Correlation between angiography-based physiology and plaque characteristics and clinical outcomes in patients with coronary artery disease

Background and objective

The fractional flow reserve (FFR) pullback curve provides insights into the physiological patterns of coronary artery disease (CAD). Quantitative flow ratio (QFR), a non-invasive alternative derived from angiography, can estimate FFR. This study investigates whether QFR-based physiological disease patterns are associated with plaque morphology evaluated by optical coherence tomography (OCT) and clinical outcomes.

Methods

A total of 216 patients with ≥25 % diameter stenosis in the left anterior descending artery underwent QFR and OCT evaluation. Based on QFR pullback indices—PPG index and dQFR/ds—patients were classified into four groups: Group 1 (focal disease with major gradient), Group 2 (focal without gradient), Group 3 (diffuse with major gradient), and Group 4 (diffuse without gradient).

Results: Group 3 showed the highest number of lipid-rich plaques and thin-cap fibroatheromas (2.2 ± 1.1 and 1.3 ± 1.0, respectively), followed by Groups 1, 4, and 2 (p = 0.002 and p = 0.016). Groups 1 and 3 had higher lipid arc and lipid arc index values at the peak dQFR/ds segment. Kaplan–Meier analysis revealed that patients in Group 3 had significantly worse clinical outcomes. On multivariable logistic regression, only the Group 3 physiological pattern (low PPG and high dQFR/ds) was independently associated with adverse events.

Conclusions

QFR-derived physiological disease patterns are closely associated with plaque vulnerability and prognosis in CAD. QFR provides a practical tool for identifying high-risk patients and may inform individualized treatment strategies.