Early neurological deterioration (END) in acute ischemic stroke is a common event. However, the underlying pathophysiological bases are heterogenous and hard to explain. Immature platelet fraction (IPF) is the useful marker of increased platelet production and turnover which could occur in patients with increased platelet activation. High value of IPF was reported in acute coronary syndrome. 

A total 1655 of acute ischemic stroke patients in single tertiary academic center was enrolled from January 2013 to October 2018 via stroke registry. IPF levels were quantified by whole blood flow cytometry with automated assays (Sysmex XE-2100^TM). High IPF was defined as the IPF level was more than 5%. Early neurological deterioration was defined as an increment change of at least one point in motor power or total National Institute of Health Stroke Scale (NIHSS) score deterioration ≥2 points within the first week after admission.

A total of 72 patients (4.4%) experienced END. END was more prevalent in the patients with high IPF [13 (11.7%) vs 59 (3.8%), p<0.0001]. Multivariate logistic regression analysis showed high IPF was an independent predictor of the prevalence of END (adjust odds ratio = 1.32; 95% confidence interval = 1.03–1.70).

A high IPF levels was associated with the prevalence of END in acute ischemic stroke patients. Future investigation might be needed to evaluate the effective treatment of the high IPF in acute phase of ischemic stroke.