Acute Kidney Injury and Mortality following Ventricular Assist Device Implantation

Abstract

Background: Ventricular assist devices (VADs) are increasingly common, and their surgical implantation predisposes patients to an increased risk of acute kidney injury (AKI). We sought to evaluate the incidence, risk factors and short- and long-term all-cause mortality of patients with AKI following VAD implantation. Methods: We identified all patients who underwent VAD implantation at the University of Chicago between January 1, 2008, and January 31, 2012. We evaluated the incidence of AKI, defined as a ≥50% increase in serum creatinine over the first 7 postoperative days (RIFLE Risk-Creatinine). A logistic regression model was used to identify risk factors for the development of AKI, and a Cox proportional hazards model was used to examine factors associated with 30-day and 365-day all-cause mortality. Results: A total of 157 eligible patients had VAD implantations with 44 (28%) developing postimplantation AKI. In a multivariate analysis, only diabetes mellitus [odds ratio = 2.25 (1.03-4.94), p = 0.04] was identified as a significant predictor of postoperative AKI. Using a multivariable model censored for heart transplantation, only AKI [hazard ratio, HR = 3.01 (1.15-7.92), p = 0.03] and cardiopulmonary bypass time [HR = 1.01 (1.001-1.02), p = 0.02] were independent predictors of 30-day mortality. Preoperative body mass index [HR = 0.95 (0.90-0.99), p = 0.03], preoperative diabetes mellitus [HR = 1.89 (1.07-3.35), p = 0.03] and postimplantation AKI [HR = 1.85 (1.06-3.21), p = 0.03] independently predicted 365-day mortality. Conclusion: AKI is common following VAD implantation and is an independent predictor of 30-day and 1-year all-cause mortality.