Key Points:
- Pharmaco-invasive (PI) strategy with half-dose tenecteplase (TNK) is compared to routine primary percutaneous coronary intervention (pPCI) in STEMI patients over 60 years of age who presented within 3 hours and unable to undergo pPCI within 1 hour.
- Primary efficacy endpoints were the percentage of patients with ≥ 50% ST-segment resolution after TNK and before and after PCI, the need for rescue PCI, and the combined clinical endpoint of death, cardiogenic shock, re-infarction, and heart failure at 30 days.
- Composite outcome at 30 days (death, heart failure, MI, shock), for pharmaco-invasive therapy vs. primary PCI, was: 12.8% vs. 13.3% (relative risk 0.96, 95% confidence interval 0.62-1.48)
- The findings of the study suggest that using a pharmaco-invasive strategy with half-dose tenecteplase (TNK) is both secure and efficient in contrast to primary percutaneous coronary intervention (PCI) in older individuals with ST-segment elevation myocardial infarction (STEMI) who could not obtain timely primary PCI within an hour.
When patients with ST-elevation myocardial infarction (STEMI) are unable to receive primary percutaneous coronary intervention (PCI) within 120 minutes after the initial medical contact, their risk of mortality increases. Guidelines recommend the use of a pharmaco-invasive strategy in such situations as a significant percentage of patients transferred from community hospitals do not receive primary PCI within the recommended time frame. But results from ASSENT and STREAM-1 trails have shown there has been an increase in the rates of intracranial hemorrhage (ICH) and major non-intracranial bleeding, particularly in patients aged 60 and above, who receive full-dose alteplase or tenecteplase.
The study compared the efficacy and safety of a pharmaco-invasive (PI) strategy with half-dose tenecteplase (TNK) to routine primary percutaneous coronary intervention (pPCI) in patients with ST-elevation myocardial infarction (STEMI) over 60 years of age who presented within 3 hours and were unable to undertake pPCI within 1 hour. Antithrombotics in the PI arm included clopidogrel and enoxaparin, while antithrombotics in the pPCI arm were left to the local investigator’s discretion. The primary efficacy endpoints were the percentage of patients with ≥ 50% ST-segment resolution after TNK and before and after PCI, the need for rescue PCI, and the combined clinical endpoint of death, cardiogenic shock, re-infarction, and heart failure at 30 days. The primary safety endpoints of the study were intracranial hemorrhage (ICH), stroke, and major non-ICH bleeding within 30 days.
The study involved randomizing patients in a 2:1 ratio to receive either a pharmaco-invasive strategy with half-dose tenecteplase (TNK) followed by PCI within 6-24 hours or primary PCI. Patients in the pharmaco-invasive arm could undergo PCI earlier if ST-segment resolution of at least 50% did not occur within 90 minutes. The antithrombotic treatment for the pharmaco-invasive arm included aspirin 150-325 mg, clopidogrel 300 mg as a bolus, followed by 75 mg daily, and enoxaparin without a bolus for patients aged 75 years and above. On the other hand, patients in the primary PCI arm received aspirin 150-325 mg and P2Y12 antagonist and antithrombin treatment according to local standards. A total of 401 patients received the pharmaco-invasive strategy, while 203 received primary PCI. The percentage of patients with ≥ 50% ST-segment resolution was 85.2 % in the pharmaco-invasive strategy and 78.4% (p=0.02). Relevant findings include a primary composite outcome at 30 days (death, heart failure, MI, shock), for pharmaco-invasive therapy vs. primary PCI, was: 12.8% vs. 13.3% (relative risk 0.96, 95% confidence interval 0.62-1.48)
The study concluded that a pharmaco-invasive strategy using half-dose tenecteplase (TNK) in STEMI patients over 60 years of age who presented within 3 hours and were unable to undergo pPCI within 1 hour provided effective reperfusion based on ST-deviation resolution, angiographic results, and 30-day clinical outcomes. Pharmaco-invasive treatment with TNK can be effective and safely given to older STEMI patients if contraindications to fibrinolysis are observed and excess anticoagulation is avoided.
