The increasing prevalence of atrial fibrillation among hemodialysis patients

Abstract

A half million Americans have ESRD, which puts them at high risk for cardiovascular disease and poor outcomes. Little is known about the epidemiology of atrial fibrillation among patients with ESRD. We analyzed data from annual cohorts (1992 to 2006) of prevalent hemodialysis patients from the United States Renal Data System. In each cohort, we searched 1 year of medical claims for relevant diagnosis codes to determine the prevalence of atrial fibrillation. Among 2.5 million patient observations, 7.7% had atrial fibrillation, with the prevalence increasing 3-fold from 3.5% (1992) to 10.7% (2006). The number of affected patients increased from 3620 to 23,893 (6.6-fold) during this period. Older age, male gender, and several comorbid conditions were associated with increased risk for atrial fibrillation. Compared with otherwise similar Caucasians, the prevalence of atrial fibrillation rates was substantially lower for blacks, Asians, and Native Americans. One-year mortality was twice as high among hemodialysis patients with atrial fibrillation compared with those without (39% versus 19%), and this increased risk was constant during the 15 years of the study. In conclusion, the prevalence of diagnosed atrial fibrillation among patients receiving hemodialysis in the United States is increasing, varies by race, and remains associated with substantially increased mortality. Identifying potentially modifiable risk factors for incident atrial fibrillation requires further investigation.

Figures

Figure 1.

Trends in the prevalence of AF in U.S. patients receiving hemodialysis, 1992 to 2006. (A) Prevalence of AF among all prevalent hemodialysis patients on December 31 of 15 consecutive years: comparison of three different algorithms to ascertain AF. Prevalence of AF, defined by more than two diagnosis codes in the same calendar year, among prevalent hemodialysis patients on December 31 of 15 consecutive years by (B) age group, (C) gender, (D) race, (E) dialysis vintage, and (F) diabetes.

Figure 2.

Adjusted relative prevalences of AF by age group. Patients aged

Figure 3.

Adjusted relative prevalences of AF by calendar year. Patients in the 1992 prevalence cohort constituted the reference group. Fully adjusted model included age, gender, race, dialysis vintage, Medicaid eligibility, and all available indicators of comorbid conditions.

Figure 4.

Crude 1-year mortality in U.S. patients receiving hemodialysis, 1992 to 2005, by absence versus presence of AF. No censoring was applied for receipt of a kidney transplant or for switching to peritoneal dialysis. No data were available for the 2006 cohort because of incomplete follow-up for the year 2007.