Long COVID-19 outcomes of patients with pre-existing dementia

Background: Although COVID-19 has been linked to worse acute outcomes in patients with some neurodegenerative disorders, its long-term impact on dementia remains unclear.

Objective: To investigate the outcomes of COVID-19 survivors with dementia.

Methods: This retrospective study evaluated 9806 patients with dementia in the Montefiore Health System (January 2016 to July 2023). Comparisons were made between dementia patients with and without a positive SARS-CoV-2 polymerase-chain-reaction test who had a follow-up at least two weeks post-infection. Outcomes included all-cause mortality, major adverse cardiovascular events (MACE), new-onset dysphagia, dyspnea, fatigue, new-onset sleep disturbances, altered mental status, first-time fall, headache, new-onset depression, and new-onset anxiety. Adjusted hazard ratios (aHR) were computed adjusting for age, sex, race, ethnicity, and pre-existing comorbidities.

Results: Dementia patients with COVID-19 were younger, more likely to be male, and had a higher prevalence of major pre-existing comorbidities compared to those without COVID-19. Patients who survived acute COVID-19 were more likely to die than non-COVID controls after adjusting for covariates (aHR = 1.65 [1.43, 1.91]). COVID-19 was significantly associated with higher risk of MACE (aHR = 1.58 [1.41, 1.78]), new-onset dysphagia (aHR = 1.64 [1.42, 1.91]), dyspnea (aHR = 1.27 [1.12, 1.44]), fatigue (aHR = 1.42 [1.22, 1.65]), new-onset sleep disturbances (aHR = 1.36 [1.15, 1.60]), altered mental status (aHR = 1.36 [1.16, 1.59]), and first-time fall (aHR = 1.34 [1.09, 1.65]).

Conclusions: COVID-19 increases the risk of mortality and other adverse health outcomes in dementia patients. These findings highlight the need for closer follow-up and management strategies for dementia patients post-COVID-19.