Development of atrial fibrillation in patients with heart failure and vice versa: incidence, risk factors, and their impact on survival.

INTRODUCTION

Atrial fibrillation (AF) and heart failure (HF) frequently coexist, and their combination is associated with poorer outcomes. The bidirectional risk and the impact of which disease develops first on mortality remain unclear.

METHODS

We studied 31 374 UK Biobank participants with new-onset AF or HF (2006-22). Multivariable Cox models assessed risk factors, incidence, and mortality risk.

RESULTS

The risk of developing HF was higher in patients with AF than in those without AF (45.1 vs 3.87 per 1000 person-years; aHR 3.15, 95% CI 3.0-3.31). The risk of developing AF in patients with HF was higher than in those without HF (25.4 vs 2.27 per 1000 person-years; aHR 2.75, 95% CI 2.62-2.90). HF patients had a 31% higher risk of subsequent AF, compared with the risk of AF patients developing HF (P < .05). Mortality risk was substantially higher in patients with both conditions. AF before HF conferred a nearly four-fold increased risk (aHR 3.8, 95% CI 3.5-4.2), while HF before AF more than doubled risk (aHR 2.0, 95% CI 2.1-2.6), compared with either condition alone. Regardless of which disease was diagnosed first, there was no significant difference in mortality risk (aHR 0.95, 95% CI 0.85-1.07).

CONCLUSIONS

AF and HF strongly predispose to each other, with HF conferring a higher relative risk for incident AF. The coexistence of both diseases substantially increases mortality regardless of which disease developed first, emphasizing the need for strategies to prevent the development of HF in patients with AF and vice versa.