Investigating Neutrophil-to-Lymphocyte Ratio and Risk Factors for Hemorrhagic Transformation Following Thrombolytic Therapy: Insights from a Cross-Sectional Study

Background: Hemorrhagic transformation (HT) is a serious complication of thrombolytic therapy with recombinant tissue plasminogen activator (r-tPA) in patients with acute ischemic stroke (AIS). Objectives: This study aimed to investigate the prevalence of HT and associated risk factors in AIS patients treated with r-tPA. Methods: We conducted a descriptive-analytical cross-sectional study on AIS patients at Shahid Beheshti Hospital, Qom, Iran, from April 2019 to March 2020. A total of 175 patients treated with r-tPA within 4.5 hours of stroke onset were included. Data on demographic and clinical factors, including underlying diseases, medication history, laboratory results, and occurrence of HT, were collected and analyzed using SPSS version 22. Statistical tests such as chi-square, t-test, and logistic regression were applied, with a significance level of P < 0.05. Results: Hemorrhagic transformation was observed in 28 patients (16.0%) within 24 hours post-r-tPA administration. A significant association was found between HT and histories of diabetes, hypertension, hyperlipidemia, previous cerebrovascular accidents (CVA), and cardiovascular disease (P < 0.05). Antiplatelet and anticoagulant use were also significantly associated with HT (P < 0.05). The neutrophil-to-lymphocyte ratio (NLR) post-r-tPA showed increased predictive accuracy for HT (AUC = 0.768) compared to pre-treatment levels, indicating its potential as a reliable biomarker. Conclusions: Patients with comorbid conditions such as diabetes, hypertension, and prior antithrombotic therapy exhibited an elevated risk of HT following r-tPA treatment. Post-treatment NLR was identified as a potential biomarker for predicting HT, supporting its use in assessing patient risk after thrombolysis. These findings underscore the importance of individualized risk assessment in AIS management.