Level Of Natriuretic Peptide Determines Outcome In Atrial Fibrillation.

Background: Natriuretic peptide (NP) is high in atrial fibrillation (AF) and may decrease after cardioversion to sinus rhythm and the levels of atrial NP (ANP) and brain NP (BNP) in different types of AF and whether ANP and BNP have predictive values for relapsed AF have not been determined. Purpose: We aimed to examine the levels of ANP and BNP in AF to determine their roles in different types of AF, including a predictive value in relapsed AF. Methods and Results: ANP and BNP were measured in 100 consecutive patients with AF and without heart dysfunction at baseline and in 20 controls. All patients had higher levels than controls (p<0.01). After cardioversion treatment with antiarrhythmic therapy, 40 patients failed to cardioversion successfully and still showed AF, whereas 60 patients were successful. ANP and BNP levels decreased significantly after cardioversion (163.55±54.27pg/ml vs. 200.20±55.63 pg/ml; 124.15±43.00 pg/ml vs. 161.99±48.04 pg/ml, for ANP and BNP respectively, both p<0.0001). 18 of the 60 successfully cardioverted patients had AF recurred within 24 hours, who were then excluded from 500-day follow-up and the remaining 42 patients were enrolled. During 500-day follow-up period, AF relapsed in 16 patients. Comparing with the 42 patients, the 16 patients showed higher concentrations of ANP (187.72±32.79 pg/ml vs. 138.42±30.65 pg/ml, p<0.0001). Besides, both ANP and BNP were significantly higher in the relapsed patients than those remained SR during follow-up (153.38±29.61pg/ml vs. 129.21±27.98pg/ml for ANP, p=0.01 and 147.41±25.95pg/ml vs. 121.87±20.53pg/ml for BNP, p=0.001). The area under the receiver-operating characteristic curve was 0.799 for BNP and 0.706 for ANP in predicting a relapse of AF. Using the BNP optimized cut-off level of 138 pg/ml, relapsed AF can be predicted with relatively acceptable accuracy. CONCLUSIONS ANP and BNP decrease significantly after cardioversion in patients with AF, and both can be useful predictors of relapsed AF.