Chloride Homeostasis in End Stage Heart Failure and LVAD Recipients

Abstract

Purpose Abnormal chloride homeostasis is associated with worse survival in patients with chronic heart failure. Maladaptive neurohormonal responses and chronic diuretic use deplete serum chloride levels. However, the prognostic implications of serum chloride levels in LVAD patients is not fully elucidated. Our objective was to determine the effect of pre-LVAD hypochloremia on long term survival in LVAD patients. Methods We performed a retrospective analysis of all 166 LVAD implants between January 2011 and June 2018 at a single center. Patients were classified into either [hypochloremia (serum chloride 106mEq/L and one with incomplete data. Median chloride levels were used to assess the impact of LVAD therapy. Unadjusted and adjusted cox models were used to examine for association between hypochloremia and 2-year all-cause mortality . We compared survival between both groups using Kaplan-Meir plot and log-rank statistics. Results Chloride levels in group A normalized over three months and peaked at 24 months with a 7mEq/l rise from baseline. Group B levels remained normal with a marginal 0.5mEq/L rise from baseline at 24 months. No significant association between hypochloremia and survival was found [unadjusted HR= 1.01 (0.62 - 1.64), p=0.98] [adjusted HR= 0.88 (0.53 - 1.44), p=0.60]. Conclusion LVAD therapy normalizes chloride homeostasis via cardio-renal axis and stresses its prognostic value. Survival in the long run may be multi-factorial besides chloride levels alone.