Hyponatremia after LVAD Implantation is Associated with Adverse Outcomes

Abstract

Purpose Hyponatremia is a known predictor of adverse outcomes in patients with chronic systolic heart failure (HF). It is unclear if persistent hyponatremia after LVAD implantation has an adverse influence on outcomes including mortality and recurrent hospitalizations. Methods We conducted a retrospective analysis of patients who received a continuous-flow LVAD from 2008-2017. Sodium levels were assessed prior to surgery and at discharge. Hyponatremia was defined as sodium <135 mEq/L. One-year outcomes were compared to patients with normal sodium levels at discharge. Logistic regression was used to evaluate for difference in outcomes between groups. Results Our population consisted of 143 patients, mean age 57.4 (range 25-79), 75.5% of male gender and 55% had an ischemic etiology of HF. Mean sodium level in patients with persistent hyponatremia at discharge was 132±2.7 mEq/L compared to 138.3±2.7 mEq/L in patients with normonatremia, p-value <0.001. One-year mortality in patients with hyponatremia was 19.1% compared to 7.35% in patient with normal sodium, p-value 0.03. There were no significant differences in burden of hospital readmissions (table 1). Conclusion Hyponatremia is thought to be the pathophysiological sequela of progressive heart failure. LVAD implantation often restores normal hemodynamics and leads to correction of pre-existing hyponatremia in HF patients. However, persistent hyponatremia at the time of discharge is not uncommon and is associated with higher 1-year mortality. Further studies are needed to elucidate the etiology of hyponatremia in this population. Hyponatremia is a known predictor of adverse outcomes in patients with chronic systolic heart failure (HF). It is unclear if persistent hyponatremia after LVAD implantation has an adverse influence on outcomes including mortality and recurrent hospitalizations. We conducted a retrospective analysis of patients who received a continuous-flow LVAD from 2008-2017. Sodium levels were assessed prior to surgery and at discharge. Hyponatremia was defined as sodium <135 mEq/L. One-year outcomes were compared to patients with normal sodium levels at discharge. Logistic regression was used to evaluate for difference in outcomes between groups. Our population consisted of 143 patients, mean age 57.4 (range 25-79), 75.5% of male gender and 55% had an ischemic etiology of HF. Mean sodium level in patients with persistent hyponatremia at discharge was 132±2.7 mEq/L compared to 138.3±2.7 mEq/L in patients with normonatremia, p-value <0.001. One-year mortality in patients with hyponatremia was 19.1% compared to 7.35% in patient with normal sodium, p-value 0.03. There were no significant differences in burden of hospital readmissions (table 1). Hyponatremia is thought to be the pathophysiological sequela of progressive heart failure. LVAD implantation often restores normal hemodynamics and leads to correction of pre-existing hyponatremia in HF patients. However, persistent hyponatremia at the time of discharge is not uncommon and is associated with higher 1-year mortality. Further studies are needed to elucidate the etiology of hyponatremia in this population.