Relationship between risk stratification at admission and treatment effects of early invasive management following fibrinolysis: insights from the Trial of Routine ANgioplasty and Stenting After Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI)

Abstract

Aims: We sought to determine the effectiveness of early routine percutaneous coronary intervention (PCI) post-fibrinolysis for ST-elevation myocardial infarction (STEMI) in relation to baseline risk status.

Methods and results: In this post hoc subgroup analysis of Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI), we stratified 1059 STEMI patients receiving tenecteplase into low-intermediate [Global Registry of Acute Coronary Events (GRACE) risk score<155; n=889] vs. high-risk (GRACE risk score ≥155; n=170) groups, based on the GRACE risk score for in-hospital mortality. There was a significant interaction between treatment assignment and risk status for the composite endpoint of death/re-MI at 30 days (P for interaction<0.001). Compared with the standard treatment, pharmacoinvasive therapy (early routine PCI) was associated with a lower rate of death/re-MI at 30 days in the low-intermediate risk stratum (8.1 vs. 2.9%, P<0.001), but a higher rate of death/re-MI in the high-risk group (13.8 vs. 27.8%, P=0.025). We found similar heterogeneity in the treatment effects on 30-day mortality and death/re-MI at 1 year (P for interaction=0.008 and 0.001, respectively), when the GRACE risk score was analysed as a continuous variable (P for interaction<0.001) and when patients were stratified by the Thrombolysis In Myocardial Infarction (TIMI) risk score (P for interaction=0.001).

Conclusion: We observed a strong heterogeneity in the treatment effects of a pharmacoinvasive strategy after fibrinolysis for STEMI, which is associated with improved outcomes only among patients with a low-intermediate GRACE risk score. Conversely, the early invasive strategy is associated with worse outcomes in high-risk patients. These novel findings should be considered exploratory only and require confirmation in other trials and meta-analyses.

Clinical trial registration information: http://www.clinicaltrials.gov/ct2/show/NCT00164190 ClinicalTrials.gov number, NCT00164190.