Is Thrombocytopenia an In-Hospital Mortality Risk Factor among Patients with Acute Ischemic Stroke? A Propensity Score-Matched Analysis from the MIMIC-IV Database

(1) Background: We aimed to evaluate the aspect of thrombocytopenia in patients with acute ischemic stroke (AIS); (2) Methods: Patients with AIS were recruited in the Medical Information Mart for Intensive Care IV database from 2008 to 2019. The thrombocytopenia was defined as a platelet blood count of less than 150 K/µL. We compared the patient characteristics and clinical outcomes using propensity score matching (PSM); (3) Results: Thrombocytopenia affected 151 out of the 1236 patients (12.2%). Patients with thrombocytopenia were older (70.5 ± 12.8 vs. 68.4 ± 14.4; SMD = 0.154) and had a higher Charlson comorbidity index (7.3 ± 2.5 vs. 6.7 ± 2.7; SMD = 0.228) and acute physiology score III (44.8 ± 21.0 vs. 38.2 ± 19.1; SMD = 0.328) than those without thrombocytopenia. The risk of in-hospital mortality did not increase linearly or nonlinearly with a lower platelet count (overall p value = 0.794; nonlinear p value = 0.646). After PSM, 147 pairs remained. Thrombocytopenia was not linked with in-hospital mortality (HR: 1.06, 95% CIs: 0.60–1.88); (4) Conclusions: We described the clinical characteristics of patients admitted for thrombocytopenia and AIS who did not receive reperfusion therapy; additionally, we found that thrombocytopenia was not an independent short-term risk factor of in-hospital mortality.