The Clinical Importance of Hyponatremia in Patients with Left Ventricular Assist Devices

Abstract

Hyponatremia is associated with increased morbidity and mortality in heart failure (HF) patients. The implication of hyponatremia during left ventricular assist device (LVAD) therapy remains unknown. In this retrospective study, consecutive LVAD patients implanted between April 2014 and March 2018 were stratified by the presence of hyponatremia (serum sodium <135 mEq/L) at 30 days post-LVAD. Incidence of HF readmissions and survival during 1-year follow-up were compared between the groups. Of 204 patients identified, 170 were included. Serum sodium levels improved significantly from pre-LVAD to 1-year post-LVAD (136 [133, 139] mEq/L to 137 [135, 140] mEq/L, p < 0.001). At 30 days, 35 patients (21%) were in the hyponatremia group.No difference was observed for 1-year survival between groups (77% vs. 81%, p = 0.66). However, the incidence of HF readmissions was significantly higher in the hyponatremia group (44% vs. 15%, p = 0.001). Among the patients with pre-LVAD hyponatremia (N = 60), those with normalized serum sodium levels (N = 42) had a lower incidence of HF readmissions compared with those with persistent hyponatremia (12% vs. 44%, p = 0.008). Hyponatremia in LVAD patients is associated with a higher incidence of HF readmissions. Further studies are needed to elucidate whether therapies directed at hyponatremia (e.g., vasopressin antagonists) would improve outcomes in LVAD patients.

Postoperative tolvaptan use in left ventricular assist device patients: The TOLVAD randomized pilot study

“…Unfortunately, despite the improved Na level with tolvaptan, this did not translate into any significant difference in clinical outcomes. Retrospective data have indicated more frequent heart failure hospitalizations with post‐operative hyponatremia, though patients were considered hyponatremic at 1‐month following implantation, while our study evaluated hyponatremia during the post‐operative index hospitalization 13 . Tolvaptan has not been associated with improved clinical outcomes in heart failure patients without LVADs, though the sub‐group of the EVEREST trial with Na < 130 mEq did have improved cardiovascular mortality with tolvaptan use 6 .…”

“…Retrospective data have indicated more frequent heart failure hospitalizations with postoperative hyponatremia, though patients were considered hyponatremic at 1-month following implantation, while our study evaluated hyponatremia during the post-operative index hospitalization. 13 Tolvaptan has not been associated with improved clinical outcomes in heart failure patients without LVADs, though the sub-group of the EVEREST trial with Na < 130 mEq did have improved cardiovascular mortality with tolvaptan use. 6 In our study, there were no significant differences in clinical outcomes, HRAEs, or hemocompatibility scores over a 6-month follow-up, thus, but our study was not powered to detect such differences.…”

“…These patients often require escalating doses of diuretics. Furthermore, persistent hyponatremia after LVAD implantation is associated with increased heart failure hospitalizations, regardless of pre‐operative sodium level 13 . However, there are limited data on the efficacy of tolvaptan use in patients with LVADs.…”

“…Furthermore, persistent hyponatremia after LVAD implantation is associated with increased heart failure hospitalizations, regardless of pre-operative sodium level. 13 However, there are limited data on the efficacy of tolvaptan use in patients with LVADs. A previous retrospective study showed that tolvaptan use was safe following LVAD implantation, and was associated with improvement in serum Na levels and increased urine output, and the need for a prospective, randomized assessment of tolvaptan in LVAD patients was highlighted.…”

Clinical Characteristics, Management, and In-Hospital Mortality in Patients with Heart Failure with Reduced Ejection Fraction According to Sex and the Presence of Type 2 Diabetes Mellitus

“…The presence of hyponatremia was greater in diabetic women than in diabetic men in the study. This indicates a higher risk of mortality due to this electrolyte alteration [22][23][24].…”