NPPB and gangrene: Independent risk factors for overall mortality were Gangrene (HR = 3.003, 95% CI = 1.343–9.431), Cardiac involved (HR = 5.370, 95% CI = 1.910–15.472), Scl-70 (HR = 3.569, 95% CI = 1.333–10.869), Elevated BNP (HR = 2.135, 95% CI = 1.293–9.564).