Trajectory of mean platelet volume changes after aneurysmal subarachnoid hemorrhage in patients with or without delayed cerebral ischemia

The morbidity of aneurysmal subarachnoid hemorrhage (aSAH) remains high, particularly because of secondary cerebral lesions that significantly aggravate the primary lesions. The main type of secondary lesions is delayed cerebral ischemia (DCI), in which platelets (PLT) appear to play a key role. Mean platelet volume (MPV) is an indirect marker of platelet activation. We aimed to determine the individual trajectories of MPV over time in patients with and without DCI during the course of aSAH. This is a single-center, retrospective, longitudinal analysis of individual trajectories of MPV over time, in a cohort of aSAH patients included in the Prospective, Observational Registry of Patient with Subarachnoid Hemorrhage in Neurocritical Care Unit (ProReSHA). A mixed-effects linear regression model was used to compare the trajectories of MPV and MPV/PLT ratio between patients who developed a DCI and those who did not. A total of 3634 MPV values were collected in 587 patients. The analysis of MPV as a function of DCI occurrence showed a significant difference in the trajectory over time between patients with DCI and those without, with an estimate of 0.02 (95%CI 0.01, 0.04, p = 0.009). The analysis of the MPV/PLT ratio as a function of DCI occurrence and other covariates showed a significant difference in the trajectory over time only for patients with a modified Fisher score less than 3, with an estimate of -0.59 (95%CI: -0.94, -0.23, p = 0.001). The individual trajectories of MPV over time differ between patients with DCI and those without. However, MPV values vary greatly over time and between patients. Thus it does not appear as a reliable biomarker for stratifying patients based on their specific risk of developing DCI. ClinicalTrials.gov identifier: (NCT02890004), registered in August 2016.