NPPB and amyloidosis: ECVCT also tracked various important clinical parameters including reduced 6-min walk test distance and increasing NT-proBNP, as well as amyloid burden in transthyretin-related amyloid—when measured semi-quantitatively by 99mTc-3,3-diphsphono-1,2-propanodicarboxylic acid (DPD) scintigraphy [32].