Predictive value of NT-proBNP for cardioversion in a new onset atrial fibrillation

To detect the clinical use of N-terminal pro B-type natriuretic peptide (NT-proBNP) values for predicting cardioversion in a new onset atrial fibrillation (AF) in the emergency department.

NT-proBNP was measured in 200 patients admitted to the emergency department, in the observational unit with primary diagnosis of a new onset AF (<2 weeks). Cohort was divided into rate-control and rhythm-control groups according to the strategy used by the admitting physician. Patients treated with electric cardioversion were excluded. Primary endpoint was conversion to sinus rhythm during hospital admission.

In rhythm and rate controls, NT-proBNP was lower in patients who restored sinus rhythm (P<0.001). Same result was observed even when logistic regression was used to adjust for differences at baseline clinical characteristics. NT-proBNP of less than 450 pg/ml was associated with cardioversion in both the groups (likelihood ratio of 0.19 for rate control, and 0.27 for rhythm control) whereas a value of more than 1800 pg/ml was associated with persistent AF at discharge (likelihood ratio of 2.02 and 2.01, respectively).

In the acute setting of a new onset AF, NT-proBNP seems to predict cardioversion in rate-control and rhythm-control strategies when it is less than 450 pg/ml or more than 1800 pg/ml. In this ranges of values it might help to allocate resources and plan for patient admission and further management. There is a grey area (450-1800 pg/ml) in which NT-proBNP did not seem to be clinically useful.