A practical guide to multimodality imaging of transcatheter aortic valve replacement

Myocardial Blood Flow Reserve, Microvascular Coronary Health, and Myocardial Remodeling in Patients With Aortic Stenosis

BACKGROUND

Coronary microvascular function and hemodynamics may play a role in coronary circulation and myocardial remodeling in patients with aortic stenosis (AS). We aimed to evaluate the relationship between myocardial blood flow and myocardial function in patients with AS, no AS, and aortic valve sclerosis.

METHODS AND RESULTS

We included consecutive patients who had resting transthoracic echocardiography and clinically indicated positron emission tomography myocardial perfusion imaging to capture their left ventricular ejection fraction, global longitudinal strain (GLS), and myocardial flow reserve (MFR). The primary outcome was major adverse cardiovascular event (all-cause mortality, myocardial infarction, or late revascularization). There were 2778 patients (208 with aortic sclerosis, 39 with prosthetic aortic valve, 2406 with no AS, and 54, 49, and 22 with mild, moderate, and severe AS, respectively). Increasing AS severity was associated with impaired MFR (P<0.001) and GLS (P<0.001), even when perfusion was normal. Statistically significant associations were noted between MFR and GLS, MFR and left ventricular ejection fraction, and MFR and left ventricular ejection fraction reserve. After a median follow-up of 349 (interquartile range, 116-662) days, 4 (7.4%), 5 (10.2%), and 6 (27.3%) patients experienced a major adverse cardiovascular event in the mild, moderate, and severe AS groups, respectively. In a matched-control analysis, patients with mild-to-moderate AS had higher rates of impaired MFR (52.9% versus 39.9%; P=0.048) and major adverse cardiovascular event (11.8% versus 3.0%; P=0.002).

CONCLUSIONS

Despite lack of ischemia, as severity of AS increased, MFR decreased and GLS worsened, reflecting worse coronary microvascular health and myocardial remodeling. Positron emission tomography-derived MFR showed a significant independent correlation with left ventricular ejection fraction and GLS. Patients with prosthetic aortic valve showed a high prevalence of impaired MFR.

Transcatheter aortic valve replacement: Past, present, and future

Transcatheter aortic valve replacement (TAVR) has emerged as a ground-breaking, minimally invasive alternative to traditional open-heart surgery, primarily designed for elderly patients initially considered unsuitable for surgical intervention due to severe aortic stenosis. As a result of successful large-scale trials, TAVR is now being routinely applied to a broader spectrum of patients. In deciding between TAVR and surgical aortic valve replacement, clinicians evaluate various factors, including patient suitability and anatomy through preprocedural imaging, which guides prosthetic valve sizing and access site selection. Patient surgical risk is a pivotal consideration, with a multidisciplinary team making the ultimate decision in the patient's best interest. Periprocedural imaging aids real-time visualization but is influenced by anaesthesia choices. A comprehensive postprocedural assessment is critical due to potential TAVR-related complications. Numerous trials have demonstrated that TAVR matches or surpasses surgery for patients with diverse surgical risk profiles, ranging from extreme to low risk. However, long-term follow-up data, particularly in low-risk cases, remains limited, and the applicability of published results to younger patients is uncertain. This review delves into key TAVR studies, pinpointing areas for potential improvement while delving into the future of this innovative procedure. Furthermore, it explores the expanding role of TAVR technology in addressing other heart valve replacement procedures.

Current Usefulness of Transesophageal Echocardiography in Patients Undergoing Transcatheter Aortic Valve Replacement

This review article describes in depth the current usefulness of transesophageal echocardiography in patients who undergo transcatheter aortic valve replacement. Pre-intervention, 3D-transesophageal echocardiography allows us to accurately evaluate the aortic valve morphology and to measure the valve annulus, helping us to choose the appropriate size of the prosthesis, especially useful in cases where the computed tomography is not of adequate quality. Although it is not currently used routinely during the intervention, it remains essential in those cases of greater complexity, such as for patients with greater calcification and bicuspid valve, mechanical mitral prosthesis, and "valve in valve" procedures. Three-dimensional transesophageal echocardiography is the best technique to detect and quantify paravalvular regurgitation, a fundamental aspect to decide whether immediate valve postdilation is needed. It also allows to detect early any immediate complications such as cardiac tamponade, aortic hematoma or dissection, migration of the prosthesis, malfunction of the prosthetic leaflets, or the appearance of segmental contractility disorders due to compromise of the coronary arteries ostium. Transesophageal echocardiography is also very useful in follow-up, to check the proper functioning of the prosthesis and to rule out complications such as thrombosis of the leaflets, endocarditis, or prosthetic degeneration.

ACR Appropriateness Criteria® Preprocedural Planning for Transcatheter Aortic Valve Replacement: 2023 Update

This document discusses preprocedural planning for transcatheter aortic valve replacement, evaluating the imaging modalities used in initial imaging for preprocedure planning under two variants 1) Preintervention planning for transcatheter aortic valve replacement: assessment of aortic root; and 2) Preintervention planning for transcatheter aortic valve replacement: assessment of supravalvular aorta and vascular access. US echocardiography transesophageal, MRI heart function and morphology without and with IV contrast, MRI heart function and morphology without IV contrast and CT heart function and morphology with IV contrast are usually appropriate for assessment of aortic root. CTA chest with IV contrast, CTA abdomen and pelvis with IV contrast, CTA chest abdomen pelvis with IV contrast are usually appropriate for assessment of supravalvular aorta and vascular access. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Multi-modality imaging in aortic stenosis: an EACVI clinical consensus document

In this EACVI clinical scientific update, we will explore the current use of multi-modality imaging in the diagnosis, risk stratification, and follow-up of patients with aortic stenosis, with a particular focus on recent developments and future directions. Echocardiography is and will likely remain the key method of diagnosis and surveillance of aortic stenosis providing detailed assessments of valve haemodynamics and the cardiac remodelling response. Computed tomography (CT) is already widely used in the planning of transcutaneous aortic valve implantation. We anticipate its increased use as an anatomical adjudicator to clarify disease severity in patients with discordant echocardiographic measurements. CT calcium scoring is currently used for this purpose; however, contrast CT techniques are emerging that allow identification of both calcific and fibrotic valve thickening. Additionally, improved assessments of myocardial decompensation with echocardiography, cardiac magnetic resonance, and CT will become more commonplace in our routine assessment of aortic stenosis. Underpinning all of this will be widespread application of artificial intelligence. In combination, we believe this new era of multi-modality imaging in aortic stenosis will improve the diagnosis, follow-up, and timing of intervention in aortic stenosis as well as potentially accelerate the development of the novel pharmacological treatments required for this disease.

Automatic Assessment of Transcatheter Aortic Valve Implantation Results on Four-Dimensional Computed Tomography Images Using Artificial Intelligence

Transcatheter aortic valve implantation (TAVI) is a procedure to treat severe aortic stenosis. There are several clinical concerns related to potential complications after the procedure, which demand the analysis of computerized tomography (CT) scans after TAVI to assess the implant's result. This work introduces a novel, fully automatic method for the analysis of post-TAVI 4D-CT scans to characterize the prosthesis and its relationship with the patient's anatomy. The method enables measurement extraction, including prosthesis volume, center of mass, cross-sectional area (CSA) along the prosthesis axis, and CSA difference between the aortic root and prosthesis, all the variables studied throughout the cardiac cycle. The method has been implemented and evaluated with a cohort of 13 patients with five different prosthesis models, successfully extracting all the measurements from each patient in an automatic way. For Allegra patients, the mean of the obtained inner volume values ranged from 10,798.20 mm3 to 18,172.35 mm3, and CSA in the maximum diameter plane varied from 396.35 mm2 to 485.34 mm2. The implantation of this new method could provide information of the important clinical value that would contribute to the improvement of TAVI, significantly reducing the time and effort invested by clinicians in the image interpretation process.

Advances in TEE-Centric Intraprocedural Multimodal Image Guidance for Congenital and Structural Heart Disease

Percutaneous interventions are gaining rapid acceptance in cardiology and revolutionizing the treatment of structural heart disease (SHD). As new percutaneous procedures of SHD are being developed, their associated complexity and anatomical variability demand a high-resolution special understanding for intraprocedural image guidance. During the last decade, three-dimensional (3D) transesophageal echocardiography (TEE) has become one of the most accessed imaging methods for structural interventions. Although 3D-TEE can assess cardiac structures and functions in real-time, its limitations (e.g., limited field of view, image quality at a large depth, etc.) must be addressed for its universal adaptation, as well as to improve the quality of its imaging and interventions. This review aims to present the role of TEE in the intraprocedural guidance of percutaneous structural interventions. We also focus on the current and future developments required in a multimodal image integration process when using TEE to enhance the management of congenital and SHD treatments.

Impact of Preprocedure Imaging for Left Atrial Appendage Occlusion: Insights From the NCDR LAAO Registry

BACKGROUND

The impact of preprocedure imaging on the safety and effectiveness of left atrial appendage occlusion (LAAO) remains unclear.

OBJECTIVES

This study sought to determine the rates of use of preprocedure computed tomography (CT)/cardiac magnetic resonance (CMR) and its association with safety and effectiveness of LAAO procedures.

METHODS

The National Cardiovascular Data Registry LAAO Registry was used to evaluate patients who underwent attempted LAAO with the WATCHMAN and WATCHMAN FLX devices between January 1, 2016, and June 30, 2021. Safety and effectiveness of LAAO procedures was compared by use vs nonuse of preprocedural CT/CMR. Outcomes of interest included implantation success (deployment and release of device), device success (device released with peridevice leak <5 mm), and procedure success (device released with peridevice leak <5 mm and no in-hospital major adverse events [MAE]). Multivariable logistic regression was used to assess the relationship between preprocedure imaging and outcomes.

RESULTS

Preprocedure CT/CMR was used for 18.2% (n = 20,851) of the 114,384 procedures in this study. CT/CMR use was more common among government and university hospitals and hospitals in the Midwest and South; it was less common among patients with uncontrolled hypertension, with abnormal renal function, and without prior thromboembolism. Overall rates of implantation success, device success, and procedure success were 93.4%, 91.2%, and 89.4%, respectively. Preprocedure CT/CMR was independently associated with an increased likelihood of implantation success (OR: 1.08; 95% CI: 1.00-1.17), device success (OR: 1.10; 95% CI: 1.04-1.16), and procedural success (OR: 1.07; 95% CI: 1.02-1.13). MAE were uncommon (2.3%) and not associated with use of preprocedure CT/CMR (OR: 1.02; 95% CI: 0.92-1.12).

CONCLUSIONS

Preprocedure CT/CMR was associated with an increased likelihood of successful LAAO implantation; however, the magnitude of benefit appears small and it was not associated with MAE.

Mild aortic insufficiency following transcatheter aortic valve replacement: A systematic review and meta-analysis

BACKGROUND

Post-procedural aortic insufficiency (AI) continues to be prevalent following transcatheter aortic valve replacement (TAVR). While several studies have assessed the outcomes of moderate-severe AI following TAVR, the incidence, predictors, and outcomes of mild AI remain unclear.

METHODS

A systematic literature review was performed to identify studies reporting on mild AI following TAVR. The primary outcome was pooled incidence of post-TAVR mild AI. Secondary outcomes included pooled incidence of mild AI at 30 days and long term. The pooled incidence of midterm mortality in patients with post-TAVR mild AI was also evaluated. The random effect generalized linear mixed-effects model with logit-transformed proportions and Hartung-Knapp adjustment was used to calculate pooled incidence rates. Meta-regression was performed to identify predictors of mild AI.

RESULTS

The pooled analysis included 19,241 patients undergoing TAVR across 50 studies. The mean age of patients ranged from 73 to 85 years, and female patients ranged from 20.0% to 83.3%. The overall pooled incidence of post-TAVR mild AI was 56.1% (95% confidence interval [CI] 0.31-0.64). The pooled incidence of mild AI at 30 days was 33.7% (95% CI 0.12-0.37). At mean follow-up of 1.15 years, the pooled incidence of mild AI was 37.0% (95% CI 0.16-0.45). The overall pooled incidence of Midterm mortality (mean follow-up 1.22 years) in patients with mild AI was 14.8% (95% CI 0.10-0.25). At meta-regression, none of the explored variables correlated with a difference in mild AI incidence.

CONCLUSIONS

In published studies to date, 50% of patients undergoing TAVR develop mild AI postoperatively. In 37% of patients, this persists in long term. Though the incidence of AI is likely improving with newer generation TAVR valves, the prevalence and outcomes of mild AI should be closely monitored as TAVR volume and indications expand to younger patients with long life expectancy. The long-term outcomes of mild AI remain unclear. Further dedicated studies on post-TAVR mild AI are needed.

The Use of Contrast May Improve Aortic Valve Assessment During Transesophageal Echocardiography

OBJECTIVES

The Doppler profile that quantifies the degree of aortic stenosis is essential, as an inaccurate measurement can alter the surgical plan. The authors aimed to examine the level of agreement between the contrast and noncontrast methods of aortic valve sizing during intraoperative transesophageal echocardiography (TEE).

SETTING

At a tertiary hospital.

PARTICIPANTS

A total of 30 patients undergoing surgical aortic valve replacement for a stenotic valve.

INTERVENTIONS

Perflutren lipid microsphere contrast injection.

MEASUREMENTS AND MAIN RESULTS

The authors reviewed Doppler studies of 30 consecutive patients undergoing aortic valve replacement in whom a contrast agent was given (perflutren lipid microsphere). They measured the peak and/or mean aortic valve gradients and velocity time integral readings through the left ventricular outflow tract (LVOT), and the aortic valve before and after administering the contrast agent. The aortic valve area was then calculated using both methods. Paired t tests and Bland-Altman analyses were used to examine the bias and the level of agreement between the 2 processes. By not using a contrast agent, the aortic valve area was overestimated by 0.26 cm² compared to those measured by transthoracic echocardiography (TTE) (p < 0.001). Using a contrast agent, TEE measurements were comparable to those obtained by TTE. Moreover, the peak and mean aortic valve gradients were underestimated by 19 and 11 mmHg, respectively (p value <0.001). Adding contrast did not affect the pulse-wave Doppler readings of the V1 velocity of the LVOT.

CONCLUSION

This discrepancy is significant and could affect the decision to replace the aortic valve. When evaluating the aortic valve with TEE, the authors recommend using a contrast agent to improve the Doppler profile and to obtain a more accurate measurement of the aortic valve area.

Morphological changes of the tricuspid valve complex in functional tricuspid regurgitation on contrast-enhanced computed tomography

Background

Whether it is possible to perform morphological evaluation of functional tricuspid regurgitation (FTR) on contrast-enhanced computed tomography (CT) was examined by evaluating the relationships between the parameters measured on contrast-enhanced CT and TR severity on transthoracic echocardiography.

Methods

Fifty patients underwent contrast-enhanced CT. Tricuspid annulus area (TAA), tricuspid annulus circumference (TAC), right ventricular volume (RVV), and the distances between the tips and bases of the papillary muscles were measured on contrast-enhanced CT in diastole and systole. The 50 cases were divided into 34 in the TR ≤ mild group (no TR: 3 cases, trivial TR: 24 cases, mild TR: 7 cases), and 16 in the TR ≥ moderate group (moderate TR: 8 cases, severe TR: 8 cases) using the TR grade measured by transthoracic echocardiography, and then differences between the groups were examined.

Results

Significant differences were found in TAA, TAC, and RVV (p < 0.01) and the distances between the tips of the anterior and posterior papillary muscles (p < 0.05) in both diastole and systole. Since the septal papillary muscle could not be identified in 18 cases (36.0%), only the distance between the anterior and posterior papillary muscles was measurable in all cases. On receiver-operating characteristic (ROC) curve analysis, the areas under the ROC curves (AUCs) of TAA, TAC, and RVV were all > 0.7, and the maximum AUC was 0.925 for dRVV.

Conclusions

TAA, TAC, RVV, and the distance between the tips of the anterior and posterior papillary muscles measured on contrast-enhanced CT were shown to be significantly increased in the TR ≥ moderate group. Detailed morphological assessment of FTR is possible by contrast-enhanced CT.

Transcatheter Aortic Valve Replacement Optimization Strategies: Cusp Overlap, Commissural Alignment, Sizing, and Positioning

As transcatheter aortic valve replacement (TAVR) rapidly expands to younger patients and those at low surgical risk, there is a compelling need to identify patients at increased risk of post-procedural complications, such as paravalvular leak, prosthesis–patient mismatch, and conduction abnormalities. This review highlights the incidence and risk factors of these procedural complications, and focuses on novel methods to reduce them by using newer generation transcatheter heart valves and the innovative cusp-overlap technique, which provides optimal fluoroscopic imaging projection to allow for precise implantation depth which minimizes interaction with the conduction system. Preserving coronary access after TAVR is another important consideration in younger patients. This paper reviews the significance of commissural alignment to allow coronary cannulation after TAVR and discusses recently published data on modified delivery techniques to improve commissural alignment.

Automatic Identification of Bioprostheses on X-ray Angiographic Sequences of Transcatheter Aortic Valve Implantation Procedures Using Deep Learning

Transcatheter aortic valve implantation (TAVI) has become the treatment of choice for patients with severe aortic stenosis and high surgical risk. Angiography has been established as an essential tool in TAVI, as this modality provides real-time images required to support the intervention. The automatic interpretation and parameter extraction on such images can lead to significative improvements and new applications in the procedure that, in most cases, rely on a prior identification of the transcatheter heart valve (THV). In this paper, U-Net architecture is proposed for the automatic segmentation of THV on angiographies, studying the role of its hyperparameters in the quality of the segmentations. Several experiments have been conducted, testing the methodology using multiple configurations and evaluating the results on different types of frames captured during the procedure. The evaluation has been performed in terms of conventional classification metrics, complemented with two new metrics, specifically defined for this problem. Those new metrics provide a more appropriate assessment of the quality of the results, given the class imbalance in the dataset. From an analysis of the evaluation results, it can be concluded that the method provides appropriate segmentation results for this dataset.

Paravalvular Leak: A Systemic Review

BACKGROUND

Paravalvular Leak (PVL) refers to the retrograde flow of blood in the space between an implanted cardiac valve and native tissue. These are unfortunately but luckily relatively uncommon complications of prosthetic valve replacement that, especially when moderate or severe, have important clinical consequences.

OBJECTIVE

Addressing PVL requires a multidisciplinary team to properly diagnose this process and choose the corrective option most likely to result in success.

METHODS

A comprehensive literature search was undertaken to formulate this narrative review.

RESULTS

This review highlights the complex nature of PVL and the promising contemporary treatments available.

CONCLUSION

Clinicians should be adept at recognizing PVL and characterizing it using multimodality imaging. Using the many available tools and a multidisciplinary approach should lead to favorable outcomes in patients with PVL.

Aortic annulus sizing in bicuspid and tricuspid aortic valves using CT in patients with surgical aortic valve replacement

The purpose of this study was to evaluate whether bicuspid anatomy affects the discrepancy between CT-derived annular size and intraoperative size. We retrospectively analyzed annular measurements in 667 patients who underwent surgical aortic valve replacement (AVR). Preoperative CT measurements of the aortic annulus were compared to surgically implanted valve sizes. To evaluate whether the bicuspid valve affects the differences between CT annulus diameter and surgical AVR size, patients with diameter larger by > 10% (CT-Lg group) on CT, compared to surgical AVR size, were compared with those having size difference < 10% (CT-Sim group). Propensity score matching yielded 183 matched patients from each group. Bicuspid aortic valve annulus parameters significantly correlated with surgical aortic valve size (r = 0.52-0.71; for all, p < 0.01). The most representative measurements corresponded to surgical aortic valve size were area-derived diameters in tricuspid aortic valve (r = 0.69, p < 0.001) and bicuspid without raphe (r = 0.71, p < 0.001), and perimeter-derived diameter in bicuspid with raphe (r = 0.63, p < 0.001). After propensity score matching, native valve type was not different between CT-Sim and CT-Lg groups. In multivariable analysis, the difference between CT-derived diameter and surgical AVR size was affected by the operator factor and types of prosthesis. Bicuspid aortic annulus diameters measured on CT showed a significant correlation with surgical aortic valve size. The difference between CT-derived diameter and surgical AVR size is affected by operator factor and the types of prosthesis but not affected by the bicuspid valve.

How to Image and Manage Prosthesis-Related Complications After Transcatheter Aortic Valve Replacement

PURPOSE OF REVIEW

In this review, we provide an overview of potential prosthesis - related complications after transcatheter aortic valve replacement, their incidences, the imaging modalities best suited for detection, and possible strategies to manage these complications.

RECENT FINDINGS

Therapy for severe aortic valve stenosis requiring intervention has increasingly evolved toward transcatheter aortic valve replacement over the past decade, and the number of procedures performed has increased steadily in recent years. As more and more centers favor a minimalistic approach and largely dispense with general anesthesia and intra-procedural imaging by transesophageal echocardiography, post-procedural imaging is becoming increasingly important to promptly detect dysfunction of the transcatheter valve and potential complications. Complications after transcatheter aortic valve replacement must be detected immediately in order to initiate adequate therapeutic measures, which require a profound knowledge of possible complications that may occur after transcatheter aortic valve replacement, the imaging modalities best suited for detection, and available treatment options.

Aortic Annular Sizing Using Novel Software in Three-Dimensional Transesophageal Echocardiography for Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

(1) Background: We performed this study to evaluate the agreement between novel automated software of three-dimensional transesophageal echocardiography (3D-TEE) and multidetector computed tomography (MDCT) for aortic annular measurements of preprocedural transcatheter aortic valve replacement (TAVR); (2) Methods: PubMed, EMBASE, Web of Science, and Cochrane Library (Wiley) databases were systematically searched for studies that compared 3D-TEE and MDCT as the reference standard for aortic annular measurement of the following parameters: annular area, annular perimeter, area derived-diameter, perimeter derived-diameter, maximum and minimum diameter. Meta-analytic methods were utilized to determine the pooled correlations and mean differences between 3D-TEE and MDCT. Heterogeneity and publication bias were also assessed. Meta-regression analyses were performed based on the potential factors affecting the correlation of aortic annular area; (3) Results: A total of 889 patients from 10 studies were included in the meta-analysis. Pooled correlation coefficients between 3D-TEE and MDCT of annulus area, perimeter, area derived-diameter, perimeter derived-diameter, maximum and minimum diameter measurements were strong 0.89 (95% CI: 0.84-0.92), 0.88 (95% CI: 0.83-0.92), 0.87 (95% CI: 0.77-0.93), 0.87 (95% CI: 0.77-0.93), 0.79 (95% CI: 0.64-0.87), and 0.75 (95% CI: 0.61-0.84) (Overall p < 0.0001), respectively. Pooled mean differences between 3D-TEE and MDCT of annulus area, perimeter, area derived-diameter, perimeter derived-diameter, maximum and minimum diameter measurements were -20.01 mm2 ((95% CI: -35.37 to -0.64), p = 0.011), -2.31 mm ((95% CI: -3.31 to -1.31), p < 0.0001), -0.22 mm ((95% CI: -0.73 to 0.29), p = 0.40), -0.47 mm ((95% CI: -1.06 to 0.12), p = 0.12), -1.36 mm ((95% CI: -2.43 to -0.30), p = 0.012), and 0.31 mm ((95% CI: -0.15 to 0.77), p = 0.18), respectively. There were no statistically significant associations with the baseline patient characteristics of sex, age, left ventricular ejection fraction, mean transaortic gradient, and aortic valve area to the correlation between 3D-TEE and MDCT for aortic annular area sizing; (4) Conclusions: The present study implies that 3D-TEE using novel software tools, automatically analysis, is feasible to MDCT for annulus sizing in clinical practice.

Technical and clinical study of x-ray-based surface echo probe tracking using an attached fiducial apparatus

PURPOSE

Several types of structural heart intervention (SHI) use information from multiple imaging modalities to complete an interventional task. For example, in transcatheter aortic valve replacement (TAVR), placement and deployment of a bioprosthetic aortic valve in the aorta is primarily guided by x-ray fluoroscopy (XRF), and echocardiography provides visualization of cardiac anatomy and blood flow. However, simultaneous interpretation of independent x-ray and echo displays remains a challenge for the interventionalist. The purpose of this work was to develop a novel echo/x-ray co-registration solution in which volumetric transthoracic echo (TTE) is transformed to the x-ray coordinate system by tracking the three-dimensional (3D) pose of a probe fiducial attachment from its appearance in two-dimensional (2D) x-ray images.

METHODS

A fiducial attachment for a commercial TTE probe consisting of rings of high-contrast ball bearings was designed and fabricated. The 3D pose (position and orientation) of the fiducial attachment is estimated from a 2D x-ray image using an algorithm in which a virtual point cloud model of the attachment is iteratively rotated, translated, and forward-projected onto the image until the average sum-of-squares of grayscale values at the projected points is minimized. Fiducial registration error (FRE) and target registration error (TRE) of this approach were evaluated in phantom studies using TAVR-relevant gantry orientations and four standard acoustic windows for the TTE probe. A patient study was conducted to assess the clinical suitability of the fiducial attachment prototype during TTE imaging of patients undergoing SHI. TTE image quality for the task of guiding a transcatheter procedure was evaluated in a reviewer study.

RESULTS

The 3D FRE ranged from 0.32 ± 0.03 mm (mean ± SD) to 1.31 ± 0.05 mm, depending on C-arm orientation and probe acoustic window. The 3D TRE ranged from 1.06 ± 0.03 mm to 2.42 ± 0.06 mm. Fiducial pose estimation was stable when >75% of the fiducial markers were visible in the x-ray image. A panel of reviewers graded the presentation of heart valves in TTE images from 48 SHI patients. While valve presentation did not differ significantly between acoustic windows (P > 0.05), the mitral valve did achieve a significantly higher image quality compared to the aortic and tricuspid valves (P < 0.001). Overall, reviewers perceived sufficient image quality in 76.5% of images of the mitral valve, 54.9% of images of the aortic valve, and 48.6% of images of the tricuspid valve.

CONCLUSIONS

Fiducial-based tracking of a commercial TTE probe is compatible with clinical SHI workflows and yields 3D target registration error of less than 2.5 mm for a variety of x-ray gantry geometries and echo probe acoustic windows. Although TTE image quality with respect to target valve anatomy was sufficient for the majority of cases examined, prescreening of patients for sufficient TTE quality would be helpful.

Tube Voltage, DNA Double-Strand Breaks, and Image Quality in Coronary CT Angiography

OBJECTIVE

To evaluate the effects of tube voltage on image quality in coronary CT angiography (CCTA), the estimated radiation dose, and DNA double-strand breaks (DSBs) in peripheral blood lymphocytes to optimize the use of CCTA in the era of low radiation doses.

MATERIALS AND METHODS

This study included 240 patients who were divided into 2 groups according to the DNA DSB analysis methods, i.e., immunofluorescence microscopy and flow cytometry. Each group was subdivided into 4 subgroups: those receiving CCTA only with different tube voltages of 120, 100, 80, or 70 kVp. Objective and subjective image quality was evaluated by analysis of variance. Radiation dosages were also recorded and compared.

RESULTS

There was no significant difference in demographic characteristics between the 2 groups and 4 subgroups in each group (all p > 0.05). As tube voltage decreased, both image quality and radiation dose decreased gradually and significantly. After CCTA, γ-H2AX foci and mean fluorescence intensity in the 120-, 100-, 80-, and 70-kVp groups increased by 0.14, 0.09, 0.07, and 0.06 foci per cell and 21.26, 9.13, 8.10, and 7.13 (all p < 0.05), respectively. The increase in the DNA DSB level in the 120-kVp group was higher than those in the other 3 groups (all p < 0.05), while there was no significant difference in the DSBs levels among these latter groups (all p > 0.05).

CONCLUSION

The 100-kVp tube voltage may be optimal for CCTA when weighing DNA DSBs against the estimated radiation dose and image quality, with further reductions in tube voltage being unnecessary for CCTA.

Role of computed tomography in transcatheter aortic valve implantation and valve-in-valve implantation: complete review of preprocedural and postprocedural imaging

: Since 2002, transcatheter aortic valve implantation (TAVI) has revolutionized the treatment and prognosis of patients with aortic stenosis. A preprocedural assessment of the patient is vital for achieving optimal outcomes from the procedure. Retrospective ECG-gated cardiac computed tomography (CT) today it is the gold-standard imaging technique that provides three-dimensional images of the heart, thus allowing a rapid and complete evaluation of the morphology of the valve, ascending aorta, coronary arteries, peripheral access vessels, and prognostic factors, and also provides preprocedural coplanar fluoroscopic angle prediction to obtain complete assessment of the patient. The most relevant dimension in preprocedural planning of TAVI is the aortic annulus, which can determine the choice of prosthesis size. CT is also essential to identify patients with increased anatomical risk for coronary artery occlusion in Valve in Valve (ViV) procedures.Moreover, CT is very useful in the evaluation of late complications, such as leakage, thrombosis and displacements. At present, CT is the cornerstone imaging modality for the extensive and thorough work-up required for planning and performing each TAVI procedure, to achieve optimal outcomes. Both the CT procedure and analysis should be performed by trained and experienced personnel, with a radiological background and a deep understanding of the TAVI procedure, in close collaboration with the implantation team. An accurate pre-TAVI CT and post-processing for the evaluation of all the points recommended in this review allow a complete planning for the choice of the valve dimensions and type (balloon or self-expandable) and of the best percutaneous access.

Comparison of postoperative outcomes following multidetector computed tomography based vs transesophageal echocardiography based annulus sizing for transcatheter aortic valve replacement: A systematic review and meta-analysis

BACKGROUND

The purpose of this paper was to evaluate the difference in postoperative outcomes following multidetector computed tomography (MDCT) and transesophageal echocardiography (TEE)-based annulus sizing for transcatheter aortic valve replacement (TAVR).

METHODS

Electronic search of PubMed, Biomed Central, Scopus, and Google Scholar databases was conducted until August 15, 2019. We included all types of studies comparing MDCT-based annulus sizing with TEE-based annulus sizing and assessing paravalvular regurgitation (PVR). Data were summarized using the Mantel-Haenszel odds ratio (OR) with 95% confidence intervals (CI).

RESULTS

A total of six studies were included. Pooled analysis of 431 participants in the MDCT group and 509 participants in the TEE group demonstrated that MDCT-based annulus sizing is associated with a significantly lower incidence of more than moderate PVR as compared to 2DTEE-based sizing (OR: 0.31, 95% CI: 0.18-0.54, P < .0001; I2  = 0%). There was no statistical difference in annulus rupture (OR: 0.57, 95% CI: 0.12-2.66, P = .91; I2  = 0%), procedural mortality (OR: 0.97, 95% CI: 0.19-4.86, P = .97; I2  = 0%), and 30-day mortality (OR: 0.63, 95% CI: 0.26-1.50, P = .29; I2  = 0%) with MDCT or 2DTEE-based annulus sizing. Compared with 3DTEE, the incidence of PVR in the MDCT group was lower, but there was no statistical difference in 30-day mortality.

CONCLUSION

Use of MDCT in comparison with 2DTEE is associated with significantly lower incidence of more than moderate PVR after TAVR. There seems to be no difference in annulus rupture and 30-day mortality with either imaging modality.

Imaging of transcatheter aortic valve replacement complications

Aortic stenosis is increasing in incidence and is now commonly managed with transcatheter aortic valve replacement (TAVR) in intermediate and high-risk patients. Radiologists are likely to encounter patients undergoing this procedure both pre- and postoperatively, and therefore, an understanding of procedural complications is essential. Complications may relate to the access site or approach, or the valve itself. This article will review the most common complications described in literature and focuses on the role of multidetector computed tomography (CT) in their evaluation either exclusively, or complementary to other imaging methods.

The emerging applications of cardiovascular magnetic resonance imaging in transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement in selected patients with severe symptomatic aortic stenosis (AS) and high surgical risk. The planning and follow-up of TAVI requires an array of imaging techniques, each has advantages and limitations. Echocardiography and multidetector computer tomography (MDCT) have established applications in patient selection and procedure guidance, but are limited in some patients. TAVI applications of cardiovascular magnetic resonance imaging (CMRI) are emerging. CMRI can provide the structural and functional imaging details required for TAVI procedure in away comparable or superior to that obtained by echocardiography and MDCT combined. In this review, we look at the continuously evolving role of CMRI as a complimentary or an alternative to more established imaging techniques and address the advantages and disadvantages of CMRI in this setting. We discuss the role of CMRI in selecting anatomically suitable patients for the TAVI procedure and in the post-TAVI follow-up with particular emphasis on its applications for assessing AS severity and haemodynamic impact, vascular imaging for TAVI access route, quantification of paravalvular leaks and LV remodelling in the post TAVI setting as well as providing imaging biomarkers tool for AS risk-stratification.

Validation of a Novel Software Tool for Automatic Aortic Annular Sizing in Three-Dimensional Transesophageal Echocardiographic Images

BACKGROUND

Accurate aortic annulus (AoA) sizing is crucial for transcatheter aortic valve implantation planning. Three-dimensional (3D) transesophageal echocardiography (TEE) is a viable alternative to the standard multidetector row computed tomography (MDCT) for such assessment, with few automatic software solutions available. The aim of this study was to present and evaluate a novel software tool for automatic AoA sizing by 3D TEE.

METHODS

One hundred one patients who underwent both preoperative MDCT and 3D TEE were retrospectively analyzed using the software. The automatic software measurements' accuracy was compared against values obtained using standard manual MDCT, as well as against those obtained using manual 3D TEE, and intraobserver, interobserver, and test-retest reproducibility was assessed. Because the software can be used as a fully automatic or as an interactive tool, both options were addressed and contrasted. The impact of these measures on the recommended prosthesis size was then evaluated to assess if the software's automated sizes were concordant with those obtained using an MDCT- or a TEE-based manual sizing strategy.

RESULTS

The software showed very good agreement with manual values obtained using MDCT and 3D TEE, with the interactive approach having slightly narrower limits of agreement. The latter also had excellent intra- and interobserver variability. Both fully automatic and interactive analyses showed excellent test-retest reproducibility, with the first having a faster analysis time. Finally, either approach led to good sizing agreement against the true implanted sizes (>77%) and against MDCT-based sizes (>88%).

CONCLUSIONS

Given the automated, reproducible, and fast nature of its analyses, the novel software tool presented here may potentially facilitate and thus increase the use of 3D TEE for preoperative transcatheter aortic valve implantation sizing.

Accuracy and reproducibility of aortic annular measurements obtained from echocardiographic 3D manual and semi-automated software analyses in patients referred for transcatheter aortic valve implantation: implication for prosthesis size selection

Aims

A 3D transoesophageal echocardiography (3D-TOE) reconstruction tool has recently been introduced. The system automatically configures a geometric model of the aortic root and performs quantitative analysis of these structures. We compared the measurements of the aortic annulus (AA) obtained by semi-automated 3D-TOE quantitative software and manual analysis vs. multislice computed tomography (MSCT) ones.

Methods and results

One hundred and seventy-five patients (mean age 81.3 ± 6.3 years, 77 men) who underwent both MSCT and 3D-TOE for annulus assessment before transcatheter aortic valve implantation were analysed. Hypothetical prosthetic valve sizing was evaluated using the 3D manual, semi-automated measurements using manufacturer-recommended CT-based sizing algorithm as gold standard. Good correlation between 3D-TOE methods vs. MSCT measurements was found, but the semi-automated analysis demonstrated slightly better correlations for AA major diameter (r = 0.89), perimeter (r = 0.89), and area (r = 0.85) (all P < 0.0001) than manual one. Both 3D methods underestimated the MSCT measurements, but semi-automated measurements showed narrower limits of agreement and lesser bias than manual measurements for most of AA parameters. On average, 3D-TOE semi-automated major diameter, area, and perimeter underestimated the respective MSCT measurements by 7.4%, 3.5%, and 4.4%, respectively, whereas minor diameter was overestimated by 0.3%. Moderate agreement for valve sizing for both 3D-TOE techniques was found: Kappa agreement 0.5 for both semi-automated and manual analysis. Interobserver and intraobserver agreements for the AA measurements were excellent for both techniques (intraclass correlation coefficients for all parameters >0.80).

Conclusion

The 3D-TOE semi-automated analysis of AA is feasible and reliable and can be used in clinical practice as an alternative to MSCT for AA assessment.

Measurement of the Aortic Annulus Area and Diameter by Three-Dimensional Transesophageal Echocardiography in Transcatheter Aortic Valve Replacement

OBJECTIVES

Sizing of the aortic valve is crucial for transcatheter aortic valve replacement (TAVR). Multidetector computed tomography (MDCT) is used for sizing. Recently, three-dimensional transesophageal echocardiography (3DTEE) has enabled accurate measurement of the aortic annulus area and diameter in cases that are difficult to measure. The authors compared measurements of aortic annulus areas and diameters acquired by MDCT and 3DTEE.

DESIGN

Retrospective observational study.

SETTING

Single national center.

PARTICIPANTS

Sixty-eight patients who underwent TAVR replacement between September 2015 and March 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors extracted and compared preoperative measurements of the aortic annulus area, as well as the long- and short-axis diameter, measured by MDCT and 3DTEE. There was no significant difference in the aortic annulus area (409 ± 74 v 414 ± 70 mm², p = 0.15) or short-axis diameter (20.4 ± 2.0 v 20.6 ± 1.9 mm, p = 0.103) between 3DTEE and MDCT, but the long-axis diameter differed significantly (25.0 ± 2.4 v 25.8 ± 2.0 mm, p < 0.001), respectively. Prosthesis sizes based on 3DTEE and MDCT were the same, except in 3 patients who could not stay still during MDCT measurement; in those cases, prosthesis sizes based on 3DTEE were adopted.

CONCLUSIONS

Measurements of the aortic annulus area and diameter in TAVR were similar between 3DTEE and MDCT. Patients who have difficulty remaining still during MDCT measurement because of dementia should have their prostheses sized based on 3DTEE measurements.

Aortic annulus measurement with computed tomography angiography reduces aortic regurgitation after transfemoral aortic valve replacement compared to 3-D echocardiography: a single-centre experience

BACKGROUND

Accurate assessment of the aortic annulus is crucial for successful transcatheter aortic valve replacement (TAVR), in particular to prevent paravalvular regurgitation (PVR). We compared aortic annular sizing using multidetector computed tomography (MDCT) and three-dimensional transoesophageal echocardiography (3-D TEE) to determine the predictive value of MDCT.

METHODS AND RESULTS

All patients admitted for transfemoral TAVR [n = 227; 48.9% balloon expandable (Edwards Sapien 3); 51.1% self-expandable (Core Valve, Evolut R)] at our institution from January 2015 until December 2016 were analysed retrospectively. Aortic annular parameters were obtained either by MDCT or 3-D TEE. Additionally, we included a cohort of patients (n = 27) assessed by both MDCT and 3D TEE between October 2017 and April 2018 to enable intra-individual comparison of the two methods. Indications for TAVR were severe degenerative aortic stenosis (AS; 94.7%) or re-stenosis after surgical AVR (5.3%). 74.4% were classified as high-gradient AS. The mean age was 80 (37-94) years and 75.8% presented with NYHA III/IV. STS risk of mortality was intermediate (3.5 ± 2.3). MDCT and 3-D TEE were performed in 116 and 111 patients for aortic annulus sizing, respectively. Significantly larger implants were chosen in the CT group irrespective of prosthesis type or post-dilatation. Follow-up (median at 79 days) revealed significantly less PVR in the MDCT compared to 3-D TEE group (absence of PVR in 59.3% and 40.7%, p = 0.016), without differences in mortality. Patients without PVR or mild PVR had a better clinical performance according to NYHA class (p = 0.016).

CONCLUSION

MDCT is superior to 3-D TEE in terms of sizing accuracy and clinical outcomes. Reduction of PVR after TAVR with MDCT is likely due to valve annulus undersizing by TEE.

Outcomes of incidental findings on multi-detector computed tomography for transcatheter aortic valve implantation assessment: A single-centre study and review of the literature

INTRODUCTION

Patients with severe aortic stenosis (AS) require multi-detector computed tomography (MDCT) when considered for transcatheter aortic valve implantation (TAVI). Incidental findings on MDCT are common given the age group and region imaged. Our aim was to evaluate the frequency and outcome of incidental findings (IF) identified on MDCT and the impact on survival.

METHODS

This single-centre analysis retrospectively reviewed severe AS patients who underwent MDCT during TAVI workup. MDCT reports were reviewed for any IF and defined into three categories: IF of no relevant clinical significance (IF-NoCS), IF of non-immediate clinical significance (IF-NICS) and IF of immediate clinical significance (IF-ICS). Demographics, follow-up of IF and survival were calculated from MDCT date.

RESULTS

Two hundred and sixty-five patients underwent MDCT for TAVI suitability (mean age 83 ± 6 years, 52% male). The majority proceeded to TAVI (65%). Renal lesions (25%) and lung nodules (18%) were the most common IF. Fifty-nine patients (22%) had IF-NICS; 39% (23/59) were benign, 59% were not further investigated and one patient had suspected lung cancer. Six patients (2.3%) had IF-ICS and all were diagnosed with lung cancer. During a median follow-up of 272 days, there was no survival difference between patients with IF-ICS or IF-NICS versus patients without IF or IF-NoCS in the overall cohort (P = 0.44) or in TAVI patients (P = 0.88).

CONCLUSION

Incidental findings on MDCT are common with one-quarter having IF-ICS or IF-NCIS. Most patients with IF-NICS did not undergo further investigation. Standardized reporting of MDCT may assist in clarifying the need for further investigation which will in turn influence decision and timing to proceed with TAVI.

Three-dimensional transesophageal echocardiography is an attractive alternative to cardiac multi-detector computed tomography for aortic annular sizing: Systematic review and meta-analysis

BACKGROUND

Cardiac imaging is the cornerstone of the pretranscatheter aortic valve replacement (TAVR) assessment. Multi-detector computed tomography (MDCT) is considered the conventional imaging modality. However, there is still no definitive gold standard. Targeted cohort of inoperable high-risk patients with underlying comorbidities, particularly renal impairment, makes apparent the need for MDCT alternative. We aimed to demonstrate the correlation extent between MDCT and three-dimensional transesophageal echocardiography (3DTEE) aortic annular area measures and to answer the question: Is 3DTEE a good alternative to MDCT?

METHODS

A systematic literature search and meta-analysis were conducted to evaluate the degree of correlation and agreement between 3DTEE and MDCT aortic annular sizing. A thorough assessment of EMBASE, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL) was performed. All studies comparing 3DTEE and MDCT in relation to aortic annular sizing were included.

RESULTS

Thirteen studies were included (N = 1228 patients). A strong linear correlation was found between 3DTEE and MDCT measurements of aortic annulus area (r = 0.84, P < 0.001), mean perimeter (r = 0. 0.85, P < 0.001), and mean diameter (r = 0.80, P < 0.001). Bland-Altman plots revealed smaller mean 3DTEE values in comparison to MDCT for aortic annular area, the mean difference being -2.22 mm² with 95% limits of agreement -12.79 to 8.36.

CONCLUSION

Aortic annulus measurements obtained by 3DTEE demonstrated a high level of correlation with those evaluated by MDCT. This makes 3DTEE a feasible choice for aortic annulus assessment, with advantage of real time assessment, lack of contrast, and no radiation exposure.

The role of computed tomography in the planning of transcatheter aortic valve implantation: a retrospective analysis in 200 procedures

AIM

The aim of our study is to show the importance of multislice computed tomography (CT) assessment in the overall management and diagnostic framework of transcatheter aortic valve replacement (TAVI) procedure candidates.

METHODS

Between June 2015 and April 2017, 200 patients with severe aortic stenosis, not eligible for surgery, were enrolled, as defined by EuroSCORE; they were submitted to TAVI at the interventional cardiology department of the Tor Vergata Polyclinic. CT studies were performed using a 64-slice scanner.

RESULTS

The reports and datasets produced during the pre-TAVI CT evaluation were retrospectively evaluated.

DISCUSSION

In TAVI candidates, accurate aortic valve shape and dimensions evaluation is crucial for the proper deployment of the prosthetic valve and in order to reduce postprocedural complications. ECG retrospective gated cardiac CT gives the clinician three-dimensional images of the heart, with high spatial resolution and multiplanar reconstructions allowing accurate visualization of the aortic annulus and coronary ostia to be obtained, and the evaluation of arterial calcifications. Furthermore, CT can provide data on the suitability of peripheral vascular accesses. Moreover, this technique can point out the presence of clinically relevant extracardiac findings. Therefore, CT evaluation assures a safe, reliable and prognostically relevant method for TAVI preprocedural planning.

CONCLUSION

Our study remarks the importance of CT assessment in the overall management and diagnostic framework of TAVI candidates; the information provided is essential in order to minimize possible complications and to improve the quality of the therapeutic planning.

Assessment of aortic valve tract dynamics using automatic tracking of 3D transesophageal echocardiographic images

The assessment of aortic valve (AV) morphology is paramount for planning transcatheter AV implantation (TAVI). Nowadays, pre-TAVI sizing is routinely performed at one cardiac phase only, usually at mid-systole. Nonetheless, the AV is a dynamic structure that undergoes changes in size and shape throughout the cardiac cycle, which may be relevant for prosthesis selection. Thus, the aim of this study was to present and evaluate a novel software tool enabling the automatic sizing of the AV dynamically in three-dimensional (3D) transesophageal echocardiography (TEE) images. Forty-two patients who underwent preoperative 3D-TEE images were retrospectively analyzed using the software. Dynamic measurements were automatically extracted at four levels, including the aortic annulus. These measures were used to assess the software's ability to accurately and reproducibly quantify the conformational changes of the aortic root and were validated against automated sizing measurements independently extracted at distinct time points. The software extracted physiological dynamic measurements in less than 2 min, that were shown to be accurate (error 2.2 ± 26.3 mm² and 0.0 ± 2.53 mm for annular area and perimeter, respectively) and highly reproducible (0.85 ± 6.18 and 0.65 ± 7.90 mm² of intra- and interobserver variability, respectively, in annular area). Using the maximum or minimum measured values rather than mid-systolic ones for device sizing resulted in a potential change of recommended size in 7% and 60% of the cases, respectively. The presented software tool allows a fast, automatic and reproducible dynamic assessment of the AV morphology from 3D-TEE images, with the extracted measures influencing the device selection depending on the cardiac moment used to perform its sizing. This novel tool may thus ease and potentially increase the observer's confidence during prosthesis' size selection at the preoperative TAVI planning.

Temporal Trends in Gender-Related Differences and Outcomes in Patients Who Underwent Transcatheter Aortic Valve Implantation (from the Israeli Transcatheter Aortic Valve Implantation Multicenter Registry)

We evaluated temporal trends in gender-related differences in patients who underwent transcatheter aortic valve implantation (TAVI) for severe symptomatic aortic stenosis from a multicenter TAVI registry during the years 2008 to 2016. Our final cohort included 1,159 males and 1,370 females, with a median follow-up of 2.3 (IQR 1.2, 4.4) years. For temporal trends analysis, the entire population was divided according to period of procedure: 2008 to 2012 and 2013 to 2016. During the 2008 to 2012 period, the rates of in-hospital aortic paravalvular leak, myocardial infarction, pacemaker implantation, and stroke were higher among men than women, but became comparable between the gender during the 2013 to 2016 period. Multivariate analysis demonstrated that female patients who underwent TAVI between the years 2008 and 2012 had a 26% lower risk of death compared with male patients (p = 0.004), but there were no gender-related differences in mortality risk between the years 2013 and 2016 (hazard ratio 1.07, p = 0.6; gender-by-year of procedure, p = 0.027 for interaction). In conclusion, the favorable long-term prognosis described in female patients during the earlier TAVI period seemed to diminish with contemporary TAVI. This might be attributed to current technological advances and improved valve sizing, with a more significant benefit in favor of male patients.

Outcomes and Safety of Transcatheter Aortic Valve Implantation With and Without Routine Use of Transesophageal Echocardiography

Transesophageal echocardiography (TEE) has been extensively used historically for Transcatheter aortic valve implantation (TAVI) but focus is shifting from routine use of TEE and general anesthesia to "as needed" use. We evaluated patients who had TAVI in our institution from September 2012 to February 2017. Decision for implantation and use of TEE during procedure was made by the structural heart team on a case-to-case basis, based on FDA approved indications. Data including procedural details, length of stay and rehospitalizations were obtained from all patients. TAVI was performed on 178 patients during the study period of which 104 of 178 had TEE during TAVI. Baseline characteristics were fairly comparable in both groups. Similar proportion of self-expanding and balloon expanding valves were deployed. Patients in TEE group had longer overall procedure time (107 minute vs 83 minute, p = 0.0002) and longer length of stay (5.01days vs 2.49days, p < 0.0001). Echocardiographic study postprocedure showed similar incidence of paravalvular leak and similar gradients and velocities across aortic valve. Rates of 30-day readmissions were similar in both groups. In conclusion, in this single-center retrospective analysis-TAVI without the 'routine use' of TEE was comparable with those done with TEE guidance in terms of periprocedural complications and 30-day readmissions. Overall procedure length and length of stay was predictably higher in the TEE group.

Short versus conventional hydration for prevention of kidney injury during pre-TAVI computed tomography angiography

BACKGROUND

Computed tomography angiography (CTA) is required in the work-up for transcatheter aortic valve implantation (TAVI). However, CTA may cause contrast-induced acute kidney injury (CI-AKI). We hypothesised that a short (1 h, 3 ml/kg/h sodium bicarbonate) hydration protocol is not inferior to conventional (24 h, 1 ml/kg/h saline) hydration in avoiding a decline in renal function in patients with impaired renal function.

METHODS AND RESULTS

Single-centre randomised non-inferiority trial in patients with impaired renal function who underwent pre-TAVI CTA. Patients were randomised on a 1:1 ratio to short hydration (SHORT; 1 h sodium bicarbonate, 3 ml/kg/h) or conventional hydration (CONV; 24 h saline, 1 ml/kg/h). Outcomes included percentage change in serum creatinine until 2-6 days after CTA with a non-inferiority margin of 10% and an increase on the Borg dyspnoea scale ≥1 point. Seventy-four patients were included. Increase in creatinine was 6 µmol/l (95% CI 2.5-9.3) in the SHORT versus 2 µmol/l (95% CI-1.4 to 6.3) in the CONV arm (p = 0.167). The percentage change was 4.6% (95% CI 2.0-7.3%) in the SHORT arm versus 2.5% (95% CI: 0.8 to 5.8%) in the CONV arm. The difference in percentage increase in creatinine between the two arms was 2.1% (95% CI: 2.0-6.2%; p-value non-inferiority: <0.001). CI-AKI and a need for dialysis were not observed. An increase of ≥1 point on the Borg scale (dyspnoea scale ranging from 1 (lowest) to 10 (highest)) was seen in 1 patient in the SHORT arm versus 5 patients in the CONV arm (2.9% vs 16.1%, p = 0.091).

CONCLUSION

For patients with impaired renal function undergoing pre-TAVI CTA, a short 1‑h, low-volume hydration protocol with sodium bicarbonate is not inferior to conventional 24-h, high-volume saline hydration.

Paravalvular Regurgitation After Transcatheter Aortic Valve Replacement: Is the Problem Solved?

Paravalvular regurgitation is a frequent complication after transcatheter aortic valve replacement and its association with worse outcomes depends on the degree of its severity. Despite substantial improvement in transcatheter heart valve design, sizing and implantation technique, moderate or severe paravalvular regurgitation still occurs in 2% to 7% of patients and is associated with a more than 2-fold increase in mortality. This review provides a state-of-the-art approach to (i) paravalvular regurgitation prevention by optimizing patient selection, valve sizing, and positioning and (ii) the detection, quantitation and management of paravalvular regurgitation during and after valve implantation.

Large-field intravascular ultrasound for annular sizing and predicting paravalvular regurgitation during TAVR: comparisons with multidetector computed tomography and transoesophageal echocardiography

Aims

The use of contrast media with multidetector computed tomography (MDCT) may induce acute kidney injury in patients with renal failure undergoing transcatheter aortic valve replacement (TAVR). We investigated the role of large-field intravascular ultrasound (IVUS) vs. MDCT and two-dimensional transoesophageal echocardiography (2D-TEE) for annular sizing and predicting paravalvular regurgitation (PVR) during TAVR.

Methods and Results

The aortic annulus was measured by large-field IVUS and 2D-TEE, and compared with MDCT in 50 patients undergoing TAVR. The IVUS and MDCT annular areas and diameters were not significantly different (446 ± 87 mm2 and 23.8 ± 84 mm vs. 466 ± 84 mm2 and 24 ± 2.1 mm, respectively; P > 0.05). IVUS and MDCT mean annular diameters were significantly greater than TEE diameter (23.8 ± 2.4 and 24 ± 2.1 vs. 22 ± 0.65 mm, respectively; P < 0.01). PVR ≥ Mild occurred in 13 patients (26%); 5 patients required post-dilation and 2 patients a second valve. Receiver operating characteristic analyses showed that transcatheter heart valve (THV) area - IVUS or MDCT areas equally predicted of ≥ mild PVR (areas under the curve [AUC] 0.79 and 0.81, respectively; P < 0.001), and were greater than THV diameter-TEE diameter (AUC 0.79 and 0.81 vs. 0.56, respectively; P < 0.05).

Conclusions

The aortic annular measurements and predicting PVR by large field IVUS were not significantly different from those of MDCT, but were greater than those of TEE. Large filed IVUS can be reliably used in lieu of MDCT for annular sizing in patients with aortic stenosis and renal failure or suboptimal MDCT images.

CT angiography prior to TAVI procedure using third-generation scanner with wide volume coverage: feasibility, renal safety and diagnostic accuracy for coronary tree

OBJECTIVE:

To evaluate feasibility, image quality and accuracy of a reduced contrast volume protocol for pre-procedural CT imaging in transcatheter aortic valve implantation (TAVI) using a third generation wide array CT scanner.

METHODS:

115 consecutive patients (51F, mean age 82.5 ± 6.2 y, mean BMI 26.7 ± 3.6) referred for TAVI were examined with wide-array CT scanner with a combined scan protocol and a total amount of 50 ml contrast agent. A 4-point visual scale (4-1) was used to assess image quality . Contrast attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the level of the aortic root, ascending/descending aorta, subrenal aorta and at the level of right and left common femoral arteries. Coronary tree was assessed and compared with invasive coronary angiography (ICA). Aortic annulus measurements were compared with final procedural results. Patients creatinine was monitored at the baseline and 72 h after procedure.

RESULTS:

Median quality score value was >3. Mean CNR at the level of the aortic root, ascending/descending aorta, subrenal aorta and at the level of right and left common femoral arteries were 14.8 ± 2.3, 15.7 ± 1.7, 14.9 ± 3.1, 15.8 ± 4.7, 20.3 ± 9.9, 20.8 ± 6.9 respectively. Only 1 patient had moderate paravalvular regurgitation. In comparison with ICA for coronary assessment CTA showed in a segment based analysis sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 97, 85, 99,62 and 88% respectively. Mean creatinine before CT and 72 h after procedure were 1.21 ± 0.52 and1.22 ± 0.49 mg dl^-1. Mean DLP was 442.4 ± 21.2 mGy/cm.

CONCLUSION:

CT with low contrast volume is feasible and clinically useful, allowing precise pre-procedural TAVI planning with accurate assessment of coronary tree.

ADVANCES IN KNOWLEDGE:

third generation CT scanner with whole heart coverage allows examinations for assessment of aorta and coronary arteries in TAVI planning using low dose of contrast medium maintaining good quality and high diagnostic accuracy.

The Pivotal Role of Imaging in TAVR Procedures

PURPOSE OF REVIEW

Transcatheter aortic valve replacement (TAVR) is underpinned by an array of imaging techniques designed to not only select an appropriately sized implant but also to identify potential obstacles to procedural success. This review presents currently important aspects of TAVR imaging, describing the salient features of each modality as well as recent developments in the field.

RECENT FINDINGS

The latest data on TAVR outcomes reflects the increasing experience of operators and the significant role of pre-procedural imaging. Debate continues as to which modality sizes the aortic annulus most accurately, 3D transoesophageal echocardiography (TEE) or MDCT, as well as to whether the merits of real-time peri-procedural 3D imaging guidance outweigh the possible adverse consequences of general anaesthesia which is requisite for intraprocedural 3D TEE. TAVR is now largely based on pre-acquired roadmaps of the truncal vasculature and intense pre-procedural planning. TEE and Multi-detector computed tomography (MDCT) have been shown to perform similarly in annulus sizing. However, given the complexity of many TAVR patients and the importance of identifying the most suitable pathway to the valve as well as any potentially confounding other structural or functional heart disease, both modalities remain relevant in current TAVR.

Imaging of Left Ventricular Hypertrophy: a Practical Utility for Differential Diagnosis and Assessment of Disease Severity

PURPOSE OF REVIEW

Left ventricular hypertrophy (LVH) is often encountered in clinical practice, and it is a risk factor for cardiac mortality and morbidity. Determination of the etiology and disease severity is important for the management of patients with LVH. The aim of this review is to show the remarkable progress in cardiac imaging and its importance in clinical practice.

RECENT FINDINGS

This review focuses on clinical features and characteristic cardiac imaging in LVH caused by various diseases including hypertension, aortic valve stenosis, hypertrophic cardiomyopathy, and secondary cardiomyopathies. The usefulness of echocardiography as a tool of general versatility including hemodynamic evaluation and the usefulness of cardiac magnetic resonance imaging for assessment of cardiac morphology and myocardial tissue characteristics of relevance for LVH are described. Imaging modalities now have central roles in the differentiation and prognostic assessment of LVH.