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

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.

Coronary Artery Revascularization in Patients Undergoing Transcatheter Aortic Valve Replacement

Patients with concomitant severe aortic stenosis and significant coronary artery disease present a diagnostic and therapeutic challenge in clinical practice. There are no clear-cut guidelines as to the timing of revascularization in these patients who are referred for transcatheter aortic valve replacement (TAVR). This article aims to show that in patients without high-grade proximal coronary artery disease, revascularization after TAVR is safe, feasible, and practical. Additionally, the use of preoperative TAVR computed tomographic angiography might be used in both intermediate and high-risk patients rather than invasive coronary angiography to assess for significant proximal coronary artery disease to help guide the timing of revascularization.

Computed tomography imaging in preprocedural planning of transcatheter valvular heart interventions

Cardiac Computed Tomography (CCT) has become a reliable imaging modality in cardiology providing robust information on the morphology and structure of the heart with high temporal and isotropic spatial resolution. For the past decade, there has been a paradigm shift in the management of valvular heart disease since previously unfavorable candidates for surgery are now provided with less-invasive interventions. Transcatheter heart valve interventions provide a real alternative to medical and surgical management and are often the only treatment option for valvular heart disease patients. Successful transcatheter valve interventions rely on comprehensive multimodality imaging assessment. CCT is the mainstay imaging technique for preprocedural planning of these interventions. CCT is critical in guiding patient selection, choice of procedural access, device selection, procedural guidance, as well as allowing postprocedural follow-up of complications. This article aims to review the current evidence of the role of CCT in the preprocedural planning of patients undergoing transcatheter valvular interventions.

Deep Learning Image Reconstruction for Transcatheter Aortic Valve Implantation Planning: Image Quality, Diagnostic Performance, Contrast volume and Radiation Dose Assessment

RATIONALE AND OBJECTIVES

To assess image quality, contrast volume and radiation dose reduction potential and diagnostic performance with the use of high-strength deep learning image reconstruction (DLIR-H) in transcatheter aortic valve implantation (TAVI) planning CT.

METHODS

We prospectively enrolled 128 patients referred to TAVI-planning CT. Patients were randomly divided into two groups: DLIR-H group (n = 64) and conventional group (n = 64). The DLIR-H group was scanned with tube voltage of 80kVp and body weighted-dependent contrast injection rate of 28mgI/kg/s, images reconstructed using DLIR-H; the conventional group was scanned with 100kVp and contrast injection rate of 40mgI/kg/s, and images reconstructed using adaptive statistical iterative reconstruction-V at 50% (ASIR-V 50%). Radiation dose, contrast volume, contrast injection rate, and image quality were compared between the two groups. The diagnostic performance of TAVI planning CT for coronary stenosis in 115 patients were calculated using invasive coronary angiography as golden standard.

RESULTS

DLIR-H group significantly reduced radiation dose (4.94 ± 0.39mSv vs. 7.93 ± 1.20mSv, p < 0.001), contrast dose (45.28 ± 5.38 mL vs. 63.26 ± 9.88 mL, p < 0.001), and contrast injection rate (3.1 ± 0.31 mL/s vs. 4.9 ± 0.2 mL/s, p < 0.001) compared to the conventional group. Images in DLIR-H group had significantly higher SNR and CNR (all p < 0.001). For the diagnostic performance on a per-patient basis, TAVI planning CT in the DLIR-H group provided 100% sensitivity, 92.1% specificity, 100% negative predictive value (NPV), and 84.2% positive predictive value for the detection of > 50% stenosis. In the conventional group, the corresponding results were 94.7%, 95.3%, 97.6%, and 90.0%, respectively.

CONCLUSION

DLIR-H in TAVI-planning CT provides improved image quality with reduced radiation and contrast doses, and enables satisfactory diagnostic performance for coronary arteries stenosis.

Cardiac Computed Tomography Angiography in the Evaluation of Coronary Artery Disease: An Interventional Perspective

Cardiac computed tomography angiography (CCTA) has become the gold standard for noninvasive anatomic assessment of the coronary arteries. With high positive predictive value and even higher negative predictive value, CCTA allows for rapid determination of the presence or absence of coronary plaque and triage of patients' need for further invasive evaluation and treatment. From an interventional cardiologist's perspective, CCTA (more so than stress testing) is helpful in determining the need for invasive therapy. In conjunction with functional assessments, the anatomic evaluation from CCTA mirrors the anatomical assessment of a coronary angiogram more than any other noninvasive assessment. This allows for catheter selection, percutaneous coronary intervention preplanning, as well as additional decision making before the patient has entered the catheterization laboratory. This manuscript explores some of the more recent developments in noninvasive coronary angiography and discusses the use and utility of CCTA from an interventional cardiologist's perspective.

Feasibility and Utility of Anatomical and Physiological Evaluation of Coronary Disease With Cardiac CT in Severe Aortic Stenosis (FUTURE-AS Registry): Rationale and Design

Background

Coronary artery disease (CAD) in patients with severe aortic stenosis (AS) is common and may be associated with worse outcomes. Computed tomography coronary angiography (CTCA) and fractional flow reserve derived from computed tomography (FFRCT) are tools for comprehensive coronary assessment. The utility and safety of CTCA and FFRCT in the work-up for transcatheter aortic valve replacement (TAVR) is not established, especially in an evolving landscape that involves younger TAVR patients. The FUTURE-AS Registry will assess the utility and safety of cardiac-optimized CTCA and FFRCT to evaluate CAD and guide referral for downstream invasive coronary angiography (ICA) in patients with severe AS being considered for TAVR.

Methods

FUTURE-AS is an international, prospective, multicenter registry of patients with severe AS referred for TAVR being assessed for CAD with CTCA and FFRCT. The primary end point is the per-patient sensitivity and negative predictive value of CTCA and FFRCT for identifying anatomical and physiologically significant CAD compared to ICA and invasive FFR. The safety end point is the incidence of symptomatic hypotension or bradycardia requiring intervention following the administration of nitroglycerin or β-blocker medications. Feasibility end points include the incidence of noninterpretable CTCA scans and CTCA scans not adequate for FFR analysis. Other utility end points include specificity, positive predictive value, and accuracy of CTCA and FFRCT. Lastly, the potential of a CTCA and FFRCT guided strategy to defer pre-TAVR ICA will be assessed.

Conclusions

FUTURE-AS will characterize the utility, safety, and feasibility of CTCA and FFRCT for coronary assessment pre-TAVR.

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.