Validation of Segmental Post-PCI Physiological Gradients With IVUS-Detected Focal Lesions and Stent Underexpansion.

Background: Segmental postpercutaneous coronary intervention (PCI) pressure gradients may detect residual disease and potential targets for optimization. However, universal definitions of relevant segmental gradients are lacking.
Objectives: This study sought to evaluate the diagnostic performance of post-PCI fractional flow reserve (FFR), distal coronary pressure-to-aortic pressure ratio (Pd/Pa), and diastolic pressure ratio (dPR) gradients to detect residual focal lesions and stent underexpansion as observed by intravascular ultrasound (IVUS).
Methods: Patients from the IVUS-guided optimization arm of the FFR REACT (FFR-guided PCI Optimization Directed by High-Definition IVUS Versus Standard of Care) trial with complete IVUS and FFR pullback data were included. Patients with angiographically successful PCI and post-PCI FFR <0.90 underwent FFR, Pd/Pa, and IVUS pullbacks. dPR was calculated offline using dedicated software. Segmental pressure gradients (distal, in stent, and proximal) in segments ≥5 mm were evaluated against IVUS-detected residual disease (distal or proximal focal lesions and stent underexpansion).
Results: A total of 139 vessels were included (mean post-PCI FFR: 0.83 ± 0.05, range 0.56-0.89). Focal distal and proximal lesions were detected by IVUS in 23 (17.4%) of 132 and 14 (12.6%) of 111 vessels, respectively, whereas stent underexpansion was present in 86 (61.9%) vessels. Diagnostic ability of segmental FFR gradients to predict IVUS-detected distal and proximal lesions was moderate-to-good (area under the curve [AUC]: 0.69 and 0.84, respectively) and poor to moderate for segmental Pd/Pa and dPR gradients (AUC ranging from 0.58 to 0.69). In-stent gradients had no discriminative ability to detect stent underexpansion (FFR AUC: 0.52; Pd/Pa AUC: 0.54; dPR AUC: 0.55).
Conclusions: In patients with post-PCI FFR <0.90, segmental post-PCI pressure gradients have moderate discriminative ability to identify IVUS-detected focal lesions but no discriminative ability to identify IVUS-detected stent underexpansion.
Competing Interests: Funding Support and Author Disclosures The Erasmus Medical Center received institutional research support from ACIST Medical Systems, Inc. Ms Neleman and Dr Diletti have received institutional grant support from ACIST Medical Systems. Dr Van Mieghem has received institutional research grant support from Abbott Vascular, Boston Scientific, Edwards Lifesciences, Medtronic, Daiichi Sankyo, PulseCath BV, and Abiomed. Dr Daemen has received institutional grant/research support from Abbott Vascular, Boston Scientific, ACIST Medical Systems, Medtronic, Pie Medical, and ReCor medical; and received consulting and lecture fees from Abbott Vascular, Abiomed, ACIST Medical Systems, Boston Scientific, Cardialysis BV, CardiacBooster, Kaminari Medical, ReCor Medical, PulseCath, Pie Medical, Sanofi, Siemens Health Care and Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2023. Published by Elsevier Inc.)