Noncoronary Gated Transcatheter Aortic Valve Replacement Computed Tomography Scans Can Safely Replace Invasive Coronary Angiography Pre-Transcatheter Aortic Valve Replacement

Patients with severe aortic stenosis often have concomitant coronary artery disease (CAD), detectable in up to 65% of cases.[1]Shamekhi J. Stundl A. Weber M. et al.Impact of coronary artery disease in patients undergoing transfemoral transcatheter aortic valve implantation.Int J Cardiol. 2017; 245: 215-221https://doi.org/10.1016/J.IJCARD.2017.07.082Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar Concomitant CAD may increase adverse coronary events during transcatheter aortic valve replacement (TAVR) and, in the absence of a robust evidence base, may promote consideration of percutaneous coronary intervention (PCI) pre-TAVR.[2]D’Ascenzo F. Verardi R. Visconti M. et al.Independent impact of extent of coronary artery disease and percutaneous revascularisation on 30-day and one-year mortality after TAVI: a meta-analysis of adjusted observational results.EuroIntervention. 2018; 14: E1169-E1177https://doi.org/10.4244/EIJ-D-18-00098Crossref PubMed Scopus (63) Google Scholar Although practice is evolving, due to a lack of safety data, many Valve Teams still mandate invasive coronary angiography (ICA) as a prerequisite for patients being considered for TAVR.[3]Faroux L. Guimaraes L. Wintzer-Wehekind J. et al.Coronary artery disease and transcatheter aortic valve replacement: JACC state-of-the-art review.J Am Coll Cardiol. 2019; 74: 362-372https://doi.org/10.1016/J.JACC.2019.06.012Crossref PubMed Scopus (0) Google Scholar TAVR planning includes a noncoronary gated TAVR computed tomography (CT) scan (TAVRCT) (i.e., retrospective-gated protocol of the aortic root followed by a nongated CT of the whole aorta) in all patients. Therefore, the TAVRCT is different to the dedicated assessment of coronary anatomy achieved with a CT coronary angiogram. In severe aortic stenosis patients, complete anatomical assessment of the coronary circulation on a noncoronary gated TAVRCT is often precluded by excessive coronary calcification ± limited coronary opacification. However, detailed anatomical assessment of the proximal coronary circulation may still be feasible. In this study, we aimed to determine the diagnostic performance of noncoronary gated TAVRCT scans to identify anatomically significant proximal CAD (CADp) assessed against i) ICA as the reference standard, ii) peri-TAVR adverse coronary events (defined as either coronary obstruction and/or the need for emergency bail-out PCI), and iii) alteration in the pre-TAVR planning pathway (defined as the Valve Team decision to perform PCI pre-TAVR). We hypothesized that assessment of CADp on noncoronary gated TAVRCT would demonstrate a high negative predictive value (NPV) when judged against these criteria. One-hundred and ninety-two consecutive TAVR patients were included from May 2017 to March 2020. All patients underwent i) TAVRCT (GE Lightspeed 64-slice CT scanner), ii) pre-TAVR ICA, and iii) subsequent TAVR. TAVRCT scans were blind-reported (S.G.) to identify CADp (defined as a >50% diameter stenosis of the left-main stem, right coronary artery, or left anterior descending arteries <20mm from the coronary ostia. Coronary artery bypass graft assessment involved only patency of the left internal mammary artery [LIMA] graft). ICAs were blind-reported (C.C.) according to the same anatomical criteria. Peri-TAVR adverse coronary events and the Valve Team decision to perform PCI pre-TAVR were obtained from hospital records. The study was ethically approved by the UK Health Research Authority (ref:22/HRA/2987). The mean age was 82 ± 6 years and 61% were male. Tricuspid valve anatomy was present in 97%. Prior coronary artery bypass graft was present in 21%. Balloon expandable vs. self-expanding TAVR prostheses were used in 70.8% vs. 29.2% of cases, respectively. Mean coronary heights from the annulus were 14.1 ± 2.7mm on the left and 14.8 ± 3.0mm on the right. Peri-TAVR adverse coronary events occurred in 0.5%. PCI pre-TAVR was performed in 2.6% of patients. Proximal coronary anatomy was diagnostically interpretable in 97.4% of TAVRCTs and in 100% of ICAs. Diagnostically uninterpretable (artefact from breathing, arrhythmia, or insufficient opacification) TAVRCTs (2.6%) were default labeled as demonstrating CADp. Overall, CADp was almost twice as likely to be identified on TAVRCT vs. ICA (24.5% vs. 12.5%, respectively, p < 0.0001). The sensitivity, specificity, positive predictive value (PPV) and NPV of routine protocol TAVRCT to correctly identify CADp compared against ICA as the reference standard were 87.5%, 84.5%, 44.7%, and 97.9%, respectively. The sensitivity, specificity, PPV, and NPV of TAVRCT to predict peri-TAVR adverse coronary events were 0%, 75.4%, 0%, and 99.3%, respectively. Lastly, the sensitivity, specificity, PPV, and NPV of TAVRCT to predict the need to perform PCI pre-TAVR were 80%, 100%, 100%, and 99.5%, respectively. Additional analysis to further evaluate the diagnostic performance of TAVRCT to correctly identify CADp according to left or right proximal coronary systems was undertaken. The sensitivity, specificity, PPV, and NPV for TAVRCT to diagnose proximal stenosis in the right coronary artery was 81.8%, 89.7%, 33.3%, and 98.7%, and for the left proximal coronaries was 86.7%, 87.0%, 36.1%, and 98.7%. Our study demonstrates the clinical utility of noncoronary gated TAVRCT scans to noninvasively identify anatomically significant proximal CAD in prospective TAVR patients. Moreover, the very high NPV of TAVRCT to predict i) the need to perform PCI pre-TAVR, or ii) peri-TAVR adverse coronary events (>99% NPV for both) supports safe deferral of routine ICA in contemporary pre-procedural TAVR planning in favor of proximal coronary assessment on noncoronary gated TAVRCT (Figure 1). Additionally, the high NPV for both left and right proximal coronary systems provides reassurance that TAVRCT is seemingly effective at ruling out anatomically significant proximal coronary disease independent of proximal vessel territory.