Prognostic significance of natriuretic peptide levels in atrial fibrillation without heart failure

Objectives Natriuretic peptides are an important prognostic marker in patients with heart failure (HF). However, little is known regarding their prognostic significance in patients with atrial fibrillation (AF) without HF and natriuretic peptides levels are underused in these patients in daily practice. Methods The Fushimi AF Registry is a community-based prospective survey of patients with AF in Fushimi-ku, Kyoto, Japan. We investigated patients with AF without HF (defined as prior HF hospitalisation, New York Heart Association functional class≥2 or left ventricular ejection fraction<40%) using the data of B-type natriuretic peptide (BNP, n=388) or N-terminal pro-B-type natriuretic peptide (NT-proBNP, n=771) at enrolment. BNPs were converted to NT-proBNP using a conversion formula. We divided the patients according to quartiles of NT-proBNP levels and compared the backgrounds and outcomes. Results Of 1159 patients (mean age: 72.1±10.2 years, median CHA 2 DS 2 -VASc score: 3 and oral anticoagulant (OAC) prescription: 671 (56%)), the median NT-proBNP level was 488 (IQR 169–1015) ng/L. Patients with high NT-proBNP levels were older, had higher CHA 2 DS 2 -VASc scores and had more OAC prescription (all p<0.001). Kaplan-Meier curves demonstrated that NT-proBNP levels were significantly associated with higher incidences of stroke/systemic embolism, all-cause death and HF hospitalisation during a median follow-up period of 5.0 years (log rank, all p<0.001). Multivariable Cox regression analyses revealed that NT-proBNP levels were an independent predictor of adverse outcomes even after adjustment by various confounders. Conclusion NT-proBNP levels are a significant prognostic marker for adverse outcomes in patients with AF without HF and may have clinical value. Trial registration number UMIN000005834.