Interdialytic weight gain of less than 2.5% seems to limit cardiac damage during hemodialysis.

Aims: To investigate if a single low-flux HD induces a rise in cardiac biomarkers and if a change in clinical approach may limit such mechanism.
Material and Methods: A total of 20 chronic HD patients each underwent three different study-dialyses. Dialyzers (low-flux polysulfone, 1.8 sqm) had been stored either dry or wet (Wet) and the blood level in the venous chamber kept low or high. Laboratory results were measured at baseline, 30 and 180 min, adjusted for the effect of fluid shift. Ultrasound measured microemboli signals (MES) within the return line.
Results: Hemodialysis raised cardiac biomarkers ( p  < 0.001): Pentraxin 3 (PTX) at 30 min (by 22%) and at 180 min PTX (53%), Pro-BNP (15%), and TnT (5%), similarly for all three HD modes. Baseline values of Pro-BNP correlated with TnT (rho = 0.38, p  = 0.004) and PTX (rho = 0.52, p  < 0.001). The changes from pre- to 180 min of HD ( delta -) were related to baseline values (Pro-BNP: rho = 0.91, p  < 0.001; TnT: rho = 0.41, p  = 0.001; PTX: rho = 0.29, p  = 0.027). Delta Pro-BNP (rho = 0.67, p  < 0.001) and TnT (rho = 0.38, p  = 0.004) correlated with inter-dialytic-weight-gain (IDWG). Biomarkers behaved similarly between the HD modes. The least negative impact was with an IDWG ⩽ 2.5%. Multiple regression analyses of the Wet-High mode does not exclude a relation between increased exposure of MES and factors such as release of Pro-BNP.
Conclusion: Hemodialysis, independent of type of dialyzer storage, was associated with raised cardiac biomarkers, more profoundly in patients with higher pre-dialysis values and IDWG. A limitation in IDWG to <2.5% and prolonged ultrafiltration time may limit cardiac strain during HD, especially in patients with cardiovascular risk.