Plasma BNP in patients on maintenance haemodialysis: a guide to management?

The number of patients requiring long-term haemodialysis is increasing throughout the world. Cardiovascular disease is much more common in these patients than in the general population and accounts for the majority of deaths. New approaches to management are clearly needed to reduce this excessive cardiovascular burden. We propose that circulating levels of the cardiac natriuretic peptides, B-type natriuretic peptide (BNP) in particular, might provide a useful, objective guide to the management of their hydration status and pharmacotherapy. An overview of the literature shows that plasma levels of the cardiac natriuretic peptides are increased in this patient population and reflect cardiac preload and afterload along with cardiac pathology, thereby providing an index of cardiovascular (especially cardiac) stress and distress. Circulating levels of the cardiac peptides change in parallel with cardiac load, especially across haemodialysis. Furthermore, there is robust evidence that natriuretic peptide levels are predictive of cardiovascular outcome in these patients. Accordingly, we hypothesize that management of their haemodialysis, and pharmacotherapy designed specifically to lower plasma BNP levels to, or close to, the normal range, will reduce the excessive burden on the cardiovascular system and thereby ultimately lower the incidence of cardiovascular disease. We outline, in broad terms, how a trial to test this hypothesis might be designed.