Treatment of coronary artery disease is often guided by the degree of physiological stenosis, as assessed by measuring the fractional flow reserve (FFR). However, patients with a low degree of stenosis still experience clinical events, suggesting other factors are involved. One such factor is plaque vulnerability, determined by checking the lesion for high-risk plaque characteristics (HRPCs) using computed tomography angiography (CTA).
To determine whether physiological stenosis is associated with plaque vulnerability, Lee et al. carried out FFR measurement and coronary CTA in 772 vessels in a subset of 299 patients derived from the 3V FFR-FRIENDS trial (NCT01621438). The risk of vessel-oriented composite outcome (VOCO) at 5 years was compared according to the number of HRPCs and five different FFR categories (FFR ≤ 0.60, 0.61 to ≤ 0.70, 0.71 to ≤ 0.80, 0.81 to ≤ 0.90, and > 0.90).
The number of HRPCs increased with a decrease in FFR, and vice versa. Both FFR and number of HRPCs were independent predictors for the risk of VOCO. Vessels in the highest FFR categories that nevertheless had high-risk plaques, had a significantly higher risk of VOCO than when the plaques were low risk. The presence of ³ 3 HRPCs was independently associated with the risk of VOCO in the FFR > 0.80 group (HR: 3.975; 95% CI: 1.351 to 11.696; p = 0.012) but not in the FFR ≤ 0.80 group (HR: 0.929; 95% CI: 0.187 to 4.624; p = 0.929).
The authors suggest that combining both physiological stenosis severity and plaque characteristics would provide better prognostic stratification than either component alone, especially in patients with an FFR > 0.80.
Original article: J Am Coll Cardiol 2019;73:2413-24.
Author: Sally Hill