(768) Biomarkers and Outcomes in Traumatic Brain Injury Patients on Angiotensin Receptor Blockers

Introduction: Biomarkers released after TBI have been linked to injury severity and are potential TBI drug treatment monitoring targets. Studies suggest that angiotensin receptor blockers (ARB) have neuroprotective effects in acute TBI animal models, such as improving cerebral circulation, decreasing neuroinflammation, reducing oxidative stress, protecting the blood brain barrier, and promoting angiogenesis. This study aims to evaluate biomarker trends and outcomes in TBI patients who did or did not receive pre-injury or in-hospital high dose ARB (HD-ARB).

Methods: This retrospective cohort study utilizes the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) database conducted at 18 level-1 trauma centers in the US from 2014-2018. Patients ages ≥17 with documented outcomes were assessed, with follow-up to 12 months postinjury. Patient groups receiving preinjury or in-hospital HD-ARB were compared to propensity-matched controls. Outcomes were evaluated using various assessment tools at 2 weeks, 3 and 6 months post-injury. Biomarker mean peak concentrations (Cp) were compared for GFAP, UCHL-1, NSE, S100, CRP, NFL, IL-10, IL-6, TNF-𝛼 and Tau.

Results: Mean NFL Cp at 2 weeks post injury were 68% lower in the HD-ARB (n=19) group as compared to the control group (n=232). CRP Cp occurred at 3 days in the ARB group as compared to 5 days in the control group. CRP Cp were 46% less on day 5 post injury. NSE Cp in the ARB group was lower on day 1 (p=0.049) and displayed a downward trend from day 1-5 compared to controls. Although these trends may be clinically meaningful, they were not statistically significant. The HD-ARB group showed a beneficial effect on most clinical assessments at 2 weeks and 6 months.

Conclusions: Preinjury or in-hospital treatment with HD-ARB showed promising trends in TBI biomarker concentrations and improved clinical assessment scores, although most were not statistically significant. This may be due to a small sample size and multiple comparisons between study groups. Prospective ARB neuroprotective studies are needed to confirm these favorable clinical outcomes and biomarkers as potential drug monitoring targets.