Utilizing the quantitative flow ratio derived indices for short and long-term outcomes of elective percutaneous coronary intervention in patients with chronic coronary syndrome

Abstract Background Virtual assessments using Quantitative Flow Ratio (QFR) provide a QFR-derived pullback pressure gradient (QFR-PPG) and an angiography-based index of microcirculatory resistance (angio-IMR). The predictive value of these indices for immediate post–percutaneous coronary intervention (PCI) results and long-term clinical outcomes remains unknown. Purpose This study sought to investigate the predictive value of QFR-derived indices for both short-term and long-term clinical outcomes in patients with chronic coronary syndrome (CCS). Methods This retrospective study included patients with CCS who underwent elective PCI for de novo, functionally significant lesions (invasive fractional flow reserve ≤0.80) and had both pre- and post-PCI physiological assessments, as well as angiographic images suitable for QFR evaluation. We examined whether pre-PCI QFR-derived indices were associated with suboptimal revascularization, defined as a post-PCI FFR ≤0.80, as well as with vessel-oriented composite outcomes (VOCO) and major adverse cardiac events (MACE), including cardiac death, nonfatal myocardial infarction, heart failure, stroke, and ischemia-driven revascularization. Results A total of 402 CCS patients undergoing elective PCI for a de novo lesion were included. The median pre- and post-PCI FFR values were 0.70 and 0.86, respectively. Among these patients, 81 (20.1%) had suboptimal post-PCI FFR (≤0.80), 32 (8.0%) experienced VOCO, and 70 (17.4%) developed MACE during a median follow-up of 4.1 years. In multivariate analysis, the QFR-PPG index (OR: 0.012, 95% CI: 0.001–0.113, p=0.001) and IMR-angio (OR: 0.965, 95% CI: 0.939–0.990, p=0.008) were significant predictors of suboptimal post-PCI FFR. After adjustment for post-PCI FFR, IMR-angio was significantly associated with MACE (HR: 0.965, 95% CI: 0.942–0.989, p=0.004) but not with VOCO (HR: 0.969, 95% CI: 0.933–1.007, p=0.110). Conclusion Pre-PCI pathophysiological evaluations using QFR-derived indices demonstrated significant predictive efficacy for identifying suboptimal hemodynamic outcomes and long-term adverse events following PCI. These indices may serve as valuable tools for predicting both acute and long-term outcomes and could help guide a more personalized, aggressive management strategy after PCI.