A Prognostic Score for the Prediction of Hemorrhagic Progression of Contusion After Traumatic Brain Injury - The COUP Score, a Multicenter Cohort

Introduction: Contusion after traumatic brain injury (TBI) is frequently (20-50%) aggravated by the phenomenon of hemorrhagic progression of contusion (HPC). HPC is associated with higher mortality and unfavorable outcomes. Risk assessment of HPC is fundamental for greater rationality in decision making regarding the level and intensity of surveillance and indication and timing of possible surgical interventions. There is no prospectively validated prognostic score for HPC. This study aims to create a prognostic score for the prediction of HPC after TBI.

Methods: This cohort study followed TBI patients admitted to three tertiary hospitals in Brazil with the following inclusion criteria: mild TBI with indication for head computed tomography (CT) or moderate or severe TBI; and contusion on admission. The variables of interest were demography, previous medical history, current medications, trauma characteristics, laboratory parameters, admission and follow-up head CT and clinical management on the first 72h. The primary outcome was HPC up to 72h. Independent prognostic variables were identified by multivariable logistic regression.

Results: A total of 298 patients were included between January/2019 and Oct/2021(87.9% male; mean age 43.7y±18.8; severe TBI 37.9%). Median initial contusion volume was 3(2-6) ml. HPC incidence was 51.5%, of which 46.9% led to neurological worsening and 35% led to a change of decision from conservative to operative management. Higher age(each year, OR 1.03, 95%CI 1.01-1.06, p=0.002), altered INR(OR 3.08, 95%CI 1.14-8.36, p=0.027), temporal lobe location(OR 2.74, 95%CI 1.29-5.81, p=0.009) and shorter time from injury to head CT(each hour, OR 0.89, 95%CI 0.83-0.96, p=0.001) were predictive of hemorrhagic progression of the contusion. The final model AUC-ROC was 0.78(95%CI 0.71-0.85, p< 0.001) with a good calibration.

Conclusion : HPC incidence was 51.5%. Age, altered INR, temporal lobe location and time from injury to head CT were predictive of HPC. The cohort is still ongoing for the development of the COntUsion Progression score (COUP score).