In addition, other independent variables were fingertip ulcers (HR = 3.208, 95% CI = 1.149–10.986), gangrene (HR = 8.926, 95% CI = 2.408–25.965), cardiac involved (HR = 4.225, 95% CI = 1.090–16.383), velcro crackles (HR = 2.918, 95% CI = 1.340–6.354), Scl-70 (HR = 3.608, 95% CI = 1.189–10.368), elevated BNP (HR = 2.600, 95% CI = 1.070–8.776). Here, NPPB is linked to gangrene.