Exercise-Induced Natriuretic Peptide Secretion Predicts Cardioversion Outcome in Patients with Persistent Atrial Fibrillation: Discordant ANP and B-Type Natriuretic Peptide Response to Exercise Testing

BACKGROUND: Measurement of natriuretic peptide's (NP) release in response to hemodynamic stress may be complementary to its baseline assessment in individuals. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) increase in patients with atrial fibrillation (AF) and decrease after successful cardioversion, suggesting that AF may stimulate secretion of NPs. However, there are conflicting data on the predictive value of NPs on the cardioversion outcome. OBJECTIVES: The purpose of this study was to investigate whether baseline and exercise-induced NP plasma levels can be useful in predicting successful cardioversion of persistent AF and maintenance of sinus rhythm during 6-month follow-up. METHODS: A prospective study enrolled 77 consecutive subjects with persistent AF with normal left ventricular function, referred for elective cardioversion. Patients underwent a modified Bruce protocol treadmill exercise test 24 hours before cardioversion. Blood samples for ANP and BNP analyses were obtained at rest and 5 minutes after exercise peak. RESULTS: The group of successful cardioversion and stable sinus rhythm presented higher exercise ANP (110.6 ± 41.2 pg/mL vs 43.8 ± 36.1; pg/mL, P < 0.0001) and lower BNP increase (5.2 ± 5.2 pg/mL vs 40.5 ± 34.2 pg/mL, P < 0.0001) than the group of unsuccessful cardioversion or AF recurrence. Using an optimized cutoff level of ≤12% of relative exercise-induced increase in BNP concentration, and of >50 pg/mL of ANP increase, successful cardioversion can be predicted with high accuracy. CONCLUSIONS: An increase in ANP and stability of BNP plasma concentration during exercise testing are independently associated with successful cardioversion and maintenance of sinus rhythm during 6-month follow-up. (PACE 2010; 33:1203-1209).