NPPB and systemic sclerosis: For risk stratification by NT-proBNP, alone, patients with SSc were divided into low (< 300 pg/mL; N = 111), intermediate (≥ 300 pg/mL and < 1,100 pg/mL; N = 7), and high (≥ 1,100 pg/mL; N = 7) risk groups [35].