Variability in Thrombolytic Response to Alteplase among Iraqi Patients with ST-Elevation Myocardial Infarction: Clinical, Biochemical, and Electrocardiographic Predictors of Outcomes

Abstract

Objectives: This study aimed to assess the variability of thrombolytic response to Alteplase in Iraqi STEMI patients and to identify clinical, biochemical, and electrocardiographic predictors of poor outcomes. Methodology: A cross-sectional study was conducted on 100 patients with STEMI admitted to Al-Imamain Al-Kadhmian Medical City, Baghdad, from May 2023 to March 2024. Clinical evaluation included vital signs, Killip classification, chest pain assessment, and risk factor profiling. Laboratory investigations included C-reactive protein (CRP) and troponin levels. Electrocardiographic and echocardiographic assessments were performed before and after thrombolysis. The response was evaluated by chest pain resolution and ST-segment resolution on ECG. Statistical analysis was performed using R software, with logistic regression employed to identify predictors of poor outcomes. Results: Among the 100 patients (mean age 56.1 ± 12.4 years; 84.0% male), complete pain relief was reported in 60.0% of cases, partial relief in 31.0%, and no relief in 9.0%. Electrocardiographic assessment demonstrated complete ST-segment resolution in 50.0% of patients, partial in 27.0%, and no resolution in 23.0%. Hypertension (p = 0.004), prolonged chest pain before admission (p = 0.018), baseline Q-waves (p < 0.001), elevated CRP (p = 0.005), and elevated troponin levels (p < 0.001) were significantly associated with poor thrombolysis response. Inferior infarction location was associated with higher reperfusion success compared to anterior infarctions (p = 0.040). Conclusion: More than half of STEMI patients achieved complete response to thrombolytic therapy with Alteplase. However, predictors of poor outcomes included delayed hospital presentation, hypertension, Q-wave presence, and elevated inflammatory and myocardial injury markers. These findings highlight the importance of early intervention, risk stratification, and the potential role of adjunctive therapies to improve clinical outcomes in resource-limited settings.