Assays for b-type natriuretic peptide analogues resistant to prolyl-specific dipeptidyl degradation

A method for the treatment of cardiovascular disease comprising

• a) contacting a sample from a subject with a first antibody selected to bind biologically active forms of the natriuretic peptide of interest contacting the sample with a second antibody selected to bind all biologically active and biologically inactive forms of the natriuretic peptide of interest and performing an assay in which the signal depends upon the selected antibody specifically binding to a biologically active form of the natriuretic peptide of interest, but not specifically binding to a biologically inactive form of the natriuretic peptide of interest;
• and
• b) administering a therapeutically effective amount of a dipeptidyl peptidase inhibitor to said subject when the presence of said biologically active form of said natriuretic peptide is present, and wherein said administration preserves the presence of said biologically active form of said natriuretic peptide.