Effect of reduced ultrafiltration rate on the cardiac biomarkers NT-proBNP and troponin T: a prospective crossover study.

BACKGROUND: High interdialytic weight gain (IDWG) and ultrafiltration rate have been associated with increased mortality in patients undergoing haemodialysis. Cardiac biomarkers reflecting strain, including N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (TnT), are known to increase during haemodialysis sessions. Previous studies suggest that these intradialytic increases may be related to ultrafiltration rate, with a proposed threshold of 0.6 IDWG per hour. This study therefore aimed to prospectively evaluate whether reducing ultrafiltration rate attenuates the haemodialysis-associated increase in these cardiac biomarkers. METHOD: In this multicentre, prospective study prevalent haemodialysis patients with a relative IDWG > 2.5% of body weight and ultrafiltration rate ≥ 0.72 IDWG per hour underwent one standard and one prolonged haemodialysis session with a ≥ 20% reduction in ultrafiltration rate, targeting an ultrafiltration rate ≤ 0.6 IDWG per hour. NT-proBNP and TnT were analysed directly before dialysis, at 180 minutes, and at the end of each haemodialysis session. RESULTS: Of 238 screened patients, 65 met the inclusion criteria and none of the exclusion criteria. Of these, 56 were enrolled and 41 included in the final analysis, meeting the pre-specified sample size required to detect a clinically relevant difference. NT-proBNP and TnT increased significantly during both dialysis sessions (p < 0.001). However, no difference was observed in ∆NT-proBNP (p = 0.967) or ∆TnT (p = 0.823) between treatments with different ultrafiltration rates. Achieving an ultrafiltration rate ≤ 0.6 IDWG per hour required a mean treatment duration of 423 ± 139 minutes (min 246, max 775). Among the 12 patients (29.3%) who achieved the targeted ultrafiltration rate of ≤0.6 IDWG per hour, changes in NT-proBNP (p = 0.062) and TnT (p = 0.114) did not differ significantly between sessions with different ultrafiltration rates. CONCLUSIONS: In stable, prevalent haemodialysis patients who tolerate their ordinary treatment, reducing the ultrafiltration rate by at least 20% did not attenuate the increase in NT-proBNP and TnT during a single haemodialysis session. In these patients, achieving an ultrafiltration rate ≤ 0.6 IDWG/h generally required treatment durations that are not feasible in routine in-centre haemodialysis. TRIAL REGISTRATION: Registered at clinicaltrials.gov (NCT06153888) November 6 2023 (Retrospectively registered).