China: Study on Angiography-Derived Radial Wall Strain

A recent study has shown that angiography-derived radial wall strain (RWS) significantly corresponds with plaque composition and vulnerability in patients with intermediate coronary stenosis. The study appeared in the journal EuroIntervention.

The thin-cap fibroatheroma (TCFA) and the lipid-to-cap ratio (LCR) derived from optical coherence tomography indicate plaque vulnerability. Huihong Hong from Fujian Medical University Union Hospital in Fuzhou, China, and colleagues aimed to explore the association of a novel method for estimating RWS from angiography with features of plaque vulnerability assessed by OCT and plaque composition.

For this purpose, the researchers analyzed anonymized data from patients with intermediate stenosis who underwent CAG (coronary angiography) and OCT in a core laboratory. The TCFA and LCR were determined automatically on OCT images by an algorithm recently validated based on artificial intelligence. The angiography-derived RWSmax was computed as the lumen diameter's maximum deformation throughout the cardiac cycle, determined as a percentage of the largest lumen diameter.

Study Findings

• CAG and OCT images from 114 patients (124 vessels) were analyzed. The average time for the analysis of RWSmax was 57 seconds.
• The RWSmax in the interrogated plaques was 12% and corresponded positively with the LCR (r=0.584) and lipidic plaque burden (r=0.411) and negatively with fibrous cap thickness (r= −0.439).
• An RWSmax >12% was an angiographic predictor for an LCR>0.33 (AUC (area under the curve)=0.86) and TCFA (AUC=0.72).
• Lesions with RWSmax >12% had a higher TCFA prevalence (22.0% versus 1.5%), thinner fibrous cap thickness (71 μm versus 101 μm), more significant lipidic plaque burden (23.3% versus 15.4%), and higher maximum LCR (0.41 versus 0.18) compared to lesions with RWSmax ≤12%.

"In patients with intermediate coronary stenosis, angiography-derived RWS was significantly correlated with plaque composition and known OCT features of plaque vulnerability," the researchers concluded.

Reference

Hong H, Li C, Gutiérrez-Chico JL, Wang Z, Huang J, Chu M, Kubo T, Chen L, Wijns W, Tu S. Radial wall strain: a novel angiographic measure of plaque composition and vulnerability. EuroIntervention. 2022 Sep 8:EIJ-D-22-00537. doi: 10.4244/EIJ-D-22-00537. Epub ahead of print. PMID: 36073027.