COMPARISON OF DIGITAL ANGIOGRAMS WITH CONVENTIONAL CINEANGIOGRAMS FOR THE QUANTITATION OF CORONARY-ARTERY STENOSIS BEFORE AND AFTER ANGIOPLASTY

Background: It is currently unknown how digital images viewed during angioplasty compare with cineangiograms taken at the end of the procedure for estimating lesion severity, and detecting intimal dissection. The aim of this study, therefore, was to compare the two imaging techniques in assessing lesion severity and morphology before and after angioplasty. Methods: Digital angiograms and cineangiograms acquired before and after 50 consecutive angioplasties were analyzed blindly by two experienced observers. To assess inter-observer variability, angiograms were also analyzed independently by a second pair of observers. Results: There was no significant difference in the overall mean percent diameter stenosis measured by the two imaging techniques (preangioplasty: 77% cine, 80% digital, mean difference 2.6%, postangioplasty: 34% cine, 35% digital, mean difference 1.7%), suggesting that there is no appreciable systematic difference between modalities. However, wide limits of agreement between the techniques (preangioplasty: -24.6% to 29.7%, postangioplasty: -23.1% to 26.5%) indicate relatively large discrepancies in individual measurements. Interobserver variability was of a similar magnitude, and this may account for much of the apparent variability between techniques. Concordance between imaging modalities on the presence or absence of intimal dissection was similar to concordance between observers, suggesting that detection of intimal dissection depends more on observer judgment than image quality. Importantly, interobserver variability was similar for both imaging techniques, Conclusions: The results of this study indicate that digital imaging is comparable to cineangiography in assessing lesion severity and morphology before and after coronary angioplasty. There are clear limitations to the visual assessment of coronary stenoses.