Mean platelet volume for prognostication after out-of-hospital cardiac arrest: a retrospective cohort analysis

Background: Determining patient prognosis after cardiac arrest is crucial to define proper management. The mean platelet volume (MPV) is a biomarker that is used in the prognosis of various inflammatory diseases. We investigated whether the MPV could serve as a prognostic marker for outcomes in patients with out-of-hospital cardiac arrest (OHCA). Methods: We performed a retrospective study of adult patients with OHCA who, between 2016 and 2022, were admitted to the medical intensive care unit of a single tertiary-care center in southern Thailand. We collected data on the MPV that was measured at least twice during the first 4 days of admission. The primary outcome was in-hospital mortality. The secondary outcome was poor neurological outcome at the time of hospital discharge, which was defined as a cerebral performance category score of 3–5. Results: Among the 231 patients who were screened, the study included 147 patients, 110 (74.8%) of whom had poor neurological outcomes; 82 (55.8%) died. After adjusting for factors affecting in-hospital mortality, the MPV on day 3 was strongly associated with mortality [adjusted odds ratio (OR) =2.50, 95% confidence interval (CI): 1.39–4.47, P=0.002], followed by the MPV on day 2 (adjusted OR =1.74, 95% CI: 1.08–2.81, P=0.02). There was no significant difference in the MPV between patients with good or poor neurological outcomes. The MPV on day 3 showed moderate accuracy in predicting mortality, with an area under the curve of 0.709 (95% CI: 0.599–0.818). The cutoff point of 11.7 fL achieved 94.44% specificity and 30.36% sensitivity. Conclusions: The MPV on day 3 after admission was independently associated with in-hospital mortality. Larger studies are required to validate the MPV as a predictive tool.