LAUSR

Background: Bleeding events can be critical in hospitalized patients with COVID-19, especially those with aggressive anticoagulation therapy. Objective: We aimed to investigate whether hemoglobin drop associated with increased risk of acute kidney injury (AKI) and in-hospital mortality among patients with COVID-19. Methods: This retrospective study was conducted by review of the medical records of 6,683 patients with laboratory confirmed COVID-19 hospitalized in the Mount Sinai Health system between March 1 st , 2020 and March 30 th 2021. We compared patients with and without hemoglobin drop >3g/dL during hospitalization within a week after admissions, using inverse probability treatment weighted analysis (IPTW). Outcomes of interest were in-hospital mortality and AKI which was defined as increased of creatine 1.5 times or 0.3mg/dL. Results: Of the 6,683 patients admitted due to COVID-19, 750 (11.2%) presented with a marked hemoglobin drop. Patients with hemoglobin drop were more likely to receive therapeutic anticoagulation within two days after admissions. Patients with hemoglobin drop had higher crude in-hospital mortality (40.8% versus 20.0%, P<0.001) as well as AKI (51.4% versus 23.9%, P<0.001) compared to those without. IPTW analysis showed that hemoglobin drop was associated with higher in-hospital mortality compared to those without (odds ratio (OR) [95% confidential interval (CI)]: 2.21 [1.54-2.88], P<0.001) as well as AKI (OR [95% CI]: 2.79 [2.08-3.73], P<0.001). Finally, the smooth spline curve showed the association of hemoglobin drop and adjusted odds ratio for in-hospital mortality, which reflected the association of hemoglobin drop and in-hospital mortality (Figure). Conclusions: Hemoglobin drop during COVID-19 related hospitalizations was associated with a higher risk of AKI and in-hospital mortality. Figure Legends: Smooth spline curve of the association of hemoglobin drop and adjusted odds ratio of in-hospital mortality.