For patients with COVID-19-associated acute kidney injury (AKI), the postdischarge rate of decrease in kidney function is greater than in AKI patients without COVID-19, reports a paper in JAMA Network Open.
The retrospective study included two groups of patients with AKI treated at five hospitals in a New England health system from March through August 2020. One hundred eighty-two patients had COVID-19-associated AKI, with positive results on a SARS-CoV-2 reverse transcription-polymerase chain reaction test at a study hospital. Another 1430 patients had AKI not associated with COVID-19. In both groups, all patients survived past discharge, did not require dialysis within 3 days after discharge, and had at least one subsequent outpatient creatinine level measurement.
Mixed-effects models were used to compare the postdischarge slope in estimated glomerular filtration rate (eGFR) for AKI patients with and without COVID-19. In a subgroup of 319 patients who did not have AKI recovery by discharge, time to recovery was compared between groups.
The sample included roughly equal numbers of men and women; median age was 69.7 years. Patients with COVID-19-associated AKI were more likely to be Black (40.1% versus 15.7%) or Hispanic (22% versus 8.8%). Overall comorbidity was lower in the COVID-19 group, but rates of pre-existing chronic kidney disease and hypertension were similar. Patients with COVID-19-associated AKI were more likely to be excluded due to in-hospital death. Median follow-up was longer in the COVID-19 group: about 90 versus 60 days.
The AKI patients with COVID-19 had a greater postdischarge decrease in eGFR: −11.3 mL/min/1.73 m2/y before and −12.4 mL/min/1.73 m2/y after adjustment for comorbidity. The difference remained signifi-cant in a fully adjusted model: −14.0 mL/ min/1.73 m2/y. In the subgroup analysis of patients whose eGFR did not return to normal by discharge, those in the COVID-19 group were less likely to have AKI recovery during follow-up: adjusted hazard ratio 0.57.
AKI has been reported to occur in more than one-half of patients hospitalized with COVID-19 and more than three-fourths of those admitted to the Intensive Care Unit (ICU). There are few data on the intermediate- and long-term outcomes of COVID-19-associated AKI.
The new study suggests that among hospitalized patients with AKI, cases associated with COVID-19 have a greater rate of decrease in eGFR after discharge. The difference in outcomes is unrelated to differences in comorbidity or AKI severity. “Identifying predictors of longitudinal eGFR decrease in patients with COVID-19-associated AKI may help prioritize which patients need close outpatient follow-up during the pandemic,” the researchers write [Nugent J, et al. Assessment of acute kidney injury and longitudinal kidney function after hospital discharge among patients with and without COVID-19. JAMA Netw Open 2021; 4:e211095. doi: 10.1001/jamanetworkopen.2021.1095].