Outcomes of Moderate-to-Severe Acute Kidney Injury following Left Ventricular Assist Device Implantation

Abstract

Background: Although acute kidney injury (AKI) is a common complication following cardiac surgery, less is known about the occurrence and consequences of moderate/severe AKI following left ventricular assist device (LVAD) implantation. Methods: All patients who had an LVAD implanted at our center from 2008 to 2016 were reviewed to determine the incidence of, and risk factors for, moderate/severe (stage 2/3) AKI and to compare postoperative complications and mortality rates between those with and those without moderate/severe AKI. Results: Of 246 patients, 68 (28%) developed moderate/severe AKI. A multivariable logistic regression comprising body mass index and prior sternotomy had fair predictive ability (area under the curve = 0.71). A 1-unit increase in body mass index increased the risk of moderate/severe AKI by 7% (odds ratio = 1.07; 95% confidence interval: 1.03-1.11); a prior sternotomy increased the risk more than 3-fold (odds ratio = 3.4; 95% confidence interval: 1.84-6.43). The group of patients with moderate/severe AKI had higher rates of respiratory failure and death than the group of patients with mild/no AKI. Patients with moderate/severe AKI were at 3.2 (95% confidence interval: 1.2-8.2) times the risk of 30-day mortality compared to those without. Even after adjusting for age and Interagency Registry for Mechanically Assisted Circulatory Support profile, those with moderate/severe AKI had 1.75 (95% confidence interval: 1.03-3.0) times the risk of 1-year mortality compared to those without. Discussion: Risk-stratifying patients prior to LVAD placement in regard to AKI development may be a step toward improving surgical outcomes.