Impact of atrial fibrillation on NT-proBNP levels in a 75-year-old population

Abstract

Objective: The objective of this study was to investigate the impact of atrial fibrillation (AF) on serum levels of N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) in a 75-year-old population. Methods: All 75-year-old citizens in Asker and Baerum counties in Norway were invited to participate in a prevalence study of AF. Blood samples for measurement of NT-proBNP were collected at rest from 61 subjects with AF and a gender-matched control group of 126 subjects in sinus rhythm. NT-proBNP was measured in serum using the Elecsys proBNP sandwich immunoassay (Roche Diagnostics, Basel, Switzerland). Results: Subjects with permanent AF had higher levels of NT-proBNP (median 1119pg/mL (interquartile range 701, 1643)) than subjects with paroxysmal AF (257pg/mL (169, 382)) and controls (95pg/mL (60, 171)), p<0.001 for both. The presence of AF was still significantly associated with higher log NT-proBNP (B=0.61, p<0.001) after adjusting for the presence of heart failure, coronary heart disease and hypertension. Conclusion: In this stable, out-of-hospital population of 75-year-old subjects, AF was independently associated with increased levels of NT-proBNP. Permanent AF was associated with higher NT-proBNP levels than paroxysmal AF.

Keywords::

• Aged
• atrial fibrillation
• NT-proBNP
• population
• prevalence

Acknowledgements

The ABAF study was sponsored by the Medical Research Foundation, Asker and Baerum Hospital, Norway, and an unrestricted grant from AstraZeneca, Oslo, Norway. Roche diagnostics, Oslo, Norway, provided all NT-proBNP assays used free of charge. We are grateful to Professor Knut Gjesdal, Arrhythmia Center, Ulleval University Hospital, for reviewing the manuscript and to Oystein Flesland, at the laboratory centre, Asker and Baerum Hospital for advice on laboratory analyses and quality control.

Grant support

The study was sponsored by the Medical Research Foundation, Asker and Baerum Hospital, Norway, and an unrestricted grant from AstraZeneca, Oslo, Norway. Roche Diagnostics, Oslo, Norway, provided all NT-proBNP assays free of charge.