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.