Inverted U-shaped Relationship Between Mean Platelet Volume/Platelet Count Ratio and Post-thrombolytic Early Neurological Deterioration in Patients with Mild and Moderate Stroke

Objective: The objective of this study is to investigate the relationship between mean platelet volume (MPV)/platelet count (PC) ratio and post-thrombolytic early neurological deterioration (END) in patients with mild and moderate stroke. Methods: Mild and moderate stroke patients treated with intravenous thrombolysis (IVT) at the Affiliated Changsha Central Hospital of the University of South China between January 2016 and March 2022 were prospectively and consecutively enrolled. END was defined as an increase in the total National Institutes of Health Stroke Scale (NIHSS) score of ≥4 points or an increase in the motor items of ≥1 point within 24 hours after IVT treatment. Logistic regression and restricted cubic spline models were used to estimate the relationship between the MPV/PC ratio and postthrombolytic END. Results: Among the 406 patients recruited, 64 (15.8%) patients developed END. Patients in the first quintile of MPV/PC ratio (adjusted OR = 0.27, 95% CI = 0.11-0.66, p = 0.004) and the fifth quintile (adjusted OR = 0.26, 95% CI = 0.10-0.69, p = 0.007) had a significantly lower risk of END compared with those in the third quintile. Restricted cubic spline analysis revealed an inverted U-shaped relationship between the MPV/PC ratio and END (p for nonlinearity = 0.016). MPV/PC ratio cut-off value associated with the highest END risk was 51.0. An MPV/PC ratio ≤ 51.0 was shown to be positively associated with END (adjusted OR = 1.07, 95% CI = 1.02-1.14, p = 0.012), while an MPV/PC ratio >51.0 was negatively associated with END (adjusted OR = 0.94, 95% CI = 0.88-1.00, p = 0.040). A significant interaction existed between the MPV/PC ratio and age in the low MPV/PC ratio group (p = 0.012). MPV/PC ratio was positively associated with END only in patients ≥ 60 years, whereas this association was insignificant in patients < 60 years. Conclusion: An inverted U-shaped relationship between the MPV/PC ratio on admission and postthrombolytic END was identified in patients with mild and moderate stroke, with a threshold MPV/PC ratio of 51.0. The MPV/PC ratio closer to the threshold was associated with a higher risk of post-thrombolytic END.