Comparison of Clinical Interpretation With Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary Practice: The Assessing Angiography (A2) Project

Study Questions:

What is the correlation between visual assessment and quantitative coronary angiography (QCA) in patients undergoing percutaneous coronary intervention (PCI)?


The authors compared clinical interpretation of stenosis severity in coronary lesions with an independent assessment using quantitative coronary angiography (QCA) in 175 randomly selected patients undergoing elective PCI at seven US hospitals in 2011. The mean difference in percent diameter stenosis was compared between clinical interpretation and QCA, and a Cohen weighted κ statistic was calculated.


A total of 216 lesions were treated in 175 patients. The median percent diameter stenosis was 80.0%. The average diameter stenosis was higher with clinical interpretation, with a mean difference in percent diameter stenosis between clinical interpretation and QCA being 8.2 ± 8.4% (p < 0.001). Of 213 lesions considered ≥70% by clinical interpretation, 56 (26.3%) were <70% by QCA, although none were <50%. Differences between the two measurements were largest for intermediate lesions by QCA (50% to <70%), with variation existing across sites.


The authors concluded that coronary lesions treated with PCI were assessed as more severe by clinicians compared with measurements by QCA.


The overestimation of lesion severity by visual estimation compared with QCA was first recognized almost 2 decades ago (Gottsauner-Wolf et al., Eur Heart J 1996;17:1167-74), and the current study corroborates prior data quite nicely. The limitations of coronary luminology are well recognized, and QCA is not any better at estimating functional significance of a lesion compared with visual estimation. Routine use of QCA has never been demonstrated to improve clinical outcomes or appropriateness of procedures (unlike fractional flow reserve). Until a randomized trial can demonstrate the utility of QCA for impacting such outcomes, routine use of QCA for clinical decision making or for guiding quality improvement cannot be recommended.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Patient Selection, Coronary Angiography, Cardiology, Constriction, Pathologic, Percutaneous Coronary Intervention

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