NPPB and susceptibility to pneumonia measurement: Alba et al.'s research claims that the cutoff PCT value for pneumonia excluding heart failure is 0.1 ng/ml (sensitivity 97%, specificity 69%) and for HF with pneumonia is 0.4 ng/ml (specificity 97%) and believed that the combined use of PCT and NT-proBNP can more effectively distinguish AHF and pneumonia [68].