Bidirectional association between atrial fibrillation and congestive heart failure in the elderly

AIMS: The aim of this study was to examine the bidirectional association between atrial fibrillation and congestive heart failure (CHF) in older adults. METHODS: We studied the association of atrial fibrillation at entry with incident CHF (N = 5281; 85% white, 42% male) and the association of CHF at entry with incident atrial fibrillation (N = 5233; 85% white, 42% male) in the Cardiovascular Health Study (CHS). Baseline atrial fibrillation was identified during the study electrocardiogram and by self-reported history, and incident cases were identified during subsequent study electrocardiograms and hospitalization data. Baseline CHF was identified by self-reported history and adjudication of medical records, and incident cases were identified using hospitalization data. Cox regression was used to compute hazard ratios and 95% confidence intervals (CIs) for the association between atrial fibrillation and incident CHF, and CHF and incident atrial fibrillation, separately. RESULTS: Over a median follow-up of 12.6 years, 534 (10%) participants developed atrial fibrillation. CHF was associated with an increased risk of atrial fibrillation (hazard ratio 2.0, 95% CI 1.4, 3.0). A total of 1692 (32%) participants developed CHF over a median follow-up of 11.7 years and atrial fibrillation was associated with an increased risk of CHF (hazard ratio 1.9, 95% CI 1.5, 2.2). CONCLUSION: Our results suggest that a bidirectional relationship exists between atrial fibrillation and CHF, with each condition influencing the development of the other.