Response to Letters Regarding Article, “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”

We appreciate the concerns raised by Drs Khandelwal and Kern about our recent analysis of the visual assessment of angiographic stenosis among percutaneous coronary intervention (PCI)–treated lesions in contemporary practice.1 In sum, their concerns involve the admittedly imperfect nature of quantitative coronary angiography (QCA), which they suggest should not be used as a tool for clinical assessments in the catheterization laboratory. We agree that QCA has limitations (and noted many of their points in our Discussion). In particular, we specifically acknowledged that QCA ‘as it is currently used’ does not account for many factors that should influence clinical decisions on revascularization.Nonetheless, we do believe that QCA, as an unbiased and highly reliable technique, may help quality improvement efforts by identifying (and perhaps narrowing) gaps in performance related to visual assessment. This was the overarching goal of our study, and we believe our findings strongly suggest a need to improve visual assessment. Despite several previous studies that have demonstrated deficiencies with visual assessment over the last several decades, there has been no concerted effort by the cardiology community to address extensive interobserver and intraoperator variability in the …