Community- and Hospital-Acquired Acute Kidney Injury in COVID-19: Different Phenotypes and Dismal Prognosis

Introduction: Acute kidney injury (AKI) is common in coronavirus disease 2019 (COVID-19). It is unknown if hospital-acquired AKI (HA-AKI) and community-acquired AKI (CA-AKI) convey a distinct prognosis. Methods: The study aim was to evaluate the incidence and risk factors associated with both CA-AKI and HA-AKI. Consecutive patients hospitalized at a reference center for COVID-19 were included in this prospective cohort study. Results: We registered 349 (30%) AKI episodes in 1,170 hospitalized patients, 224 (19%) corresponded to CA-AKI, and 125 (11%) to HA-AKI. Compared to patients with HA-AKI, subjects with CA-AKI were older (61 years [IQR 49-70] vs. 50 years [IQR 43-61]), had more comorbidities (hypertension [44 vs. 26%], CKD [10 vs. 3%]), higher Charlson Comorbidity Index (2 points [IQR 1-4] vs. 1 point [IQR 0-2]), and presented to the emergency department with more severe disease. Mortality rates were not different between CA-AKI and HA-AKI (119 [53%] vs. 63 [50%], p = 0.66). In multivariate analysis, CA-AKI was strongly associated to a history of CKD (OR 4.17, 95% CI 1.53-11.3), hypertension (OR 1.55, 95% CI 1.01-2.36), Charlson Comorbidity Index (OR 1.16, 95% CI 1.02-1.32), and SOFA score (OR 2.19, 95% CI 1.87-2.57). HA-AKI was associated with the requirement for mechanical ventilation (OR 68.2, 95% CI 37.1-126), elevated troponin I (OR 1.95, 95% CI 1.01-3.83), and glucose levels at admission (OR 1.05, 95% CI 1.02-1.08). Discussion/Conclusions: CA-AKI and HA-AKI portend an adverse prognosis in CO-VID-19. Nevertheless, CA-AKI was associated with a higher comorbidity burden (including CKD and hypertension), while HA-AKI occurred in younger patients by the time severe multiorgan disease developed.