Efficacy of Early Invasive Management After Fibrinolysis for ST-Segment Elevation Myocardial Infarction in Relation to Initial Troponin Status.

Background: We examined whether the efficacy of an early invasive strategy after fibrinolysis in ST-segment elevation myocardial infarction (STEMI) differs in relation to the initial troponin status.

Methods: In the Trial of Routine Angioplasty and Stenting After Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI), patients with STEMI presenting to a non-percutaneous coronary intervention (PCI)-capable hospital who received fibrinolysis were randomized to either a pharmacoinvasive or standard strategy for subsequent angiography and PCI. In this post hoc subgroup analysis, we compared the efficacy of these strategies in relation to the initial troponin status at hospital presentation for the primary composite end point of mortality, reinfarction, recurrent ischemia, heart failure, and cardiogenic shock at 30 days. We assessed the heterogeneity of treatment effect with initial troponin status using the Breslow-Day test and tested for interaction after adjustment for baseline Global Registry of Acute Coronary Events (GRACE) risk score.

Results: Among 1059 patients, those with abnormal initial troponin levels (n = 514 [48.5%]) were older with worse Killip class, had a longer time from symptom onset to fibrinolysis, and had higher GRACE and Thrombolysis In Myocardial Infarction risk scores. Patients with abnormal troponin levels had higher rates of the primary end point (17.5% vs 10.8%; P = 0.002) and cumulative mortality or reinfarction at 1 year (14.0% vs 8.1%; P = 0.003). In stratified analyses, pharmacoinvasive management reduced the primary end point only among patients with normal initial troponin status. However, there was no significant treatment heterogeneity (all P ≥ 0.10) and no interaction between initial troponin status and treatment assignment after adjusting for GRACE risk score.

Conclusions: Patients with STEMI and abnormal initial troponin levels had worse short-term and long-term outcomes. Accounting for overall baseline risk with the GRACE risk score, troponin status did not modulate the efficacy of pharmacoinvasive management.