Discordance between Physiology and Imaging Guided PCI in Intermediate Coronary Lesions: Who to trust?

As regards intermediate coronary lesion intervention, physiological assessment is essential for culprit lesion identification and clinical decision making. It has been shown, in a randomized study, that physiology-guided percutaneous coronary intervention (PCI), along with intravascular ultrasound (IVUS), is not inferior for the combined two-year outcome of all-cause death, acute myocardial infarction (AMI), and revascularization.

Currently, the combination of these strategies is considered best practice. However, their discrepancies and clinical implications remain unclear.

The aim of this post-hoc analysis of the FLAVOUR study (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients with Intermediate Stenosis) was to evaluate the discrepancy and relevance of physiological assessment in IVUS-guided PCI.

The Primary Endpoint was major adverse cardiovascular events (MACE) incidence, defined as a composite of death, acute myocardial infarction (AMI), and revascularization, at one-year follow-up.

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The Secondary Endpoint included angina frequency and quality of life, a per the Seattle Angina Questionnaire. Patients were classified based on IVUS use for PCI guidance (performed vs. deferred PCI) and QFR value, as follows:

Deferred Group: Negative QFR + deferred PCI.

Performed Group: Negative QFR + performed PCI.

Reference Group: Positive QFR + performed PCI.

34.4% of the 784 analyzed patients belonged to the deferred group, 29.3% to the performed group, and 31.5% to the reference group. Mean age was approximately 65, and most participants were male. The most frequently treated coronary artery was the left anterior descending, followed by the right coronary.

Cumulative MACE incidence at two years was 4.5%, 3.9%, and 9.4% for the deferred, performed, and reference groups, respectively (P = 0.019). MACE risk resulted higher among reference group patients vs. the performed group (HR: 2.46; 95% CI: 1.13–5.35; P = 0.023) and the deferred group (HR: 2.17; 95% CI: 1.07–4.38; P = 0.031). 

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In patients with negative QFR, there were no prognostic differences between the performed and deferred groups as regards MACE (HR: 0.88; 95% CI: 0.37–2.11; P = 0.779) or AMI (HR: 1.48; 95% CI: 0.49–4.45; P = 0.484), and neither were there differences in secondary end point.

Conclusión 

Angiography-based physiological assessment may provide additional prognostic information in patients undergoing IVUS-guided PCI. IVUS guided PCI may not be beneficial in patients with functionally non-significant lesions. This sub-analysis should serve as springboard to generate new hypotheses and continue to evaluate the combination of these two therapeutic tools.

Original Title: Clinical Relevance of Discordance Between Physiology-and Imaging Guided PCI Strategies in Intermediate Coronary Stenosis.

Reference: Jinlong Zhang,MD,PHD et al JACC Cardiovasc Interv 2024.