Background: Some small studies have suggested that low levels of brain natriuretic peptide (BNP) measured before electrical cardioversion for atrial fibrillation (AF) may be associated with maintenance of sinus rhythm after the procedure. We hypothesized that 1) plasma levels of N-terminal fragment of proBNP (NT-proBNP) measured before cardioversion were predictive of AF recurrence, 2) treatment with candesartan would influence the levels of NT-proBNP, and 3) restoration of sinus rhythm would reduce the levels of NT-proBNP.
Methods: We investigated 171 patients with persistent AF who underwent electrical cardioversion in a prospective, blinded, placebo-controlled clinical trial (Candesartan in the Prevention of Relapsing Atrial Fibrillation, CAPRAF). Plasma levels of NT-proBNP were measured at baseline and at the end of the study. Patients with congestive heart failure were excluded from the study.
Results: Baseline NT-proBNP levels were similar in patients with unsuccessful cardioversion (n=22), patients with successful cardioversion remaining in sinus rhythm (n=40) and patients with successful cardioversion who had a relapse of AF (n=89): median (interquartile range) 73.9 pmol/L (43.2, 145.6); 88.2 pmol/L (59.2, 147.5) and 90.0 pmol/L (55.3, 138.4), respectively. Maintenance of sinus rhythm was associated with a significant reduction in NT-proBNP levels, whereas NT-proBNP levels were not affected by treatment with candesartan.
Conclusions: Plasma NT-proBNP concentration measured before electrical cardioversion did neither predict cardioversion success nor relapse of AF in patients without heart failure. Treatment with candesartan did not affect the levels of NT-proBNP. Maintained sinus rhythm during follow-up was associated with a significant reduction in NT-proBNP levels.