Associations of Antithrombotic Timing and Regimen with Ischemic Stroke and Bleeding Complications in Blunt Cerebrovascular Injury.

Background: Blunt cerebrovascular injuries (BCVIs) are associated with long-term neurological effects. The first-line treatment for BCVIs is antithrombotics, but consensus on the optimal choice and timing of treatment is lacking.

Methods: This was a retrospective study on patients aged at least 18 years admitted to 6 level 1 trauma centers between 1/1/2014 and 12/31/2017 with grade 1-4 BCVI and treated with antithrombotics. Differences in treatment practices were examined across the 6 centers. The primary outcome was ischemic stroke, and secondary outcomes were related to bleeding complications: blood transfusion and intracranial hemorrhage (ICH). Treatment characteristics examined were time to diagnosis and first computerized tomography angiography, time of total treatment course, time on each antithrombotic (anticoagulants, antiplatelets, combination), time from hospital arrival to antithrombotic initiation, and treatment interruption, i.e., treatment halted for a surgical procedure and restarted postoperatively. Chi-square, Fisher exact, Spearman's rank-order correlation, Wilcoxon rank-sum, Kruskal-Wallis, and Cox proportional hazards models with time-varying covariates were used to evaluate associations with the outcomes.

Results: A total of 189 patients with BCVI were included. The median (IQR) time from arrival to antithrombotic initiation was 27 (8-61) hours, and 28% of patients had treatment interrupted. The ischemic stroke rate was 7.5% (n = 14), with most strokes (64%, n = 9) occurring between arrival and treatment initiation. Treatment interruption was associated with ischemic stroke (75% of patients with stroke had an interruption versus 24% of patients with no stroke; P < .01). Time on anticoagulants was not associated with ischemic stroke (P = .78), transfusion (P = .43), or ICH (P = .96). Similarly, time on antiplatelets (P = .54, P = .65, P = .60) and time on combination therapy (P = .96, P = .38, P = .57) were not associated with these outcomes.

Conclusions: The timing and consistency of antithrombotic administration are critical in preventing adverse outcomes in patients with BCVI. Most ischemic strokes in this study population occurred between arrival and antithrombotic initiation, representing events that may potentially be intervened upon by earlier treatment. Future studies should examine the safety of continuing treatment through surgical procedures.