The following is a summary of “Short-Term Risk Stratification of Non–Flow-Limiting Coronary Stenosis by Angiographically Derived Radial Wall Strain,” published in the February 2023 issue of Cardiology by Tu, et al.

For a study, researchers sought to determine the incremental value of radial wall strain (RWS) derived from angiography in risk stratification of non-flow-limiting mild coronary narrowings. 

The study involved 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. The primary outcome was the vessel-oriented composite endpoint (VOCE), which included vessel-related cardiac death, vessel-related myocardial infarction (nonprocedural), and ischemia-driven target vessel revascularization at 1-year follow-up. 

During the 1-year follow-up, VOCE occurred in 46 of the 824 vessels, resulting in 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% versus 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). In addition, 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). 

The results suggested that angiography-derived RWS analysis may further identify vessels at risk of 1-year VOCE among those with preserved coronary flow.

Reference: jacc.org/doi/10.1016/j.jacc.2022.11.056