Angiography-based quantitative flow ratio versus fractional flow reserve in patients with coronary artery disease and severe aortic stenosis.

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.

Risk Prediction Model for Cardiac Implantable Electronic Device Implantation After Transcatheter Aortic Valve Replacement.

OBJECTIVES: The aim of this study was to develop and validate a risk prediction model for high-grade atrioventricular block requiring cardiac implantable electronic device (CIED) implantation after transcatheter aortic valve replacement (TAVR). BACKGROUND: High-grade atrioventricular block requiring CIED remains a significant sequelae following TAVR. Although several pre-operative characteristics have been associated with the risk of post-operative CIED implantation, an accurate and validated risk prediction model is not established yet. METHODS: This was a single center, retrospective study of consecutive patients who underwent TAVR from March 10, 2011, to October 8, 2018. This cohort sample was randomly divided into a derivation cohort (group A) and a validation cohort (group B). A scoring system for risk prediction of post-TAVR CIED implantation was devised using logistic regression estimates in group A and the calibration and validation were done in group B. RESULTS: A total of 1,071 patients underwent TAVR during the study period. After excluding pre-existing CIED, a total of 888 cases were analyzed (group A: 507 and group B: 381). Independent predictive variables were as follows: self-expanding valve (1 point), hypertension (1 point), pre-existing first-degree atrioventricular block (1 point), and right bundle branch block (2 points). The resulting score was calculated from the total points. The internal validation in group B showed an ideal linear relationship in calibration plot (R2 = 0.933) and a good predictive accuracy (area under the curve: 0.693; 95% confidence interval: 0.627 to 0.759). CONCLUSIONS: This prediction model accurately predicts post-operative risk of CIED implantation with simple pre-operative parameters.