ST-elevation myocardial infarction (STEMI) occurs when a coronary artery is completely blocked, and it is the most dangerous and severe type of heart attack. The STREAM-2 (Strategic Reperfusion in Elderly Patients Early After Myocardial Infarction) study, recently published in Circulation, sought to determine if a pharmoco-invasive treatment with half-dose tenecteplase, a clot-busting drug used to prevent death in STEMI patients, can be both beneficial and safe in older STEMI patients.
In the study, 604 STEMI patients who were 60 years of age or older presenting within 3 hours of symptom onset, and unable to undergo percutaneous coronary intervention (PCI), a procedure used to open a blocked artery within 1 hour, were randomized (2:1) to either a pharmaco-invasive treatment of half-dose tenecteplase followed by coronary angiography (a test to find blockages in a coronary artery) and PCI (if indicated) within 24 hours of randomization, or to timely primary PCI.
The results of the study demonstrate that a pharmaco-invasive strategy that halved the dose of tenecteplase in older STEMI patients resulted in better reperfusion than primary PCI as assessed by resolution of ST-segment elevation on the electrocardiogram (ECG). Whereas clinical outcomes of efficacy including death, shock, heart failure and recurrent myocardial infarction were similar, the study authors note that the risk of intracranial hemorrhage was higher than expected with half-dose tenecteplase than primary PCI, and attributed this, in part, to protocol violations that involved excess anticoagulation. Specifically, it has been previously shown that excessive anticoagulation with heparins and treatment of patients with contraindications increase the risk of bleeding events.
“Our study provides new data supporting a reasonable alternative treatment strategy relevant to the large population of older STEMI patients world-wide who have high morbidity and mortality, especially if they are unable to undergo primary PCI in a timely fashion,” said study Co-Chair, Dr. Paul Armstrong.
The STREAM-2 trial was coordinated by the University of Leuven in Belgium, with Canadian contributions led by the CVC. Dr. Paul Armstrong along with Dr. Frans Van de Werf served as Co-Chairs. In addition to being a member of the Executive Committee and a Co-Principal Investigator for the study, Dr. Robert Welsh and his team of interventional cardiologists – ably supported by an excellent paramedical emergency and cardiac catheterization laboratory personnel – were the highest enrolling site in this international trial. Furthermore, the CVC ECG Core Laboratory, led by Dr. Kevin Bainey with key support from Tracy Temple and Eric Ly, as well as Yinggan (Gray) Zheng and co-author Dr. Cynthia Westerhout, who conducted a careful analysis of the key trial endpoint, played a pivotal role in this project.
This investigator-initiated trial received funding from the Department of Research and Development of KU Leuven, Life Science Research Partners, and Boehringer Ingelheim.
