Predictors and Prognostic Implications of Incident Heart Failure in Patients With Prevalent Atrial Fibrillation

Objectives The purpose of this study was to determine the significant clinical predictors of incident heart failure (HF) and its prognostic effect on long-term outcomes among community-based patients with established atrial fibrillation (AF). Background AF is associated with an increased risk of HF. However, in this population, little focus is placed on risk stratification for and the prevention of HF. Methods Patients with AF but without HF at baseline enrolled in the ORBIT-AF (Outcomes Registry for Informed Treatment of Atrial Fibrillation) registry were included. Separate multivariable-adjusted Cox frailty regression models were used to identify significant predictors of HF incidence and determine the associated risk of adverse clinical events. Results The study included 6,545 participants with AF from 173 participating sites. Incident HF developed in 236 participants (3.6%) over the 2-year follow-up period; ejection fraction was preserved (>40%) in 64%, reduced (≤40%) in 13.5%, and missing in 22.5%. In multivariable analysis, traditional HF risk factors (age, coronary artery disease, renal dysfunction, and valvular disease), presence of permanent AF (hazard ratio [HR]: 1.60 [95% confidence interval (CI): 1.18 to 2.16]; reference group: paroxysmal AF), and elevated baseline heart rate (HR: 1.07 [95% CI: 1.02 to 1.13] per 5 beats/min higher heart rate) were independently associated with incident HF risk. Incident HF among patients with AF was independently associated with higher risk of mortality, all-cause hospitalization, and bleeding events. Conclusions Incident HF among patients with AF is common, is more likely to be HF with preserved ejection fraction, and is associated with poor long-term outcomes. Traditional HF risk factors, AF type, and baseline heart rate are independent clinical predictors of incident HF.