MO338: Long-Term Kidney Outcomes After Acute Kidney Injury in Patients With COVID-19
Authors: Khruleva Yulia , Efremovtseva Marina , Kobalava Zhanna 
Published: May 2022

Abstract

BACKGROUND AND AIMS
The acute effects of the novel coronavirus infection (COVID-19) on short-term kidney outcomes have been studied, the long-term kidney outcomes after COVID-19-associated acute kidney injury (AKI) in comparison with hospitalized patients without AKI are insufficiently researched. Our aim was to evaluate the impact of AKI in acute COVID-19 on long-term kidney outcomes in hospitalized patients with COVID-19.

METHOD
We performed a cohort study on 1000 patients hospitalized from April to July 2020 with laboratory-confirmed COVID-19 and lung injury by computer tomography (CT). We excluded patients with re-hospitalization, acute surgical pathology and a single serum creatinine measurement during hospitalization. In the prospective part, patients with serum creatinine measurement within 180 days after discharge were included. Definition of AKI and chronic kidney disease (CKD) were based on KDIGO criteria. P-value &lt;0.05 was considered statistically significant.

RESULTS
The prospective part included 446/792 (56%) surviving patients [47% males, mean age 66 (57;74) years, mean Charlson index 3 (2;5), 74% with hypertension (HTN), 51% with obesity, 28% with diabetes mellitus (DM), 17% with coronary artery disease (CAD) and 14% with chronic kidney disease (CKD)]. 13% of patients were hospitalized in the intensive care unit (ICU).
A total of 103 (23%) of discharge patients had AKI in acute COVID-19. The majority of patients with AKI had the stage 1 (84%), 9% had the stage 2 and 7% had the stage 3. There were no patients who underwent renal replacement therapy during acute COVID-19 in the survivors’ group.
Patients with AKI were older [71 (61;76) versus 65 (56;73) years; P = .006, compared with patients without AKI], more frequently had higher Charlson index [4 (3;5) versus 3 (2;4); P = .0002], CAD (25% versus 15%; P = .02) and CKD (20% versus 12%; P = .04) before hospitalization. There were no differences in the frequency of HTN and DM. Also, AKI patients had more severe lung injury by CT in acute COVID-19 (lung injury &gt;50%: 36% versus 23%; P = .005), more frequently were hospitalized in ICU (25% versus 10%; P &lt; .001) and were treated with mechanical ventilation (15% versus 4%; P &lt; .001).
At discharge 27% patients did not recover from AKI. The mean serum creatinine level at discharge was 93 (77;114) mmol/L in patients with AKI and 81 (70;94) mmol/L in patients without (P &lt; .0001), mean glomerular rate filtration (GFR) CKD-EPI 2012 was 65 (50;81) versus 75 (62;91) mL/min, respectively (P &lt; .0001). Mean serum creatinine level after 180 days of follow-up was 94 (74;117) mmol/L in patients with AKI and 78 (66;92) mmol/L in patients without (P &lt; .0001), mean GRF was 65 (49;82) versus 80 (63;94) mL/min, respectively (P &lt; 0.0001).
After 180 days of follow-up, the frequency of CKD was statistically higher in both groups compare with time before COVID-19, especially in patients with AKI in acute COVID-19 (47% versus 23%; P &lt; .001). Patients with AKI more frequently had CKD de novo (27% versus 11%; P&lt; .001) and a reduction of GFR CKD-EPI by 30% compared with GFR at discharge (18% versus 4%; P &lt; .001) after 180 days of follow-up.

CONCLUSION
In this study, patients who survived COVID-19 had an increased risk of poor long-term kidney outcomes. Patients after COVID-19-associated AKI had worse kidney outcomes. Post-acute COVID-19 care should include attention to kidney disease.