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

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 1119 pg/mL (interquartile range 701, 1643)) than subjects with paroxysmal AF (257 pg/mL (169, 382)) and controls (95 pg/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.