Impact of Awareness and Patterns of Nonhospitalized Atrial Fibrillation on the Risk of Mortality: The Reasons for Geographic And Racial Differences in Stroke (REGARDS) Study

Clin Cardiol. 2016 Feb;39(2):103-10. doi: 10.1002/clc.22501. Epub 2016 Feb 16.


Background: Although mortality associated with atrial fibrillation (AF) has been reported to decrease over prior decades, the mortality risk of asymptomatic, nonhospitalized AF has not been examined.

Hypothesis: Asymptomatic, nonhospitalized AF is associated with an increased risk of death.

Methods: This analysis included 25,976 participants (mean age, 65 ± 9.4 years; 55% female; 38% black) from the Reasons for Geographic And Racial Differences (REGARDS) study. Atrial fibrillation was detected on the baseline electrocardiogram (ECG AF) or by self-reported history. Atrial fibrillation unawareness was defined as present if ECG evidence of the arrhythmia was detected but no self-reported history was reported. All-cause mortality was confirmed during follow-up through March 31, 2014.

Results: A total of 2208 (8.5%) participants had AF at baseline (ECG: n = 371/17%; self-reported: n = 1837/83%). Over a median follow-up of 7.6 years, 3481 deaths occurred. In a multivariable Cox regression model, AF was associated with a 32% increased risk of mortality (95% confidence interval [CI]: 1.19-1.46). Risk of death was higher among those with ECG AF (hazard ratio: 1.71, 95% CI: 1.42-2.07) compared with self-reported cases (hazard ratio: 1.15, 95% CI: 1.03-1.29). Those who were unaware of their AF diagnosis had a 94% increased risk of death (95% CI: 1.50-2.52) compared with AF participants who were aware of their diagnosis.

Conclusions: Asymptomatic, nonhospitalized AF is associated with an increased risk of mortality in the general population. Mortality is higher in those with ECG-confirmed cases and among those who are unaware of their diagnosis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Asymptomatic Diseases
  • Atrial Fibrillation / diagnosis
  • Atrial Fibrillation / epidemiology*
  • Atrial Fibrillation / ethnology
  • Atrial Fibrillation / mortality
  • Awareness*
  • Cause of Death
  • Chi-Square Distribution
  • Electrocardiography
  • Female
  • Health Knowledge, Attitudes, Practice* / ethnology
  • Health Status Disparities*
  • Humans
  • Incidence
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Proportional Hazards Models
  • Risk Assessment
  • Risk Factors
  • Stroke / diagnosis
  • Stroke / epidemiology*
  • Stroke / ethnology
  • Stroke / mortality
  • Time Factors
  • United States / epidemiology