Platelet function testing does not predict hemorrhage progression in mild traumatic brain injury

Antiplatelet medications are frequently assumed to increase the risk of radiographic progression following traumatic intracranial hemorrhage (ICH), influencing guidelines that recommend prolonged observation and repeat imaging. However, antiplatelet use does not uniformly result in functional platelet inhibition, and the clinical relevance of therapeutic response remains unclear.

We conducted a retrospective cohort study of adult patients with traumatic ICH and a Glasgow Coma Scale (GCS) score of 13-15 who were on antiplatelet therapy and underwent platelet function testing (VerifyNow PRU or PFA) on admission. Patients were classified as therapeutic or non-therapeutic based on test thresholds. All patients received follow-up CT imaging within 24 h. Clinical variables and outcomes, including radiographic progression, surgical intervention, and mortality, were compared between groups. A sensitivity analysis excluded patients with hematocrit <30 % or platelet count <100,000.

A total of 239 patients were included: 190 in the non-therapeutic group and 49 in the therapeutic group. Radiographic progression occurred in 17.6 % of patients overall, with no significant difference between therapeutic and non-therapeutic groups (20.4 % vs. 16.8 %; p = 0.53). Surgical intervention (p = 0.57) and mortality (p = 0.38) rates were similarly low and comparable. Sensitivity analyses confirmed these findings (p = 0.81).

Therapeutic platelet inhibition was not associated with increased risk of radiographic or clinical worsening in patients with mild traumatic ICH. These findings challenge current assumptions regarding antiplatelet risk and suggest that platelet function testing may have limited utility in this setting. These findings support the need to reevaluate current guidelines and validate risk stratification approaches through prospective multicenter studies.