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”

Abstract

CorrespondenceWe 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 interpretation of coronary angiography. Indeed, the fact that we found significant differences across hospitals in how visual assessments compared with QCA suggests that factors other than random variability are at play. Because challenges with visual assessment in clinical practice still exist, they need to be explored and should be addressed with innovative solutions because the implications for clinical care are substantial.Both Dr Khandelwal and Dr Kern argue for assessment of the functional significance of lesions using tools like fractional flow reserve (FFR) as the better approach. We agree with this, both conceptually and in practice, and mentioned the importance of this tool in our Discussion. However, the use of FFR in our study cohort was rare, which indicates the continued reliance on visual assessment in current practice. Contemporary data from the American College of Cardiology-National Cardiovascular Data Registry CathPCI Registry also indicate that use of FFR in elective PCI is uncommon.2 In fact, as we wrote in our article, we believe that feedback and educational initiatives about visual assessment through tools like QCA may actually "enhance clinical decision making on the need for further testing (eg, FFR) before PCI." 1 We also believe that even with the widespread adoption of tools for physiological assessment of lesions like FFR, accurate visual assessment of coronary anatomy by cardiologists remains a fundamental skill required for performing coronary angiography. And we need to ensure that cardiologists are good at it.Finally, it is important to emphasize that we are not advocating for the implementation of QCA as a way to replace clinical decision making by cardiologists. Instead, we are interested in ...

Interoperator and intraoperator (in)accuracy of stent selection based on visual estimation

“…They found that physicians tended to over‐assess the severity of stenosis in lesions treated by PCI. This study did not assess the measurement of lesion lengths or assess stent selection .…”

Coronary Angiography

“…13 The mean percent diameter stenosis assessed clinically was about 8% higher than that obtained by QCA. Interestingly there was a large difference between the two analysis strategies for the visually assessed severe stenoses (70-90%).…”

“…It is unclear if the technological advancements and adaptation of digital imaging have impacted our ability to accurately discern the degree of coronary disease by visual assessment. In this issue, Nallamothu and colleagues 13 compared routine clinical assessment of CAD to QCA of over 200 coronary lesions from randomly selected patients prior to percutaneous coronary intervention (PCI). They extracted the clinical assessment of each epicardial lesion from catheterization and clinical reports.…”

Comparison of Everolimus- versus Sirolimus-eluting stents in the provisional Bifurcation stenting guided by intravascular ultrasound: mid-term results of the J-REVERSE registry

“…However, in the IVUS analysis, the mean minimal lumen area in both MV and SB before PCI (Table 5) was less than the cut-off value of \3.07 mm 2 significantly correlated with a fractional flow reserve\0.80 [25]. A recent study demonstrated that the mean difference in %DS between the visual estimation and QCA was ?8.2 ± 8.4 % [26]. IVUS contributes to the assessment of complex bifurcation lesions, plaque burden and location, bifurcation angles, morphology of the carina, and ostial lesions [12][13][14][15].…”