Recovery from acute kidney injury is an independent predictor of survival at 30 days only after out-of-hospital cardiac arrest who were treated by targeted temperature management

Background: Development of acute kidney injury (AKI) after out-of-hospital cardiac arrest (OHCA) is associated with mortality and poor neurological outcome. However, the effect of recovery from AKI after OHCA is uncertain. This study investigates whether recovery from AKI was associated with the rate of survival and neurological outcome at 30 days after OHCA. Methods: This is a prospective multicentre observational cohort study of adult OHCA patients treated with targeted temperature management (TTM) across five hospitals in South Korea between February 2019 and July 2020. AKI was diagnosed using the Kidney Disease: Improving Global Outcomes criteria. The primary outcome was the rate of survival at 30 days, and the secondary outcome was the rate of survival with a favourable neurological outcome at 30 days, defined by a score of 3 or less on the modified Rankin scale. Results: Among the 2,018 patients with OHCA, 79 were treated with TTM. After excluding two patients with incomplete data on outcomes, 77 were analysed. AKI developed in 43 (56%) patients. Among them, 22 (51%) recovered from AKI. Although the rate of survival at 30 days for the recovery group was superior to the non-recovery group (82% vs. 24%, P < 0.001), the rate of survival with a favourable neurological outcome at 30 days for the recovery group was not different than that for the non-recovery group (32% vs. 10%, P = 0.132). Recovery from AKI was an independent predictor of survival at 30 days after OHCA in the multivariate analysis (adjusted odds ratio, 22.737; 95% confidence interval, 3.814-135.533; P = 0.001); however, it was not associated with a favourable neurological outcome at 30 days after OHCA in the multivariate analysis. Conclusion: Recovery from AKI was an independent predictor of survival at 30 days only after OHCA who were treated by TTM.