Prevalence and prognostic significance of atrial fibrillation in outpatients with heart failure due to left ventricular systolic dysfunction.

Introduction: Atrial fibrillation (AF) is common in patients with heart failure (HF) due to left ventricular systolic dysfunction (LVSD), with conflicting prognostic data. The aim of our study was to assess the prevalence and incidence of AF in patients with HF and to determine the prognostic impact of baseline AF and the development of new onset AF.

Methods And Results: We included 1019 outpatients with HF due to LVSD; follow-up time ranged from 3 to 64 months. At baseline 26.4% of patients had AF. Of the 284 patients with a follow-up ECG and baseline SR, 18.7% developed new onset AF. Patients with AF were older (p<0.001), more often male (p=0.04), and more likely to have a history of stroke (p=0.03), but were less likely to have IHD (p<0.001). Baseline rhythm was independent of LVEF and NYHA-class. Baseline AF was associated with increased all-cause mortality (HR 1.38; CI 1.07-1.78, p=0.01) and all-cause mortality/hospitalisation (HR 1.43; CI 1.22-1.68, p<0.001). When adjusted for baseline covariates, baseline AF was independently associated with an increased risk of experiencing the combined endpoint (HR 1.29; CI 1.05-1.58; p=0.02), but did not predict all-cause mortality. By multivariable analyses, new-onset AF was associated with increased risk of all-cause mortality/hospitalisation (HR 1.45; CI 1.05-2.00; p=0.02).

Conclusion: In outpatients with HF due to LVSD, AF is a common co-morbidity, which adversely affects morbidity and mortality outcomes.