Impact of Hemoglobin Levels on Composite Cardiac Arrest or Stroke Outcome in Patients With Respiratory Failure Due to COVID-19.

Objectives: Anemia has been associated with an increased risk of both cardiac arrest and stroke, frequent complications of COVID-19. The effect of hemoglobin level at ICU admission on a composite outcome of cardiac arrest or stroke in an international cohort of COVID-19 patients was investigated.
Design: Retrospective analysis of prospectively collected database.
Setting: A registry of COVID-19 patients admitted to ICUs at over 370 international sites was reviewed for patients diagnosed with cardiac arrest or stroke up to 30 days after ICU admission. Anemia was defined as: normal (hemoglobin ≥ 12.0 g/dL for women, ≥ 13.5 g/dL for men), mild (hemoglobin 10.0-11.9 g/dL for women, 10.0-13.4 g/dL for men), moderate (hemoglobin ≥ 8.0 and < 10.0 g/dL for women and men), and severe (hemoglobin < 8.0 g/dL for women and men).
Patients: Patients older than 18 years with acute COVID-19 infection in the ICU.
Interventions: None.
Measurements and Main Results: Of 6926 patients (median age = 59 yr, male = 65%), 760 patients (11.0%) experienced stroke (2.0%) and/or cardiac arrest (9.4%). Cardiac arrest or stroke was more common in patients with low hemoglobin, occurring in 12.8% of patients with normal hemoglobin, 13.3% of patients with mild anemia, and 16.7% of patients with moderate/severe anemia. Time to stroke or cardiac arrest by anemia status was analyzed using Cox proportional hazards regression with death as a competing risk. Covariates selected through clinical knowledge were age, sex, comorbidities (diabetes, hypertension, obesity, and cardiac or neurologic conditions), pandemic era, country income, mechanical ventilation, and extracorporeal membrane oxygenation. Moderate/severe anemia was associated with a higher risk of cardiac arrest or stroke (hazard ratio, 1.32; 95% CI, 1.05-1.67).
Conclusions: In an international registry of ICU patients with COVID-19, moderate/severe anemia was associated with increased hazard of cardiac arrest or stroke.
Competing Interests: Drs. Suen, Li Bassi, and Fraser received support for article research from the Bill and Melinda Gates Foundation. Drs. Fraser’s, Suen’s, and Li Bassi’s institutions received funding from The Bill and Melinda Gates Foundation. Dr. Suen is funded by the Advance Queensland fellowship program, Queensland Government, Australia. Dr. Li Bassi’s institution received funding from Fisher & Paykel. Dr. Li Bassi is a recipient of the Biomedical international training research programme for excellent clinician-scientists (BITRECS) fellowship; the “BITRECS” project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 754550 and from the “La Caixa” Foundation (ID 100010434), under the agreement LCF/PR/GN18/50310006. Dr. Cho received funding from Hyperfine. Dr. Arora has received honoraria from Edwards Lifesciences, HLS Therapeutics, and Bioporto as well is on the advisory board for Renibus Therapeutics for work unrelated to this article. The remaining authors have disclosed that they do not have any potential conflicts of interest.
(Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)