Clinical relevance of cardiac natriuretic peptides measured by means of competitive and non-competitive immunoassay methods in patients with renal failure on chronic hemodialysis

Increased levels of cardiac natriuretic peptides in patients undergoing hem odialysis may be a marker of cardiomyopathy and in consequence may be suita ble prognostic indicators for the risk of development of cardiac disease. W e measured plasma levels of ANP, BNP, proANP(1-98) and proBNP(1-76)-related peptides with some competitive and non-competitive immunoassay methods in patients with renal failure on chronic hemodialysis in order to compare the analytical performances of these methods and to evaluate the clinical usef ulness of each assay for patients with chronic renal failure. ANP and BNP v alues significantly decreased after hemodialysis (on average, ANP by 36% an d BNP by 16%); while all proANP and proBNP values tended to increase, but o nly proANP(1-30) (by 14.4%) and Nt-proBMP (by 9.5%) significantly. Although significant correlations were found among all the circulating levels of ca rdiac peptides studied, N-terminal pro-peptides correlated better among the mselves than with ANP and BNP; ANP was only slightly correlated with all th e other peptides, the only exception being BNP. Only BNP levels significant ly increased according to the degree of ventricular hypertrophy and/or vent ricular function in patients with chronic renal failure. The ANP assay is p referable in physiological and clinical studies for the rapid changes in at rial pre-load. BNP would be more useful in the follow-up of cardiac complic ations in patients with end-stage renal disease on regular hemodialysis. Th e assays of N-terminal proANP(1-98) -and proBNP(1.76)-related peptides prov ed to be of limited use, because they were not able to detect acute changes in pre-load during hemodialysis and were less useful than BNP levels as ma rkers of ventricular hypertrophy and/or functional cardiac impairment.