Angiography-derived radial wall strain corresponds with plaque composition and vulnerability: Study

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

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

CAG and OCT images from 114 patients (124 vessels) were analyzed.

Following were the study's salient findings:

• The average time for the analysis of RWSmax was 57 seconds.
• The RWSmax in the interrogated plaques was 12% and correlated 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 (area under the curve [AUC]=0.86) and TCFA (AUC=0.72).
• Lesions with RWSmax >12% had a higher prevalence of TCFA (22.0% versus 1.5%), thinner fibrous cap thickness (71 μm versus 101 μm), more considerable lipidic plaque burden (23.3% versus 15.4%), and higher maximum LCR (0.41 versus 0.18) compared to lesions with RWSmax ≤12%.

The researchers conclude, "in patients with intermediate coronary stenosis, angiography-derived RWS was notably correlated with plaque composition and known OCT features of plaque vulnerability."

Reference:

The study titled "Radial wall strain: a novel angiographic measure of plaque composition and vulnerability" was published in EuroIntervention. DOI: 10.4244/EIJ-D-22-00537