Platelet Mass Index as a Predictor of Prognosis in Hemorrhagic Stroke

Aim: Platelet mass index (PMI) is an inexpensive parameter which can be easily calculated from complete blood count. It has been recently claimed as a good inflammation parameter that is closely related to platelet function and is also believed to indicate the aggregation capacity of platelets. The present study aimed to investigate the prognostic value of PMI in patients with acute hemorrhagic stroke. Material and Methods: All patients aged 18 years or over who were diagnosed with subarachnoid or intracerebral hemorrhage between 2014 and 2018 were included in the study. Platelet mass index was calculated with the formula “PMI = platelet count x MPV”. The type and localization of hemorrhagic stroke, presence of secondary brain injury, laboratory parameters, need for surgical intervention, length of hospital stay, and 30-day mortality were compared between survivor and non-survivor patients. Receiver Operating Characteristic (ROC) analysis was performed in order to discriminate surviving patients on the 30th day. Results: A total of 103 patients were included. PMI was significantly higher in the surviving patients (1912 [IQR 25‒75%: 1544.2-2468.2]) compared to the non-surviving ones (1722.1 [IQR 25‒75%: 1332.2-2114])(p=0.039). There was no significant difference in the parameters showing platelet function and inflammation, including PMI levels in patients with and without secondary injuries or surgical intervention (p> 0.05 for all). AUC value was found to be 0.628 (95% CI: 0.517-0.738) for PMI in discriminating surviving patients on the 30th day. Conclusion: This study revealed that the patients who died by 30th day after hemorrhagic stroke had lower PMI levels. However, the predictive accuracy of PMI for 30-day survival was poor. Therefore, we believe that PMI cannot be used alone in predicting prognosis of hemorrhagic stroke, but in combination with other markers of platelet function and inflammation, it may contribute to clinicians in patient risk assessment.