Predictors of Change in Left-Ventricular Structure and Function in a Trial of Extended Hours Hemodialysis

Background: Myocardial pathology is common in patients undergoing hemodialysis. To explore the effects of differing 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 hours dialysis.

Methods and results: A Clinical Trial of IntensiVE (ACTIVE) Dialysis randomized 200 patients undergoing hemodialysis to extended dialysis hours (≥ 24 hours/week) or standard hours (12-18 hours/week) for 12 months. In a prespecified substudy, 95 participants underwent cardiac magnetic resonance imaging (CMR) at baseline and at the study's end. Generalized linear regression was used to model the relationship between changes in LV parameters and markers of volume status (normalized ultrafiltration rate and total weekly interdialytic weight gain), hemodynamic changes (systolic and diastolic blood pressure) and solute control (urea clearance, dialysis hours and phosphate). Randomization to extended hours dialysis was not associated with change in any CMR parameter. Reduction in ultrafiltration rate was associated with reduction in LV mass index (P = 0.049) and improved ejection fraction (P = 0.024); reduction in systolic blood pressure was also associated with improvement in ejection fraction (P = 0.045); reduction in interdialytic weight gain was associated with reduced stroke volume (P = 0.038). There were no associations between change in urea clearance, 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.