What are the implications of a patient having a ST-Elevation Myocardial Infarction (STEMI) with Percutaneous Coronary Intervention (PCI) delayed by 2 hours?

From the Guidelines

For a patient with STEMI where primary PCI is delayed by 2 hours, immediate fibrinolytic therapy should be administered if there are no contraindications, as the benefit of fibrinolysis is time-dependent and greatest when given within the first 2 hours of symptom onset 1. The goal is to restore coronary blood flow as quickly as possible to salvage myocardium and reduce mortality.

• The recommended fibrinolytic agents include tenecteplase (weight-based dosing, typically 30-50 mg IV bolus) or alteplase (100 mg over 90 minutes) 1.
• Additionally, administer anticoagulation with unfractionated heparin (60 U/kg bolus, maximum 4000 U, followed by 12 U/kg/hr infusion, maximum 1000 U/hr) or enoxaparin (30 mg IV bolus followed by 1 mg/kg SC every 12 hours) 1.
• After fibrinolysis, transfer the patient immediately for PCI (pharmacoinvasive approach) to further reduce mortality risk and improve outcomes 1. The American Heart Association guidelines recommend that the interval between first medical contact and reperfusion should not exceed 120 minutes (Class I, LOE C-EO) 1. In STEMI patients presenting within 2 hours of symptom onset, immediate fibrinolysis rather than PPCI may be considered when the expected delay to PPCI is more than 60 minutes (Class IIb, LOE C-LD) 1. The benefit of fibrinolytic therapy is most effective when provided promptly, and the ACCF/AHA guideline sets a benchmark time goal from hospital arrival to drug administration, or DTN time, to be ≤30 min 1.

From the FDA Drug Label

Prasugrel tablets are indicated to reduce the rate of thrombotic CV events (including stent thrombosis) in patients with acute coronary syndrome (ACS) who are to be managed with percutaneous coronary intervention (PCI) as follows: Patients with unstable angina (UA) or non-ST-elevation myocardial infarction (NSTEMI) Patients with ST-elevation myocardial infarction (STEMI) when managed with primary or delayed PCI.

The implications of a patient having a ST-Elevation Myocardial Infarction (STEMI) with Percutaneous Coronary Intervention (PCI) delayed by 2 hours are not directly addressed in the provided drug label. However, it is indicated that prasugrel tablets can be used in patients with STEMI when managed with primary or delayed PCI.

• The label does mention that in the clinical trial that established the efficacy and safety of prasugrel tablets, the loading dose of prasugrel tablets was administered at the time of diagnosis in STEMI patients presenting within 12 hours of symptom onset, although most received prasugrel tablets at the time of PCI.
• It is generally recommended that antiplatelet therapy be administered promptly in the management of ACS because many cardiovascular events occur within hours of initial presentation.
• However, the label does not provide specific information on the implications of delaying PCI by 2 hours in STEMI patients. 2

From the Research

Implications of Delayed PCI in STEMI Patients

• A delay of 2 hours in Percutaneous Coronary Intervention (PCI) for patients with ST-Elevation Myocardial Infarction (STEMI) may have significant implications on patient outcomes 3, 4, 5.
• The current guidelines recommend that PCI should be performed within 120 minutes from first medical contact, and door-to-balloon time should be <60 minutes to reduce long-term mortality 5.
• Delayed PCI beyond the recommended time window may still be beneficial for STEMI patients, with improved outcomes compared to medication therapy alone 6.
• Early upstream antithrombotic therapy administration, including aspirin, ticagrelor, and heparin, may also improve clinical outcomes in STEMI patients with prolonged transport times to primary percutaneous intervention 7.

Clinical Outcomes

• Delayed PCI has been associated with reduced mortality and incidence of major adverse cardiac events (MACEs) compared to medication therapy alone 6.
• Early upstream antithrombotic therapy administration has been shown to improve pre-PCI TIMI flow and reduce definite acute stent thrombosis in STEMI patients 7.
• However, the optimal timing and strategy for PCI in STEMI patients with delayed presentation remains a topic of debate, and further research is needed to determine the best approach 4, 5.

Treatment Strategies

• Fibrinolytic therapy may be considered as an alternative to PCI if there is a significant delay in performing PCI, although this approach is not without risks and benefits 3.
• The use of glycoprotein IIb/IIIa inhibitors, dual antiplatelet therapy, and bare-metal stents or drug-eluting stents may also be considered as part of the treatment strategy for STEMI patients undergoing PCI 4.
• The development of STEMI networks and regionalization of pPCI treatment may help to improve outcomes for STEMI patients by reducing delays and improving access to timely reperfusion therapy 5.