Predictors are Lacking for Change in Kidney Function After Left Ventricular Assist Device Implantation

Abstract

Introduction Nearly half of heart failure patients have chronic kidney disease (CKD). Implantation of a left ventricular assist device (LVAD) can improve kidney function in some but not all patients, and lack of improvement is associated with worse outcomes. Pre-implantation factors that predict change in kidney function after LVAD are not well-described. Hypothesis Clinically available variables can predict change in kidney function after LVAD implantation. Methods Single center observational study of patients undergoing LVAD implantation investigating the association of 48 different clinical, laboratory, echocardiographic and hemodynamic variables before LVAD implantation with change in estimated glomerular filtration rate (eGFR) at 1 month using univariable and multivariable linear regression. Age, sex, race and pre-implantation factors significantly associated with 1-month change in eGFR were further evaluated for their independent association with eGFR change from baseline at 3-, 6-, and 12-months after implantation. Results Among the 131 patients who underwent LVAD implantation, average age was 60 ± 13 years, 83% were male, 47% had pre-existing CKD, and mean pre-implantation eGFR was 55 ± 20 ml/min/1.73m2. At 1-month following LVAD implantation, eGFR improved in 98 (75%) patients. Variables associated with 1-month increases in eGFR were younger age, higher pre-LVAD BUN, higher ALT, higher bilirubin, absence of diabetes mellitus (DM), and use of inotropes prior to implantation. In multivariable models, higher BUN (β 7.05 ml/min/1.73m2 per standard deviation [SD] higher BUN, 95% CI 2.24 to 11.87), higher ALT (β 5.27 ml/min/1.73m2 per SD, 95% CI 1.04 to 9.51) and absence of DM (β 13.45 ml/min/1.73m2, 95% CI 3.65 to 23.26) pre-implantation were each independently associated with 1-month improvement in eGFR (Table). Only higher pre-implantation BUN was associated with change in eGFR at 3 and 6 months, but not 12 months. Conclusion Among 48 diverse variables, only higher BUN and ALT and absence of DM were associated with improvement in eGFR at 1-month. Prediction of eGFR change at 1-month and later time points is currently limited with current pre-implantation measures.