The physiologic assessment of coronary artery disease and ischemia-guided percutaneous coronary intervention (PCI) has become a standard practice for patients with coronary artery disease. Fractional flow reserve (FFR) represents hyperemic flow limitation caused by an epicardial coronary stenosis and its clinical usefulness has been proven by many clinical studies. However, the FFR is limited to clinical use despite the fact that it is recommended by the guideline due to the inconvenience of patients using medications used to induce maximum hyperemia, and the need for additional procedure time. Recently, a physiologic index which does not require hyperemia, instantaneous wave free ratio (iFR), was introduced and recent trials showed non-inferiority of iFR-guided strategy for 1-year clinical outcome, compared with FFR-guided strategy. Recently, not only iFR but also various intravascular pressure measurement techniques have been developed, one of which is diastolic hyperemia-free ratio (DFR). DFR uses the mean Pd/Pa calculated over the period in diastole defined as that during which arterial pressure is negatively sloped and below the mean arterial pressure. DFR showed equivalence as compared to gold standard FFR in the discrimination of non-culprit lesions requiring revascularization in patients with NSTEMI. In the case of DFR, there is no issue in terms of safety because it is conducted in the same way as iFR, but there are not many studies on the validation between DFR and FFR. Therefore, the present study aimed to identify the quality of concordance between DFR and FFR, determine the features associated with discrepancies in DFR and FFR.
The investigators aimed to identify the value of concordance between the diastolic hyperemia-free ratio (DFR) and fractional flow reserve (FFR) during pre-interventional and post-interventional period using a 0.014 COMET II Pressure Guidewire