Acute kidney injury is associated with poor long-term outcomes in hospitalized patients with covid-19

Abstract BACKGROUND AND AIMS The acute effects of the acute kidney injury (AKI) on short-term mortality in patients with novel coronavirus infection (COVID-19) have been studied, but the long-term outcomes after COVID-19-associated AKI are not well understood. Our aim was to evaluate the impact of AKI in acute COVID-19 in the prediction of long-term mortality in a population of 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. Definition of AKI was based on KDIGO criteria. According to the ESC guidelines, the term acute decompensated heart failure (ADHF) is used to describe patients with previously history of chronic stable heart failure with the typical symptoms and/or signs of decompensation of HF during hospitalization. Multivariate Cox regression was conducted to explore the potential predictors for long-term mortality. A P-value < 0.05 was considered statistically significant. RESULTS The prospective part included 691/792 (87%) surviving patients [47% males, mean age 67 (55;78) years, mean Charlson index 3 (2;5), 69% with hypertension (HTN), 50% with obesity, 26% with diabetes mellitus (DM) and 15% with coronary artery disease (CAD)]. And 12.6% of patients were hospitalized in the intensive care unit (ICU). A total of 137 (20%) patients had AKI in acute COVID-19 and discharged from the hospital. The majority of survival patients with AKI had the 1 stage (77%), 17%—the 2 and 6%–the 3. There were no patients who underwent renal replacement therapy during acute COVID-19 in the survivors’ group. Patients with AKI were older [71 (62;78) versus 64 (52;73) years, P < .0001, compared with patients without AKI], had HTN (83% versus 66%, P < .001), DM (33% versus 24%, P = .03), CAD (25% versus 13%, P < .001) and higher Charlson index [4 (3;5) versus 3 (1;4), P < .0001]. Also, AKI patients had more severe lung injury by CT in acute COVID-19 (lung injuries >50%, 38% versus 26%, P = .004) and more frequently were hospitalized in ICU (23% versus 10%, P < .001). A total of 74% patients recovered from AKI at the discharge time. During 180 days of follow-up, 41 (6%) patients died in the whole study group. The most common cause of death was a heart attack or stroke (29%). In the group without AKI, the mortality rate was 4.5%, among patients with AKI—11.8% (P < .001). In multivariate Cox regression, AKI in the acute phase of COVID-19 [hazard ratio (HR) 2.83, 95% confidence interval (95% CI) 1.28–6.26; P = .01] and the Charlson index (HR 1.46, 95% CI 1.19–1.79; P < .001) were independently associated with higher mortality from all causes within 180 days after discharge after adjusting for age, gender, frequency of obesity, HTN, CAD, DM, ADHF, hospitalization in the ICU and lesions of more than 50% lung volume in the acute phase of COVID-19. CONCLUSION AKI in the acute phase of COVID-19 and the Charlson index are independently associated with higher mortality within 180 days after discharge.