A half-dose of tenecteplase shows similar outcomes to primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI) patients who are 60 years of age or older, a new analysis shows. Furthermore, the 1-year follow-up analysis of the STREAM-2 study suggests that tenecteplase offers an alternative reperfusion strategy for patients who cannot undergo PCI within 1 hour after first medical contact. These findings were reported by Peter R. Sinnaeve, MD, of the University Hospitals Leuven, Belgium, in a Featured Science presentation Monday at the American Heart Association Scientific Sessions 2023 in Philadelphia. Mortality risk increases when patients with STEMI do not receive primary PCI within 120 minutes after the first medical contact. Current guidelines suggest pharmaco-invasive therapies for patients with STEMI who are unable to urgently undergo PCI. Beginning at around 60 years of age, patients who receive full doses of alteplase or tenecteplase have increased risks of intracranial hemorrhage and major non-intracranial bleeding.. The STREAM-2 trial examined the effects of pharmaco-invasive treatment with a half-dose of tenecteplase given to the STEMI patients before transportation to a hospital capable of performing PCI. Patients then underwent coronary angiography. The tenecteplase was given to patients at or over 60 years old who presented within 3 hours of symptom onset and could not undergo primary PCI within 1 hour. The STREAM-2 trial initial results indicated similar rates of the primary endpoint, a composite of death, shock, heart failure or reinfarction at 30 days, as well as improved resolution of ST-segment deviations, in patients with the pharmaco-treatment compared with primary PCI. Patients who received tenecteplase also had higher rates of intracranial hemorrhage, partially due to protocol violations, and lower rates of the composite endpoint when they were randomized within 1 hour of symptom onset. The two key safety endpoints were intracranial bleeding at 30 days and major non-intracranial bleeding at 30 days. A total of 401 patients were randomized to receive the pharmaco-invasive strategy, and 203 patients were randomized to receive primary PCI. All-cause mortality and rehospitalization for cardiovascular causes at 1-year follow-up were the endpoints for the 1-year analysis. At 30-day follow-up, pharmaco-invasive strategy and primary PCI patients showed similar outcomes in death from any cause (12.8% vs 13.3%, relative risk [RR]=1.04; 95% confidence interval [CI]: 0.61, 1.79), cardiogenic shock (4.5% vs 5.4%, RR=0.83; 95% CI: 0.40, 1.72), heart failure (3.5% vs 4.4%, RR=0.79; 95% CI: 0.35, 1.79), repeat MI (2.5% vs 2.5%, RR=1.02 and death from cardiac causes (7.3 vs 8.4, relative risk=0.87). At the Scientific Sessions, Sinnaeve explained that the investigators also saw benefits in microvascular perfusion at 30 days in both groups. Most patients were available at 1-year follow-up (pharmaco-invasive=99.5%, primary PCI=99.0%). Cardiac death at 1-year (pharmaco-invasive 8.5% vs primary PCI 9.9%) and death at 1-year (12.0% vs 11.8%) were measured. Most of the deaths occurred in the first 30 days (pharmaco-invasive=9.3% vs. primary PCI=8.9%), with the rates between 30 days and 1 year of 2.7% in the pharmaco-invasive group and 3% in the primary PCI group. The rate of all-cause death or rehospitalization for cardiovascular causes (pharmaco-invasive=14.2% vs primary PCI=14.8%) was also similar between groups as (log-rank p=0.869). Panelists congratulated the study investigators for the yearlong follow-up on the patients, as it is difficult to follow patients for long periods of time after acute events such as STEMI. The investigators noted that the pharmaco-invasive strategy provides an alternative for patients who are unable to rapidly undergo primary PCI. Overall, all-cause mortality was similar between groups in STEMI patients who were 60 years of age or older who underwent pharmaco-invasive therapy or primary PCI within 1 hour for treatment of STEMI. Photo Credit: Jason Wermers/CRTonline.org Photo Caption: Peter R. Sinnaeve, MD, presents 1-year findings from the STREAM-2 trial during a Featured Science session at the American Heart Association Scientific Sessions 2023 in Philadelphia.