Mean platelet volume and clinical outcomes in patients with acute ischemic stroke: A systematic review and meta-analysis

Objective: Mean platelet volume (MPV) is a laboratory marker that reflects platelet activity and has been linked to a higher risk of thromboembolic events. This study aimed to evaluate MPV as a potential biomarker for clinical outcomes in acute ischemic stroke. Methods: A systematic search was conducted in PubMed, Embase, Scopus, Web of Science, and Google Scholar up to March 2024. Risk of bias was assessed using the Newcastle-Ottawa Scale. When meta-analysis was not feasible, a narrative synthesis was performed. Subgroup and sensitivity analyses were planned, and the certainty of evidence was graded using the GRADE approach. Results: Out of 534 studies, 57 were included (10,979 patients). Higher MPV levels were associated with poor functional outcomes (modified Rankin Scale [mRS] >2) at 90 days, although with high heterogeneity (MD: 0.50; 95% CI: 0.31–0.70; I²=82%). A weak positive correlation was found between MPV and impairment measure (National Institutes of Health Stroke Scale [NIHSS]: r=0.140–0.221). MPV was also associated with mortality at 3 months (OR: 3.88) and 1 year (OR: 1.76). No significant associations were observed with one-year disability, hemorrhagic transformation, cerebral microbleeds, or in-hospital complications. Conclusions: In summary, MPV may be associated with worse 90-day functional outcomes and mortality; however, its correlation with impairment severity measured by NIHSS was weak. Further studies are needed to establish optimal cut-off values and incorporate MPV into predictive models.