Myocardial markers are highly altered by higher rates of fluid removal during hemodialysis.

INTRODUCTION: Although hemodialysis is lifesaving in patients with kidney failure extensive interdialytic weight gain (IDWG) between dialyses worsens the prognosis. We recently showed a strong correlation between IDWG and predialytic values of cardiac markers. The aim of the present study was to evaluate if the cardiac markers N-terminal pro-B-type natriuretic peptide (proBNP) and troponin T were influenced by IDWG and speed of fluid removal (ultrafiltration-rate).

METHODS: Twenty hemodialysis patients performed in total 60 hemodialysis (three each). Predialytic values of proBNP and troponin T and changes from predialysis to 180 min hemodialysis (180-0 min) were compared with the IDWG calculated in percent of body weight. The ultrafiltration-rate was adjusted (UF-rateadj ) to IDWG: (100 × weight gain between dialysis [kg])/(estimated body dry weight [kg] × length of hemodialysis session [hours]).

RESULTS: UF-rateadj correlated (Spearman) with (1) predialytic values of IDWG (r = 0.983, p < 0.001), proBNP (r = 0.443, p < 0.001), and troponin T (r = 0.296, p = 0.025); and (2) differences in proBNP180-0min (r = 0.572, p < 0.001) and troponin T180-0min (r = 0.400, p = 0.002). UF-ratesadj above a breakpoint of 0.60 caused more release of proBNP180-0min (p = 0.027). Remaining variables in multiple regression analysis with ProBNP180-0min as dependent factor were predialytic proBNP (p < 0.001) and the ultrafiltration-rate (p < 0.001).

CONCLUSION: Higher UF-rateadj during dialysis was correlated to increased levels of cardiac markers. Data support a UF-rateadj lower than 0.6 to limit such increase. Further studies may confirm if limited fluid intake and a lower UF-rateadj should be recommended to prevent cardiac injury during dialysis.