STREAM Trial Compares Treatment Strategies for Cardiac Mortality

Dallas—The Strategic Reperfusion Early After Myocardial Infarction (STREAM) trial assessed ST-elevation myocardial infarction (STEMI) patients presenting within 3 hours after onset of symptoms and unable to undergo primary percutaneous coronary intervention (PCI) within 1 hour.

Peter Sinnaeve, University of Leuven, Leuven, Belgium, presented the results of the STREAM trial at the AHA Scientific Sessions in a session titled Therapeutic Advances in Coronary and Peripheral Vascular Disease. 

Prior results from other studies—including Comparison of Primary Angioplasty and Pre-hospital Fibrinolysis in Acute Myocardial Infarction (CAPTIM), Which Early ST-Elevation Myocardial Infarction Therapy (WEST), and Field Ambulance Study of Thrombolysis in Myocardial Infarction (FAST-MI)—suggested a beneficial long-term effect of fibrinolysis with bolus tenecteplase (TNK) before transport to a PCI-capable hospital followed by timely coronary angiography in STEMI patients.

Study participants were randomized to a pharmacoinvasive strategy or standard primary PCI according to local practice. The pharmacoinvasive strategy included TNK, clopidogrel, and enoxaparin with dose adjustments in the older population. 

The primary end points were composite of all-cause death, shock, congestive heart failure (CHF), or reinfarction up to 30 days after randomization.

The study results found that in the pharmacoinvasive group, primary end points—death, shock, congestive heart failure, and reinfarction—at 30 days were nominally lower in this group than in the primary PCI group (12.4% vs 14.3%; P=.21).

The incidence of CHF was lower in the pharmacoinvasive group (6.1% vs 7.6%; P=.18) and the incidence of shock was lower in the pharmacoinvasive group as well (4.4% vs 5.9%; P=.13).

The pharmacoinvasive patients were more likely to undergo coronary artery bypass grafting surgery (4.7% vs 2.1%; P=.002), which the researchers noted may be due to the avoidance of urgent PCI in approximately one-third of the pharmacoinvasive patients.

More aborted infarctions were observed in the pharmacoinvasive cohort (11.1% vs 6.9%; P<.01). These results suggest more salvage of ischemic myocardium due to earlier reperfusion. The median time between symptom onset and TNK treatment was 100 minutes versus the median time between symptom onset and primary PCI was 178 minutes (P<.001).

One-year data were collected from all patients who survived the first 30 days post-treatment. The last patient was randomized on July 26, 2012, and the study database was locked on September 30, 2013 (<.08% of patients were lost to follow-up).

The all-cause and cardiac mortality rates at 1-year were similar between the 2 treatment cohorts.

According to the researchers, the study suggests that the pharmacoinvasive group was similarly effective when compared with the primary PCI group; associated with a small increased risk of intracerebral hemorrhage bleeding; and associated with a nonsignificant 1.5% absolute lower incidence of cardiogenic shock and CHF.