Serum NT-proBNP Levels In Patients With Non-valvular Atrial Fibrillation And The Impact Of Beta-blocker On Serum NT-proBNP Levels

【Objectives】1. To examine serum N-terminal fragment pro-brain natriuretic peptide(NT-proBNP) levels in patient with atrial fibrillation(AF). To investigate the relationship between serum NT-proBNP levels and AF. To analyse the impact of the type of AF in serum NT-proBNP levels.2. To evaluate the impact of Beta-blocker on serum NT-proBNP levels.3. To investigate the predictors of serum NT-proBNP levels.【Methods】One hundred and thirty-six subjects(mean age 70.26±8.35years), 95 males and 41 females, with cardiac diseases and left ventricular ejection fraction(LVEF)≥50%, were enrolled and divided into 2 groups according to cardiac rhythm (90 cases with AF and 46 cases with sinus rhythm). Subjects were excluded if they had a history of myocardial infarction, cardiomyopathy, rheumatic heart disease, or hyperthyroidism that proceded the onset of AF. Control subjects(30 cases) were obtained from a healthy outpatient primary care population. Serum NT-proBNP levels were measured by ELISA.【Results】Individuals with AF had significantly higher serum NT-proBNP levels(689.56±251.87) fmol/ml than those with sinus rhythm(456.11±148.14) fmol/ml and control subjects(415.83±62.02) fmol/ml(P＜0.01, respectively). In individuals with sinus rhythm and control subjects did not show significant difference at serum NT-proBNP levels (P＞0.05). Individuals with paroxysmal AF had higher serum NT-proBNP levels (731.09±286.31 ) fmol/ml than those with persistant AF (676.92±241.30) fmol/ml, but there was no siginificant difference (P = 0.3912). Individuals with lone AF had lower serum NT-proBNP levels (634.25±232.22) fmol/ml than those with cardiac diseases and AF (702.44±256.01) fmol/ml, but there was no siginificant difference (P = 0.3715). Furthermore, whether in AF or SR group, patients treated withβ-blockers had higher serum NT-proBNP levels than those withoutβ-blockers(non-β-blockers), but there was no siginificant difference(P＞0.05).The final regression model showed that presence of AF, older age, and larger diameters of right atrium were independently predictive of higher serum NT-proBNP values.【Conclutions】 1. The present study showed that serum NT-proBNP levels were significantly higher in nonvalvular AF patients with normal ventricular contriction function and whether with or without heart diseases than in those without AF. This study demonstrated that the presence of AF affected NT-proBNP secretion from myocyte, but the type of AF did not significantly affect serum NT-proBNP levels.2. This study also demonstrates serum NT-proBNP levels were higher in patients treated withβ-blockers than in those withoutβ-blockers therapy, but there was no statistical significance.3. Presence of AF, older age, and larger diameters of right atrium were independently predictive of higher serum NT-proBNP values.