Objective To investigate the value of plasma NT-proBNP levels in predicting the effect of drug conversion for paroxysmal atrial fibrillation.

Method The 132 patients with non-valvular paroxysmalatrial fibrillation were treated by oral loading – dose of propafenon (450–600 ng/l) within 1 h after admission. The plasma NT-proBNP concentrations were measured before and after conversion therapy.

Result Atrial fibrillation was converted to sinus rhythm in 83 patients (62.87%) after oral loading-dose of propafenone. The plasma NT-proBNP levels before drug conversion in patients with successful conversion were lower than that in patients with non-successful conversion (419.53±43.83) ng/l vs (458.11. 76±66.09) ng/l, p<0.01; and it decreased significantly after successful drug conversion (189.61±37.38) ng/l vs (419.53±43.83) ng/l, p<0.01. There was no significant difference of plasma NT-proBNP concentration before and after propefenone treatment (458.11. 76±66.09) ng/l vs (444.76±67.28) ng/l (p>0.05) in patients not converted to sinus rhythm. Receiver Operating Characteristic Curve (ROC curve) analysis was used to determine the optimal cut-off (432.25 ng/l) of this assay for identifying individuals who converted to sinus rhythm from those did not.

Conclusion Atrial fibrillation is a significant factor influencing the secretion of BNP in patients with non-valvular heart disease and plasma NT-proBNP levels can be used as a biomarker to predict the effect of drug conversion for paroxysmal atrial fibrillation.