Topic Discussion: Outcomes of AKI in COVID-19

 As COVID19 surged the NY area, March-May 2020 is when the AKI surge happened at most northeast hospitals. Initial reports from us and others showed that the incidence of AKI was high- close to 40%. 

At that time, almost 39% of patients were still admitted. Now there are 99% discharged allowing for complete outcome analysis. Here is our data on the outcomes of AKI in AJKD when all have been discharged. 

The aim of this study was to investigate in-hospital death and kidney outcomes among hospitalized patients with COVID-19 and AKI.  We reviewed health records of 9657 patients hospitalized with #COVID-19 between March1- April 27^th, 2020, and followed up to the day of discharge/death. The data was from 13 hospitals. To investigate the impact of AKI on in-hospital death, we performed cox regression using AKI as a time-varying exposure and in-hospital death as the outcome.

In the cohort 40% of patients developed AKI (incidence rate of 38.3 per 1000 patient-days). Those who developed AKI had higher proportion with DM, heart disease, chronic kidney disease and had a more severe illness. The death rate was much higher in the AKI requiring dialysis( 6.4 times more) compared to AKI not requiring dialysis (3.4 times more) compared to no AKI. 

What matters to us is what happens to patients who survived? - how many had CKD, how many were sent on dialysis?  The big finding-- Among patients with AKI non-dialysis requiring who had survived, 74% had kidney recovery at the time of discharge. For patients with AKI-on dialysis and survived, 67% had kidney recovery at discharge. For the remainder who did not have kidney recovery, 91.7% remained on dialysis at the time of discharge.  Among those with AKI-on dialysis who survived, the presence of chronic kidney disease was the only independent risk factor associated with need for dialysis at discharge. 60 and 90 day outcomes are lacking and will be eventually useful. 

Regardless of need for dialysis or kidney recovery at discharge, hospitalized COVID-19 patients who experienced any form of AKI should be followed closely post-discharge to assess ongoing kidney function.  Our 13 hospital sites were all in metropolitan NY during the early part of the pandemic; is the major limitation.  

So in patients hospitalized with #COVID-19, those with AKI was associated with higher risk of death, particularly among those who needed dialysis. Most surviving patients with AKI had kidney recovery upon discharge.

Another recent study from a NY metro area showed similar findings in JASN.  Of 3993 hospitalized patients with COVID-19, AKI occurred in 1835 (46%) patients; 347 (19%) of the patients with AKI required dialysis. Of survivors with AKI who were discharged, 35% had not recovered to baseline kidney function by the time of discharge. An additional 36% patients who had not recovered kidney function at discharge did so on posthospital follow-up.

Finally, a research letter in CJASN showed some outcomes data from yet another NY center. Patients with AKI had higher mortality than patients without AKI (40% versus 8%).  Among the patients with AKI, 48% recovered to their baseline kidney function. Among the 52% who did not recover to their baseline kidney function, 43 received dialysis, among which 34 were dialysis dependent and 26 died (60%), and 111 did not receive dialysis, among which 80 (72%) died.