Deferred vs. Performed Percutaneous Coronary Intervention for Coronary Stenosis with Grey-Zone Fractional Flow Reserve Values

Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) has shown better clinical outcomes than conventional angiography-guided PCI. The optimal FFR cut-off value for revascularization is debated. With FFR ≤ 0.75, revascularization for coronary artery disease (CAD) stenosis is associated with improved clinical outcomes, whereas with FFR ≥ 0.8, medical treatment has been shown to result in favorable long-term outcomes. However, there has been controversy over revascularization decision-making for coronary stenosis with FFR between 0.75 and 0.80, the so-called grey zone.