Association Between IVUS and OCT Parameters and Invasive Physiologic Indices
Association Between IVUS and OCT Parameters and Invasive Physiologic Indices
1. to evaluate diagnostic accuracy and performance of IVUS and OCT-derived quantitative
 parameters to predict functional significance of stenosis defined using all the
 available physiologic indices.

 2. to explores the association between intravascular imaging-derived plaque characteristics
 and invasive physiologic indices.
Given the inherent limitations of coronary angiography to depict the presence of functionally
 significant epicardial coronary stenosis and discrepancy between angiographic stenosis
 severity and the presence of myocardial ischemia, invasive physiologic indices such as
 fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) has been a standard
 method to guide decision of revascularization.

 Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are an intracoronary
 imaging method able to provide information about lumen area, vessel area, plaque burden, and
 plaque characteristics that can be used for the guidance of revascularization procedure.
 Several previous studies explored the diagnostic performance of intravascular imaging-defined
 quantitative parameters to predict functional significance defined by FFR, however,
 quantitative parameter derived from intravascular imaging showed only moderate diagnostic
 accuracy and the optimal cut-off value of intravascular imaging-derived minimal lumen area
 (MLA) or minimal lumen diameter (MLD) were varied according to the patient population,
 interrogated vessels, and the location of target lesions, suggesting limited clinical
 relevance of judging functional significance of target stenosis using intravascular imaging
 alone. Nevertheless, the adoption rate of FFR-guided decision has been limited due to various
 reasons and intravascular image-guided decision has been still used in substantial proportion
 of the patients.

 Recently, new resting pressure-derived indices including resting full-cycle ratio (RFR) or
 diastolic pressure ratio (dPR) have been introduced as other substitutes for iFR, which does
 not require administration of hyperemic agents, therefore, possess more convenient in daily
 practice. Recent study with the largest sample size demonstrated identical diagnostic
 property and prognostic implication among iFR, RFR, and dPR. As those resting
 pressure-derived indices might have more generalizability for daily practice, it is expected
 to raise the adoption rate of physiologic interrogation. Therefore, understanding the
 association between all the available physiologic indices and intravascular imaging-derived
 quantitative and qualitative parameters might be important in clinical decision for patient
 who underwent invasive coronary angiography.

 In this regard, the investigators sought to evaluate diagnostic accuracy and performance of
 intravascular imaging-derived quantitative parameters to predict functional significance of
 stenosis defined using all the available physiologic indices and further explores the
 association between IVUS and OCT-derived plaque characteristics and invasive physiologic
 indices.
Inclusion Criteria:

 -  Patients who suspected ischemic heart disease, and underwent invasive physiologic
 assessment and intravascular ultrasound

 Exclusion Criteria:

 -  Cardiogenic shock

 -  Graft vessel

 -  In-stent restenosis