Impact of Optical Coherence Tomography-Based Post-PCI Physiology Assessment to Predict Clinical Outcomes An ILUMIEN-IV Substudy

BACKGROUND: A novel optical coherence tomography (OCT)-based physiology assessment technique, virtual flow reserve (VFR), has been demonstrated to perform as a reliable surrogate for invasive physiology. OBJECTIVES: The authors sought to examine the performance of post-percutaneous coronary intervention (PCI) VFR as a predictor of 2-year clinical outcomes independent from the OCT-based minimal stent area (MSA). METHODS: The ILUMIEN IV (Optical Coherence Tomography [OCT] Guided Coronary Stent Implantation Compared With Angiography: A Multicenter Randomized Trial in PCI) trial prospectively recruited 2,487 patients with diabetes or high-risk coronary lesions randomizing to OCT- vs angiography-guided drug-eluting stent implantation. All patients with single-lesion treatment who had a final OCT imaging available underwent retrospective post-PCI VFR analysis offline. Of 2,128 eligible patients, VFR analysis was successfully performed in 2,057 (96.6%). Independent OCT predictors for the primary endpoint of 2-year target vessel failure (TVF), a composite of cardiac death, target-vessel myocardial infarction, and ischemia-driven target vessel revascularization, were evaluated by multivariable analysis. RESULTS: The median post-PCI VFR was 0.90 (Q1-Q3: 0.86-0.92), with a significant difference in VFR observed between the angiography- and OCT-guided groups (0.89 [Q1-Q3: 0.86-0.92] vs 0.90 [Q1-Q3: 0.87-0.92]; P < 0.001). By multivariable analysis, both MSA (per 1 mm²) and VFR (per 0.1 mm Hg/mm Hg) were independent predictors of 2-year TVF. Overall, MSA, proximal edge dissection and VFR independently predicted both TVF and target lesion failure. CONCLUSIONS: Post-PCI OCT-based VFR assessment is predictive of 2-year clinical outcomes independent of MSA. Online VFR analysis can provide operators with an immediate assessment of post-PCI physiology in addition to OCT anatomy, providing incremental value in assessing procedural success and informing on clinical prognosis (ILUMIEN IV [Optical Coherence Tomography (OCT) Guided Coronary Stent Implantation Compared With Angiography: A Multicenter Randomized Trial in PCI]; NCT03507777).