Role of NT-proANP and NT-proBNP in patients with atrial fibrillation: Association with atrial fibrillation progression phenotypes

BACKGROUND: Electroanatomic remodeling in atrial fibrillation (AF) leads to disease initiation and perpetuation. Although atrial natriuretic peptide (ANP) is specifically expressed in the atria and is involved in atrial remodeling, B-type natriuretic peptide (BNP) is associated with mortality and cardiovascular events in AF. OBJECTIVE: The purpose of this study was to investigate the association between N-terminal (NT)-proBNP and NT-proANP levels with 3 AF progression phenotypes: persistent AF, left atrial diameter (LAD) dilation, and left atrial low-voltage areas (LVAs). METHODS: We studied NT-proBNP and NT-proANP in a discovery cohort (n = 51) and replicated the findings in a validation cohort (n = 241) undergoing first AF catheter ablation. Blood plasma samples from femoral vein were collected before catheter ablation. LVAs were determined using high-density maps and defined as <0.5 mV. RESULTS: In our pilot cohort (age 62 +/- 10 years; 63% male; 59% persistent AF; 22% LVA), NT-proANP-but not NT-proBNP-levels were significantly higher in LVA patients (14.1 vs 8.6 ng/mL; P = .009) and correlated with LAD (r(2) = 0.362; P = .011). These results were replicated in the validation cohort (age 64 +/- 11 years; 59% male; 59% persistent AF; 27% LVA) (12.7 vs 8.8 ng/mL; P = .016) and correlated with LAD (r(2) = 0.180; P = .019). NT-proANP levels increased according to 4 disease progression groups: paroxysmal AF without LVA, persistent AF without LVA, paroxysmal AF with LVA, and persistent AF with LVA (mean 15, 20, 19, and 27 ng/mL, respectively; P = .004). CONCLUSION: Natriuretic peptides show different sensitivity for phenotypes of AF progression. The clinical impact of NT-proANP in refining individualized therapy and disease prevention should be addressed in larger studies