Serial evaluation of loop diuretic efficiency following left ventricular assist device implantation

Abstract

More than 50% of heart failure (HF) patients require diuretic therapy after left ventricular assist device (LVAD). Although few data related to diuretic response (DR) exist in stage D patients, tubular sodium reabsorption may be clinically prognostic independent of estimated glomerular filtration rate (eGFR) and proteinuria within this cohort. We aimed to characterize DR serially before and after LVAD implantation in a stage D population. We conducted a prospective, observational cohort study of HF patients receiving diuretics with plans to undergo LVAD implantation. We measured urine sodium (U_Na) and creatinine (U_Cr) at three points after diuretic therapy: pre-LVAD, post-LVAD prior to discharge, and as an outpatient. Prior to LVAD, patients (N = 19) had an average eGFR of 54.0 ± 18.0 mL/min/1.73 m², spot U_Na of 74.8 ± 28.0 mmol/L, and fractional excretion of sodium (FE_Na) of 3.1 ± 2.7%. Pre-LVAD, eGFR did not correlate with spot U_Na nor FE_Na (p > 0.05 for both). LVAD implantation did not improve DR post-LVAD (mean change FE_Na per 40 mg IV furosemide 0.5 ± 1.0%; p = 0.84), and 90% of patients required loop diuretics at 90 days post-surgery. Improved hemodynamics following LVAD may not improve DR or tubular function; larger studies are needed to confirm our results and assess the utility of DR to predict post-LVAD outcomes.