Brain health trajectories 3 years after hospitalization for COVID-19, pneumonia, myocardial infarction, or critical illness

BACKGROUND: Long-term consequences of COVID-19 seem to persist several years after initial infection; however, it is still unknown whether these consequences differ from those occurring after hospitalization for similar diseases and if they remain stable, improve, or worsen over time.

METHODS: This is a prospective cohort study assessing 36-month follow-up of individuals previously monitored up to 18 months post-hospitalization. We included COVID-19 patients; hospitalized controls admitted for pneumonia, myocardial infarction or conditions requiring intensive care admission; and healthy controls. The hospitalized groups were admitted between March 1, 2020, and June 30, 2021, at two academic hospitals in Copenhagen. All participants were examined in-person between October 2023 and July 2024.

RESULTS: We investigated 242 participants. Eighty-four hospitalized COVID-19 patients (mean [SD] age 62 [12]; 39 females [46 %]), 80 hospitalized controls (mean age, 65 [11]; 30 females [38 %]), and 78 healthy controls (mean age, 65 [14]; 45 females [58 %]). Compared to the healthy controls, COVID-19 patients had poorer SCIP scores (estimated mean: 68.0 [95 %CI, 65.6-70.5] vs 74.4 [95 %CI, 71.6-77.2]) and non-significantly higher anxiety, depression, and neurological scores. COVID-19 patients performed comparably to hospitalized controls in all outcomes (all p > .06). Cognitive function improved over time among both COVID-19 and hospitalized controls, while mental-health improved mainly in COVID-19 patients.

CONCLUSION: This study shows comparable brain function impairments in COVID-19 patients and hospitalized controls 36 months post-hospitalization, with gradual improvement over time. These findings are relevant for guiding patients with long-lasting symptoms after critical illness.