Very high NT-proBNP values present in the blood serum of patients with severe valvular heart disease may indicate significant damage to the overloaded left ventricular muscle, which may be confirmed by the significant correlation shown in the study between the preoperative NT-proBNP concentration and the NYHA class, preoperative hs-TnT level and left ventricular systolic function assessed using LVEF. This evidence concerns the gene NPPB and heart valve disorder.