NPPB and heart failure: However, the concentration of CST increased significantly with the NYHA class (R = 0.58; p < 0.001) and correlated significantly with the currently used markers of heart failure, including TNT (R = 0.22; p = 0.016) and NT-proBNP (R = 0.44; p < 0.001), but did not show a significant correlation with BMI (R = −0.0004; p = 0.997).