LAUSR

BACKGROUND Myocardial pathology is common in hemodialysis patients. To explore the effects of different aspects of dialysis treatment on its evolution, we examined the impact of change in markers of volume status, hemodynamics and solute clearance on left ventricular (LV) parameters in a randomized trial of extended dialysis hours. METHODS ACTIVE Dialysis randomized 200 hemodialysis patients to extended dialysis hours (≥ 24 hours/week) or standard hours (12-18 hours/week) for 12 months. In a pre-specified substudy, 95 participants underwent cardiac magnetic resonance imaging (CMR) at baseline and study end. Generalized linear regression was used to model the relationship between changes LV parameters and markers of volume status (normalized ultrafiltration [UF] rate and total weekly interdialytic weight gain [IDWG]), hemodynamic changes (systolic and diastolic blood pressure [BP]) and solute control (Kt/V, dialysis hours and phosphate). RESULTS Randomization to extended hours dialysis was not associated with change in any CMR parameter. Reduction in UF rate was associated with reduction in LV mass index (LVMI) (P=0.049) and improved ejection fraction (EF) (P=0.024); reduction in systolic BP was also associated with improvement in EF (P=0.045); reduction in IDWG was associated with reduced stroke volume (SV) (P=0.038). There were no associations between change in Kt/V, phosphate or total hours per week, and CMR parameters. CONCLUSIONS Reduction in ultrafiltration rate and blood pressure are associated with improved myocardial parameters in hemodialysis recipients independently of solute clearance or dialysis time. These findings underscore the importance of fluid status and related parameters as potential treatment targets in this population.