BackgroundThe objective of this study was to evaluate the association between red cell distribution width/platelet ratio (RPR) and 30-day and 1-year mortality in acute ischemic stroke (AIS).MethodsData for the retrospective cohort study were collected from the Medical Information Mart for Intensive Care (MIMIC) III database. RPR was divided into two groups: RPR ≤ 0.11 and RPR > 0.11. The study outcomes were 30-day mortality and 1-year mortality from AIS. Cox proportional hazard models were utilized to assess the association between RPR and mortality. Subgroup analyses were applied based on age, tissue-type plasminogen activator (IV-tPA), endovascular treatment, and myocardial infarction.ResultsA total of 1,358 patients were included in the study. Short- and long-term mortality occurred in 375 (27.61%) and 560 (41.24%) AIS patients, respectively. A high RPR was significantly associated with increased 30-day [hazard ratio (HR): 1.45, 95% confidence interval (CI): 1.10 to 1.92,P= 0.009] and 1-year mortality (HR: 1.54, 95%CI: 1.23 to 1.93,P< 0.001) in AIS patients. Meanwhile, RPR was found to be significantly related to 30-day mortality in AIS patients aged < 65 years (HR: 2.19, 95% CI: 1.17 to 4.10, P = 0.014), without IV-tPA use (HR: 1.42, 95% CI: 1.05 to 1.90,P= 0.021), without using endovascular treatment (HR: 1.45, 95% CI: 1.08 to 1.94,P= 0.012), and without myocardial infarction (HR: 1.54, 95% CI: 1.13 to 2.10,P= 0.006). Additionally, RPR was associated with 1-year mortality in AIS patients aged < 65 years (HR: 2.54, 95% CI: 1.56 to 4.14,P< 0.001), aged ≥ 65 years (HR: 1.38, 95% CI: 1.06 to 1.19,P= 0.015), with (HR: 1.46, 95% CI: 1.15 to 1.85,P= 0.002) and without using IV-tPA (HR: 2.30, 95% CI: 1.03 to 5.11,P= 0.041), without using endovascular treatment (HR: 1.56, 95% CI: 1.23 to 1.96,P< 0.001), and without myocardial infarction (HR: 1.68, 95% CI: 1.31 to 2.15,P< 0.001).ConclusionElevated RPR is associated with a high risk of short-term and long-term mortality in AIS.