The investigators aim to investigate the additive prognostic value of lesion-specific hemodynamic index such as ΔFFR, non-hyperemic pressure ratio such as RFR, over % diameter stenosis and FFR according to treatment strategy, and to find the prognostic implications of post-PCI FFR after adjustment of various clinical and disease characteristics, and to construct a comprehensive risk prediction model for post-PCI outcomes.

Fractional flow reserve (FFR)-based revascularization is the currently best practice recommended by guidelines. In addition to the use of coronary physiological indices as a vessel-specific metric, recent studies suggested the clinical importance of local hemodynamics in prediction of risk for target vessel failure or acute coronary syndrome in patients with coronary artery disease. In patients who receive percutaneous coronary intervention (PCI), the absolute value and pattern of FFR change after stenting are helpful in defining the additional target for PCI and risk stratification after PCI. However, there has been no prospective study that proved the benefit of change in FFR across the lesion (ΔFFR) in daily clinical practice, and FFR usage after stenting is much less than before stenting. Accordingly, we will prove the benefit of ΔFFR in addition to FFR, prognostic implications of combining RFR and FFR, and the comprehensive risk model with post-PCI FFR, clinical and disease characteristics in a prospective study, to maximize the benefit of invasive physiologic assessment.

Inclusion Criteria:

1. Age ≥20 years
2. All comers who underwent successful FFR measurement and pullback tracing

Exclusion Criteria:

1. Chronic renal failure (estimated glomerular filtration rate <30)
2. ST-elevation myocardial infarction within 72 hours or previous coronary artery bypass graft surgery history
3. Primary myocardial or valvular disease
4. Left ventricular ejection fraction < 30%
5. Hemodynamically unstable clinical conditions
6. Life expectancy < 2 years

Patients with suspected coronary artery disease who undergo FFR measurement and pullback tracing will be included. If the patients receive PCI after FFR measurement, those with available both preprocedural and postprocedural FFR measurement will be included.

The sharing plan will be decided by the study committee.