Early Acute Kidney Injury Recovery in Elderly Patients Undergoing Valve Replacement Surgery.

Objectives: This study was designed to determine the incidence, contributing factors, and prognostic implications of acute kidney injury (AKI) recovery patterns in patients who experienced AKI after valve replacement surgery (VRS).

Design: A retrospective cohort study was conducted.

Setting: The work took place in a postoperative care center in a single large-volume cardiovascular center.

Participants: Patients undergoing VRS between January 2010 and December 2019 were enrolled.

Intervention: Patients were categorized into three groups based on their postoperative AKI status: non-AKI, AKI with early recovery (less than 48 hours), and persistent AKI.

Measurement And Main Results: The primary outcome was in-hospital major adverse clinical events. The secondary outcomes included in-hospital and 1-year mortality. A total of 4,161 patients who developed AKI following VRS were included. Of these, 1,513 (36.4%) did not develop postoperative AKI, 1,875 (45.1%) experienced AKI with early recovery, and 773 (18.6%) had persistent AKI. Advanced age, diabetes, New York Heart Association III-IV heart failure, moderate-to-severe renal dysfunction, anemia, and AKI stages 2 and 3 were identified as independent risk factors for persistent AKI. In-hospital major adverse clinical events occurred in 59 (3.9%) patients without AKI, 88 (4.7%) with early AKI recovery, and 159 (20.6%) with persistent AKI (p < 0.001). Persistent AKI was independently associated with an increased risk of in-hospital adverse events and 1-year mortality. In contrast, AKI with early recovery did not pose additional risk compared with non-AKI patients.

Conclusions: In patients who develop AKI following VRS, early AKI recovery does not pose additional risk compared with non-AKI. However, AKI lasting more than 48 hours is associated with an increased risk of in-hospital and long-term adverse outcomes.