VARIABILITY IN MEASURES OF CORONARY LUMEN DIMENSIONS USING QUANTITATIVE CORONARY ANGIOGRAPHY

Objectives: The purpose of this study was to determine the true total variability of quantitative coronary angiographic measures and their c omponents in the clinical setting. Background: Many studies describe q uantitative coronary angiographic variability on the basis of repeated quantitative coronary angiographic measures from the same cineangiogr am. Although these studies characterize well the performance of quanti tative coronary angiographic analysis methods, they do not include oth er potentially important sources of variability in results of this pro cedure, such as day to day variations in patients and equipment or var iability in selection of frames for analysis. Methods: Coronary angiog rams from 20 patients who underwent diagnostic angiography followed by percutaneous transluminal coronary angioplasty an average of 2.9 days later were reviewed. A total of 30 lesions well visualized in both fi lms were analyzed multiple times using an automated first-derivative e dge-detection quantitative coronary angiographic technique. Results: T he coefficient of variation for quantitative coronary angiographic mea sures of the same lesions from separate angiograms ranged from 8.11% t o 14.01%. Average diameter was the least variable and percent diameter stenosis the most variable. Day to day variations in the patient, pro cedure and equipment accounted for an average of 30% of the total vari ability. Of the remaining variability, only 13.26% was due to variabil ity in frame selection. Conclusions: These results provide useful info rmation for planning clinical studies using quantitative coronary angi ography, identify areas where additional improvements in this technolo gy are needed and define more clearly the applicability of quantitativ e coronary angiography in the setting of routine clinical practice.