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

Abstract

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.

Keywords: Acute kidney injury; Cardiac surgery; Renal replacement therapy.