Angiography-Derived Quantitative Functional Assessment Versus Pressure-Derived FFR and IMR: The FAIR Study

Diagnostic Performance of Angiography-Derived Quantitative Functional Assessment Compared to Pressure-Derived Fractional Flow Reserve and Index of Microcirculatory Resistance: The FAIR Study

Coronary angiography-derived FFR assessment (AngioQFA) is a novel technique for physiological lesion assessment based on 3-dimensional (3D) quantitative coronary angiography (QCA) and virtual hyperemic flow derived from contrast frame count without drug-induced hyperemia. The goal of this prospective, multicenter trial is to compare the diagnostic performance of AngioQFA with invasive FFR as the reference standard. The secondary purpose is to compare the diagnostic accuracies of the computational fluid dynamics (CFD)-based index of microcirculatory resistance (IMR) using wire-based IMR as the reference standard.

Inclusion Criteria

• General Inclusion Criteria:

  1. Age ≥18 years.
  2. Coronary angiography is required for patients with suspected or confirmed coronary artery disease.
  3. The subject has been informed of the nature of the study, agrees to its provisions and has provided written informed consent.

• Angiographic Inclusion Criteria:

  1. Diameter stenosis of 30%-90% by visual estimate
  2. Reference vessel size ≥2 mm in stenotic segment by visual estimate

Exclusion Criteria:

Patients meeting any of the following criteria will be excluded:

• General Exclusion Criteria:

  1. Subject has undergone CABG of the target vessel.
  2. Evidence of an acute myocardial infarction within one week prior to the intended procedure.
  3. Severe heart failure (NYHA≥III)
  4. Patients with other serious conditions not eligible for clinical trials, such as severe arrhythmia or tachycardia, sinus syndrome, asthma, severe chronic obstructive pulmonary disease.
  5. Serum creatinine level of >150µmol / L.
  6. Subject has known allergy to iodinated contrast agents, adenosine, or ATP.
  7. Pregnant or breastfeeding.
  8. Repeated enrollment.
  9. Any other factors that the researchers consider not suitable for diagnostic intervention or FFR and IMR detection, such as the target vessel has collateral circulation, coronary spasm, the target vessel plaque rupture resulting in myocardial infarction, or other reasons deemed unsuitable for inclusion.

• Angiographic Exclusion Criteria:

  1. Myocardial bridge or coronary artery fistula on the study lesions.
  2. The target lesion ≥50% diameter stenosis in the left main coronary artery or ostial lesions less than 3 mm to the RCA.
  3. Low-quality angiography with poor contrast agent filling or inability to detect vascular boundaries due to various reasons, vascular overlap or severe distortion of the target vessel to fully expose the lesion location is not expected to be calculated.