Evaluation of Variable Thin-Cap Fibroatheroma Definitions and Association of Virtual Histology-Intravascular Ultrasound Findings With Cavity Rupture Size
Abstract
The accepted definition of virtual histology intravascular ultrasound (IVUS-VH) thin-cap fibroatheroma (TCFA) is only a modest predictor of plaque rupture (PR). We sought to determine the relation between IVUS-VH findings and culprit lesions with PR using computational analysis.
A total of 80 culprit lesions from 80 patients with stable angina (n = 37), unstable angina (n = 20), and myocardial infarction (n = 23) were divided into those with (n = 15) and without PR (n = 65). By use of automated computational analysis, the standard IVUSVH TCFA criterion and 124 additional criteria were compared.
The standard TCFA definition demonstrated modest ability to discriminate lesions with and without PR (sensitivity 87%, specificity 37%, PPV 0.24, and NPV 0.92). Of 124 additional IVUS-VH TCFA definitions, only 2 improved the discriminative ability even modestly.
However, a positive correlation was demonstrated between cavity size and necrotic core percentage (r = 0.78, p<0.01) and a negative correlation with percentage of fibrous tissue (r = 0.81, p<0.01). In conclusion, IVUSVH criteria were only modestly associated with PR, without significant improvement by varying IVUS-VH TCFA features, but IVUS-VH features of ruptured plaques were strongly correlated with cavity size.