Characteristics of ST-elevation myocardial infarction with failed thrombolysis

BACKGROUND: Fibrinolytic therapy is an important reperfusion strategy, especially when primary percutaneous coronary interventions cannot be offered to ST-elevation myocardial infarction patients. Given that failed reperfusion after fibrinolytic therapy is common, it is pragmatic that the predictors, outcomes, and angiographic profiles of patients with failed thrombolysis are carefully scrutinized. METHODS: We prospectively studied clinical variables and outcomes over 30 months in 243 ST-elevation myocardial infarction patients who received fibrinolytics as primary treatment. Logistic regression analysis was used to identify predictors of failed thrombolysis. RESULTS: Failed thrombolysis occurred in 38.68% of patients with a mean window period of 6.58 ± 1.42 h, and 55.32% of patients with failed thrombolysis had Killip class >I on presentation. Risk factors such as diabetes mellitus (55.32%), dyslipidemia (60.64%) and obesity (77.66%) were frequently associated with failed thrombolysis; 73.40% of patients with failed thrombolysis had Thrombolysis in Myocardial Infarction flow grade 0/1 in the infarct-related artery, and 58.51% of such patients needed a rescue percutaneous coronary intervention. The mean Thrombolysis in Myocardial Infarction risk score was 5.46 ± 2.77 in failed thrombolysis patients, with mortality of 4.25% at the 6-month follow-up. CONCLUSION: Non-resolution of presenting symptoms and ST changes on electrocardiography at 90 min served as the earliest indicators of failed thrombolysis, with a significant angiographic correlation. Clinical variables such as delayed presentation (>6 h), dyspnea, Killip class >I, cardiogenic shock, Thrombolysis in Myocardial Infarction score, and conventional risk factors including diabetes mellitus, dyslipidemia, and obesity represented cluster of predictors of failed thrombolysis.