Background: The novel coronavirus disease 2019 (COVID-19) has demonstrated a range of presentations and outcomes affecting multiple organ systems. Acute kidney injury (AKI) associated with hospitalized patients with COVID-19 and related outcomes vary widely according to early reports. This study aimed to determine the prevalence of AKI, AKI in the setting of chronic kidney disease (CKD) and AKI requiring hemodialysis (HD) in patients with COVID-19 in a U.S. cohort. We also evaluated the association between markers of abnormal kidney function and death in patients with COVID-19. Finally, we determined pre-disposing factors that lead to AKI, such as: cardiac history, diabetes mellitus, hypertension and cerebrovascular disease.
Methods: A single-center retrospective analysis was conducted involving all patients greater than 18 years of age with a confirmed diagnosis of COVID-19 via reverse transcriptase-polymerase chain reaction assays (RT-PCR) or molecular PCR via nasopharyngeal swab between March 15 and May 31, 2020. Initial descriptive statistics were used to summarize the data and represent basic patient population characteristics. Univariate logistic regression and chi square analysis was performed to study the odds of the different outcomes with respect to AKI. AKI and its severity were defined according to the KDIGO criteria.
Results: Out of 368 hospitalized patients with COVID-19, 177 patients (56.7%) had AKI; of this, 35%, 10.9% and 10.3% had stage 1, 2 and 3 respectively. 2.4% of all patients who developed AKI required renal replacement therapy (RRT). Initial analysis demonstrated that patients with increasing severity of kidney disease had a significantly higher risk of in-hospital death (AKI stage 1 OR 1.07 [95% CI, 0.67, 1.72], AKI stage 2 OR 2.75 [95% CI, 1.47, 5.13], AKI stage 3 OR 3.47 [95% CI, 1.90, 6.34]). Overall, patients with AKI were found to have increased mortality, compared to those patients who did not have AKI (OR 5.82 [95% CI, 3.31, 10.27]). Patients with AKI on CKD had a mortality rate of 3.06 [95% CI, 1.33, 4.11]. There was not enough power to see a significant effect on ESRD. Next, several comorbid factors were found to increase risk of AKI. Cardiac history (coronary artery disease, congestive heart failure, arrhythmias and valvular disease) was found to be significant in increasing risk of AKI (OR 1.62 [95% CI, 1.07, 2.46]). Hypertension, diabetes and cerebrovascular accident were also found to be statistically significant (OR 2.64 [95% CI, 1.65, 4.26], OR 1.82 [95% CI, 1.20, 2.77], OR 2.50 [95% CI, 1.59, 3.93], respectively). We hypothesize that these comorbidities increase COVID-19 disease severity and in turn, increase risk of AKI.
Conclusions: Our findings highlight a prevalence of AKI in COVID-19 patients on admission. The development of AKI during hospitalization in patients with COVID-19 is high and is associated with in-hospital mortality. Furthermore, we found that patients with comorbidities including cardiac history, hypertension, diabetes and cerebrovascular accident are all factors that lead to higher risk of AKI in COVID-19 patients. Going forward, clinicians should aim to increase their awareness of and factors posing an increased risk of AKI in patients with severe COVID-19.