Modified Pharmaco-Invasive Strategy Shows Promise in Older STEMI Patients: STREAM-2 Trial

A modified pharmaco-invasive reperfusion strategy could be a viable option for older patients with ST-segment elevation myocardial infarction (STEMI) who are unable to receive timely angioplasty, according to the findings of the STREAM-2 trial. Led by Dr. Frans Van de Werf and his team from KU Leuven, Belgium, the study compared the effectiveness of half-dose tenecteplase (TNKase) with primary percutaneous coronary intervention (PCI) in STEMI patients presenting within 3 hours of symptom onset.

The results revealed that half-dose tenecteplase produced electrocardiogram (ECG) changes that were at least as effective as primary PCI in the cohort of patients who were unable to undergo primary PCI within 1 hour. The pharmaco-invasive treatment group showed a significant majority (≥50%) resolution of ST-segment elevation compared to the upfront primary PCI group. AdditionallyCirculation, the median sums of ST deviations were significantly lower in the tenecteplase group. The findings were published in Circulation and presented at the American College of Cardiology meeting.

However, it is worth noting that brain bleeds occurred at a higher rate than expected, echoing the excess intracranial haemorrhages (ICHs) observed in the preceding STREAM-1 trial with standard-dose tenecteplase. Among the study participants, there were 10 strokes in total, with six cases of ICHs in the pharmaco-invasive arm and none in the primary PCI arm. The researchers emphasized the need for clear and timely communication among healthcare teams to minimize complications and protocol violations.

Despite the higher incidence of brain bleeds, the 30-day composite endpoint, which included death, shock, heart failure, or reinfarction, was similar between the two groups. The study concluded that a pharmaco-invasive approach can be an effective reperfusion strategy for older patients with early presentation of STEMI, provided contraindications to fibrinolysis are observed and excess anticoagulation is avoided. In situations where timely primary PCI is not achievable, both reperfusion therapies can be considered viable options for appropriately selected patients.

The current guidelines recommend primary PCI for reperfusion of STEMI within 2 hours after initial medical contact. However, this goal is often unattainable for patients initially presenting to non-PCI-capable hospitals. In such cases, a pharmaco-invasive strategy is endorsed as an alternative approach.

The STREAM-2 trial was an open-label study conducted in 49 centers across 10 countries. The participants had an average age of 70.5 years, and nearly one-third were women. The median Thrombolysis In Myocardial Infarction (TIMI) risk score was 4.

Patients with STEMI were randomly assigned to receive either half-dose tenecteplase followed by coronary angiography and potential rescue PCI if necessary, or upfront primary PCI. The median times from symptom onset to randomization were 97 minutes for the pharmaco-invasive group and 92 minutes for the primary PCI group. The use of half-dose tenecteplase and advancements in antithrombotic treatment, along with the increased

utilization of radial access and interventional technologies, may have contributed to the positive outcomes and low incidence of major non-intracranial bleeding observed in this higher-risk population.

Further research is needed to refine the pharmaco-invasive strategy and identify the ideal patient selection criteria. However, the results of the STREAM-2 trial provide valuable insights into the management of STEMI in older patients and support the use of a modified reperfusion strategy when timely primary PCI is not feasible.

Reference:

Circulation Van de Werf F, et al" Half-dose tenecteplase or primary percutaneous coronary intervention in older patients with ST-segment–elevation myocardial infarction in STREAM-2: A randomized, open-labeltrial"Circulation2023;DOI:10.1161/CIRCULATIONAHA.123.064521