Angiography-derived functional assessment of left main coronary stenoses

Area of Science:

• Cardiovascular Imaging
• Interventional Cardiology
• Diagnostic Accuracy Studies

Background:

• Quantitative flow ratio (QFR) is accurate for non-left main (LM) coronary stenoses.
• Limited data exists on QFR's diagnostic value in LM disease.

Purpose of the Study:

• To evaluate the diagnostic accuracy of QFR in left main (LM) coronary stenoses.
• To compare QFR with Fractional Flow Reserve (FFR) in LM stenosis assessment.

Main Methods:

• Retrospective, observational, multicenter study of 67 patients with LM stenoses.
• QFR calculated from conventional angiograms, blinded to FFR results.
• Exclusion of significant ostial LM disease cases.

Main Results:

• Moderate correlation between QFR and FFR (r=0.590).
• QFR sensitivity and specificity were 85.4% and 69.6%, respectively.
• QFR's AUC (0.82) was significantly better than %DS (0.45) and minimum lumen diameter (0.60).

Conclusions:

• QFR demonstrates acceptable diagnostic performance for LM stenosis functional relevance.
• QFR is superior to conventional angiography for LM stenosis assessment.
• Caution is recommended when using functional angiography for LM stenosis due to its unique anatomy.