Kidney Function Following Left Ventricular Assist Device Implantation: An Observational Cohort Study

Abstract

Rationale & Objective Nearly half the patients with heart failure have chronic kidney disease. Implantation of a left ventricular assist device (LVAD) improves kidney function in some but not all patients, and lack of improvement is associated with worse outcomes. Preimplantation factors that predict change in kidney function after LVAD placement are not well described. Study Design Single-center observational study. Setting & Participants Consecutive patients undergoing LVAD implantation. Predictors 48 diverse preimplantation variables including demographic, clinical, laboratory, hemodynamic, and echocardiographic variables. Outcomes The primary outcome was change in estimated glomerular filtration rate (eGFR) at 1 month after implantation. Secondary outcomes included eGFR changes at 3, 6, and 12 months. Analytic Approach Univariable and multivariable linear regression. Results Among 131 patients, average age was 60 ± 13 years, 83% were men, 47% had pre-existing chronic kidney disease, and mean preimplantation eGFR was 57 ± 23 mL/min/1.73 m2. At 1-month following LVAD implantation, eGFR improved in 98 (75%) patients. Variables associated with 1-month increases in eGFR were younger age, absence of diabetes mellitus (DM), use of inotropes, lower implantation eGFR, and higher implantation serum urea nitrogen, alanine aminotransferase, bilirubin, and creatinine levels. In multivariable models, younger age (β = 7.14 mL/min/1.73 m2 per SD; 95% CI, 3.17-11.10), lower eGFR (β = 7.72 mL/min/1.73 m2 per SD; 95% CI, 3.10-12.34), and absence of DM (β = 10.36 mL/min/1.73 m2; 95% CI, 2.99-17.74) were each independently associated with 1-month improvement in eGFR. Only younger age and lower eGFR were associated with improvements in eGFR at later months. Limitations Single-center study. Loss to follow-up from heart transplantation and death over duration of study. Conclusions Only younger age, lower eGFR, and absence of DM were associated with improvement in eGFR at 1 month. Thus, prediction of eGFR change at 1 month and beyond is limited by using preimplantation variables.