The STREAM study demonstrated that a pharmaco-invasive strategy was at least as effective as primary PCI (pPCI) in patients presenting early with ST-elevation myocardial infarction (STEMI). The current trial is a response to the finding that reduced intracranial hemorrhage (ICH) in patients ≥75 years occurred after halving the dose of tenecteplase. Additionally, a subsequent analysis of full dose tenecteplase or alteplase in the Assessment of the Safety and Efficacy of a New Thrombolytic (ASSENT) trials demonstrated a steep increase in bleeding events beginning around the age of 60 years.

STREAM-2 will compare the efficacy and safety of a novel pharmaco-invasive strategy as compared to routine pPCI in STEMI patients ≥60 years presenting within 3 hours from symptom onset. In the pharmaco-invasive arm patients will receive half-dose tenecteplase, as soon as possible before transport to a PCI center. In the pPCI arm, patients will be treated according to optimal standard of care defined by local practice. The key criteria for efficacy will be the number of patients achieving ≥50% ST-segment resolution before and after PCI in lead with maximal ST elevation at baseline and the clinical endpoints of death, congestive heart failure, shock or re-infarction, rescue PCI and aborted myocardial infarction, both singularly and as a composite at 30 days. Key safety criteria are total stroke, ICH and major non-intracranial bleeds. Approximately 600 patients will be randomized (400 to pharmaco-invasive treatment and 200 to pPCI). An interim analysis is planned after 300 patients are enrolled to consider adapting the trial to include a larger sample size aimed at undertaking a formal confirmatory trial.

The study will provide new insights aimed at establishing an effective and safer pharmaco-invasive treatment for the growing population of older STEMI patients who cannot undergo timely pPCI.