Intradialytic kinetics of cardiac biomarkers during high-flux haemodialysis and postdilution haemodiafiltration: study protocol for a randomised crossover trial

Introduction Cardiovascular disease (CVD) is the leading cause of mortality in patients undergoing chronic haemodialysis (HD). However, relatively few data exist regarding the influence of dialysis treatment on cardiac biomarkers such as high-sensitivity cardiac troponin I and T (hs-cTnI and hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), complicating their interpretation in the diagnosis of acute coronary syndrome and heart failure. This study aims to investigate the intradialytic kinetics of hs-cTnT, hs-cTnI and NT-proBNP, during HD and haemodiafiltration (HDF), in patients treated with chronic HD. Methods and analysis Single-centre, randomised, open-label, crossover study, comparing high-flux HD (FX 100 dialyser) and postdilution HDF (FX 1000 dialyser), regarding their potential clearance of hs-cTnI, hs-cTnT and NT-proBNP, in 24 stable patients treated with in-centre HD without acute CVD. The study will investigate changes in concentrations during and after high-flux HD and postdilution HDF and calculate reduction ratios, dialyser clearance and clearance by adsorption to the membrane of the selected cardiac biomarkers. Blood samples will be collected at baseline, after 10, 30, 60, 120, 180 and 240 min of dialysis and 30 min postdialysis. After 120 min of dialysis, dialysate will also be collected from the dialyser outlet line. The primary outcome is change from baseline in concentrations of hs-cTnI, hs-cTnT and NT-proBNP during high-flux HD and postdilution HDF. Ethics and dissemination The study has been approved by the North Denmark Region Committee on Health Research Ethics (N-20240016). Results will be published in an international peer-reviewed journal and disseminated at national and international research meetings. Trial registration number NCT06526702 .