Significant predictors of the 6MWD were (ordered by decreasing explanatory power): high-sensitivity Troponin T, NT-proBNP, NAC disease stage, estimated glomerular filtration rate, atrial fibrillation, hemoglobin, hepatic vein dilation, mitral E-wave maximum velocity, left ventricular ejection fraction, and the tricuspid valve maximal regurgitation pressure gradient. The gene discussed is NPPB; the disease is atrial fibrillation.