Fluid overload modifies ambulatory blood pressure and pulse wave characteristics in hemodialysis patients undergoing targeted fluid management.

Background: Ambulatory blood pressure (BP) and pulse wave characteristics (PWCs) are stronger predictors of mortality than conventional pre-/post-dialytic BP in hemodialysis. While BP is recommended to be managed primarily by reducing fluid overload (FO), associations of FO with interdialytic BP/PWCs remain unknown. Methods: Bioimpedance-derived FO and interdialytic 44-h BP/PWCs were analyzed at baseline and follow-up of a quality improvement project involving targeted fluid management. Trended cosinor linear mixed-effects models assessed intra-patient associations of post-dialysis FO with interdialytic BP/PWCs. Results: We analyzed 120 visits (77/43 at baseline/follow-up) from 80 patients (70% male; mean age 68 ± 14 years; median dialysis vintage 38 [18-64] months). Post-dialysis FO decreased in baseline hypervolemic patients from 2.7 ± 1.3 L to 0.9 ± 1.7 L. Every 1 L increase in post-dialysis FO at the patient level was associated with increased peripheral BP (systolic: 4.54 mmHg, Conclusions: We showed that FO in hemodialysis is associated with increased interdialytic BP and PWCs on a patient level, and that FO blunts interdialytic BP/PWC trends. We further establish that physiological BP/PWC patterns may be associated with euvolemic fluid status, hence making the case for tailoring target weight using bioimpedance spectroscopy.