Evolving concepts of angiogram: fractional flow reserve discordances in 4000 coronary stenoses

Area of Science:

• Cardiology
• Interventional Cardiology
• Diagnostic Imaging

Background:

• Coronary artery disease (CAD) assessment relies on both anatomical (angiography) and physiological (FFR) measures.
• Discordance between these methods can impact clinical decision-making.

Purpose of the Study:

• To investigate the clinical and physiological significance of discrepancies between angiographic stenosis severity and FFR.
• To evaluate the prevalence and implications of discordance in a large, unselected patient cohort.

Main Methods:

• Quantitative coronary angiography (QCA) and FFR measurements were performed in 2986 patients with intermediate coronary stenoses.
• Analysis focused on the correlation between percent diameter stenosis (DS) and FFR values.
• Sensitivity, specificity, and diagnostic accuracy were calculated for various DS thresholds.

Main Results:

• A significant, albeit slight, correlation was observed between DS and FFR (r = -0.38).
• Discordance occurred in 35% of cases when using a ≥50% DS threshold to predict FFR ≤0.80.
• Left main stenoses were frequently underestimated by the 50% DS cut-off compared to FFR.

Conclusions:

• A substantial proportion of patients demonstrate discordance between angiographic and FFR-derived stenosis severity.
• This discordance, particularly in left main lesions, suggests limitations of angiography alone.
• Further research is warranted to understand the clinical implications and underlying mechanisms of this discordance.