Diagnostic accuracy of multidetector computed tomography coronary angiography in 325 consecutive patients referred for transcatheter aortic valve replacement

Assessment of bystander coronary artery disease in transcatheter aortic valve replacement (TAVR) patients using noncoronary-dedicated planning computed tomography angiography (CTA): diagnostic accuracy in a retrospective real-world cohort

AIM

To assess the diagnostic potential of a noncoronary-dedicated pre-TAVR CT angiography (CTA) conducted as a prospective ECG-gated scan without premedication and standard cardiac reconstructions in evaluating bystander coronary artery disease (CAD) against invasive coronary angiography (ICA) as the gold standard.

MATERIALS AND METHODS

This retrospective study included 232 patients who underwent both CTA and ICA as part of their pre-TAVR evaluation. Exclusion criteria included prior stent, pacemaker, coronary artery bypass, or valve surgery. Coronary arteries were analysed solely through thin-slice axial reconstructions, with observers blinded to ICA results. Stenosis was categorised as mild (< 50%), moderate (50%-69%), or severe (≥70%). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for 50% and 70% diameter stenosis (DS) thresholds.

RESULTS

At the 50% DS threshold, CTA demonstrated 71% sensitivity, 74% specificity, 92% NPV, and 38% PPV. At the 70% DS threshold, results included 46% sensitivity, 91% specificity, 93% NPV, and 41% PPV. The highest vessel-specific NPV at 50% DS was for the left main (98%) and left anterior descending (LAD) (91%); at 70% DS, left main (LM) (98%) and left circumflex (LCX) (94%) showed the highest NPV. Image quality impacted NPV, with excellent or very good image quality linked to higher diagnostic performance.

CONCLUSION

Noncoronary-dedicated pre-TAVR CTA shows promise for ruling out significant CAD effectively and may act as a gatekeeper for ICA, aligning with typical coronary CT angiography (CCTA) outcomes.

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

AIMS

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.

METHODS AND RESULTS

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.

CONCLUSIONS

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.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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%.

CONCLUSIONS

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.

KEY POINTS

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.

Preprocedural assessment of coronary artery disease in patients undergoing transcatheter aortic valve implantation: Rationale and design of the EASE-IT CT registry

BACKGROUND

Invasive coronary angiography (ICA) is the standard for pre-procedural assessment of coronary artery disease (CAD) in patients undergoing transcatheter aortic valve implantation (TAVI). However, it requires hospitalization and can be associated with complications. Computed tomography angiography (CTA) may be a viable alternative to rule out prognostically relevant CAD.

METHODS

The EASE-IT CT Registry is an investigator-initiated, prospective, observational, multicentre pilot registry involving patients aged ≥75 years with severe aortic stenosis (AS) intended to implant a transcatheter heart valve (THV) of the SAPIEN family. A total of 150 patients will be recruited from four sites in Germany and Austria. The registry will consist of two prospective cohorts: the investigational CTA-only cohort and the CTA + ICA control cohort. The CTA-only cohort will enrol 100 patients in whom significant (≥50%) left main (LM) and/or proximal left anterior descending artery (LAD) stenosis are ruled out on CTA. The CTA + ICA control cohort will enrol 50 patients who have undergone both CTA and ICA before TAVI and in whom ≥50% LM/proximal LAD stenosis has been ruled out by CTA. Three composite endpoints will be assessed at 3 months post-TAVI: CAD-specific endpoints, VARC-3-defined device success and early safety.

CONCLUSION

The EASE-IT CT Registry evaluates whether TAVI can be carried out safely without performing ICA if prognostically relevant CAD of the LM/proximal LAD is ruled out with CTA. If so, the omission of ICA would help streamline the pre-procedural workup of TAVI patients.

Advanced CT measures of coronary artery disease with intermediate stenosis in patients with severe aortic valve stenosis

BACKGROUND

Coronary artery disease (CAD) and severe aortic valve stenosis (AS) frequently coexist. While pre-transcatheter aortic valve replacement (TAVR) computed tomography angiography (CTA) allows to rule out obstructive CAD, interpreting hemodynamic significance of intermediate stenoses is challenging. This study investigates the incremental value of CT-derived fractional flow reserve (CT-FFR), quantitative coronary plaque characteristics (e.g., stenosis degree, plaque volume, and composition), and peri-coronary adipose tissue (PCAT) density to detect hemodynamically significant lesions among those with AS and CAD.

MATERIALS AND METHODS

We included patients with severe AS and intermediate coronary lesions (20-80% diameter stenosis) who underwent pre-TAVR CTA and invasive coronary angiogram (ICA) with resting full-cycle ratio (RFR) assessment between 08/16 and 04/22. CTA image analysis included assessment of CT-FFR, quantitative coronary plaque analysis, and PCAT density. Coronary lesions with RFR ≤ 0.89 indicated hemodynamic significance as reference standard.

RESULTS

Overall, 87 patients (age 77.9 ± 7.4 years, 38% female) with 95 intermediate coronary artery lesions were included. CT-FFR showed good discriminatory capacity (area under receiver operator curve (AUC) = 0.89, 95% confidence interval (CI) 0.81-0.96, p < 0.001) to identify hemodynamically significant lesions, superior to anatomical assessment, plaque morphology, and PCAT density. Plaque composition and PCAT density did not differ between lesions with and without hemodynamic significance. Univariable and multivariable analyses revealed CT-FFR as the only predictor for functionally significant lesions (odds ratio 1.28 (95% CI 1.17-1.43), p < 0.001). Overall, CT-FFR ≤ 0.80 showed diagnostic accuracy, sensitivity, and specificity of 88.4% (95%CI 80.2-94.1), 78.5% (95%CI 63.2-89.7), and 96.2% (95%CI 87.0-99.5), respectively.

CONCLUSION

CT-FFR was superior to CT anatomical, plaque morphology, and PCAT assessment to detect functionally significant stenoses in patients with severe AS.

CLINICAL RELEVANCE STATEMENT

CT-derived fractional flow reserve in patients with severe aortic valve stenosis may be a useful tool for non-invasive hemodynamic assessment of intermediate coronary lesions, while CT anatomical, plaque morphology, and peri-coronary adipose tissue assessment have no incremental or additional benefit. These findings might help to reduce pre-transcatheter aortic valve replacement invasive coronary angiogram.

KEY POINTS

• Interpreting the hemodynamic significance of intermediate coronary stenoses is challenging in pre-transcatheter aortic valve replacement CT. • CT-derived fractional flow reserve (CT-FFR) has a good discriminatory capacity in the identification of hemodynamically significant coronary lesions. • CT-derived anatomical, plaque morphology, and peri-coronary adipose tissue assessment did not improve the diagnostic capability of CT-FFR in the hemodynamic assessment of intermediate coronary stenoses.

Utility of Coronary Computed Tomography Angiography in Patients Undergoing Transcatheter Aortic Valve Implantation: A Meta-Analysis and Meta-Regression Based on Published Data from 7458 Patients

BACKGROUND

Coronary CT angiography (CCTA) may detect coronary artery disease (CAD) in transcatheter aortic valve implantation (TAVI) patients and may obviate invasive coronary angiography (ICA) in selected patients. We assessed the diagnostic accuracy of CCTA for detecting CAD in TAVI patients based on published data.

METHODS

Meta-analysis and meta-regression were performed based on a comprehensive electronic search, including relevant studies assessing the diagnostic accuracy of CCTA in the setting of TAVI patients compared to ICA. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated on a patient and per segment level.

RESULTS

Overall, 27 studies (total of 7458 patients) were included. On the patient level, the CCTA's pooled sensitivity and NPV were 95% (95% CI: 93-97%) and 97% (95% CI: 95-98%), respectively, while the specificity and PPV were at 73% (95% CI: 62-82%) and 64% (95% CI: 57-71%), respectively. On the segmental coronary vessel level, the sensitivity and NPV were 90% (95% CI: 79-96%) and 98% (95% CI: 97-99%).

CONCLUSIONS

This meta-analysis highlights CCTA's potential as a first-line diagnostic tool although its limited PPV and specificity may pose challenges when interpreting heavily calcified arteries. This study underscores the need for further research and protocol standardization in this area.

Artificial intelligence in cardiac computed tomography

Artificial Intelligence (AI) is a broad discipline of computer science and engineering. Modern application of AI encompasses intelligent models and algorithms for automated data analysis and processing, data generation, and prediction with applications in visual perception, speech understanding, and language translation. AI in healthcare uses machine learning (ML) and other predictive analytical techniques to help sort through vast amounts of data and generate outputs that aid in diagnosis, clinical decision support, workflow automation, and prognostication. Coronary computed tomography angiography (CCTA) is an ideal union for these applications due to vast amounts of data generation and analysis during cardiac segmentation, coronary calcium scoring, plaque quantification, adipose tissue quantification, peri-operative planning, fractional flow reserve quantification, and cardiac event prediction. In the past 5 years, there has been an exponential increase in the number of studies exploring the use of AI for cardiac computed tomography (CT) image acquisition, de-noising, analysis, and prognosis. Beyond image processing, AI has also been applied to improve the imaging workflow in areas such as patient scheduling, urgent result notification, report generation, and report communication. In this review, we discuss algorithms applicable to AI and radiomic analysis; we then present a summary of current and emerging clinical applications of AI in cardiac CT. We conclude with AI's advantages and limitations in this new field.

Effectiveness of Pre-TAVR CTA as a Screening Tool for Significant CAD Before TAVR

BACKGROUND

Computed tomography angiography (CTA) and invasive coronary angiography (ICA) are routinely performed before transcatheter aortic valve replacement (TAVR) to assess aortic root anatomy and screen for coronary artery disease (CAD), respectively.

OBJECTIVES

This study explored the efficacy of CTA as a screening tool for significant proximal CAD before TAVR.

METHODS

With proper ethical oversight, patients undergoing TAVR at Cleveland Clinic with a preprocedural CTA and invasive coronary angiography (ICA), and no prior percutaneous intervention, were identified from 2015 to 2021. Blinded to ICA results, the authors reviewed the left main, proximal left anterior descending coronary artery, proximal left circumflex coronary artery, and proximal right coronary artery by CTA coronary reconstruction to assess for nonsignificant stenosis (0% to 49%), moderate stenosis (50% to 69%), and severe stenosis (≥70%). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Cohen Kappa statistic were analyzed.

RESULTS

2,217 patients (53.4% male, age 79.2 ± 8.5 years) met inclusion criteria. CTA evaluation revealed a sensitivity of 90%, specificity of 92%, PPV of 74%, and NPV of 97% for detecting ≥50% stenosis. Using a ≥70% stenosis cutoff, evaluation revealed a sensitivity of 91%, specificity of 97%, PPV of 83%, and NPV of 99%. Assessment of bypass graft patency revealed a sensitivity of 86%, specificity of 97%, PPV of 84%, and NPV of 98%. Cohen Kappa analysis indicated substantial to near perfect agreement between pre-TAVR CTA and ICA.

CONCLUSIONS

Pre-TAVR CTA has a high NPV for high-grade proximal stenosis of each coronary artery. As a result, CTA can be used as a screening tool to rule out significant proximal CAD in patients undergoing TAVR.

Management of coronary artery disease in patients with aortic stenosis in the era of transcatheter aortic valve replacement

Aortic stenosis (AS) is a common valve disorder among the elderly, and these patients frequently have concomitant coronary artery disease (CAD). Risk factors for calcific AS are similar to those for CAD. Historically, the treatment of these conditions involved simultaneous surgical replacement of the aortic valve (AV) with coronary artery bypass grafting. Since the advancement of transcatheter AV therapies, there have been tremendous advancements in the safety, efficacy, and feasibility of this procedure with expanding indications. This has led to a paradigm shift in our approach to the patient with AS and concomitant CAD. Data regarding the management of CAD in patients with AS are largely limited to single-center studies or retrospective analyses. This article aims to review available literature around the management of CAD in patients with AS and assist in the current understanding in approaches toward management.

Computed tomography-based pericoronary adipose tissue attenuation in patients undergoing TAVR: a novel method for risk assessment

Objectives

This study aims to assess the attenuation of pericoronary adipose tissue (PCAT) surrounding the proximal right coronary artery (RCA) in patients with aortic stenosis (AS) and undergoing transcatheter aortic valve replacement (TAVR). RCA PCAT attenuation is a novel computed tomography (CT)-based marker for evaluating coronary inflammation. Coronary artery disease (CAD) in TAVR patients is common and usually evaluated prior to intervention. The most sensible screening method and consequential treatment approach are unclear and remain a matter of ceaseless discussion. Thus, interest remains for safe and low-demand predictive markers to identify patients at risk for adverse outcomes postaortic valve replacement.

Methods

This single-center retrospective study included patients receiving a standard planning CT scan prior to TAVR. Conventional CAD diagnostic tools, such as coronary artery calcium score and significant stenosis via invasive coronary angiography and coronary computed tomography angiography, were determined in addition to RCA PCAT attenuation using semiautomated software. These were assessed for their relationship with major adverse cardiovascular events (MACE) during a 24-month follow-up period.

Results

From a total of 62 patients (mean age: 82 ± 6.7 years), 15 (24.2%) patients experienced an event within the observation period, 10 of which were attributed to cardiovascular death. The mean RCA PCAT attenuation was higher in patients enduring MACE than that in those without an endpoint (-69.8 ± 7.5 vs. -74.6 ± 6.2, P = 0.02). Using a predefined cutoff of >-70.5 HU, 20 patients (32.3%) with high RCA PCAT attenuation were identified, nine (45%) of which met the endpoint within 2 years after TAVR. In a multivariate Cox regression model including conventional CAD diagnostic tools, RCA PCAT attenuation prevailed as the only marker with significant association with MACE (P = 0.02). After dichotomization of patients into high- and low-RCA PCAT attenuation groups, high attenuation was related to greater risk of MACE (hazard ration: 3.82, P = 0.011).

Conclusion

RCA PCAT attenuation appears to have predictive value also in a setting of concomitant AS in patients receiving TAVR. RCA PCAT attenuation was more reliable than conventional CAD diagnostic tools in identifying patients at risk for MACE .

Comparison of First-generation and Third-generation Dual-source Computed Tomography for Detecting Coronary Artery Disease in Patients Evaluated for Transcatheter Aortic Valve Replacement

PURPOSE

This study compared image quality and evaluability of coronary artery disease (CAD) in routine preparatory imaging for transcatheter aortic valve replacement using 64-slice (first-generation) to 192-slice (third-generation) dual-source computed tomography(DSCT).

MATERIALS AND METHODS

The CT data sets of 192 patients (122 women, median age 82 y) without severe renal dysfunction or known CAD were analyzed retrospectively. Half were examined using first-generation DSCT (June 2014 to February 2016) and the other half with third-generation DSCT (April 2016 to April 2017). Per protocol, contrast material (110 [110 to 120] vs. 70 [70 to 70] mL, P <0.001) and radiation dose of multiphasic retrospectively gated thoracic CT angiography (dose-length-product, 1001 [707 to 1312] vs. 727 [474 to 1369] mGy×cm, P <0.001) were significantly lower with third-generation DSCT. Significant CAD was defined as CAD-RADS ≥4 by CT. Invasive coronary angiography served as the reference standard (CAD is defined as ≥70% stenosis or fractional flow reserve ≤0.80).

RESULTS

In comparison with first-generation DSCT, third-generation DSCT showed significantly better subjective (3 [interquartile range 2 to 3] vs. 4 [3 to 4.25] on a 5-point scale, P <0.001) and objective image quality (signal-to-noise ratio of left coronary artery 12.8 [9.9 to 16.4] vs. 15.2 [12.4 to 19.0], P <0.001). Accuracy (72.9% vs. 91.7%, P =0.001), specificity (59.7% vs. 88.3%, P <0.001), positive (61.0% vs. 83.3%, P <0.001), and negative predictive value (91.9% vs. 98.2%, P =0.045) for detecting CAD per-patient were significantly better using third-generation DSCT, while sensitivity was similar (92.3% vs. 97.2%, P =0.129).

CONCLUSIONS

Coronary artery evaluation with CT angiography before TAVI is feasible in selected patients. Compared with first-generation DSCT, state-of-the-art third-generation DSCT technology is superior for this purpose, allowing for less contrast medium and radiation dose while providing better image quality and improved diagnostic performance.

Combined CT Coronary Artery Assessment and TAVI Planning

Computed tomography angiography (CTA) of the aorta and the iliofemoral arteries is crucial for preprocedural planning of transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis (AS), because it provides details on a variety of aspects required for heart team decision-making. In addition to providing relevant diagnostic information on the degree of aortic valve calcification, CTA allows for a customized choice of the transcatheter heart valve system and the TAVI access route. Furthermore, current guidelines recommend the exclusion of relevant coronary artery disease (CAD) prior to TAVI. The feasibility of coronary artery assessment with CTA in patients scheduled for TAVI has been established previously, and accumulating data support its value. In addition, fractional flow reserve determined from CTA (CT-FFR) and machine learning-based CT-FFR were recently shown to improve its diagnostic yield for this purpose. However, the utilization of CTA for coronary artery evaluation remains limited in this specific population of patients due to the relatively high risk of CAD coexistence with severe AS. Therefore, the current diagnostic work-up prior to TAVI routinely includes invasive catheter coronary angiography at most centers. In this article, the authors address technological prerequisites and CT protocol considerations, discuss pitfalls, review the current literature regarding combined CTA coronary artery assessment and preprocedural TAVI evaluation, and provide an overview of unanswered questions and future research goals within the field.

Feasibility of Non-Invasive Coronary Artery Disease Screening with Coronary CT Angiography before Transcatheter Aortic Valve Implantation

Coronary artery disease (CAD) screening is usually performed before transcatheter aortic valve implantation (TAVI) by invasive coronary angiography (ICA). Computed coronary tomography angiography (CCTA) has shown good diagnostic performance for CAD screening in patients with a low probability of CAD and is systematically performed before TAVI. CCTA could be an efficient alternative to ICA for CAD screening before TAVI. We sought to investigate the diagnostic performance of CCTA in a population of unselected patients without known CAD who were candidates for TAVI. All consecutive patients referred to our center for TAVI without known CAD were enrolled. All patients underwent CCTA and ICA, which were considered the gold standard. A statistical analysis of the diagnostic performance per patient and per artery was performed. 307 consecutive patients were enrolled. CCTA was non-analyzable in 25 patients (8.9%). In the per-patient analysis, CCTA had a sensitivity of 89.6%, a specificity of 90.2%, a positive predictive value of 65.15%, and a negative predictive value of 97.7%. Only five patients were classified as false negatives on the CCTA. Despite some limitations of the study, CCTA seems reliable for CAD screening in patients without known CAD who are candidates for TAVI. By using CCTA, ICA could be avoided in patients with a CAD-RADS score ≤ 2, which represents 74.8% of patients.

Usefulness of Coronary Artery Calcium Score to Rule Out Obstructive Coronary Artery Disease Before Transcatheter Aortic Valve Implantation

Pretranscatheter aortic valve implantation (pre-TAVI) coronary evaluation using computed tomography coronary angiography (CTA) remains suboptimal. We aimed to evaluate whether coronary artery calcium score (CAC) may rule out obstructive coronary artery disease (CAD) pre-TAVI. TAVI candidates (n = 230; mean age 80 ± 8 years), 49% men, underwent preprocedural CTA and invasive coronary angiography. Obstructive CAD was defined as luminal diameter stenosis of ≥50% of left main or 3 major vessels ≥70%. Vessels with coronary stents or bypass were excluded. CAC score was calculated using the Agatston method. Receiver operating characteristic was applied to establish the CAC threshold for obstructive CAD. Multivariable analysis with adjustment for clinical covariates was applied. Net reclassification for nonobstructive disease using CAC score was calculated among nondiagnostic CT scans. Median CAC score was 1,176 (interquartile range 613 to 1,967). Receiver operating characteristic analysis showed high negative predictive value (NPV) for obstructive CAD as follows: left main CAC score 252, NPV 99%; left anterior descending CAC score 250, NPV 97%; left circumflex CAC score 297, NPV 92%; and right coronary artery CAC score 250, NPV 91%. Multivariate analysis showed the highest tertile of CAC score (≥1,670) to be an independent predictor of obstructive CAD (odds ratio 10.7, 95% confidence interval 4.6 to 25, p <0.001). Among nondiagnostic CTA, net reclassification showed reclassification of 76%, 13%, 45%, and 34% of left main, left anterior descending, left circumflex, and right coronary artery for nonobstructive CAD, respectively. In conclusion, CAC score cutoffs can be used to predict nonobstructive CAD. Implementing CAC score on pre-TAVI imaging can reduce a significant proportion of invasive coronary angiography.

Diagnostic Performance of CCTA and CT-FFR for the Detection of CAD in TAVR Work-Up

BACKGROUND

The work-up for transcatheter aortic valve replacement (TAVR) currently uses computed tomography to evaluate the annulus diameter and peripheral vascular access plus invasive coronary angiography (ICA) to assess significant coronary artery disease (CAD). ICA might partially be redundant with the use of coronary computed tomography angiography (CCTA). Prior studies found an improvement of the diagnostic accuracy of CCTA with the use of computed tomography-derived fractional flow reserve (CT-FFR).

OBJECTIVES

The aim of this study was to assess the diagnostic performance of CT-FFR for the diagnosis of CAD in the work-up for TAVR.

METHODS

Consecutive patients with severe symptomatic aortic valve stenosis who underwent TAVR work-up between 2015 and 2019 were included in this retrospective cross-sectional study. All patients underwent CCTA and ICA within 3 months, and the diagnostic performance of both CCTA and CT-FFR was assessed using ICA as the reference.

RESULTS

Seventy-six of the 338 patients included in the analysis had ≥1 significant coronary stenosis on ICA. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy per patient were 76.9%, 64.5%, 34.0%, 92.1%, and 66.9% for CCTA and 84.6%, 88.3%, 63.2%, 96.0%, and 87.6% for CT-FFR. The area under the receiver-operating characteristic curve was significantly different between CCTA and CT-FFR (0.84 vs 0.90, P = 0.02). A CT-FFR-guided approach could avoid ICA in 57.1% versus 43.6% of patients using CCTA.

CONCLUSIONS

CT-FFR significantly improves the diagnostic accuracy of CCTA without additional testing and increases the proportion of patients in whom ICA could have been safely avoided. It has the potential to be integrated in the current clinical work-up for TAVR for diagnosing stable CAD requiring treatment.

Percutaneous Coronary Intervention Pre-TAVR: Current State of the Evidence

PURPOSE OF REVIEW

This review intends to give an up-to-date overview of the current state of evidence in the treatment of coronary artery disease (CAD) in patients undergoing transcatheter aortic valve replacement (TAVR), focusing on percutaneous coronary interventions (PCI) pre-TAVR.

RECENT FINDINGS

The recently published ACTIVATION trial is the 1st randomized trial comparing coronary revascularization (PCI) versus medical treatment in patients with significant CAD undergoing TAVR. With the caveat of several major limitations of the trial, the results of this study raised the question about the appropriateness of the common practice to routinely revascularize coronary stenosis before TAVR. Aortic valve stenosis is the most common valvular heart disease among the elderly and it often co-occurs with CAD. TAVR is increasingly considered an alternative to surgical aortic valve replacement not only in the elderly population but also in younger and lower-risk patients. The impact of co-existing CAD on clinical outcomes as well as the optimal timing of PCI in TAVR candidates is still unclear and the subject of ongoing randomized trials. Meanwhile, it is common practice in many centers to routinely perform invasive coronary angiography and PCI for significant coronary disease as part of the TAVR workup. While computed tomography angiography has emerged as a possible alternative to the invasive coronary angiography in patients with low pre-test probability for CAD, the value of functional invasive assessment of coronary lesions in the pre-TAVR setting has still to be clarified. Also, there is an increasing interest in the clinical relevance and optimal management of the potentially challenging coronary access post-TAVR, requiring further research.

Appropriateness criteria for the use of cardiac computed tomography, SIC-SIRM part 2: acute chest pain evaluation; stent and coronary artery bypass graft patency evaluation; planning of coronary revascularization and transcatheter valve procedures; cardiomyopathies, electrophysiological applications, cardiac masses, cardio-oncology and pericardial diseases evaluation

In the past 20 years, cardiac computed tomography (CCT) has become a pivotal technique for the noninvasive diagnostic workup of coronary and cardiac diseases. Continuous technical and methodological improvements, combined with fast growing scientific evidence, have progressively expanded the clinical role of CCT. Randomized clinical trials documented the value of CCT in increasing the cost-effectiveness of the management of patients with acute chest pain presenting in the emergency department, also during the pandemic. Beyond the evaluation of stents and surgical graft patency, the anatomical and functional coronary imaging have the potential to guide treatment decision-making and planning for complex left main and three-vessel coronary disease. Furthermore, there has been an increasing demand to use CCT for preinterventional planning in minimally invasive procedures, such as transcatheter valve implantation and mitral valve repair. Yet, the use of CCT as a roadmap for tailored electrophysiological procedures has gained increasing importance to assure maximum success. In the meantime, innovations and advanced postprocessing tools have generated new potential applications of CCT from the simple coronary anatomy to the complete assessment of structural, functional and pathophysiological biomarkers of cardiac disease. In this complex and revolutionary scenario, it is urgently needed to provide an updated guide for the appropriate use of CCT in different clinical settings. This manuscript, endorsed by the Italian Society of Cardiology (SIC) and the Italian Society of Medical and Interventional Radiology (SIRM), represents the second of two consensus documents collecting the expert opinion of cardiologists and radiologists about current appropriate use of CCT.

Diagnostic performance of quantitative coronary artery disease assessment using computed tomography in patients with aortic stenosis undergoing transcatheter aortic-valve implantation

BACKGROUND

Computed tomography angiography (CTA) is a cornerstone in the pre- transcatheter aortic valve replacement (TAVI) assessment. We evaluated the diagnostic performance of CTA and coronary artery calcium score (CACS) for CAD evaluation compared to invasive coronary angiography in a cohort of TAVI patients.

METHODS

In consecutive TAVI patients without prior coronary revascularization and device implants, CAD was assessment by quantitative analysis in CTA. (a) Patients with non-evaluable segments were classified as obstructive CAD. (b) In patients with non-evaluable segments a CACS cut-off of 100 was applied for obstructive CAD. The reference standard was quantitative invasive coronary angiography (QCA, i.e. ≥ 50% stenosis).

RESULTS

100 consecutive patients were retrospectively included, age was 82.3 ± 6.5 years and 30% of patients had CAD. In 16% of the patients, adequate visualization of the entire coronary tree (all 16 segments) was possible with CTA, while 84% had at least one segment which was not evaluable for CAD analysis due to impaired image quality. On a per-patient analysis, where patients with low image quality were classified as CAD, CTA showed a sensitivity of 100% (95% CI 88.4-100.0), specificity of 11.4% (95% CI 5.1-21.3), PPV of 32.6% (95% CI 30.8-34.5), NPV of 100% and diagnostic accuracy of 38% (95% CI 28.5-48.3) for obstructive CAD. When applying a combined approach of CTA (in patients with good image quality) and CACS (in patients with low image quality), the sensitivity and NPV remained at 100% and obstructive CAD could be ruled out in 20% of the TAVI patients, versus 8% using CTA alone.

CONCLUSION

In routinely acquired pre-TAVI CTA, the image quality was insufficient in a high proportion of patients for the assessment of the entire coronary artery tree. However, when adding CACS in patients with low image quality to quantitative CTA assessment in patients with good image quality, obstructive CAD could be ruled-out in 1/5 of the patients and may therefore constitute a strategy to streamline pre-procedural workup, and reduce risk, radiation and costs in selected TAVI patients without prior coronary revascularization or device implants.

Feasibility and Comparison of Resting Full-Cycle Ratio and Computed Tomography Fractional Flow Reserve in Patients with Severe Aortic Valve Stenosis

Background: Computed tomography derived Fractional Flow Reserve (CT-FFR) has been shown to decrease the referral rate for invasive coronary angiography (ICA). The purpose of the study was to evaluate the diagnostic performance of CT-FFR compared to hyperemia-free index Resting Full-cycle Ratio (RFR) in patients with relevant aortic stenosis (AS) and intermediate coronary stenosis. Methods: 41 patients with 46 coronary lesions underwent ICA with quantitative coronary angiography (QCA), pressure wire assessment and routine pre-transcatheter aortic valve replacement (TAVR) computed tomography (CT). CT-FFR analysis was performed using prototype on-site software. Results: RFR showed a significant correlation with CT-FFR (Pearson’s correlation, r = 0.632, p < 0.001). On a per-lesion basis, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 82.6% (95% CI 68.6−92.2), 69.6% (95% CI 47.1−86.8), 95.7% (95% CI  78.1−99.9), 94.1% (95% CI 69.8−99.1), and 75.9% (95% CI 62.7−85.4), respectively. The optimal cutoff value of the CT-FFR for RFR ≤ 0.89 prediction was 0.815. The area under the receiver curve showed a larger area under the curve for CT-FFR (0.87; 95% CI 0.75−0.98) compared with CTA stenosis of ≥50% (0.54, 95% CI 0.38−0.71), CTA ≥ 70% (0.72, 95% CI 0.57−0.87) and QCA ≥ 50% (0.67, 95% CI 0.52−0.83). Conclusions: CT-FFR assessed by routine pre-TAVR CT is safe and feasible and shows a significant correlation with RFR in patients with AS. CT-FFR is superior to QCA ≥ 50%, CT ≥ 50% and CT ≥ 70% in assessing the hemodynamic relevance of intermediate coronary lesions. Thus, CT-FFR has the potential to guide revascularization in patients with AS.

Computed tomography predictors of structural valve degeneration in patients undergoing transcatheter aortic valve implantation with balloon-expandable prostheses

OBJECTIVES

Computed tomography (CT) provides excellent anatomy assessment of the aortic annulus (AoA) and is utilized for pre-procedural planning of transcatheter aortic valve implantation (TAVI). We sought to investigate if geometrical characteristics of the AoA determined by CT may represent predictors of structural valve degeneration (SVD) in patients undergoing TAVI with balloon-expandable valves.

METHODS

This is a retrospective study on 124 consecutive patients (mean age: 79 ± 7 years; female: 61%) undergoing balloon-expandable TAVI prospectively enrolled in a registry. AoA maximum diameter (D_max), minimum diameter (D_min), and area were assessed using pre-procedural CT. SVD was identified during follow-up with transthoracic echocardiography documenting structural prosthetic valve abnormalities with or without hemodynamic changes.

RESULTS

The mean follow-up was 5.9 ± 1.7 years. SVD was found in 48 out of 124 patients (38%). AoA D_max, D_min, and area were significantly smaller in patients with SVD compared to patients without SVD (25.6 ± 2.2 mm vs. 27.1 ± 2.8 mm, p = 0.012; 20.5 ± 2.1 mm vs. 21.8 ± 2.1 mm, p = 0.001 and 419 ± 77 mm² vs. 467 ± 88 mm², p = 0.002, respectively). At univariable analysis, female sex, BSA, 23-mm prosthetic valve size, D_max < 27.1 mm, and a D_min < 19.9 mm were associated with SVD, whereas at multivariable analysis, only D_min < 19.9 mm (OR = 2.873, 95% CI: 1.191-6.929, p = 0.019) and female sex (OR = 2.659, 95% CI: 1.095-6.458, p = 0.031) were independent predictors of SVD.

CONCLUSIONS

Female sex and AoA D_min < 19.9 mm are associated with SVD in patients undergoing TAVI with balloon-expandable valves. When implanting large prostheses in order to avoid paraprosthetic regurgitation, caution should be observed due to the risk of excessive stretching of the AoA D_min, which may play a role in SVD.

KEY POINTS

• Long-term durability is a concern for transcatheter aortic valve bioprosthesis. • CT provides an excellent assessment of the aortic annulus's geometrical characteristics for prosthesis sizing before transcatheter aortic valve implantation (TAVI). • Female sex and a small minimum aortic annulus diameter measured with CT are independent predictors of structural valve degeneration in patients undergoing TAVI with balloon-expandable valves.

Clinical applications of cardiac computed tomography: a consensus paper of the European Association of Cardiovascular Imaging-part II

Cardiac computed tomography (CT) was initially developed as a non-invasive diagnostic tool to detect and quantify coronary stenosis. Thanks to the rapid technological development, cardiac CT has become a comprehensive imaging modality which offers anatomical and functional information to guide patient management. This is the second of two complementary documents endorsed by the European Association of Cardiovascular Imaging aiming to give updated indications on the appropriate use of cardiac CT in different clinical scenarios. In this article, emerging CT technologies and biomarkers, such as CT-derived fractional flow reserve, perfusion imaging, and pericoronary adipose tissue attenuation, are described. In addition, the role of cardiac CT in the evaluation of atherosclerotic plaque, cardiomyopathies, structural heart disease, and congenital heart disease is revised.

Challenges in Diagnosis and Functional Assessment of Coronary Artery Disease in Patients With Severe Aortic Stenosis

More than half of patients with severe aortic stenosis (AS) over 70 years old have coronary artery disease (CAD). Exertional angina is often present in AS-patients, even in the absence of significant CAD, as a result of oxygen supply/demand mismatch and exercise-induced myocardial ischemia. Moreover, persistent myocardial ischemia leads to extensive myocardial fibrosis and subsequent coronary microvascular dysfunction (CMD) which is defined as reduced coronary vasodilatory capacity below ischemic threshold. Therefore, angina, as well as noninvasive stress tests, have a low specificity and positive predictive value (PPV) for the assessment of epicardial coronary stenosis severity in AS-patients. Moreover, in symptomatic patients with severe AS exercise testing is even contraindicated. Given the limitations of noninvasive stress tests, coronary angiography remains the standard examination for determining the presence and severity of CAD in AS-patients, although angiography alone has poor accuracy in the evaluation of its functional severity. To overcome this limitation, the well-established invasive indices for the assessment of coronary stenosis severity, such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), are now in focus, especially in the contemporary era with the rapid increment of transcatheter aortic valve replacement (TAVR) for the treatment of AS-patients. TAVR induces an immediate decrease in hyperemic microcirculatory resistance and a concomitant increase in hyperemic flow velocity, whereas resting coronary hemodynamics remain unaltered. These findings suggest that FFR may underestimate coronary stenosis severity in AS-patients, whereas iFR as the non-hyperemic index is independent of the AS severity. However, because resting coronary hemodynamics do not improve immediately after TAVR, the coronary vasodilatory capacity in AS-patients treated by TAVR remain impaired, and thus the iFR may overestimate coronary stenosis severity in these patients. The optimal method for evaluating myocardial ischemia in patients with AS and co-existing CAD has not yet been fully established, and this important issue is under further investigation. This review is focused on challenges, limitations, and future perspectives in the functional assessment of coronary stenosis severity in these patients, bearing in mind the complexity of coronary physiology in the presence of this valvular heart disease.

Combined Coronary CT-Angiography and TAVI Planning: Utility of CT-FFR in Patients with Morphologically Ruled-Out Obstructive Coronary Artery Disease

Background: Coronary artery disease (CAD) is a frequent comorbidity in patients undergoing transcatheter aortic valve implantation (TAVI). If significant CAD can be excluded on coronary CT-angiography (cCTA), invasive coronary angiography (ICA) may be avoided. However, a high plaque burden may make the exclusion of CAD challenging, particularly for less experienced readers. The objective was to analyze the ability of machine learning (ML)-based CT-derived fractional flow reserve (CT-FFR) to correctly categorize cCTA studies without obstructive CAD acquired during pre-TAVI evaluation and to correlate recategorization to image quality and coronary artery calcium score (CAC). Methods: In total, 116 patients without significant stenosis (≥50% diameter) on cCTA as part of pre-TAVI CT were included. Patients were examined with an electrocardiogram-gated CT scan of the heart and high-pitch scan of the torso. Patients were re-evaluated with ML-based CT-FFR (threshold = 0.80). The standard of reference was ICA. Image quality was assessed quantitatively and qualitatively. Results: ML-based CT-FFR was successfully performed in 94.0% (109/116) of patients, including 436 vessels. With CT-FFR, 76/109 patients and 126/436 vessels were falsely categorized as having significant CAD. With CT-FFR 2/2 patients but no vessels initially falsely classified by cCTA were correctly recategorized as having significant CAD. Reclassification occurred predominantly in distal segments. Virtually no correlation was found between image quality or CAC. Conclusions: Unselectively applied, CT-FFR may vastly increase the number of false positive ratings of CAD compared to morphological scoring. Recategorization was virtually independently from image quality or CAC and occurred predominantly in distal segments. It is unclear whether or not the reduced CT-FFR represent true pressure ratios and potentially signifies pathophysiology in patients with severe aortic stenosis.

Diagnostic accuracy of coronary computed tomography angiography for the evaluation of obstructive coronary artery disease in patients referred for transcatheter aortic valve implantation: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic accuracy of coronary computed tomography angiography (CCTA) for the evaluation of obstructive coronary artery disease (CAD) in patients referred for transcatheter aortic valve implantation (TAVI).

METHODS

EMBASE, PubMed/MEDLINE, and CENTRAL were searched for studies reporting accuracy of CCTA for the evaluation of obstructive CAD compared with invasive coronary angiography (ICA) as the reference standard. QUADAS-2 tool was used to assess the risk of bias. A bivariate random effects model was used to analyze, pool, and plot the diagnostic performance measurements across studies. Pooled sensitivity, specificity, positive ( + LR) and negative (-LR) likelihood ratio, diagnostic odds ratio (DOR), and hierarchical summary ROC curve (HSROC) were evaluated. Prospero registration number: CRD42021252527.

RESULTS

Fourteen studies (2533 patients) were included. In the intention-to-diagnose patient-level analysis, sensitivity and specificity for CCTA were 97% (95% CI: 94-98%) and 68% (95% CI: 56-68%), respectively, and + LR and -LR were 3.0 (95% CI: 2.1-4.3) and 0.05 (95% CI: 0.03 - 0.09), with DOR equal to 60 (95% CI: 30-121). The area under the HSROC curve was 0.96 (95% CI: 0.94-0.98). No significant difference in sensitivity was found between single-heartbeat and other CT scanners (96% (95% CI: 90 - 99%) vs. 97% (95% CI: 94-98%) respectively; p = 0.37), whereas the specificity of single-heartbeat scanners was higher (82% (95% CI: 66-92%) vs. 60% (95% CI: 46 - 72%) respectively; p < 0.0001). Routine CCTA in the pre-TAVI workup could save 41% (95% CI: 34 - 47%) of ICAs if a disease prevalence of 40% is assumed.

CONCLUSIONS

CCTA proved an excellent diagnostic accuracy for assessing obstructive CAD in patients referred for TAVI; the use of single-heartbeat CT scanners can further improve these findings.

KEY POINTS

• CCTA proved to have an excellent diagnostic accuracy for assessing obstructive CAD in patients referred for TAVI. • Routine CCTA in the pre-TAVI workup could save more than 40% of ICAs. • Single-heartbeat CT scanners had higher specificity than others in the assessment of obstructive CAD in patients referred for TAVI.

Combined Coronary CT Angiography and Evaluation of Access Vessels for TAVR Patients in Free-Breathing with Single Contrast Medium Injection Using a 16-cm-Wide Detector CT

RATIONALE AND OBJECTIVES

To investigate the feasibility of combining coronary computed tomography (CT) angiography (CCTA) and CTA to evaluate access vessels for transcatheter aortic valve replacement (TAVR) patients in free-breathing and with single contrast medium injection using a 16-cm-wide detector CT.

MATERIALS AND METHODS

One hundred and twenty-one consecutive patients (73.33 ± 6.43 years) referred for TAVR underwent a serious CT scans in free-breathing after one contrast injection: ECG-triggered one-heartbeat axial CCTA, followed by non-ECG-gated neck, thoracic, and abdominal CTA. Patient weight-dependent contrast dose volume at 1.0 mL/kg was used. CT attenuation values of the coronary, neck, aortic, iliac, and femoral arteries were measured and their image quality was evaluated with a 4-point score method. Stenosis (≥50%) in CCTA was evaluated using invasive coronary angiography result as a reference standard. Radiation and contrast doses were assessed.

RESULTS

The total dose-length-product for the entire examination was 411.4 ± 91.2 mGy.cm, and the total contrast dose was 57.3 ± 9.9 mL. There were adequate attenuations (>400 HU) in all arteries, and the peripheral access vessels and aortic annulus were evaluable in all patients. In neck CTA, 5 patients had vascular tortuosity, 6 patients had aberrant arteries and there were 212 plaques and 13 severe stenoses among the patients. In CCTA, on the per-segment, per-vessel, and per-patient analysis, CCTA showed a sensitivity and negative predictive value of (95% and 99%), (95% and 99%), and (96% and 98%), respectively, for the entire patient cohort, and (92% and 98%), (92% and 98%), and (88% and 93%), respectively, for patients with atrial fibrillation or heart rate higher than 75 beats.

CONCLUSION

It is feasible to perform a combined CCTA and CTA for evaluating access vessels for TAVR patients in free-breathing with single contrast injection. This approach generates acceptable image quality for all vessels and a high negative predictive value in excluding coronary artery disease with relatively low radiation and contrast doses.

Combined Coronary CT-Angiography and TAVR Planning for Ruling Out Significant Coronary Artery Disease: Added Value of Machine-Learning-Based CT-FFR

OBJECTIVES

To analyze the ability of machine-learning (ML)-based computed tomography (CT)-derived fractional flow reserve (CT-FFR) to further improve the diagnostic performance of coronary CT angiography (cCTA) for ruling out significant coronary artery disease (CAD) during pre-transcatheter aortic valve replacement (TAVR) evaluation in patients with a high pre-test probability for CAD.

BACKGROUND

CAD is a frequent comorbidity in patients undergoing TAVR. Current guidelines recommend its assessment before TAVR. If significant CAD can be excluded on cCTA, invasive coronary angiography (ICA) may be avoided. Although cCTA is a very sensitive test, it is limited by relatively low specificity and positive predictive value, particularly in high-risk patients.

METHODS

Overall, 460 patients (79.6 ± 7.4 years) undergoing pre-TAVR CT were included and examined with an electrocardiogram-gated CT scan of the heart and high-pitch scan of the vascular access route. Images were evaluated for significant CAD. Patients routinely underwent ICA (388/460), which was omitted at the discretion of the local Heart Team if CAD could be effectively ruled out on cCTA (72/460). CT examinations in which CAD could not be ruled out (CAD⁺) (n = 272) underwent additional ML-based CT-FFR.

RESULTS

ML-based CT-FFR was successfully performed in 79.4% (216/272) of all CAD⁺ patients and correctly reclassified 17 patients as CAD negative. CT-FFR was not feasible in 20.6% because of reduced image quality (37/56) or anatomic variants (19/56). Sensitivity, specificity, positive predictive value, and negative predictive value were 94.9%, 52.0%, 52.2%, and 94.9%, respectively. The additional evaluation with ML-based CT-FFR increased accuracy by Δ+3.4% (CAD⁺: Δ+6.0%) and raised the total number of examinations negative for CAD to 43.9% (202/460).

CONCLUSIONS

ML-based CT-FFR may further improve the diagnostic performance of cCTA by correctly reclassifying a considerable proportion of patients with morphological signs of obstructive CAD on cCTA during pre-TAVR evaluation. Thereby, CT-FFR has the potential to further reduce the need for ICA in this challenging elderly group of patients before TAVR.

Diagnostic Work-Up of the Aortic Patient: An Integrated Approach toward the Best Therapeutic Option

Aortic stenosis (AS) is the most common valvular heart disease. In the last decade, transcatheter aortic valve implantation (TAVI) has become the standard of care for symptomatic patients at high surgical risk. Recently, indications to TAVI have also been extended to the low surgical risk and intermediate surgical risk populations. Consequently, in this setting, some aspects acquire greater relevance: surgical risk evaluation, clinical assessment, multimodality imaging of the valve, and management of coronary artery disease. Moreover, future issues such as coronary artery re-access and valve-in-valve interventions should be considered in the valve selection process. This review aims to summarize the principal aspects of a multidimensional (multidisciplinary) and comprehensive preprocedural work-up. The Heart Team is at the center of the decision-making process of the management of aortic valve disease and bears responsibility for offering each patient a tailored approach based on an individual evaluation of technical aspects together with the risks and benefits of each modality. Considering the progressive expansion in TAVI indication and technological progress, the role of a work-up and multidisciplinary Heart Team will be even more relevant.

Image quality and diagnostic performance evaluation in transcatheter aortic valve implantation candidates with atrial fibrillation using a whole-heart coverage CT scanner

OBJECTIVE

To evaluate the image quality and diagnostic performance for obstructive coronary artery disease of transcatheter aortic valve implantation (TAVI) patients with atrial fibrillation (AF) during TAVI planning CT using a whole-heart coverage CT scanner.

METHODS

Eighty-eight consecutive TAVI candidates with AF (50 men, 74 ± 6 years) who underwent both TAVI planning CT and invasive coronary catheter angiography (ICA) were retrospectively analyzed. With ICA results as the reference standard, the accuracy of TAVI planning CT for lesion detection on a per-vessel and per-patient level was calculated. Meanwhile, image quality, contrast volume, and effective dose (ED) were evaluated. A 5-point visual scale (1-5) was used to assess the subjective image quality. The CT value and signal-to-noise ratio were measured for the left main coronary artery (LM), left anterior descending (LAD), left circumflex (LCX), and right coronary arteries (RCA).

RESULTS

The ED for CCTA was 3.25 ± 1.39 mSv and contrast volume was 58.14 ± 12.34 mL. A total of 1371 (1371/1408 = 97.4%) segments with diameter > 1.5 mm were analyzed. For the subjective evaluation, the mean score was 3.99 ± 0.96 for overall image quality. The mean CT values in LM, RCA, LCX, and LAD were all above 400 HU. For the detection of > 50% stenosis, TAVI planning CT provided on the per-vessel and per-patient basis 97.06% and 100% in sensitivity, 96.23% and 89.06% in specificity, 99.7% and 100% in negative predictive value, and 73.3% and 77.4% in positive predictive value, respectively.

CONCLUSION

TAVI planning CT with whole-heart coverage demonstrates good CCTA image quality and a high sensitivity and NPV in excluding obstructive CAD in TAVI candidates with AF.

KEY POINTS

• Transcatheter aortic valve implantation planning (TAVI) CT with whole-heart coverage enables good image quality of CCTA in TAVI candidates with atrial fibrillation. • Obstructive coronary artery disease may be excluded with high accuracy in transcatheter aortic valve implantation (TAVI) candidates with atrial fibrillation with the usage of whole-heart coverage TAVI planning CT.

Pre-procedural high-pitch coronary CT angiography assessment of patients undergoing transcatheter aortic valve implantation (TAVI) without patient-specific adjustment: analysis of diagnostic performance

AIM

To evaluate the ability to assess the coronary arteries using pre-procedural computed tomography (CT; high-pitch mode) in patients referred for transcatheter aortic valve implantation (TAVI).

METHODS AND MATERIALS

CT and invasive coronary angiography (ICA) were performed pre-TAVI in 100 patients (46 women; 79 ± 5.9 years). CT was performed in prospectively ECG-triggered high-pitch mode after intravenous administration of 70 ml iodinated contrast medium. Image quality was assessed using a four-point scale (graded 0-3). Significant coronary artery stenosis (≥50% diameter) was graded as either present or absent by one observer and in one-third of patients by two observers independently. ICA was the standard of reference. Results were reported per segment and per patient.

RESULTS

Twenty-two percent of patients had known coronary artery disease (CAD). In two cases, a coronary anomaly was detected. Diagnostic image quality (grade 1-3) was achieved in 30.3% of segments. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 75%, 80.5%, 16%, and 98.5%, respectively. Significant coronary stenosis could be ruled out completely in all segments in three patients. The interrater agreement per patient was excellent (kappa = 1).

CONCLUSION

Relevant coronary findings can frequently be observed in high-pitch TAVI-planning CT. Despite the limitations of the technique and in patients referred to pre-TAVI evaluation (rapid heart rate, coronary calcifications, etc.), a valid evaluation of coronary arteries is possible in a considerable proportion of segments with a high NPV; however, few studies were completely free of motion artefacts to dependably exclude CAD using this technique in this challenging group of patients.

DEtection of ProxImal Coronary stenosis in the work-up for Transcatheter aortic valve implantation using CTA (from the DEPICT CTA collaboration)

Objectives

Computed tomography angiography (CTA) is performed routinely in the work-up for transcatheter aortic valve implantation (TAVI), and could potentially replace invasive coronary angiography (ICA) to rule out left main (LM) and proximal coronary stenosis. The objectives were to assess the diagnostic yield and accuracy of pre-TAVI CTA to detect LM and proximal coronary stenosis of ≥ 50% and ≥ 70% diameter stenosis (DS).

Methods

The DEPICT CTA database consists of individual patient data from four studies with a retrospective design that analyzed the diagnostic accuracy of pre-TAVI CTA to detect coronary stenosis, as compared with ICA. Pooled data were used to assess diagnostic accuracy to detect coronary stenosis in the left main and the three proximal coronary segments on a per-patient and a per-segment level. We included 1060 patients (mean age: 81.5 years, 42.7% male).

Results

On ICA, the prevalence of proximal stenosis was 29.0% (≥ 50% DS) and 15.7% (≥ 70% DS). Pre-TAVI CTA ruled out ≥ 50% DS in 51.6% of patients with a sensitivity of 96.4%, specificity of 71.2%, PPV of 57.7%, and NPV of 98.0%. For ≥ 70% DS, pre-TAVI CTA ruled out stenosis in 70.0% of patients with a sensitivity of 96.7%, specificity of 87.5%, PPV of 66.9%, and NPV of 99.0%.

Conclusion

CTA provides high diagnostic accuracy to rule out LM and proximal coronary stenosis in patients undergoing work-up for TAVI. Clinical application of CTA as a gatekeeper for ICA would reduce the need for ICA in 52% or 70% of patients, using a threshold of ≥ 50% or ≥ 70% DS, respectively.

Key Points

• Clinical application of CTA as a gatekeeper for ICA would reduce the need for ICA in 52% or 70% of TAVI patients, using a threshold of ≥ 50% or ≥ 70% diameter stenosis.

• The diagnostic accuracy of CTA to exclude proximal coronary stenosis in these patients is high, with a sensitivity of 96.4% and NPV of 98.0% for a threshold of ≥ 50%, and a sensitivity of 96.7% and NPV of 99.0% for a threshold of ≥ 70% diameter stenosis.

• Atrial fibrillation and heart rate did not significantly affect sensitivity and NPV. However, a heart rate of < 70 b/min during CTA was associated with a significantly improved specificity and PPV.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08095-2.

Aortic Valve Disease and Associated Complex CAD: The Interventional Approach

Coronary artery disease (CAD) is highly prevalent in patients with severe aortic stenosis (AS). The management of CAD is a central aspect of the work-up of patients undergoing transcatheter aortic valve implantation (TAVI), but few data are available on this field and the best percutaneous coronary intervention (PCI) practice is yet to be determined. A major challenge is the ability to elucidate the severity of bystander coronary stenosis independently of the severity of aortic valve stenosis and subsequent impact on blood flow. The prognostic role of CAD in patients undergoing TAVI is being still debated and the benefits and the best timing of PCI in this context are currently under evaluation. Additionally, PCI in the setting of advanced AS poses some technical challenges, due to the complex anatomy, risk of hemodynamic instability, and the increased risk of bleeding complications. This review aims to provide a comprehensive synthesis of the available literature on myocardial revascularization in patients with severe AS undergoing TAVI. This work can assist the Heart Team in individualizing decisions about myocardial revascularization, taking into account available diagnostic tools as well as the risks and benefits.

Computed Tomography Angiography for the Diagnosis of Coronary Artery Disease Among Patients Undergoing Transcatheter Aortic Valve Implantation

Background

Computed tomography angiography (CTA) is used to plan TAVI procedures. We investigated the performance of pre-TAVI CTA for excluding coronary artery disease (CAD).

Methods

In total 127 patients were included. CTA images were analyzed for the presence of ≥ 50% (significant CAD) and ≥ 70% (severe CAD) diameter stenoses in proximal coronary arteries. Results were compared with invasive coronary angiography (ICA) at vessel and patient levels. Primary endpoint was the negative predictive value (NPV) of CTA for the presence of CAD.

Results

A total of 342 vessels were analyzable. NPV of CTA was 97.5% for significant CAD and 96.3% for severe CAD. Positive predictive value and accuracy were 44.8% and 87.1% for significant CAD and 56.3% and 94.4% for severe CAD. At patient level, NPV for significant CAD was 88.6%.

Conclusion

Pre-TAVI CTA shows good performance for ruling out CAD and could be used as a gatekeeper for ICA in selected patients.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12265-021-10099-8.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Coronary Artery Disease in Patients with Aortic Stenosis and Transcatheter Aortic Valve Implantation: Implications for Management

Aortic valve stenosis (AS) is the most common valvular heart disease among elderly patients. Since the pathophysiology of degenerative AS shares common pathways with atherosclerotic disease, the severity of AS in the elderly population is often concurrent to the presence of coronary artery disease (CAD). Although surgical aortic valve replacement has been the standard treatment for severe AS, the high operative morbidity and mortality in complex and fragile patients was the trigger to develop less invasive techniques. Transcatheter aortic valve implantation (TAVI) has been posed as the standard of care for elderly patients with severe AS with various risk profiles, which has meant that the concomitant management of CAD has become a crucial issue in such patients. Given the lack of randomised controlled trials evaluating the management of CAD in TAVI patients, most of the recommendations are based on retrospective cohort studies so that the Heart Team approach - together with an assessment of multiple parameters including symptoms and clinical characteristics, invasive and non-invasive ischaemic burden and anatomy - are crucial for the proper management of these patients. This article provides a review of current knowledge about assessment and therapeutic approaches for CAD and severe AS in patients undergoing TAVI.

Cardiac imaging procedures and the COVID-19 pandemic: recommendations of the European Society of Cardiovascular Radiology (ESCR)

The severe acute respiratory syndrome coronavirus 2019 (SARS-CoV-2) pandemic currently constitutes a significant burden on worldwide health care systems, with important implications on many levels, including radiology departments. Given the established fundamental role of cardiovascular imaging in modern healthcare, and the specific value of cardiopulmonary radiology in COVID-19 patients, departmental organisation and imaging programs need to be restructured during the pandemic in order to provide access to modern cardiovascular services to both infected and non-infected patients while ensuring safety for healthcare professionals. The uninterrupted availability of cardiovascular radiology services remains, particularly during the current pandemic outbreak, crucial for the initial evaluation and further follow-up of patients with suspected or known cardiovascular diseases in order to avoid unnecessary complications. Suspected or established COVID-19 patients may also have concomitant cardiovascular symptoms and require further imaging investigations. This statement by the European Society of Cardiovascular Radiology (ESCR) provides information on measures for safety of healthcare professionals and recommendations for cardiovascular imaging during the pandemic in both non-infected and COVID-19 patients.

Statement from the North American Society for Cardiovascular Imaging on imaging strategies to reduce the scarcity of healthcare resources during the COVID-19 outbreak

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an evolving global pandemic that is predicted to strain healthcare resources at multiple locations throughout North America and the World. As of April 6, 2020, the apex of infection rates is predicted to occur within 1 to 5 weeks at various locations. Widespread reports of personal protective equipment (PPE) shortages, and healthcare worker exposure to disease have become commonplace. To mitigate this crisis, we are suggesting imaging strategies that aim to use the least PPE, require the smallest number of potential staff exposures, and streamlines utilization of imaging. They are broadly organized by (1) substituting a noninvasive diagnostic test in place of a semi-invasive or invasive diagnostic tests, and (2) consolidating diagnostic imaging.

Assessment and management of coronary artery disease in patients undergoing transcatheter aortic valve replacement

PURPOSE OF REVIEW

Coronary artery disease (CAD) is commonly observed in patients undergoing transcatheter aortic valve replacement (TAVR). Significant variability exists across institutions for strategies used for CAD diagnosis and its management. The heart team often relies upon traditional practice patterns and the decision for revascularization by percutaneous coronary intervention (PCI) is influenced by patient, angiographic, operator, and system-related factors.

RECENT FINDINGS

Contemporary coronary tomography angiography (CTA) shows significant promise for detection of clinically important CAD and preliminary data support CTA use for TAVR patients. The prognostic implications of CAD in a TAVR population remain unclear with studies showing conflicting data for the benefits of PCI. Recent trials show that medical management is an effective initial treatment strategy for stable CAD, a finding likely also applicable for asymptomatic and stable TAVR patients. In addition, PCI performed pre-TAVR, concomitant with TAVR or after TAVR has been shown to produce similar outcomes. Dual antiplatelet therapy (DAPT) is mandated after PCI but associated with increased risk of bleeding in TAVR population with accumulating evidence for single antiplatelet therapy (SAPT) post-TAVR unless DAPT or anticoagulation is indicated for another reason.

SUMMARY

Although coronary angiography remains the predominant modality for CAD assessment, CTA is increasingly being used in TAVR patients. There is limited evidence to guide CAD management in TAVR patients with significant variability in practice patterns. Medical therapy is recommended for asymptomatic and stable CAD patients with applicability for TAVR population. Despite prior concerns, recent studies suggest successful coronary access post-TAVR and similar outcomes for PCI offered pre-TAVR, concomitant with TAVR and post-TAVR settings. Safety of DAPT should be an important consideration for PCI in TAVR patients. Ongoing studies will determine the preferred testing for CAD diagnosis, benefit of revascularization, timing of PCI, and optimum antithrombotic therapy for TAVR populations.

Combined Coronary CT-Angiography and TAVI-Planning: A Contrast-Neutral Routine Approach for Ruling-out Significant Coronary Artery Disease

BACKGROUND

Significant coronary artery disease (CAD) is a common finding in patients undergoing transcatheter aortic valve implantation (TAVI). Assessment of CAD prior to TAVI is recommended by current guidelines and is mainly performed via invasive coronary angiography (ICA). In this study we analyzed the ability of coronary CT-angiography (cCTA) to rule out significant CAD (stenosis ≥ 50%) during routine pre-TAVI evaluation in patients with high pre-test probability for CAD.

METHODS

In total, 460 consecutive patients undergoing pre-TAVI CT (mean age 79.6 ± 7.4 years) were included. All patients were examined with a retrospectively ECG-gated CT-scan of the heart, followed by a high-pitch-scan of the vascular access route utilizing a single intravenous bolus of 70 ml iodinated contrast medium. Images were evaluated for image quality, calcifications, and significant CAD; CT-examinations in which CAD could not be ruled out were defined as positive (CAD+). Routinely, patients received ICA (388/460; 84.3%; Group A), which was omitted if renal function was impaired and CAD was ruled out on cCTA (Group B). Following TAVI, clinical events were documented during the hospital stay.

RESULTS

cCTA was negative for CAD in 40.2% (188/460). Sensitivity, specificity, PPV, and NPV in Group A were 97.8%, 45.2%, 49.6%, and 97.4%, respectively. Median coronary artery calcium score (CAC) was higher in CAD+-patients but did not have predictive value for correct classification of patients with cCTA. There were no significant differences in clinical events between Group A and B.

CONCLUSION

cCTA can be incorporated into pre-TAVI CT-evaluation with no need for additional contrast medium. cCTA may exclude significant CAD in a relatively high percentage of these high-risk patients. Thereby, cCTA may have the potential to reduce the need for ICA and total amount of contrast medium applied, possibly making pre-procedural evaluation for TAVI safer and faster.

Coronary Artery Disease and Transcatheter Aortic Valve Replacement: JACC State-of-the-Art Review

About one-half of transcatheter aortic valve replacement (TAVR) candidates have coronary artery disease (CAD), and controversial results have been reported regarding the effect of the presence and severity of CAD on clinical outcomes post-TAVR. In addition to coronary angiography, promising data has been recently reported on both the use of computed tomography angiography and the functional invasive assessment of coronary lesions in the work-up pre-TAVR. While waiting for the results of ongoing randomized trials, percutaneous revascularization of significant coronary lesions has been the routine strategy in TAVR candidates with CAD. Also, scarce data exists on the incidence, characteristics, and management of coronary events post-TAVR, and increasing interest exist on potential coronary access challenges in patients requiring coronary angiography/intervention post-TAVR. This review provides an updated overview of the current landscape of CAD in TAVR recipients, focusing on its prevalence, clinical impact, pre- and post-procedural evaluation and management, unresolved issues and future perspectives.

Coronary Artery Disease Assessed by Computed Tomography-Based Leaman Score in Patients With Low-Risk Transcatheter Aortic Valve Implantation

We aimed to evaluate the burden of coronary artery disease (CAD) using the computed tomography (CT) Leaman score in low-risk transcatheter aortic valve implantation (TAVI) patients. The extent of CAD in low-risk patients with aortic stenosis who are candidates for TAVI has not been accurately quantified. The CT Leaman score was developed to quantify coronary CT angiography (CCTA) atherosclerotic burden and has been validated to evaluate the extent of CAD. CT Leaman score >5 has been associated with an increase in major adverse cardiac events over long-term follow-up. The study population included patients enrolled in the Low Risk TAVI trial who underwent CCTA before the procedure. For the CT Leaman score, we used 3 sets of weighting factors: (1) location of coronary plaques, (2) type of plaque, and (3) degree of stenosis. A total of 200 patients were enrolled in the Low Risk TAVI trial. Excluded were 31 patients who had no analyzable CCTA imaging. For the remaining 169 patients, the mean CT Leaman score was 6.27 ± 0.27, of whom 102 (60.4%) had CT Leaman score >5. Nearly all analyzed patients (97%) had coronary plaques. Furthermore, 33 patients (19.5%) had potentially obstructive coronary plaques (>50% stenosis by CCTA) in proximal segments. Most low-risk TAVI patients have significant CAD burden by CCTA. It should be a priority for future TAVI devices to guarantee unimpeded access to the coronary arteries for selective angiography and interventions.

Diagnostic accuracy of computed tomography angiography for the exclusion of coronary artery disease in candidates for transcatheter aortic valve implantation

Coronary CT angiography (CTA) is currently considered a reliable method to exclude obstructive coronary artery disease (CAD) before valvular heart surgery in patients with low pretest probability. However, its role in excluding obstructive CAD before transcatheter aortic valve implantation (TAVI) is less well established. Single-center retrospective study where patients with severe symptomatic aortic stenosis underwent both CTA and invasive coronary angiography (ICA) as part of TAVI planning. CTA exams were conducted on a 64-slice dual source scanner, with a median interval of 45 days to ICA (IQR 25–75 [13–82]). In both tests, obstructive CAD was defined as a ≥50% stenosis in an epicardial vessel ≥2 mm diameter. Per-patient, per-vessel and per-proximal segment analyses were conducted, excluding and including non-evaluable segments. The study included 200 patients (120 women, mean age 83 ± 6 years). The prevalence of obstructive CAD on ICA was 35.5% (n = 71). On a per-patient analysis (assuming non-evaluable segments as stenotic), CTA showed sensitivity of 100% (95% CI, 95–100%), specificity of 42% (95% CI, 33–51%), and positive and negative predictive values of 48% (95% CI, 44–51%) and 100% (95% CI, 92–100%), respectively. CTA was able to exclude obstructive CAD in 54 patients (27%), in whom ICA could have been safely withheld. Despite the high rate of inconclusive tests, pre-procedural CTA is able to safely exclude obstructive CAD in a significant proportion of patients undergoing TAVI, possibly avoiding the need for ICA in roughly one quarter of the cases.