Long-Term and Temporal Relationships Between Post-Stent Fractional Flow Reserve and Clinical Outcomes

Background Fractional flow reserve (FFR) following percutaneous coronary intervention (PCI) reflects the degree of flow limitation caused by residual disease after PCI. Objectives The aim of this study was to evaluate the long-term and temporal prognostic impact of post-PCI FFR on clinical outcomes over a 5-year follow-up period. Methods A total of 2,128 patients who underwent angiographically successful drug-eluting stent implantation with post-PCI FFR measurement and completed 5 years of follow-up were analyzed. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization (TVR). Results The risk for TVF was higher in the low post-PCI FFR group than in the high post-PCI FFR group at 5 years (adjusted HR [aHR]: 1.95; 95% CI: 1.46-2.62; P < 0.001). The higher risk for TVF in the low post-PCI FFR group compared with the high post-PCI FFR group was prominent within 3 years after PCI (aHR: 2.00; 95% CI: 1.44-2.78; P < 0.001) and attenuated 3 years after PCI (aHR: 1.80; 95% CI: 0.94-3.44; P = 0.076). Contrary to other clinical outcomes, only TVR in the nonstented segment showed a higher risk in the low post-PCI FFR group compared with the high post-PCI within (aHR: 2.78; 95% CI: 1.43-5.39; P = 0.003) and beyond (aHR: 6.73; 95% CI: 2.02-22.37; P = 0.002) 3 years after PCI. Conclusions The prognostic impact of post-PCI FFR on TVF persisted over a 5-year follow-up period, but it was more prominent during the first 3 years after PCI. In contrast, its impact on TVR in the nonstented segments was sustained throughout the entire 5-year follow-up period.