Validation of a simplified intravascular ultrasound core lab analysis method in stented coronary arteries

Objectives: To validate a simplified core laboratory intravascular ultrasound (IVUS) analysis method based on frames with visually determined minimal lumen areas (MLAs) as compared with a comprehensive (per frame) analysis method.

Background: IVUS-guided percutaneous coronary intervention has proven to be superior to angiography-guided stenting. In clinical practice, cross-sections with visually determined MLA are measured to determine lesion severity or minimal stent area (MSA), however, its accuracy has not been compared with a comprehensive per frame analysis method.

Methods: A total of 50 stented coronary segments of anonymized core lab datasets were analyzed using a comprehensive analysis method and reanalyzed by two core lab analysts using the simplified method including a maximum of seven frames to be analyzed (the visually determined MSA, the first and last frame, and the MLA of each reference segment). The main parameters of interest were MSA, MLA in the reference segments, and plaque burden.

Results: The simplified method showed moderate agreement for measurement of the proximal MLA (7.51 ± 2.52 vs. 6.32 ± 1.88 mm² , intraclass correlation coefficient [ICC] = 0.73), good agreement for the distal MLA (5.41 ± 1.85 vs. 5.11 ± 1.38 mm² , ICC = 0.84) and plaque burden proximal (0.49 ± 0.12 vs. 0.50 ± 0.11, ICC = 0.88), and excellent agreement for the MSA (5.35 ± 1.05 vs. 5.32 ± 0.99 mm² , ICC = 0.94) and plaque burden distal (0.47 ± 0.14 vs. 0.47 ± 0.12, ICC = 0.92), when compared with the comprehensive analysis method. Inter- and intraobserver analysis revealed good-to-excellent agreement for all parameters.

Conclusions: Measuring poststenting IVUS cross-sections with visually determined MLAs by experienced core lab analysts is an accurate and reproducible method to identify MLAs.