What is the role of fractional flow reserve (FFR) in assessing non‑culprit vessels in patients with acute ST‑elevation myocardial infarction (STEMI)?

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Last updated: September 18, 2026 • View editorial policy

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FFR-Guided Assessment of Non-Culprit Vessels in Acute STEMI

FFR should be used to guide treatment of non-culprit vessels in STEMI patients with multivessel disease, with revascularization performed before hospital discharge for lesions with FFR ≤0.80. 1

Guideline-Based Recommendation

The 2017 ESC STEMI Guidelines explicitly state that treatment of severe stenosis in non-infarct-related arteries (non-IRA) should be evaluated either by angiography or FFR, with intervention considered before hospital discharge 1. This can be performed either immediately during the index PCI or staged at a later time. In cardiogenic shock specifically, non-IRA PCI should be considered during the index procedure 1.

FFR Threshold and Timing Considerations

The established FFR threshold of ≤0.80 should guide revascularization decisions in non-culprit vessels 2. This threshold has been validated to reliably exclude functionally significant stenoses and is evidence-based for treatment decisions 2.

Critical Timing Caveat

A major pitfall exists regarding FFR measurement timing in STEMI patients. Recent evidence demonstrates that FFR values measured during the acute phase may be unreliable, particularly in pharmaco-invasive approaches. One study showed FFR values changed significantly at 2-3 week follow-up in 15% of patients, leading to altered management strategies 3. The prolonged jeopardized state of myocardium appears responsible for this instability 3.

Therefore, when feasible, consider staged FFR assessment 2-3 weeks after the index event rather than immediate measurement, particularly in pharmaco-invasive strategies or when microvascular dysfunction is suspected.

Clinical Outcomes Evidence

The most recent and compelling evidence strongly supports FFR-guided complete revascularization:

  • 10-year follow-up data (2026) demonstrates that deferring PCI based on FFR >0.80 was associated with significantly increased risk of the composite endpoint (all-cause mortality, MI, or urgent revascularization) compared to treating FFR-positive lesions (adjusted HR 0.64,95% CI: 0.44-0.95, p=0.025) 4. Critically, cardiovascular mortality was also significantly higher in the PCI-deferral group (adjusted HR 0.48,95% CI: 0.24-0.97, p=0.040) 4.

  • Meta-analysis (2025) confirms FFR-guided complete revascularization reduces major adverse cardiac events (RR: 0.66,95% CI: 0.46-0.94) and ischemia-driven revascularization (RR: 0.27,95% CI: 0.19-0.40) compared to culprit-only revascularization 5.

  • Discordance between FFR assessment and treatment strategy carries consequences: vessels with discordant management (particularly those with FFR ≤0.80 but deferred revascularization) showed significantly worse outcomes with only 90.6% freedom from vessel-oriented events versus 97.5% in concordant vessels (p=0.003) 6.

Practical Algorithm

  1. After successful culprit vessel PCI, assess all non-culprit vessels with ≥50% angiographic stenosis
  2. Measure FFR in non-culprit vessels (using intravenous adenosine with ≥1 minute for steady-state hyperemia) 2
  3. If FFR ≤0.80: Proceed with revascularization either during index procedure or staged before discharge
  4. If FFR >0.80: Medical management is appropriate, but consider repeat assessment at 2-3 weeks if initial measurement was performed in acute setting
  5. In cardiogenic shock: Consider immediate complete revascularization of FFR-positive lesions during index procedure 1

Resting Indices Alternative

While resting Pd/Pa has 80% diagnostic accuracy compared to FFR (optimal cutoff 0.905 for FFR ≤0.80) 7, when FFR and Pd/Pa are discrepant, FFR is superior in identifying which vessels can be safely deferred (p=0.048) 7. Therefore, FFR remains the gold standard for physiologic assessment in this population.

Key Pitfalls to Avoid

  • Do not rely solely on angiographic appearance - FFR provides superior risk stratification 6
  • Do not measure FFR too early in pharmaco-invasive cases - microvascular dysfunction may render measurements unreliable 3
  • Do not defer treatment of FFR-positive lesions indefinitely - complete revascularization before discharge improves long-term outcomes including mortality 4
  • Ensure adequate hyperemia - allow ≥1 minute for steady-state with intravenous adenosine 2

References

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.