Long-term outcomes of COVID-19 survivors with hospital AKI: association with time to recovery from AKI

Abstract Background Although COVID-19 patients who developed in-hospital AKI have worse short-term outcomes, their long-term outcomes have not been fully characterized. We investigated 90-day and one-year outcomes after hospital AKI grouped by time to recovery from AKI. Methods This study consisted of 3,296 COVID-19 patients with hospital AKI stratified by early recovery (<48 hours), delayed recovery (2-7 days), and prolonged recovery (>7-90 days). Demographics, comorbidities, laboratory values were obtained at admission and up to one-year follow-up. Incidence of major adverse cardiovascular event (MACE) and major adverse kidney event (MAKE), rehospitalization, recurrent AKI, and new-onset chronic kidney disease (CKD) were obtained 90-days post COVID-19 discharge. Results The incidence of hospital AKI was 28.6%. Of COVID-19 patients with AKI, 58.0% experienced early recovery, 14.8% delayed recovery and 27.1% prolonged recovery. Patients with longer AKI recovery time had higher prevalence of CKD (p<0.05) and were more likely to need invasive mechanical ventilation (p<0.001) and to die (p<0.001). Many COVID-19 patients developed MAKE, recurrent AKI, and new-onset CKD within 90 days, and these incidences were higher in the prolonged recovery group (p<0.05). Incidence of MACE peaked 20-40 days post-discharge, whereas MAKE peaked 80-90 days post-discharge. Logistic regression models predicted 90-day MACE and MAKE with 82.4±1.6% and 79.6.9±2.3% accuracy, respectively. Conclusion COVID-19 survivors who developed hospital AKI are at high risk for adverse cardiovascular and kidney outcomes, especially those with longer AKI recovery time and those with history of CKD. These patients may require long-term follow-up for cardiac and kidney complications.