PM1037: Left Ventricular Global Constructive Work Is Preload-dependent and Progressively Declines During Hemodialysis in Children

Background: Cardiovascular complications remain significant in pediatric hemodialysis (HD). Myocardial work measures myocardial performance non-invasively based on pressure-strain loop, which accounts for both deformation and afterload. We aimed to investigate changes in myocardial work indices in pediatric patients during HD.

Methods: Patients < 21 years old with HD vintage > 3 months were enrolled. Echocardiography was performed at the start of HD (pre-HD), 2 hours later (mid-HD), and at the end HD (post-HD). Simultaneous blood pressure (BP) was obtained at the time of echocardiography. Global longitudinal strain (GLS), myocardial work index (GWI), constructive work (GCW), wasted work, and work efficiency were measured on GE EchoPAC 204, and compared to age- and gender-matched controls. Left ventricular end-diastolic volume (LVEDV) was measured using the 5/6 area length method. Friedman test was performed to evaluate changes in 3 repeated measures, Wilcoxon rank-sum test to compare HD-dependent subjects and matched controls, and Spearman’s correlation to assess if GWI, GCW, and GLS changes were related to LVEDV changes.

Results: We enrolled 15 subjects at a median age of 12 years (IQR 8, 16) and median HD vintage of 13 months (IQR 9, 25). Pre-HD myocardial work indices were not different compared to control subjects. There was marked intradialytic decline in GWI and GCW (but not wasted work or work efficiency) compared to baseline and control subjects (Table). Median LVEDV reduction during HD (26 ml, IQR 14, 36) was associated with decline in GCW (ΔGCW = 693 mmHg% (IQR 325, 831), r = 0.56, p = 0.026, Figure), but not GWI (r = 0.39, p = 0.1) nor GLS (r = 0.45, p = 0.09).

Conclusion: We observed progressive decline in GWI and GCW during a 4-hour HD in children, despite normalization of BP but unchanged GWW and GWE. The change in GCW was pre-load dependent. Longitudinal study using these novel indices may help understand the effect of cyclical hemodynamic changes on long-term cardiovascular health in children requiring chronic HD.