients on dialysis may face risk of death from atrial fibrillation: Study

The abnormal heart rhythm, atrial fibrillation, is increasingly common in patients on dialysis and is linked to a sharp rise in death, in an already at-risk population, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN).

"We found that the prevalence of this heart rhythm irregularity has increased more than three-fold from 1992 to 2006," comments Wolfgang C. Winkelmayer, MD, ScD (Stanford University School of Medicine, Palo Alto, CA).

Using data from the U.S. Renal Data System, the researchers analyzed trends in atrial fibrillation—the most common type of irregular heart rhythm (arrhythmia)—among dialysis patients. "Atrial fibrillation poses important risks for affected patients, including increased risks of stroke, heart failure, and death," Winkelmayer explains.

During the period studied, the proportion of dialysis patients with atrial fibrillation increased dramatically: from 3.5 to 10.7 percent. "However, the number of affected individuals increased six-fold, as more and more patients undergo dialysis in the United States," says Winkelmayer.

Older dialysis patients and those with other medical conditions were more likely to have atrial fibrillation. "However, only part of the increased prevalence of atrial fibrillation could be explained by increasingly older and otherwise sicker patients receiving dialysis," according to Winkelmayer. White patients were at higher risk than those of other racial/ethnic groups.

The one-year risk of death was nearly 40 percent for dialysis patients with atrial fibrillation, compared to 19 percent for those without this problem. "Having atrial fibrillation doubled the patient's mortality risk, and sadly, that excess risk did not at all decline over the 15 years of the study," Winkelmayer adds.

Take home message: Dialysis patients are at high risk of heart disease, but few studies have looked at the contribution of atrial fibrillation. The new results suggest that atrial fibrillation is a very common problem, affecting more than ten percent of dialysis patients. "Research is sorely needed to understand potentially modifiable risk factors for atrial fibrillation in this vulnerable population," Winkelmayer and colleagues conclude.

The study was limited by its reliance on billing claims data to identify patients with atrial fibrillation.