Severity Matters: Injury Severity May Limit the Protective Association of Pre-injury Statin Therapy After Traumatic Brain Injury

Introduction Severe traumatic brain injury (TBI) is the leading cause of injury-related mortality. Prior studies suggest statin medications may be associated with favorable outcomes after TBI and reduced risk of venous thromboembolism. However, the effects of statin medications in patients with severe TBI have not been evaluated. The objective of this study is to determine the effects of pre-injury statin exposure on injured patients with severe TBI. Methods Adult trauma patients with severe TBI (GCS≤8) who received pre-injury statins were compared to those who did not receive pre-injury statins. Demographics, complication rates, blood product transfusion volumes, and mortality were evaluated. Univariate and multivariable analyses were used to determine independent predictors of mortality. Results A total of 816 patients suffered a severe TBI during the study period. Of these, 151 patients (18.5%) were taking statin medications prior to injury. Patients with pre-injury statin exposure had lower early mortality than those without pre-injury exposure (6.6% vs 12.8%, P = 0.04). After adjusting for baseline differences, pre-injury statin use was not an independent predictor of mortality following multiple logistic regression. In subgroup analyses, pre-injury statin exposure was not associated with improved outcomes in those who received a blood transfusion or were in shock. Conclusion Although pre-injury statin exposure was associated with lower unadjusted early mortality in patients with severe TBI, this association did not persist after adjustment for injury severity and physiologic differences. These findings suggest that potential benefits observed in broader TBI populations may not extend to patients with severe TBI.