Impact of optical coherence tomography-based post-PCI physiology assessment to predict clinical outcomes: an ILUMIEN-IV substudy

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. We sought to examine the performance of post-PCI VFR as a predictor of 2-year clinical outcomes independent from the OCT-based minimal stent area (MSA). The ILUMIEN-IV trial prospectively recruited 2487 patients with diabetes or high-risk coronary lesions randomizing to OCT- versus 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 2128 eligible patients, VFR analysis was successfully performed in 2057 (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. The median [25th percentile, 75% percentile] post-PCI VFR was 0.90 [0.86, 0.92], with a significant difference in VFR observed between the angiography- and OCT-guided groups (0.89 [0.86, 0.92] vs 0.90 [0.87, 0.92], p<0.001). By multivariable analysis both MSA (per 1mm2) and VFR (per 0.1 mmHg/mmHg) were independent predictors of 2-year TVF. Overall, MSA, proximal edge dissection and VFR independently predicted both TVF and target lesion failure. 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.