Mean Platelet Volume and Clinical Outcomes After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-analysis
Ivan Alegre-Cordero1, Freddy Arcos Rivera1, Alonso Solano Liñan1, Gerardo Luna-Peralta2, Angela Ariana Milagros Salvador Palma1, Yenko Damjanovic-Burga1, Miguel Cabanillas Lazo3, Carlos Quispe Vicuña3
1Sociedad Científica de San Fernando, Universidad Nacional Mayor de San Marcos, Lima, Perú, 2Universidad Nacional Mayor de San Marcos, Lima, Perú, 3Grupo de Investigación NEMECS: Neurociencias, Metabolismo, Efectividad Clínica y Sanitaria, Universidad Científica del Sur, Lima, Perú.
Objective:
To summarize the current evidence on the association between mean platelet volume (MPV) and prognosis after aneurysmal subarachnoid hemorrhage (aSAH).
Background:
Elevated MPV reflects systemic and cerebral platelet hyperactivity, potentially promoting microthrombosis, persistent vasospasm, and neuroinflammation, pathophysiological mechanisms that underly aSAH main complications like delayed cerebral ischemia (DCI). Nevertheless, the prognostic significance of MPV in aSAH remains unclear, and further evidence is required to better define its clinical relevance.
Design/Methods:
A systematic search of PubMed, Embase, Scopus, Web of Science, and Google Scholar up to September 2025 identified studies assessing MPV in aSAH. Random-effects meta-analyses and sensitivity analyses were conducted to assess the robustness of pooled estimates, with narrative synthesis applied when meta-analysis was not feasible. Study quality was evaluated using the Newcastle–Ottawa Scale, and evidence certainty was graded with GRADE.
Results:
18 studies comprising a total of 5725 patients were included. MPV levels (fL) were significantly higher in patients with DCI than in those without (MD: 0.39; 7 studies; 2,488 participants; 95% CI: 0.07–0.72; I² = 94.1%), with very low certainty of evidence. Sensitivity analysis confirmed the robustness of this findings. Patients with poor functional outcomes (mRS 3–6) exhibited a nonsignificant tendency toward higher MPV levels compared with those with favorable outcomes (mRS 0–2) (MD: 0.57; 3 studies; 1,255 participants; 95% CI: −0.39 to 1.53; I² = 94.8%). A leave-one-out analysis produced similar results, supporting the stability of the findings, although the certainty of the evidence was rated as very low. 15 studies were assessed as having a low risk of bias and 3 as having a medium risk.
Conclusions:
The biomarker was significantly elevated in DCI compared with non-DCI, suggesting its potential prognostic utility and supporting its possible relevance. However, the future large-scale are warranted to validate its role as a reliable biomarker in DCI.
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