Postdischarge long-term cardiovascular outcomes of intensive care unit survivors who developed dialysis-requiring acute kidney injury after cardiac surgery

Purpose: Dialysis-requiring acute kidney injury (AKI-D) after cardiac surgery is a major cause of in-hospital mortality. However, the long-term outcome has not been previously examined. Materials and methods: We performed a nationwide, population-based cohort study using the claims data in the Korean National Health Insurance System. Patients who underwent cardiac surgery between 2006 and 2015 were considered. Results: Among 52,983 patients who underwent cardiac surgery, 1261 underwent dialysis postoperatively. During the median follow-up of 3.33 years, the AKI-D group had increased risk of all-cause mortality, end-stage renal disease (ESRD) progression, and risk of developing major adverse cardiovascular events (MACEs). These results remained consistent after multivariable analysis and propensity-score matching. Even after excluding patients who continued dialysis at discharge, the AKI-D group consistently exhibited worse mortality and an increased risk of MACEs compared to the control group. Patients who underwent continuous renal replacement therapy in the AKI-D group exhibited comparable mortality and risk of MACEs but reduced progression to ESRD compared to those who received intermittent renal replacement therapy. Conclusions: AKI-D following cardiac surgery was associated with worse long-term postdischarge mortality and elevated risks of dialysis dependency and MACE development. The outcomes were consistent even in the patients who recovered from the dialysis. (C) 2018 Elsevier Inc. All rights reserved.