Association between ST-Segment Resolution Following Thrombolysis and Reperfusion of Infarct Related Artery in Coronary Angiogram in Patients with ST-Segment Elevation Myocardial Infarction

Abstract

Background: ST-segment elevation myocardial infarction (STEMI) is the most critical form of acute coronary syndrome as having the worst overall prognosis. Following thrombolysis, if it is possible to reliably predict about the reperfusion status by means of a non-invasive, readily available tool like ECG, it will help the clinicians to determine the quality of reperfusion and select the next strategy of management. The aim of the study was to assess angiographic findings of TIMI flow in infarct related artery (IRA), compared to the ranges of ST-segment resolution, and determine their association to predict reperfusion in IRA. Methods: Thiscross-sectional observational study was conducted in the department of Cardiology at National Institute of Cardiovascular Diseases (NICVD), Dhaka, for 12-months following ethical approval. A total of 116 adult patients with acute STEMI who underwent thrombolysis with streptokinase were enrolled by convenient sampling method after taking written informed consent. The percent resolution of ST-segment deviation from baseline to 60 minutes following thrombolysis was compared with angiographic IRA TIMI flow grade in index hospitalization. Detailed history, thorough clinical examination and necessary investigations were carried out in each patient and recorded in predesigned structured questionnaire. Data were analyzed by SPSS 26.0. Results: The mean age of the patients was 50.8 ± 8.8 years with male predominance (77.6%). Among all, 45.7% had >70% ST resolution followed by 29.3% had 30-70% and 25% had <30% ST resolution. Regarding TIMI grade flow, 59.1% had grade-3, 22.7% had grade-2 and 18.2% had grade 0 or 1. TIMI grade flow significantly increased with the increased ST-segment resolution. A cut off value of ST-segment resolution ≥57.5% (AUC=0.771, 95% CI=0.684-0.858, p<0.001) in the prediction of TIMI grade flow 3 showed 67.69% sensitivity, 66.67% specificity, 74.58% PPV, 58.82% NPV and 67.27% accuracy. Multivariate logistic regression shows that timing of thrombolysis, >70% ST resolution showed higher odds ratio and >70% ST resolution showed statistically significant p-value for predicting TIMI grade flow 2 or 3. Conclusion: ST-segment resolution in electrocardiogram following thrombolysis has significant positive association with TIMI flow of infarct related artery in coronary angiogram. However, further larger study is recommended.