Prognostic Implications of Prestent Pullback Pressure Gradient and Poststent Quantitative Flow Ratio in Patients Undergoing Percutaneous Coronary Intervention.

Background Coronary diffuse disease associates with poor outcomes, but little is known about its role after percutaneous coronary intervention (PCI). We aimed to investigate the prognostic implication of pre-PCI focal or diffuse disease patterns combined with post-PCI quantitative flow ratio (QFR). Methods and Results Pre-PCI QFR derived pullback pressure gradient (PPG) (QFR-PPG) was measured to assess physiological disease patterns for 1685 included vessels; the vessels were classified according to dichotomous pre-PCI QFR-PPG and post-PCI QFR. Vessel-oriented composite outcome, a composite of vessel-related ischemia-driven revascularization, vessel-related myocardial infarction, or cardiac death at 2 years was compared among these groups. Vessels with low pre-PCI PPG (3.9% versus 2.0%, hazard ratio [HR], 1.93; 95% CI, 1.08-3.44; =0.02) or low post-PCI QFR (9.8% versus 2.7%, HR, 3.78; 95% CI, 1.61-8.87; =0.001) demonstrated higher vessel-oriented composite outcome risk after stent implantation. Of note, despite high post-PCI QFR achieved, vessels with low pre-PCI QFR-PPG presented higher risk of vessel-oriented composite outcome than those with high pre-PCI QFR-PPG (3.7% versus 1.8%, HR, 2.03; 95% CI, 1.09-3.76; =0.03) and pre-PCI QFR-PPG demonstrated direct prognostic effect not mediated by post-PCI QFR. Integration of groups classified by pre-PCI QFR-PPG and post-PCI QFR showed significantly higher discriminant and reclassification abilities than clinical factors (C-index 0.77 versus 0.72, =0.03; integrated discrimination improvement 0.93%, =0.04; net reclassification index 0.33, =0.02). Conclusions Prognostic value of pre-PCI focal or diffuse disease patterns assessed by QFR-PPG index was retained even after successful PCI, which is mostly explained by its direct effect that was not mediated by post-PCI QFR. Integration of both pre-PCI and post-PCI physiological information can provide better risk stratification in vessels with stent implantation. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05104580.