How coronary plaque morphology affects fractional flow reserve: clinical evidence from intravascular imaging studies

Fractional flow reserve (FFR) is widely used to assess the functional significance of coronary artery disease (CAD). However, the severity of anatomical stenosis does not always correspond with the extent of myocardial ischemia. This discordance highlights the limitations of angiographic assessment alone and underscores the need for more comprehensive evaluation strategies. Recent advances in intravascular imaging have provided deeper insights into the contribution of plaque itself to myocardial ischemia. A PubMed search was conducted for relevant studies published up to May 2025.

This review summarizes current evidence on the relationship between intravascular imaging-derived plaque characteristics and FFR. Key features examined include plaque burden, lipidic and calcified plaques, and plaque microstructures. Of these, large plaque burden and lipid-rich plaque characteristics show the most consistent associations with reduced FFR. Mechanistic explanations such as impaired vasodilatory capacity and localized endothelial dysfunction are also explored.

Plaque morphology contributes important diagnostic and prognostic information beyond luminal narrowing. Integrating morphological imaging with physiological assessment is expected to improve clinical decision-making and management of CAD. Future research should focus on validating integrated imaging-physiology strategies to personalize treatment and improve outcomes in patients with CAD.