NPPB and peripheral arterial disease: The ABC-CHD score [27], with risk factors identified by the Cox proportional hazards model including age, biomarkers (N-terminal prohormone of brain natriuretic peptide and troponin-T), and clinical histories (smoking, diabetes, and presence of peripheral artery disease), has a good discriminatory ability (Harrell’s C-index: 0.71) and calibration for three-year mortality.