Acute stroke patients with high CRP levels greater than 7.09 mg/L are at greater risk for developing delirium, suggests a study from Poland published in the journal Acta Psychiatrica Scandinavica.¹

For this study, researchers retrospectively analysed data from 459 patients who had been hospitalized for acute stroke or transient ischemic attack (TIA) within 24 hours with the aim to find out if including C-reactive protein (CRP) with other clinical factors (Models A and B) could enhance prediction of delirium in these patients. The factors in Model A were age and stroke severity, while in Model B,  severity of stroke, diabetes, atrial fibrillation, pre-stroke dependency and hemorrhagic stroke were the factors included. They were a part of the Prospective Observational Polish Study on Delirium (PROPOLIS), which was an observational, prospective single center study and had recruited patients with ischemic stroke, TIA or intracerebral hemorrhage from May 2014 to March 2016, within 48 hours of symptoms. Patients who had had CRP measured at baseline were enrolled for this study. Their median age was 73 years and more than half (52.7%) the study population was comprised of women. Patients were evaluated for neurological deficits (National Institutes of Health Stroke Scale [NIHSS]), cognitive decline, prestroke dependency (modified Rankin Scale) and delirium (Brief Confusion Assessment Method for verbal patients and the Confusion Assessment Method for the Intensive Care Unit for nonverbal patients).

Nearly one-third (29.2%) of patients developed delirium with 46.2% experiencing mixed delirium, 39.2% hypoactive delirium and 14.2% hyperactive delirium. The delirious patients also had higher levels (median) of CRP than those who did not have delirium; 13.2 mg/L vs 4.4 mg/L, respectively.

A cut-off level of 7.09 mg/L was identified as marking the distinction between the two groups. On univariate analysis, CRP and other clinical factors such age, diabetes, AF, prestroke dependency, Prestroke cognitive decline, NIHSS score on admission Hemorrhagic stroke were associated with increased risk for delirium. But on multivariate analysis, this association remained significant only for CRP. The risk was 3-folds higher in patients with CRP levels more than 7.09 mg/L with an adjusted odds ratio of 2.98. The researchers also noted that addition of CRP to the two clinical models examined, the “area under receiver operator curve increased from 0.77 to 0.80 for Model A and from 0.81 to 0.84 for Model B”.

Delirium in stroke patients is indicative of a poor clinical outcome. Identification of a factor that could predict development of delirium enables monitoring of at-risk patients and timely implementation of appropriate management strategies. CRP, a marker of systemic inflammation, is a commonly performed test in clinical practice. Based on their findings, the authors suggest CRP as a potential marker for risk of delirium in post-stroke patients. Acute stroke patients with high CRP levels, above the cut-off level defined in this study, should be closely monitored for delirium.

Reference

1. Elzbieta Klimiec-Moskal, et al. Serum C-reactive protein adds predictive information for post-stroke delirium: The PROPOLIS study. Acta Psychiatr Scand. 2022 Aug 23. doi: 10.1111/acps.13489.