Intradialytic Kinetics of Cardiac Biomarkers During High-Flux Hemodialysis and Post-Dilution Hemodiafiltration

Background: There are limited data on how hemodialysis influences cardiac biomarker concentrations. This study aimed to investigate concentration changes of high-sensitivity troponin I and T, and N-terminal pro-B-type natriuretic peptide before, during, and after hemodialysis and hemodiafiltration, and to compare these changes between the two dialysis modalities. Methods: Randomized crossover study including 23 stable patients treated with hemodialysis/hemodiafiltration. Patients were randomized to start with high-flux hemodialysis or post-dilution hemodiafiltration, had a washout period of 1-3 weeks, and then crossed over to receive the other modality. Blood samples were collected before dialysis, after 10, 30, 60, 120, 180, and 240 minutes of dialysis, and 30 minutes post-dialysis. Additionally, spent dialysate was collected after 120 minutes of dialysis. Linear mixed-effects models were used to investigate concentration changes and compare dialysis modalities. Results: High-sensitivity troponin I and high-sensitivity troponin T were not influenced by hemodialysis; however, hemodiafiltration resulted in a significant decline in both biomarkers. At the end of dialysis, the change was -7.7 ng/L (95% CI: -12.3 to -3.1) for high-sensitivity troponin I and -23.4 ng/L (95% CI: -31.8 to -15.0) for high-sensitivity troponin T. N-terminal pro-B-type natriuretic peptide was significantly reduced with both modalities, with a change of -2954 ng/L (95% CI: -4974 to -934) in hemodialysis and -5161 ng/L (95% CI: -7231 to -3092) in hemodiafiltration. All biomarker concentrations were significantly lower with hemodiafiltration compared to hemodialysis at the end of dialysis. Conclusions: High-sensitivity troponin I, high-sensitivity troponin T, and N-terminal pro-B-type natriuretic peptide were significantly reduced with hemodiafiltration in asymptomatic patients treated with dialysis. Hemodialysis reduced N-terminal pro-B-type natriuretic peptide. Cardiac biomarker levels are influenced by dialysis and treatment modality, which could lead to potential misinterpretation. This emphasizes that time since the last dialysis session should be considered when interpreting cardiac biomarkers for diagnostic purposes.