Coronary CTA and CT-FFR in trans-catheter aortic valve implantation candidates: a systematic review and meta-analysis.

Screening for obstructive coronary artery disease (CAD) with coronary computed tomography angiography (CCTA) could prevent unnecessary invasive coronary angiography (ICA) procedures during work-up for trans-catheter aortic valve implantation (TAVI). CT-derived fractional flow reserve (CT-FFR) improves CCTA accuracy in chest pain patients. However, its reliability in the TAVI population is unknown. This systematic review and meta-analysis assesses CCTA and CT-FFR in TAVI candidates. PubMed, Embase and Web of Science were searched for studies regarding CCTA and/or CT-FFR in TAVI candidates. Primary endpoint was correct identification and rule-out of obstructive CAD. Results were pooled in a meta-analysis. Thirty-four articles were part of the meta-analysis, reporting results for CCTA and CT-FFR in 7235 and 1269 patients, respectively. Reference standard was mostly anatomical severity of CAD. At patient level, pooled CCTA sensitivity was 94.0% and specificity 72.4%. CT-FFR sensitivity was 93.2% and specificity 70.3% with substantial variation between studies. However, in studies that compared both, CT-FFR performed better than CCTA. Sensitivity of CCTA versus CT-FFR was 74.9% versus 83.9%, and specificity was 65.5% versus 89.8%. Negative CCTA accurately rules out CAD in the TAVI population. CCTA could lead to significant reduction in pre-TAVI ICA, but false positives remain high. Diagnostic accuracy of CT-FFR was comparable to that of CCTA in our meta-analyses, but in studies performing a direct comparison, CT-FFR performed better than CCTA. However, as most studies were small and used CT-FFR software exclusively available for research, a large study on CT-FFR in TAVI work-up using commercially available CT-FFR software would be appropriate before considering routine implementation. Question Coronary artery disease (CAD) screening with invasive coronary angiography before trans-catheter aortic valve implantation (TAVI) is often retrospectively unnecessary, revealing no obstructive CAD. Findings Coronary CTA ruled out CAD in approximately half of TAVI candidates. CT-derived fractional flow reserve (CT-FFR) performed similarly overall but better than coronary CTA in direct comparison. Clinical relevance Addition of coronary CTA to TAVI planning-CT to screen for obstructive CAD could reduce negative invasive coronary angiographies in TAVI work-up. CT-FFR could reduce false-positive coronary CTA results, improving its gatekeeper function in this population, but more data is necessary.

Becker LM ，Peper J ，van Ginkel DJ ，Overduin DC ，van Es HW ，Rensing BJMW ，Timmers L ，Ten Berg JM ，Mohamed Hoesein FAA ，Leiner T ，Swaans MJ ... -  《-》

Real-world application of CCTA with CT-FFR for coronary assessment pre-TAVI: the CT2TAVI study.

This study aims to evaluate the implementation of concomitant CAD assessment on pre-TAVI (transcatheter aortic valve implantation) planning CTA (CT angiography) aided by CT-FFR (CT-fractional flow reserve) [The CT2TAVI protocol] and investigates the incremental value of CT-FFR to coronary CT angiography (CCTA) alone in the evaluation of patients undergoing CT2TAVI. This is a prospective observational real-world cohort study at an academic health system on consecutive patients who underwent CTA for TAVI planning from 1/2021 to 6/2022. This represented a transition period in our health system, from not formally reporting CAD on pre-TAVI planning CTA (Group A) to routinely reporting CAD on pre-TAVI CTA (Group B; CT2TAVI protocol). All CTAs were retrospective ECG-gated using a dual source 192 slice CT scanner without nitrate or intravenous beta blocker premedication. We assessed downstream ICA and revascularization pre-TAVI and clinical outcomes 30 days and 1 year post-TAVI in both groups. 307 patients were included with 199 patients in Group A and 108 patients in Group B. In Group B, ICA was performed pre-TAVI in only 40.7% of patients. The use of CT-FFR, which was primarily aimed at identifying hemodynamically significant proximal vessel disease, helped avoid downstream invasive testing for 60.5% (23/38) of patients who were deemed to have obstructive proximal vessel disease using CCTA alone or had one or more uninterpretable proximal segments using CCTA. All-cause mortality, cardiovascular mortality, myocardial infarction and need for revascularization at 1-year post-TAVI were comparable between groups with a higher trend toward heart failure hospitalizations in Group A. Routine ICA can safely be deferred pre-TAVI, with the CT2TAVI strategy using modern CT scanners aided by CT-FFR analysis.

Hussain K ，Lee K ，Minga I ，Wathen L ，Balasubramanian SS ，Vyas N ，Singh L ，Shetty M ，Rosenberg JR ，Levisay JP ，Karagodin I ，Liebelt J ，Edelman RR ，Ricciardi MJ ，Pursnani A ... -  《-》

Coronary CT angiography instead of invasive angiography before TAVI: Feasibility and outcomes.

Concomitant coronary artery disease (CAD) is frequent in transcatheter aortic valve implantation (TAVI) candidates. Despite societal recommendations of performing invasive coronary angiography (ICA) for coronary assessment in the pre-TAVI diagnostic workup, the prognostic value of ICA and beneficial effect of revascularization in these patients remains unclear. We aimed to determine feasibility and outcomes following a strategy of cardiac CT + coronary CT angiography (cCTA) rather than cardiac CT + ICA before TAVI. We performed a single-center, observational cohort study including all patients, without previous coronary intervention, referred to TAVI between April 2020 and November 2021. CAD was assessed by cCTA, and only patients with proximal stenosis >70 %, or left main stenosis >50 %, or cCTA was non-evaluable regarding proximal segments were subsequently referred to ICA. 240 patients were included in the study. No adverse effects to pre-cCTA-scan nitroglycerin administration were observed. On cCTA, 92 % of the patients had atheroscerosis. 191 (80 %) patients had cCTA only performed, while 49 (20 %) patients underwent subsequent ICA. During a median (range) follow-up of 15 (6-25) months, no difference in procedural complication rates, mortality rates, or number of unplanned ICA was observed between patients evaluated with only cCTA vs cCTA+ICA. Upfront cCTA instead of ICA for assessment of obstructive CAD in the diagnostic workup of patients with severe aortic stenosis referred to TAVI is feasible, safe, and with similar procedural and clinical outcomes. Randomized studies are warranted to further validate the safety of using CTA rather than ICA for coronary assessment in TAVI candidates.

Jensen RV ，Jensen JM ，Iraqi N ，Grove EL ，Mathiassen ON ，Pedersen KB ，Parner E ，Leipsic J ，Terkelsen CJ ，Nørgaard BL ... -  《-》

The value of fractional flow reserve based on coronary computed tomography angiography with low-dose contrast agent in noninvasive diagnosis of coronary artery disease.

The study aimed, using invasive coronary angiography (ICA) as the gold standard, to investigate the noninvasive diagnostic value of flow reserve fraction derived from coronary computed tomography angiography (CCTA) with low-dose contrast agent in coronary artery disease (CAD). A total of 163 patients with clinical symptoms related to CAD were enrolled between 1 January 2022 and 30 January 2023. The patients received CCTA with a low dose of contrast agent to rule out CAD. If significant (CCTA ≥ 50%) stenosis is suspected, ICA is performed to further evaluate the CCTA for coronary lesions. CT-FFR is calculated from the CCTA dataset using a machine learning-based algorithm. Compared with ICA as a reference standard, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of low-dose contrast agent CT-FFR in the diagnosis of myocardial ischemia were calculated. Coronary lesions with CT-FFR ≤0.80 were defined as hemodynamically significant. Obstructive CAD was excluded by low-contrast CCTA in 87 of 163 patients (53.7%). In the remaining 75 patients (42.35%), at least one coronary artery stenosis was greater than 50%. The accuracy, sensitivity, specificity, PPV, and NPV of low-dose contrast agent CT-FFR on a patient-based evaluation in diagnosing CAD were 93.06, 93.44, 90.01, 98.28, and 71.43%, respectively (Kappa = 0.759). The accuracy, sensitivity, specificity, PPV, and NPV of low-dose contrast agent CT-FFR on a vessel-based evaluation in diagnosing CAD were 86.72, 82.76, 91.58, 92.31, and 81.31%, respectively (Kappa = 0.735). Pearson correlation analysis showed that the ICA examination had a good correlation with CT-FFR value of low-dose contrast media ( r  = 0.731, P  < 0.01). Moreover, in 81.31% of cases, additional analysis of CT-FFR correctly excluded the hemodynamic significance of stenosis. CT-FFR based on low-dose contrast agent CCTA is a very promising noninvasive approach to exclude hemodynamically significant coronary artery stenosis in patients with suspected coronary heart disease while reducing renal burden and helping to reduce the rate of ICA in this high-risk population.

Wang Z ，Luan X ，Zhang Q ，Chu C ，Xu X ，Chai H ，Song P ... -  《-》

CT Myocardial Perfusion and CT-FFR versus Invasive FFR for Hemodynamic Relevance of Coronary Artery Disease.

Soschynski M ，Storelli R ，Birkemeyer C ，Hagar MT ，Faby S ，Schwemmer C ，Nous FMA ，Pugliese F ，Vliegenthart R ，Schlett CL ，Nikolaou K ，Krumm P ，Nieman K ，Bamberg F ，Artzner CP ... -  《-》