Temporal relationship and prognostic significance of atrial fibrillation in heart failure patients with preserved ejection fraction: a community-based study.

BACKGROUND In patients with heart failure and preserved ejection fraction (HFpEF), atrial fibrillation (AF) may predate, concur with, or develop after HFpEF diagnosis. We sought to define the temporal relationship between AF and HFpEF, to identify factors associated with AF, and to determine the prognostic impact of prevalent and incident AF in HFpEF. METHOD AND RESULTS From 1983 to 2010, 939 Olmsted County, Minnesota, residents (age, 77±12 years; 61% female) newly diagnosed with HFpEF (EF ≥0.50) were evaluated. Baseline rhythm classification included prior AF (>3 months before HFpEF diagnosis), concurrent AF (±3 months), or sinus rhythm. Incident AF (>3 months after HFpEF diagnosis) and all-cause mortality were ascertained through February 2012. Prior AF (29%) and concurrent AF (23%) were associated with older age, higher brain-type natriuretic peptide, and larger left atrial volume index at HFpEF diagnosis compared with sinus rhythm. Of HFpEF patients in sinus rhythm at diagnosis, 32% developed AF over a median follow-up of 3.7 years (interquartile range, 1.5-6.7 years; 69 events per 1000 person-years). Age and diastolic dysfunction were positively and statin use was inversely associated with incident AF. With no AF used as the referent, prior or concurrent AF (combined hazard ratio, 1.3; 95% confidence interval, 1.0-1.6; P=0.03) and incident AF, modeled as a time-dependent covariate (hazard ratio, 2.1; 95% confidence interval, 1.4-3.0; P<0.001), were independently associated with death after adjustment for pertinent covariates. CONCLUSIONS AF occurs in two thirds of HFpEF patients at some point in the natural history and confers a poor prognosis. Further study is required to determine whether intervention for AF may improve outcomes or if statin use can prevent AF in HFpEF.