From the Guidelines
A delayed Percutaneous Coronary Intervention (PCI) is generally considered to be one performed more than 120 minutes after the first medical contact in patients with ST-elevation myocardial infarction (STEMI), with the optimal timing being within 90 minutes of first medical contact for primary PCI, or within 120 minutes if the patient requires transfer to a PCI-capable facility. The distinction between timely and delayed PCI is crucial because the benefit of mechanical reperfusion diminishes significantly with time as myocardial damage becomes irreversible 1.
Key Considerations for PCI Timing
- The American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care in 2015 emphasizes the importance of timely reperfusion, recommending that the interval between first medical contact and reperfusion should not exceed 120 minutes (Class I, LOE C-EO) 1.
- For patients presenting within 2 hours of symptom onset, immediate fibrinolysis rather than primary PCI (PPCI) may be considered when the expected delay to PPCI is more than 60 minutes (Class IIb, LOE C-LD) 1.
- The 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations suggests that PPCI is appropriate if the time from symptom onset is less than 2 hours and the treatment delay is less than 60 minutes, while fibrinolysis or PPCI may be considered for delays between 60 to 120 minutes 1.
Medical Therapy for Delayed Presenters
For patients presenting late, medical therapy typically includes:
- Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor such as ticagrelor or clopidogrel.
- Anticoagulation.
- Statins.
- Other guideline-directed medical therapy while awaiting cardiac catheterization.
Importance of Timely Intervention
The benefit of mechanical reperfusion diminishes significantly with time, making timely intervention critical for improving outcomes in STEMI patients 1. Therefore, it is essential to prioritize timely PCI within the recommended 120-minute window from first medical contact to maximize the benefits of reperfusion therapy.
From the Research
Definition of Delayed Percutaneous Coronary Intervention (PCI)
- Delayed PCI is generally considered as PCI performed beyond the recommended time frame of 90 minutes from first medical contact for ST-segment Elevation Myocardial Infarction (STEMI) patients 2.
- However, the definition of delayed PCI may vary depending on the context and patient population, with some studies considering delayed PCI as intervention performed after 24 hours 3 or between 12 to 72 hours 4 after initial treatment.
Timing of PCI
- The American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommend performing primary PCI within 90 minutes of first medical contact for STEMI patients 2.
- Delayed PCI has been shown to be associated with higher mortality rates and worse outcomes compared to timely primary PCI 5.
- However, some studies suggest that delayed PCI may be a viable option for patients who are unable to undergo timely primary PCI, with similar outcomes to primary PCI performed within the recommended time frame 4.
Factors Influencing Delayed PCI
- Patient transfer from community hospitals to primary PCI centers can result in delayed revascularization, with median door-to-balloon times ranging from 106 to 142 minutes 6.
- Off-hours presentation and distance from the primary PCI center can also contribute to delayed PCI 6.
- The decision to perform delayed PCI should take into account individual patient factors, such as comorbidities and risk profile, as well as the availability of resources and expertise at the treating institution 3, 4.