Outcomes Among Patients Hospitalized With COVID-19 and Acute Kidney Injury

Abstract

Rationale & objective: Outcomes of patients hospitalized with coronavirus disease 2019 (COVID-19) and acute kidney injury (AKI) are not well understood. The goal of this study was to investigate the survival and kidney outcomes of these patients.

Study design: Retrospective cohort study.

Setting & participants: Patients (aged≥18 years) hospitalized with COVID-19 at 13 hospitals in metropolitan New York between March 1, 2020, and April 27, 2020, followed up until hospital discharge.

Exposure: AKI.

Outcomes: Primary outcome: in-hospital death.

Secondary outcomes: requiring dialysis at discharge, recovery of kidney function.

Analytical approach: Univariable and multivariable time-to-event analysis and logistic regression.

Results: Among 9,657 patients admitted with COVID-19, the AKI incidence rate was 38.4/1,000 patient-days. Incidence rates of in-hospital death among patients without AKI, with AKI not requiring dialysis (AKI stages 1-3), and with AKI receiving dialysis (AKI 3D) were 10.8, 31.1, and 37.5/1,000 patient-days, respectively. Taking those without AKI as the reference group, we observed greater risks for in-hospital death for patients with AKI 1-3 and AKI 3D (HRs of 5.6 [95% CI, 5.0-6.3] and 11.3 [95% CI, 9.6-13.1], respectively). After adjusting for demographics, comorbid conditions, and illness severity, the risk for death remained higher among those with AKI 1-3 (adjusted HR, 3.4 [95% CI, 3.0-3.9]) and AKI 3D (adjusted HR, 6.4 [95% CI, 5.5-7.6]) compared with those without AKI. Among patients with AKI 1-3 who survived, 74.1% achieved kidney recovery by the time of discharge. Among those with AKI 3D who survived, 30.6% remained on dialysis at discharge, and prehospitalization chronic kidney disease was the only independent risk factor associated with needing dialysis at discharge (adjusted OR, 9.3 [95% CI, 2.3-37.8]).

Limitations: Observational retrospective study, limited to the NY metropolitan area during the peak of the COVID-19 pandemic.

Conclusions: AKI in hospitalized patients with COVID-19 was associated with significant risk for death.

Keywords: AKI-on-CKD; COVID-19 outcomes; Coronavirus disease 2019 (COVID-19); acute kidney injury (AKI); acute renal failure (ARF); death; dialysis; hospitalization; in-hospital mortality; kidney replacement therapy (KRT); recovery; renal prognosis; renal recovery; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).