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Aims: The aim of this study was to investigate the diagnostic performance of quantitative flow ratio (QFR) in assessing the physiological relevance of coronary lesions in the presence of severe aortic valve stenosis (SAS)., Methods and Results: A total of 115 SAS patients (138 coronary arteries) were included. Functional assessment of coronary stenoses was performed with fractional flow reserve (FFR) before transcatheter aortic valve implantation (TAVI). Subsequently, QFR was calculated at a central core laboratory, blinded to FFR results. The diagnostic yield of QFR was assessed using FFR as reference. Coronary stenoses were intermediate (diameter stenosis 48±10%, FFR 0.84 [0.77-0.89], QFR 0.82 [0.73-0.89]). Per-vessel sensitivity, specificity, area under the ROC curve and accuracy of QFR were 84% (95% CI: 71-92%), 80% (95% CI: 69-88%), 0.88 (95% CI: 0.82-0.93) and 81%, respectively. Diagnostic accuracy of QFR decreased significantly in patients with aortic valve area (AVA) <0.60 cm2. Diagnostic performance of QFR was superior to angiography in assessing the FFR-based functional significance (AUC 0.88 [95% CI: 0.82-0.93] vs 0.74 [95% CI: 0.66-0.81], respectively; p=0.0002)., Conclusions: Compared with FFR, QFR has a good diagnostic yield and is superior to angiography in assessing the functional relevance of coronary lesions in SAS patients awaiting TAVI, particularly when AVA is ≥0.6 cm2.

This consensus document is the second of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near infrared spectroscopy (NIRS)-IVUS. Beyond guidance of stent selection and optimization of deployment, invasive imaging facilitates angiographic interpretation and may guide treatment in acute coronary syndrome. Intravascular imaging can provide additional important diagnostic information when confronted with angiographically ambiguous lesions and allows assessment of plaque morphology enabling identification of vulnerability characteristics. This second document focuses on useful imaging features to identify culprit and vulnerable coronary plaque, which offers the interventional cardiologist guidance on when to adopt an intracoronary imaging-guided approach to the treatment of coronary artery disease and provides an appraisal of intravascular imaging-derived metrics to define the haemodynamic significance of coronary lesions., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

We present a novel and time-efficient method for intracoronary lumen detection, which produces three-dimensional (3-D) coronary arteries using optical coherence tomographic (OCT) images. OCT images are acquired for multiple patients and longitudinal cross-section (LOCS) images are reconstructed using different acquisition angles. The lumen contours for each LOCS image are extracted and translated to 2-D cross-sectional images. Using two angiographic projections, the centerline of the coronary vessel is reconstructed in 3-D, and the detected 2-D contours are transformed to 3-D and placed perpendicular to the centerline. To validate the proposed method, 613 manual annotations from medical experts were used as gold standard. The 2-D detected contours were compared with the annotated contours, and the 3-D reconstructed models produced using the detected contours were compared to the models produced by the annotated contours. Wall shear stress (WSS), as dominant hemodynamics factor, was calculated using computational fluid dynamics and 844 consecutive 2-mm segments of the 3-D models were extracted and compared with each other. High Pearson's correlation coefficients were obtained for the lumen area (r = 0.98) and local WSS (r = 0.97) measurements, while no significant bias with good limits of agreement was shown in the Bland-Altman analysis. The overlapping and nonoverlapping areas ratio between experts' annotations and presented method was 0.92 and 0.14, respectively. The proposed computer-aided lumen extraction and 3-D vessel reconstruction method is fast, accurate, and likely to assist in a number of research and clinical applications.

Objective: To compare the sensitivity and specificity for coronary calcium detection of two fluoroscopic systems: 1) conventional system based on image intensifier chains (CONV); and 2) flat panel digital detector (FPDD) system, using intravascular ultrasound (IVUS) as the gold standard., Background: Coronary calcification represents advanced atherosclerotic disease and has implications during coronary interventions. Angiography has been reported to have low sensitivity for calcium detection compared with IVUS., Methods: Lesion calcification was assessed by two different fluoroscopic systems (FPDD and CONV), and by IVUS., Results: In two consecutive periods, a total of 200 consecutive patients were included, 100 in each group. Clinical characteristics were similar, without significant differences between groups. In the CONV group, IVUS detected calcium in 77% of cases, and angiography in 32%. Sensitivity was 41.6% and specificity 91.3%. In the FPDD group, IVUS reported calcification in 79% of patients, and angiography in 57%. Sensitivity was 72% (p < 0.0001 for comparison with CONV) and specificity was 90.4%., Conclusion: The new fluoroscopic systems, based on FPDD, considerably increase the sensitivity for calcium detection without detrimental effect on specificity.