Pharmaco-invasive Reperfusion Strategy with Half-dose Tenecteplase In Older St-Elevation Myocardial Infarction Patients
Dr. Ezgi Güzel

Published Congress: ACC 2023

Introduction:
When timely primary PCI is not possible, a pharmacoinvasive strategy of half-dose tenecteplase may provide a safe and effective reperfusion alternative in older patients with STEMI, according to an analysis from the STREAM-2 trial.

Objective:
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.

Methods:
A randomized cohort study of total 604 enrolled patients with 30 days of follow up, patients were randomized in a 2:1  to either a pharmaco-invasive strategy with half-dose TNK followed by PCI within 6-24 hours (n = 401) or primary PCI
(n = 203). In the pharmaco-invasive group, PCI could be pursued sooner if ST-segment resolution of ≥50% did not occur by 90 minutes. Patients in the pharmaco-invasive group received aspirin 150-325 mg, clopidogrel 300 mg as bolus then 75 mg daily, and enoxaparin (no bolus if age ≥75 years). Patients in the primary PCI group received aspirin 150-325 mg and P2Y12 antagonist and anti thrombin treatment according to local standards.
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.

Results:
The results of this trial indicate that pharmaco-invasive therapy with half-dose TNK is safe and effective compared with primary PCI among elderly patients presenting with STEMI who were unable to undergo timely primary PCI within 1 hour.
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%. All-cause mortality rates were 9.3% in the pharmacoinvasive group versus 8.9% in the primary PCI group, while rates of CV death were 7.3% and 8.4%, respectively; rates of any stroke were 2.3% and 0.5%, respectively; and rates of major non-intracranial bleeding were 1.3% and 1.0%, respectively. None of the differences were statistically significant.

Conclusion:
Although current STEMI guidelines continue to define pPCI as the preferred therapy, they rest upon the ability to deliver timely pPCI. The reasons for
the inability to consistently achieve timely pPCI are multifactorial and include; patient related delay such as self-presentation to a community hospital or calling an emergency number,  system issues related to pre- and in-hospital delays, unpredictable environmental issues affecting timely transport by road and/or air, unfettered availability of the pPCI facility, and, challenges in vascular access at the interventional sites.
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.