Not all in your head (and neck): Stroke after blunt cerebrovascular injury is associated with systemic hypercoagulability.

BACKGROUND: Stroke secondary to blunt cerebrovascular injury (BCVI) most often occurs before initiation of antithrombotic therapy. Earlier treatment, especially in multiply injured patients with relative contraindications to antithrombotic agents, could be facilitated with improved risk stratification; furthermore, the relationship between BCVI-attributed stroke and hypercoagulability remains unknown. We hypothesized that patients who suffer BCVI-related stroke are hypercoagulable compared with those with BCVI who do not stroke.

METHODS: Rapid thromboelastography (TEG) was evaluated for patients with BCVI-attributed stroke at an urban Level I trauma center from 2011 to 2018. Contemporary controls who had BCVI but did not stroke were selected for comparison using propensity-score matching with 20% caliper that accounted for age, sex, injury severity, and BCVI location and grade.

RESULTS: During the study period, 15,347 patients were admitted following blunt trauma. Blunt cerebrovascular injury was identified in 435 (3%) patients, of whom 28 experienced associated stroke and had a TEG within 24 hours of arrival. Forty-nine patients who had BCVI but did not suffer stroke served as matched controls. Stroke patients formed clots faster as evident in their larger angle (77.5 degrees vs. 74.6 degrees, p = 0.03) and had greater clot strength as indicated by their higher maximum amplitude (MA) (66.9 mm vs. 61.9 mm, p < 0.01). Activated clotting time was shorter among stroke patients but not significantly (113 seconds vs. 121 seconds, p > 0.05). Increased angle and elevated MA were significant predictors of stroke with odds ratios of 2.97 for angle greater than 77.3 degrees and 4.30 for MA greater than 63.0 mm.

CONCLUSION: Patients who suffer BCVI-related stroke are hypercoagulable compared with those with BCVI who remain asymptomatic. Increased angle or MA should be considered when assessing the risk of thrombosis and determining the optimal time to initiate antithrombotic therapy in patients with BCVI.

LEVEL OF EVIDENCE: Prognostic, Level III.