A new quantitative analysis system for the evaluation of coronary bifurcation lesions: comparison with current...

Objective conventional quantitative angiographic systems are designed to automatically follow the contours of straight vascular segments and not of bifurcations. Recently a new analysis method was specifically developed for bifurcation lesions, able to automatically divide the lesion into three separate segments. In this study, we aimed to assess whether the smaller interaction required by the analyst could reduce the analysis time and inter and intra observer variability when compared with a conventional analysis.

We used a dedicated system (QVA-CMS V. 6.0 with the Bifurcation Module, MEDIS, Leiden, The Netherlands) applying a minimum cost algorithm tuned to detect the contours of the proximal main vessel (PMV), distal main vessel (DMV), and side-branch (SB). We assessed the intra- and the interobserver agreement in measurements of minimal lumen diameter (MLD) and percentage diameter stenosis (%DS) of the PMV and DMV, as well as of the SB ostium in 30 angiograms of patients before and after percutaneous coronary angioplasty with stenting of both branches. The consensus between measurements by two observers and by the same observer was analyzed using the intra- and interclass correlation coefficient and the reliability coefficients for all measurements. Bland-Altman plots before and after PCI were also generated to assess the relationship between variability and absolute measurements.

Before PCI, intra- and interobserver variabilities were consistently lower for the new QVA system, with a significant difference for lesion length in the SB. Post-PCI data showed a greater variability in the assessment of diameter stenosis with both techniques. The time for analysis was significantly lower both before and after PCI for QVA compared with quantitative coronary angiography (QCA) (4.7 +/- 1.1 min versus 6.2 +/- 1.3 min, P < 0.0001).

Our results demonstrate that this new quantitative bifurcation analysis system can be consistently applied to the analysis of bifurcation lesions before and after angioplasty, with an intra- and interobserver reproducibility equal to or better than the conventional analysis system with a significantly shorter analysis time.