NPPB and atrial fibrillation: Compared to patients with a concentration of big-ET-1 < 0.95 pmol/L, patients with a concentration of big-ET-1 > 0.95 pmol/L were more likely to have atrial fibrillation, to be in NYHA classes III and IV, to have more depressed LV ejection fractions and more dilated LV, right ventricle (RV) and left atrial (LA) diameters, more likely to be taking diuretics and digoxin, and had significantly higher levels of NT pro-BNP and creatinine (Table 1).