NPPB and viral infectious disease: Compared with healthy controls, DCM patients showed significant depressed left ventricular ejection fraction (LVEF, P < 0.001), increased left ventricular end-diastolic dimension (LVEDD, P < 0.001), elevated N-terminal of the prohormone brain natriuretic peptide (NT-proBNP, P < 0.001), enhanced CRP (C-reactive protein, P < 0.001) and boosted viral infection rates including coxsackie-B3 (P < 0.001), coxsackie-B5 (P = 0.001), cytomegalovirus (P = 0.002) and enteric virus (P < 0.001).