Short-Term Risk Stratification of Non-Flow-Limiting Coronary Stenosis by Angiographically Derived Radial Wall Strain

Deferred revascularization of mildly stenotic coronary vessels based exclusively on physiological evaluation is associated with up to 5% residual incidence of future adverse events at 1 year.

We aimed to evaluate the incremental value of angiography-derived radial wall strain (RWS) in risk stratification of non-flow-limiting mild coronary narrowings.

This is a post hoc analysis of 824 non-flow-limiting vessels in 751 patients from the FAVOR III China (Comparison of Quantitative Flow Ratio Guided and Angiography Guided Percutaneous Intervention in Patients With Coronary Artery Disease) trial. Each individual vessel had ≥1 mildly stenotic lesion. The primary outcome was vessel-oriented composite endpoint (VOCE), defined as the composite of vessel-related cardiac death, vessel-related myocardial infarction (nonprocedural), and ischemia-driven target vessel revascularization at 1-year follow-up.

During 1-year follow-up, VOCE occurred in 46 of 824 vessels, with a cumulative incidence of 5.6%. Maximum RWS (RWS_max) was predictive of 1-year VOCE with an area under the curve of 0.68 (95% CI: 0.58-0.77; P < 0.001). The incidence of VOCE was 14.3% in vessels with RWS_max >12% vs 2.9% in those with RWS_max ≤12%. In the multivariable Cox regression model, RWS_max >12% was a strong independent predictor of 1-year VOCE in deferred non-flow-limiting vessels (adjusted HR: 4.44; 95% CI: 2.43-8.14; P < 0.001). The risk of deferred revascularization based on combined normal RWS_max and Murray-law-based quantitative flow ratio (μQFR) was significantly reduced compared with μQFR alone (adjusted HR: 0.52; 95% CI: 0.30-0.90; P = 0.019).

Among vessels with preserved coronary flow, angiography-derived RWS analysis has the potential to further discriminate vessels at risk of 1-year VOCE. (Comparison of Quantitative Flow Ratio Guided and Angiography Guided Percutaneous Intervention in Patients With Coronary Artery Disease [FAVOR III China Study]; NCT03656848).