Prosthesis sizing for transcatheter aortic valve implantation--comparison of three dimensional transesophageal echocardiography with multislice computed tomography

Preoperative TAVR Planning: How to Do It

Transcatheter aortic valve replacement (TAVR) is a well-established treatment option for patients with severe symptomatic aortic stenosis (AS) whose procedural efficacy and safety have been continuously improving. Appropriate preprocedural planning, including aortic valve annulus measurements, transcatheter heart valve choice, and possible procedural complication anticipation is mandatory to a successful procedure. The gold standard for preoperative planning is still to perform a multi-detector computed angiotomography (MDCT), which provides all the information required. Nonetheless, 3D echocardiography and magnet resonance imaging (MRI) are great alternatives for some patients. In this article, we provide an updated comprehensive review, focusing on preoperative TAVR planning and the standard steps required to do it properly.

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.

Application research of three-dimensional transesophageal echocardiography in predicting prosthetic valve size for transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) is an alternative method to treat patients with severe aortic valve disease. Accurate measurement of the aortic valve annulus and selection of the appropriate artificial valve are critical to the success of TAVI. Multilayer spiral computed tomography (MSCT) is recommended as the “gold standard” for assessing the aortic valve annulus before TAVI. However, MSCT scanning may not be possible for patients with iodine allergy, renal failure, or pregnancy. The purpose of this study is to evaluate the aortic valve annulus by three-dimensional transesophageal echocardiography (3D-TEE) and compare the results with MSCT, exploring the feasibility of 3D-TEE to guide the selection of artificial valve implantation in TAVI.

Methods

We retrospectively analyzed 74 patients who successfully underwent TAVI in our hospital. Before the operation, 3D-TEE and MSCT were used to measure the maximum diameter, minimum diameter, area-derived diameter, and perimeter-derived diameter of the aortic valve annulus, and the results were analyzed for consistency. To predict the valve size based on 3D-TEE and the MSCT area-derived diameter, we compared the differences between the predicted valve size and the actual implanted valve size, and analyzed the differences between 3D-TEE and MSCT for guiding the selection of the prosthetic valve size.

Results

There was no significant difference between 3D-TEE and MSCT in the measurement of the maximum diameter, minimum diameter, area, and perimeter of the aortic annulus and their derived diameter (P>0.05). The intraclass correlation coefficients for the maximum diameter, minimum diameter, area-derived diameter, and perimeter-derived diameter of the aortic annulus were 0.89, 0.83, 0.84, and 0.92, respectively. There was no statistical difference in the accuracy of both methods, 3D-TEE and MSCT, in predicting different prosthetic valve sizes for TAVI (P>0.05).

Conclusions

3D-TEE and MSCT have good agreement for measuring the values of various parameters of the aortic annulus. The accuracy of both methods was similar for predicting the aortic prosthetic valve size. 3D-TEE may provide guidance for selecting the prosthetic valve size for TAVI.

Three-Dimensional Transesophageal Echocardiography as an Alternative to Multidetector Computed Tomography in Aortic Annular Diameter Measurements for Transcatheter Aortic Valve Implantation

Simple Summary

Patients who have multiple associated comorbidities and need to change the aortic valve may have a contraindication to open-heart surgery, the alternative being transcatheter aortic valve implantation, which requires very precise measurements of the aortic annulus to determine the dimensions of the prostheses. Ultrasonographic imaging techniques, such as transesophageal echocardiography, are constantly evolving. The aim of our study was to compare the three-dimensional transesophageal echocardiography and multi-detector computer tomography methods, with the former being an alternative for patients who cannot undergo computer tomography because of a major contraindication. We have demonstrated that there were small differences between aortic annular measurements using multi-detector computer tomography (2.25 ± 0.19 cm) and three-dimensional transesophageal echocardiography (2.25 ± 0.15 cm). Thus, three-dimensional transesophageal echocardiography can be the solution for aortic annular measurements used to select the correct prosthesis for the transcatheter aortic valve implantation procedure in patients who cannot undergo computer tomography.

Abstract

Background and objectives: Transcatheter aortic valve implantation (TAVI) is a therapeutic choice for high surgical risk patients, serving as an alternative to open-heart surgery. Correct measurement of the aortic annulus, which leads to the selection of a suitable prosthesis and accurate outcome prediction, is essential for the success of TAVI. The objective of this study is to evaluate the accuracy of novel imaging te chniques in measuring the aortic annulus by comparing multi-detector computer tomography (MDCT) and three-dimensional transesophageal echocardiography (3D TEE) for the selection of the optimal prosthesis. Materials and Methods: Measurements of the aortic annulus have been performed on 25 patients using MDCT and TEE, and the correlation and agreement levels between the two measuring techniques were analyzed. MDCT measurements were used for the sizing of the prostheses. Results: MDCT and TEE measurements of aortic annular diameters were significantly correlated, with a mean difference of 0.001 cm. Conclusions: 3D TEE measurements have been in good agreement with MDCT and, therefore, 3D TEE can be used as an alternative in cases where MDCT is contraindicated or not available.

Assessment of left ventricular outflow tract and aortic root: comparison of 2D and 3D transthoracic echocardiography with multidetector computed tomography

AIMS

Accurate echocardiographic assessment of left ventricular outflow tract (LVOT) and the aortic root is necessary for risk stratification and choice of appropriate treatment in patients with pathologies of the aortic valve and aortic root. Conventional 2D transthoracic echocardiographic (TTE) assessment is based on the assumption of a circular shaped LVOT and aortic root, although previous studies have indicated a more ellipsoid shape. 3D TTE and multidetector computed tomography (MDCT) applies planimetry and are not dependent on geometrical assumptions. The aim was to test accuracy, feasibility, and reproducibility of 3D TTE compared to 2D TTE assessment of LVOT and aortic root areas, with MDCT as reference.

METHODS AND RESULTS

We examined 51 patients with 2D/3D TTE and MDCT at the same day. All patients were re-examined with 2D/3D TTE on a different day to evaluate 2D and 3D re-test variability. Areas of LVOT, aortic annulus, and sinus were assessed using 2D, 3D TTE, and MDCT. Both 2D/3D TTE underestimated the areas compared to MDCT; however, 3D TTE areas were significantly closer to MDCT-areas. 2D vs. 3D mean MDCT-differences: LVOT 1.61 vs. 1.15 cm2, P = 0.019; aortic annulus 1.96 vs. 1.06 cm2, P < 0.001; aortic sinus 1.66 vs. 1.08 cm2, P = 0.015. Feasibility was 3D 76-79% and 2D 88-90%. LVOT and aortic annulus areas by 3D TTE had lowest variabilities; intraobserver coefficient of variation (CV) 9%, re-test variation CV 18-20%.

CONCLUSION

Estimation of LVOT and aortic root areas using 3D TTE is feasible, more precise and more accurate than 2D TTE.

ROTAVI: simultaneous left main rotablation and transcutaneous aortic valve implantation in calcified coronaries and severe aortic stenosis - a case report

Background

There is a high incidence of calcified coronary artery disease in patients with severe valvular aortic stenosis (AS). With transcutaneous aortic valve replacement (TAVR) as one of the promising options for severe AS in high and intermediate surgical risk patients; we will encounter more and more patients who will require both complex percutaneous coronary intervention (PCI) with rotablation (RA) and TAVR. The timing of PCI in patients undergoing TAVR; however remains indecisive. Due to the complexity of procedures and the risks involved, very few cases of concomitant TAVR and coronary RA have been reported so far.

Case summary

Seventy-five years old high surgical risk female had severe AS with calcified left main (LM) distal and ostial left anterior descending (LAD) artery lesion. Successful PCI with RA to LM-LAD lesion was done followed by uneventful transfemoral TAVR in the same setting.

Discussion

This is probably one of the very few cases reported where PCI to LM with RA and TAVR was done successfully in the same setting. Since the calcified lesion was focal and left ventricular ejection fraction of the patient was normal, we went ahead with PCI without prior balloon dilatation of aortic valve (BAV) which was a deviation from the prior reported cases, where BAV was performed prior to complex PCI to improve the cardiac output. We herein discuss our case and thoughts about concomitant complex PCI and TAVR.

Current issues in transcatheter aortic valve replacement

Aortic stenosis is the most common valvular disease worldwide. With transcatheter aortic valve replacement (TAVR) being increasingly expanded to lower-risk populations, several challenging issues remain to be solved. The present review aims at discussing modern approaches to such issues as well as the current status of TAVR. TAVR has undergone several developments in the recent years: an increased use of transfemoral access, the development of prostheses in order to adapt to challenging anatomies, improved delivery systems with repositioning features, and outer skirts aiming at reducing paravalvular leak. The indication of TAVR is increasingly being expanded to patients with lower surgical risk. The main clinical trials supporting such expansion are reviewed and the latest data on low-risk patients are discussed. A number of challenges need still to be addressed and are also reviewed in this paper: the need for updated international guidelines including the latest evidence; a reduction of main complications such as permanent pacemaker implantation, paravalvular leak, and stroke (and its potential prevention by using anti-embolic protection devices); the appropriate role of TAVR in patients with concomitant cardiac ischemic disease; and durability of bio-prosthetic implanted valves. Finally, the future perspectives for TAVR use and next device developments are discussed.

Utility of conventional aortic root shot angiography for SAPIEN 3 prosthesis sizing in TAVI: feasibility and inter-reader variability

Background

The gold-standard approach to prosthesis sizing before transcatheter aortic valve implantation (TAVI) is multislice computed tomography (MSCT). We aimed to investigate whether conventional aortic root angiography (CA) alone can reliably facilitate valve selection and to describe its inter-reader variability.

Methods

Five TAVI specialists (3 interventional cardiologists and 2 cardiac surgeons) independently reviewed preprocedural CAs for 50 patients implanted with the Edwards SAPIEN 3 valve.

Results

The prosthesis size selected based on visual CA appraisal matched that based on MSCT in 60% of cases (range: 50%–68%), with undersizing in 11% (4%–33%) and oversizing in 29% (10%–46%; p=0.187 for equality of the proportions test). Agreement between CA-based and MSCT-based valve selection was moderate (K=0.41; Kw=0.61). Reassessment of choice following awareness of the annulus long-axis diameter did not significantly improve this agreement (0.40 and 0.63, respectively), though more undersizing (14%) and less oversizing (25%) occurred. Correct valve selection was more common in interventional cardiologists than cardiac surgeons (66% vs 53%; p=0.0391), who made more oversizing errors.

Conclusions

There is a modest agreement between CA-based and MSCT-based SAPIEN 3 selection. Although the former should not be performed routinely, it may be informative in settings where MSCT and transoesophageal echocardiography are unavailable.

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 of three-dimensional echocardiography in candidates for transcatheter aortic valve replacement

The correct determination of aortic annulus dimensions is a crucial step to avoid complications in Transcatheter Aortic Valve Replacement (TAVR). Currently, the gold standard method for the evaluation of the aortic annulus is Multidetector Computed Tomography (MDCT), which is limited by the risk of contrast-induced nephropathy. Three-dimensional transesophageal echocardiography automated software (3DTEEa) have been used as an alternative in patients with contra-indications to MDCT. We aimed to evaluate the accuracy of 3DTEEa-derived aortic annulus dimensions; to assess the influence of calcification in the agreement between 3DTEEa and MDCT; and to determine reclassification in prosthesis size choice if 3DTEEa was the only imaging method. One hundred and seven consecutive patients referred for TAVR were studied. Aortic annulus dimensions were determined using MDCT and 3DTEE manual (3DTEEm) and automated measurements. Valve calcification was assessed with MDCT. Limits of agreement (LOA) were narrower for 3DTEEa (minimum diameter: mean bias 0.60; LOA - 2.94 to 4.14; maximum diameter: mean bias 0.20; LOA - 3.82 to 4.22) as compared to 3DTEEm (minimum diameter: mean bias 0.22; LOA - 3.84 to 4.28; maximum diameter: mean bias - 1.25; LOA - 6.37; 3.86). Compared to MDCT, 3DTEEa overestimated while 3DTEEm underestimated most parameters. No differences were found in average bias between methods according to quartiles of valve calcification. Most patients would have received the same size valve (63.9%) if 3DTEEa was the only available method. Measurement of aortic annulus dimensions using a 3DTEE automatic software is feasible and not influenced by valve calcification. It may be an alternative for patients who cannot undergo MDCT.

Comparison of transthoracic and transesophageal echocardiography for transcatheter aortic valve replacement sizing in high-risk patients

BACKGROUND

Untreated symptomatic high-grade aortic stenosis remains a lethal disease requiring individually adapted valve replacement. High-risk surgical patients benefit from transcatheter aortic valve replacement (TAVR), but there is no uniform standard for patient selection and valve sizing and it is still unclear whether transthoracic (TTE) or transesophageal (TEE) echocardiography is superior in preprocedural aortic annulus sizing. As preprocedural sizing of the native aortic annulus diameter is crucial to outcome and survival, we report the results of a direct comparison between preprocedural sizing with TTE and TEE including subsequent outcomes in a high-risk TAVR population.

METHODS

A total of 149 TAVR patients were enrolled for TTE and TEE comparison, and an additional 15 patients without structural heart disease were investigated as control group to determine the influence of aortic valve calcification on TTE and TEE aortic annulus diameter measurements.

RESULTS

Overall standardized TTE and TEE measurements for aortic annulus sizing showed excellent correlation at good image quality (p < 0.01, r = 0.934). Calcification of the aortic annulus diameter was not found to exert a noteworthy negative influence on measurements for both standardized TTE and TEE and complication rates did not differ for mortality, periprocedural stroke and paraprosthetic regurgitation.

CONCLUSIONS

Transthoracic echocardiography and TEE are both equally suitable methods of preprocedural aortic annulus size evaluation in preparation of TAVR procedures.

Three-Dimensional Echocardiography for Transcatheter Aortic Valve Replacement Sizing: A Systematic Review and Meta-Analysis

Background

Transcatheter aortic valve replacement (TAVR) is the standard of care for many patients with severe symptomatic aortic stenosis and relies on accurate sizing of the aortic annulus. It has been suggested that 3‐dimensional transesophageal echocardiography (3D TEE) may be used instead of multidetector computed tomography (MDCT) for TAVR planning. This systematic review and meta‐analysis compared 3D TEE and MDCT for pre‐TAVR measurements.

Methods and Results

A systematic literature search was performed. The primary outcome was the correlation coefficient between 3D TEE– and MDCT‐measured annular area. Secondary outcomes were correlation coefficients for mean annular diameter, annular perimeter, and left ventricular outflow tract area; interobserver and intraobserver agreements; mean differences between 3D TEE and MDCT measurements; and pooled sensitivities, specificities, and receiver operating characteristic area under curve values of 3D TEE and MDCT for discriminating post‐TAVR paravalvular aortic regurgitation. A random effects model was used. Meta‐regression and leave‐one‐out analysis for the primary outcome were performed. Nineteen studies with a total of 1599 patients were included. Correlations between 3D TEE and MDCT annular area, annular perimeter, annular diameter, and left ventricular outflow tract area measurements were strong (0.86 [95% CI, 0.80–0.90]; 0.89 [CI, 0.82–0.93]; 0.80 [CI, 0.70–0.87]; and 0.78 [CI, 0.61–0.88], respectively). Mean differences between 3D TEE and MDCT between measurements were small and nonsignificant. Interobserver and intraobserver agreement and discriminatory abilities for paravalvular aortic regurgitation were good for both 3D TEE and MDCT.

Conclusions

For pre‐TAVR planning, 3D TEE is comparable to MDCT. In patients with renal dysfunction, 3D TEE may be potentially advantageous for TAVR measurements because of the lack of contrast exposure.

Aortic roots assessment by an automated three-dimensional transesophageal echocardiography: an intra-individual comparison

To evaluate the accuracy, reproducibility, and transcatheter heart valve (THV) sizing efficiency of an automated 3-dimensional transesophageal echocardiographic (3D-TEE) post-processing software in the assessments of aortic roots, intra-individually compared with multidetector computed tomography (MDCT). We prospectively studied 67 patients with normal aortic roots. We measured diameters of aortic annulus (AA), sinus of Valsalva (SOV), and sino-tubular junction (STJ) by full-automated and semi-automated methods using 3D-TEE datasets, then compared them to corresponding transthoracic echocardiography and MDCT values. THV sizes were chosen based on echocardiography and MDCT measurements according to recommended criterion. Taking MDCT planimetered diameters as reference, the full-automated (r: 0.4745-0.8792) and semi-automated (r: 0.6647-0.8805) 3D-TEE measurements were linearly correlated (p < 0.0001). The average differences between semi-automated or full-automated measurements and reference were 0.3 mm or 1.3 mm for AA, - 1.9 mm or - 0.5 mm for SOV, and - 0.1 mm or 1.9 mm for STJ, respectively. The intra-class correlation coefficients of semi-automated method were 0.79-0.96 (intra-observer) and 0.75-0.92 (inter-observer). THV sizing by semi-automated measurements using echocardiographic criteria was larger than that by MDCT measurements using MDCT criteria (p < 0.0001) but equivalent (p > 0.05) if both using MDCT standards. The new automated 3D-TEE software allows modeling and quantifying aortic roots with high reproducibility. Measurements by the semi-automated method closely approximate and well correlate with the corresponding MDCT, thus THV sizing by this modeled 3D-TEE measurements should adopt recommended MDCT criteria but not echocardiographic criteria. The full-automated 3D-TEE segmentations are yet immature. (Semi-automated assessMent of Aortic Roots by Three-dimensional transEsophageal echocaRdiography [SMARTER], NCT02724709).

[Transcatheter aortic valve implantation under extracorporeal membrane oxygenation]

Transcatheter aortic valve implantation (TAVI) has become the standard treatment for advanced age and high risk patients with severe aortic stenosis. The incidence of life-threatening complications during TAVI has significantly decreased over the last decade due to advanced current surgical experience. However, there is a risk of perioperative life-threatening complications which can require emergency hemodynamic support. Veno-arterial extracorporeal membrane oxygenation (ECMO) may represent an effective strategy for immediate hemodynamic stabilization until further treatment of the underlying complication. It is presented case report of TAVI under ECMO performed at the Kemerovo Research Institute for Complex Issues of Cardiovascular Diseases. Emergency ECMO represents a feasible strategy for stabilization until further treatment of life-threatening complications during TAVI.

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.

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.

Spotlight on the SAPIEN 3 transcatheter heart valve

Transcatheter aortic valve implantation (TAVI) is increasingly performed in patients with severe aortic stenosis. The efficacy and safety have been demonstrated in large randomized trials in patients with high- or intermediate operative risk. With latest-generation transcatheter heart valve (THV) systems, growing operator experience and improved patient selection, clinical outcome has significantly improved with a decline of TAVI-related complications. In this review, the Edwards SAPIEN 3 THV is discussed in terms of technology, procedural advances and complication trends and future developments.

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.

Incidental findings in multislice computed tomography prior to transcatheter aortic valve implantation: frequency, clinical relevance and outcome

Multislice computed tomography (MSCT) has emerged as the mainstay in patients planned for transcatheter aortic valve implantation (TAVI). Incidental findings (IF) in MSCT are common. However, the exact incidence, clinical relevance and further consequences of IF are unclear and it is controversial whether IF adversely affect patients' outcome. We analyzed MSCT data of 1050 patients screened for TAVI between January 2011 and December 2014. Median follow-up of patients was 20 months. In total, 3194 IF were identified, which were classified into clinically non-relevant IF (2872, 90%) and clinically relevant IF (322, 10%). In 25% of patients (258/1050) at least one clinically relevant IF was present. Age (80 ± 7 vs. 80 ± 7 years; p = 0.198) and EuroSCORE II (3.6% [2.1-5.7] vs. 3.6% [2.1-5.9]; p = 0.874) was similar between patients with and without a clinically relevant IF. TAVI was performed less frequently in patients with a clinically relevant IF (76% vs. 85%; p < 0.001), with more patients receiving surgical aortic valve replacement in that group (14% vs. 11%; p = 0.042), possibly due to the high rate of incidental aneurysms of the ascending aorta (n = 48). If TAVI was performed mortality did not differ (30-days: 4% vs. 3%; p = 0.339, 1-year: 11% vs. 14%; p = 0.226) between patients with and without a clinically relevant IF. Our study is the largest study to analyze prevalence, clinical relevance and therapeutic consequences of IF during screening for TAVI. IF in pre-procedural MSCT are common and clinically relevant in one-quarter of patients. However, these findings had no impact on overall mortality.

Interventional Echocardiography: Field of Advanced Imaging to Support Structural Heart Interventions

Multimodality imaging, particularly echocardiography, is paramount in planning and guiding structural heart disease interventions. Transesophageal echocardiography remains unique in its ability to provide real-time 2D and 3D imaging of valvular heart disease and anatomic cardiac defects, which directly impacts the strategy and outcome of these procedures. This review summarizes the role of transesophageal echocardiography in patients undergoing the most common structural heart disease interventions.

Influence of the Quantity of Aortic Valve Calcium on the Agreement Between Automated 3-Dimensional Transesophageal Echocardiography and Multidetector Row Computed Tomography for Aortic Annulus Sizing

Accurate aortic annulus sizing is key for selection of appropriate transcatheter aortic valve implantation (TAVI) prosthesis size. The present study compared novel automated 3-dimensional (3D) transesophageal echocardiography (TEE) software and multidetector row computed tomography (MDCT) for aortic annulus sizing and investigated the influence of the quantity of aortic valve calcium (AVC) on the selection of TAVI prosthesis size. A total of 83 patients with severe aortic stenosis undergoing TAVI were evaluated. Maximal and minimal aortic annulus diameter, perimeter, and area were measured. AVC was assessed with computed tomography. The low and high AVC burden groups were defined according to the median AVC score. Overall, 3D TEE measurements slightly underestimated the aortic annulus dimensions as compared with MDCT (mean differences between maximum, minimum diameter, perimeter, and area: -1.7 mm, 0.5 mm, -2.7 mm, and -13 mm², respectively). The agreement between 3D TEE and MDCT on aortic annulus dimensions was superior among patients with low AVC burden (<3,025 arbitrary units) compared with patients with high AVC burden (≥3,025 arbitrary units). The interobserver variability was excellent for both methods. 3D TEE and MDCT led to the same prosthesis size selection in 88%, 95%, and 81% of patients in the total population, the low, and the high AVC burden group, respectively. In conclusion, the novel automated 3D TEE imaging software allows accurate and highly reproducible measurements of the aortic annulus dimensions and shows excellent agreement with MDCT to determine the TAVI prosthesis size, particularly in patients with low AVC burden.

Feasibility, Accuracy, and Reproducibility of Aortic Annular and Root Sizing for Transcatheter Aortic Valve Replacement Using Novel Automated Three-Dimensional Echocardiographic Software: Comparison with Multi-Detector Row Computed Tomography

BACKGROUND

In transcatheter aortic valve replacement (TAVR), multi-detector row computed tomography (MDCT) is currently the standard imaging modality for correct prosthesis sizing, despite risks of radiation and contrast-induced renal injury. Three-dimensional (3D) transesophageal echocardiography (TEE) has been proposed as a potential alternative imaging technique, and recently, automated 3D transesophageal echocardiographic software (Aortic Valve Navigator [AVN], an unreleased prototype from Philips) has been developed for assessment of the aortic annulus and root. The aim of this study was to assess the feasibility, accuracy, and reproducibility of AVN measurements in TAVR candidates by performing a comparison with MDCT.

METHODS

In 150 patients with severe, symptomatic aortic stenosis referred for TAVR, data on aortic annular and root dimensions prospectively acquired using 3D TEE and MDCT were retrospectively analyzed. Image quality on 3D TEE and the duration of analysis with AVN were recorded, as well as the aortic valve Agatston score on MDCT.

RESULTS

Data were obtained using 3D TEE and MDCT in 100% of patients for aortic annular dimensions and in 89% for aortic root dimensions. The mean duration of analysis using AVN was 4.2 ± 1.0 min, but it was significantly shorter with better 3D echocardiographic image quality and lower Agatston score on MDCT. Correlation of measurements between 3D TEE and MDCT was good to excellent for all anatomic locations (sinotubular junction mean diameter, R = 0.71; sinus of Valsalva mean diameter, R = 0.87; aortic annular mean diameter, R = 0.75; aortic annular perimeter, R = 0.83; aortic annular area, R = 0.91), with low inter- and intraobserver variability (intraclass correlation coefficient ≥ 0.93 and r ≥ 0.90 for all locations). Comparison based on conventional prosthesis sizing charts yielded excellent agreement in prosthesis size choice (κ = 0.90).

CONCLUSIONS

New automated 3D transesophageal echocardiographic software allows accurate modeling and reproducible quantification of aortic annular and root dimensions with high feasibility. An excellent correlation between measurements with AVN and MDCT and agreement in prosthesis sizing suggests the use of AVN in clinical practice as potential alternative to MDCT before TAVR.

Is intra-procedure three-dimensional transesophageal echocardiogram an alternative to preprocedure multidetector computed tomography for the measurement of the aortic annulus in patients undergoing transcatheter aortic valve replacement?

BACKGROUND

The role of three-dimensional transesophageal echocardiography (3DTEE) vs multidetector computed tomography (MDCT) in aortic annular sizing has been poorly defined in patients undergoing transcatheter aortic valve replacements (TAVR). We set to determine the correlation between 3DTEE and MDCT in measuring the aortic annulus prior to TAVR.

METHODS

In an observational, retrospective study, we compared aortic annular areas measured by MDCT and 3DTEE in TAVR patients. The aortic annular area was measured by planimetry of images obtained by MDCT pre-TAVR and by intra-TAVR TEE using 3D rendering of the aortic annulus followed by planimetry. Our primary outcome was degree of correlation between mean aortic annulus area by 3DTEE and MDCT.

RESULTS

Of the 111 consecutive patients undergoing TAVR who had measurements from both modalities available for comparison between February 2012 and April 2015, 87 met inclusion criteria. The mean aortic annular area by MDCT was 4.44±0.88 cm² and by 3DTEE was 4.33±0.78 cm² . There was a strong positive linear correlation between aortic annular area measurements obtained from these two modalities with mild relative underestimation by 3DTEE (ρ=.833). This relationship can be estimated using the predictive formula: [Formula: see text] CONCLUSIONS: Three-dimensional transesophageal echocardiography measurements have a high degree of correlation with MDCT measurements and thus can assist in proper valve prosthesis selection for TAVR. Our study thus supports use of 3DTEE as a reasonable alternative imaging modality in patients undergoing TAVR.

Standard imaging techniques in transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has become a widely accepted therapeutic option for patients with severe, symptomatic aortic stenosis at intermediate, high, or extreme risk for conventional surgery as determined through a heart team approach. Two valve prostheses are currently available and the Food and Drug Administration (FDA) approved in the United States for TAVR: the self-expandable Medtronic CoreValve (Medtronic, Inc., Minneapolis, MN, USA) and the balloon-expandable Edwards Sapien Valve (Edwards Lifesciences, Irvine CA, USA). The preoperative evaluation for TAVR includes transthoracic echocardiography (TTE) for the diagnosis of aortic stenosis. Cardiac computed tomography (CTA) has become the imaging modality of choice for annular sizing. Aortic root dimensions and coronary ostia height, and the degree of annular and left ventricular outflow tract calcification are also assessed to estimate the risk of coronary obstruction, annular rupture, and postoperative aortic regurgitation. Finally, CTA is essential to determine the adequacy of the peripheral vasculature for a transfemoral approach. Intraoperatively, fluoroscopy is mandatory for valve positioning, whereas the use of TTE or transesophageal echocardiography (TEE) varies by center. TTE is used for postoperative surveillance of valve function.

International Expert Consensus on Sutureless and Rapid Deployment Valves in Aortic Valve Replacement Using Minimally Invasive Approaches

Objective

To define the benefit of sutureless and rapid deployment valves in current minimally invasive approaches in isolated aortic valve replacement.

Methods

A panel of 28 international experts with expertise in both minimally invasive aortic valve replacement and rapid deployment valves was constituted. After thorough literature review, the experts rated evidence-based recommendations in a modified Delphi approach.

Results

No guideline could be retrieved. Thirty-three clinical trials and 9 systematic reviews could be identified for detailed text analysis to obtain a total of 24 recommendations. After rating by the experts 12, final recommendations were identified: preoperative computed tomographic scan as well as intraoperative transesophageal echocardiography are highly recommended. Suitable annular sizes are 19 to 27 mm. There is a contraindication for bicuspid valves only for type 0 and for annular abscess or destruction due to infective endocarditis. The use of sutureless and rapid deployment valves reduces extracorporeal circulation and aortic cross-clamp time and leads to less early complications as prolonged ventilation, blood transfusion, atrial fibrillation, pleural effusions, paravalvular leakages and aortic regurgitation, and renal replacement therapy, respectively. These clinical outcomes result in reduced intensive care unit and hospital stay and reduced costs. The use of sutureless and rapid deployment valves will lead to a higher adoption rate of minimally invasive approaches in aortic valve replacement. Respect should be taken to a necessary short learning curve for both sutureless and minimally invasive programs.

Conclusions

Sutureless and rapid deployment aortic valve replacement together with minimally invasive approaches offers an attractive option in aortic valve placement for patients requiring biological valve replacement.

Balloon-Expandable Transcatheter Aortic Valves Can Be Successfully and Safely Implanted Transfemorally Without Balloon Valvuloplasty

OBJECTIVES

To assess the necessity for balloon aortic valvuloplasty (BAV) during transfemoral transcatheter aortic valve implantation (TAVI) when using balloon-expandable valves.

BACKGROUND

BAV is a usual part of TAVI procedures, prior to valve implantation. However, the benefits and necessity of this are unknown and recent evidence in self-expanding valves suggests it may not be necessary.

METHODS

Retrospective single-center study of 154 patients undergoing first-time, transfemoral TAVI for native aortic valve stenosis, with (N = 76), and without (N = 78), BAV as part of the procedure. Data collected included demographic, procedural, and outcome data.

RESULTS

BAV did not alter VARC-2 defined procedural success or early safety compared to not performing a BAV, including mortality, degree of aortic regurgitation, or need for post-TAVI balloon dilatation, although there was a strong trend to reduced stroke when not performing a BAV. There was a significantly reduced procedural time (P = 0.01) and fluoroscopic time (P < 0.001) without performing a BAV. There were no differences in cerebral embolization (solid, gaseous, or total emboli) noted between the 2 groups, as measured on transcranial doppler (TCD).

CONCLUSIONS

TAVI can be effectively and safely performed without a BAV and this results in reduced procedural and fluoroscopic times, although embolization to the brain is not reduced. There is a trend toward reduced stroke risk. (J Interven Cardiol 2016;29:319-324).

Automated and Manual Measurements of the Aortic Annulus with ECG-Gated Cardiac CT Angiography Prior to Transcatheter Aortic Valve Replacement: Comparison with 3D-Transesophageal Echocardiography

RATIONALE AND OBJECTIVES

Multimodality evaluation of the aortic annulus is generally advocated to plan for transcatheter aortic valve replacement (TAVR). We compared aortic annular measurements by cardiac computed tomography angiography (cCTA) to three-dimensional transesophageal echocardiography (3D-TEE), and also evaluated the use of semi-automated software for cCTA annular measurements.

MATERIALS AND METHODS

A retrospective cohort of 74 patients underwent 3D-TEE and electrocardiogram-gated cCTA of the heart within 30 days for TAVR planning. 3D-TEE measurements were obtained during mid-systole; cCTA measurements were obtained during late-systole (40% of R-R interval) and mid-diastole (80% of R-R interval). Annular area was measured independently by manual planimetry and with semi-automated software.

RESULTS

cCTA measurements in systole and diastole were highly correlated for short-axis diameter (r = 0.91), long-axis diameter (r = 0.92), and annular area (r = 0.96), although systolic measurements were significantly larger (P < 0.001), most notably for the short-axis diameter. Good correlation was observed between 3D-TEE and cCTA for short-axis diameter (r = 0.84-0.90), long-axis diameter (r = 0.77-0.79), and annular area (r = 0.89-0.90). As compared to 3D-TEE, annular area is overmeasured by 28 mm² on systolic phase cCTA (P < 0.008), but nearly identical with 3D-TEE on diastolic phase cCTA. Semi-automated and manual cCTA annulus measurements were highly correlated in systole (r = 0.94) and diastole (r = 0.93), although the semi-automated annular area measured 11-30 mm² greater than manual planimetry. Of note, the 95% limits of agreement in our Bland-Altman analysis suggest that the variability in annular area estimates for individual patients between cCTA and 3D-TEE (-100.9 to 99.6 mm²), as well as the variability between manual and automated measurements with cCTA (-105.9 to 45.2 mm²), may be sufficient to alter size selection for an aortic prosthesis.

CONCLUSIONS

Although all cCTA measurements are highly correlated with measurements by 3D-TEE, diastolic phase cCTA measurements tend to be closer to standard mid-systolic 3D-TEE measurements. Semi-automated measurement of the aortic annulus with cCTA is highly correlated with manual planimetry. Nonetheless, annular contours derived by semi-automated software should be visually inspected, as the variability in area estimates for individual cases between manual and automated measurements may alter the sizing of an aortic prosthesis.

Patient selection for transcatheter aortic valve replacement: A combined clinical and multimodality imaging approach

Transcatheter aortic valve replacement (TAVR) has been validated as a new therapy for patients affected by severe symptomatic aortic stenosis who are not eligible for surgical intervention because of major contraindication or high operative risk. Patient selection for TAVR should be based not only on accurate assessment of aortic stenosis morphology, but also on several clinical and functional data. Multi-Imaging modalities should be preferred for assessing the anatomy and the dimensions of the aortic valve and annulus before TAVR. Ultrasounds represent the first line tool in evaluation of this patients giving detailed anatomic description of aortic valve complex and allowing estimating with enough reliability the hemodynamic entity of valvular stenosis. Angiography should be used to assess coronary involvement and plan a revascularization strategy before the implant. Multislice computed tomography play a central role as it can give anatomical details in order to choice the best fitting prosthesis, evaluate the morphology of the access path and detect other relevant comorbidities. Cardiovascular magnetic resonance and positron emission tomography are emergent modality helpful in aortic stenosis evaluation. The aim of this review is to give an overview on TAVR clinical and technical aspects essential for adequate selection.

3D transoesophageal echocardiography in the TAVI sizing arena: should we do it and how do we do it?

Transcatheter aortic valve implantation (TAVI) was initially proven as an alternative to valve replacement therapy in those beyond established risk thresholds for conventional surgery. With time the technique has been methodically refined and offered to a progressively lower risk cohort, and with this evolution has come that of the significant imaging requirements of valve implantation. This review discusses the role of transoesophageal echocardiography (TOE) in the current TAVI arena, aligning it with that of cardiac computed tomography, and outlining how TOE can be used most effectively both prior to and during TAVI in order to optimise outcomes.

Role of Echocardiography Before Transcatheter Aortic Valve Implantation (TAVI)

Aortic stenosis (AS) is the most common primary valve disorder in the elderly with an increasing prevalence; transcatheter aortic valve implantation (TAVI) has become an accepted alternative to surgical aortic valve replacement (AVR) in the high risk or inoperable patient. Appropriate selection of patients for TAVI is crucial and requires a multidisciplinary approach including cardiothoracic surgeons, interventional cardiologists, anaesthetists, imaging experts and specialist nurses. Multimodality imaging including echocardiography, CT and MRI plays a pivotal role in the selection and planning process; however, echocardiography remains the primary imaging modality used for patient selection, intra-procedural guidance, post-procedural assessment and long-term follow-up. The contribution that contemporary transthoracic and transoesophageal echocardiography make to the selection and planning of TAVI is described in this article.

Impact of Methodologic Differences in Three-Dimensional Echocardiographic Measurements of the Aortic Annulus Compared with Computed Tomographic Angiography Before Transcatheter Aortic Valve Replacement

BACKGROUND

Three-dimensional (3D) echocardiographic (3DE) imaging is an alternative to multi-detector row computed tomography (MDCT) for aortic annular measurement before transcatheter aortic valve replacement (TAVR). A commonly used direct planimetry from a reconstructed short-axis view has not been compared with semiautomated 3DE methods. Typically accepted optimal cutoffs for percent prosthesis-area oversizing of the balloon-expandable SAPIEN or SAPIEN XT valve to native annular size are approximately 5% to 15%. The aim of this study was to compare semiautomated and direct planimetric 3DE methods for aortic annular sizing with a gold standard of MDCT to determine predictive value for paravalvular regurgitation (PVR) and balloon postdilatation.

METHODS

In this retrospective analysis, aortic annular cross-sectional area was measured from pre-TAVR imaging using (1) MDCT (CT_Area), (2) a 3D transesophageal echocardiographic (TEE) semiautomated method (3DE_Area_SA), and (3) a 3D TEE direct planimetric method (3DE_Area_Direct). Annular area percent oversizing was calculated. PVR after TAVR was assessed from intraoperative TEE imaging. Need for balloon postdilatation was recorded.

RESULTS

One hundred patients who underwent TAVR with either the SAPIEN or SAPIEN XT balloon-expandable prosthesis were analyzed. Twenty-three patients had mild or greater PVR after TAVR. CT_Area was 442 ± 79 mm², 3DE_Area_SA was 435 ± 81 mm², and 3DE_Area_Direct was 429 ± 82 mm². Both 3DE_Area_SA and 3DE_Area_Direct underestimated MDCT (P < .05). All methods were highly correlative (R = 0.88-0.93, P < .0001). Percent oversizing obtained by the three methods significantly predicted mild or greater PVR and need for balloon postdilatation by receiver operating characteristic analysis, with optimal cutoffs for CT_Area (9%-10%) and 3DE_Area_SA (14%) within the recommended ranges for the studied transcatheter valves and for 3DE_Area_Direct higher than the recommended range (18%-19%). Inter- and intraobserver reproducibility were lowest for 3DE_Area_Direct.

CONCLUSIONS

Caution must be used when using 3D TEE direct planimetry of the aortic annulus, as optimal percent oversizing ranges approach the level associated with root injury, and measurements are less reproducible. Therefore, semiautomated 3DE planimetry is preferred to 3DE direct planimetry for aortic annulus sizing.

The use of imaging in new transcatheter interventions: an EACVI review paper

Transcatheter therapies for the treatment of valve heart diseases have expanded dramatically over the last years. The new developments and improvements in devices and techniques, along with the increasing expertise of operators, have turned the catheter-based approaches for valvular disease into an established treatment option. Various imaging techniques are used during these procedures, but echocardiography plays an essential role during patient selection, intra-procedural monitoring, and post-procedure follow-up. The echocardiographic assessment of patients undergoing transcatheter interventions places demands on echocardiographers that differ from those of the routine evaluation of patients with valve disease, and there is a need for specific expertise for those working in the cath lab. In the context of the current rapid developments and growing use of transcatheter valve therapies, this document intends to update the previous recommendations and address new advancements in imaging, particularly for those involved in any stage of the treatment of patients with valvular heart diseases.

Robot-assisted real-time magnetic resonance image-guided transcatheter aortic valve replacement

BACKGROUND

Real-time magnetic resonance imaging (rtMRI)-guided transcatheter aortic valve replacement (TAVR) offers improved visualization, real-time imaging, and pinpoint accuracy with device delivery. Unfortunately, performing a TAVR in a MRI scanner can be a difficult task owing to limited space and an awkward working environment. Our solution was to design a MRI-compatible robot-assisted device to insert and deploy a self-expanding valve from a remote computer console. We present our preliminary results in a swine model.

METHODS

We used an MRI-compatible robotic arm and developed a valve delivery module. A 12-mm trocar was inserted in the apex of the heart via a subxiphoid incision. The delivery device and nitinol stented prosthesis were mounted on the robot. Two continuous real-time imaging planes provided a virtual real-time 3-dimensional reconstruction. The valve was deployed remotely by the surgeon via a graphic user interface.

RESULTS

In this acute nonsurvival study, 8 swine underwent robot-assisted rtMRI TAVR for evaluation of feasibility. Device deployment took a mean of 61 ± 5 seconds. Postdeployment necropsy was performed to confirm correlations between imaging and actual valve positions.

CONCLUSIONS

These results demonstrate the feasibility of robotic-assisted TAVR using rtMRI guidance. This approach may eliminate some of the challenges of performing a procedure while working inside of an MRI scanner, and may improve the success of TAVR. It provides superior visualization during the insertion process, pinpoint accuracy of deployment, and, potentially, communication between the imaging device and the robotic module to prevent incorrect or misaligned deployment.

Real-time magnetic resonance imaging-guided transcatheter aortic valve replacement

OBJECTIVES

To demonstrate the feasibility of Real-time magnetic resonance imaging (rtMRI) guided transcatheter aortic valve replacement (TAVR) with an active guidewire and an MRI compatible valve delivery catheter system in a swine model.

METHODS

The CoreValve system was minimally modified to be MRI-compatible by replacing the stainless steel components with fluoroplastic resin and high-density polyethylene components. Eight swine weighing 60-90 kg underwent rtMRI-guided TAVR with an active guidewire through a left subclavian approach.

RESULTS

Two imaging planes (long-axis view and short-axis view) were used simultaneously for real-time imaging during implantation. Successful deployment was performed without rapid ventricular pacing or cardiopulmonary bypass. Postdeployment images were acquired to evaluate the final valve position in addition to valvular and cardiac function.

CONCLUSIONS

Our results show that the CoreValve can be easily and effectively deployed through a left subclavian approach using rtMRI guidance, a minimally modified valve delivery catheter system, and an active guidewire. This method allows superior visualization before deployment, thereby allowing placement of the valve with pinpoint accuracy. rtMRI has the added benefit of the ability to perform immediate postprocedural functional assessment, while eliminating the morbidity associated with radiation exposure, rapid ventricular pacing, contrast media renal toxicity, and a more invasive procedure. Use of a commercially available device brings this rtMRI-guided approach closer to clinical reality.

Low contrast media volume in pre-TAVI CT examinations

PURPOSE

To evaluate image quality using reduced contrast media (CM) volume in pre-TAVI assessment.

METHODS

Forty-seven consecutive patients referred for pre-TAVI examination were evaluated. Patients were divided into two groups: group 1 BMI < 28 kg/m(2) (n = 29); and group 2 BMI > 28 kg/m(2) (n = 18). Patients received a combined scan protocol: retrospective ECG-gated helical CTA of the aortic root (80kVp) followed by a high-pitch spiral CTA (group 1: 70 kV; group 2: 80 kVp) from aortic arch to femoral arteries. All patients received one bolus of CM (300 mgI/ml): group 1: volume = 40 ml; flow rate = 3 ml/s, group 2: volume = 53 ml; flow rate = 4 ml/s. Attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the levels of the aortic root (helical) and peripheral arteries (high-pitch). Diagnostic image quality was considered sufficient at attenuation values > 250HU and CNR > 10.

RESULTS

Diagnostic image quality for TAVI measurements was obtained in 46 patients. Mean attenuation values and CNR (HU ± SD) at the aortic root (helical) were: group 1: 381 ± 65HU and 13 ± 8; group 2: 442 ± 68HU and 10 ± 5. At the peripheral arteries (high-pitch), mean values were: group 1: 430 ± 117HU and 11 ± 6; group 2: 389 ± 102HU and 13 ± 6.

CONCLUSION

CM volume can be substantially reduced using low kVp protocols, while maintaining sufficient image quality for the evaluation of aortic root and peripheral access sites.

KEY POINTS

• Image quality could be maintained using low kVp scan protocols. • Low kVp protocols reduce contrast media volume by 34-67 %. • Less contrast media volume lowers the risk of contrast-induced nephropathy.

Three-dimensional echocardiography vs. computed tomography for transcatheter aortic valve replacement sizing

AIMS

The accuracy of transcatheter aortic valve replacement (TAVR) sizing using three-dimensional transoesophageal echocardiography (3D-TEE) compared with the gold-standard multi-slice computed tomography (MSCT) remains unclear. We compare aortic annulus measurements assessed using these two imaging modalities.

METHODS AND RESULTS

We performed a single-centre prospective cohort study, including 53 consecutive patients undergoing TAVR, who had both MSCT and 3D-TEE for aortic annulus sizing. Aortic annular dimensions, expected transcatheter heart valve (THV) oversizing, and hypothetical valve size selection based on CT and TEE were compared. 3D-TEE and CT cross-sectional mean diameter (r = 0.69), perimeter (r = 0.70), and area (r = 0.67) were moderately to highly correlated (all P-values <0.0001). 3D-TEE-derived measurements were significantly smaller compared with MSCT: perimeter (68.6 ± 5.9 vs. 75.1 ± 5.7 mm, respectively; P < 0.0001); area (345.6 ± 64.5 vs. 426.9 ± 68.9 mm(2), respectively; P < 0.0001). The percentage difference between 3D-TEE and MSCT measurements was around 9%. Agreement between MSCT- and 3D-TEE-based THV sizing (perimeter) occurred in 44% of patients. Using the 3D-TEE perimeter annular measurements, up to 50% of patients would have received an inappropriate valve size according to manufacturer-recommended, area-derived sizing algorithms.

CONCLUSION

Aortic annulus measurements for pre-procedural TAVR assessment by 3D-TEE are significantly smaller than MSCT. In this study, such discrepancy would have resulted in up to 50% of all patients receiving the wrong THV size. 3D-TEE should be used for TAVR sizing, only when MSCT is not available or contraindicated. The clinical impact of this information requires further study.

Does the aortic annulus undergo conformational change throughout the cardiac cycle? A systematic review

Accurate annular sizing in transcatheter aortic valve implantation (TAVI) planning is essential. It is now widely recognized that the annulus is an oval structure in most patients, but it remains unclear if the annulus undergoes change in size and shape during the cardiac cycle that may impact prosthesis size selection. Our aim was to assess whether the aortic annulus undergoes dynamic conformational change during the cardiac cycle and to evaluate possible implications for prosthesis size selection. We performed a systematic search in PubMed and Embase databases and reviewed all available literature on aortic annulus measurements in at least two cardiac phases. Twenty-nine articles published from 2001 to 2014 were included. In total, 2021 subjects with and without aortic stenosis were evaluated with a mean age ranging from 11 ± 3.6 to 84.9 ± 7.2 years. Two- and three-dimensional echocardiography was performed in six studies each, magnetic resonance imaging was used in one and computed tomography in 17 studies. In general, the aortic annulus was more circular in systole and predominantly oval in diastole. Whereas the annular long-axis diameter showed insignificant change throughout the cycle, the short-axis diameter, area, and perimeter were significantly larger in systole compared with diastole. Hence, the aortic annulus does undergo dynamic changes during the cardiac cycle. In patients with large conformational changes, diastolic compared with systolic measurements can result in undersizing TAVI prostheses. Due to the complex annular anatomy and dynamic change, three-dimensional assessment in multiple phases has utmost importance in TAVI planning to improve prosthesis sizing.

Quantification of normative ranges and baseline predictors of aortoventricular interface dimensions using multi-detector computed tomographic imaging in patients without aortic valve disease

BACKGROUND

Multidetector computed tomographic (MDCT) assessment of the aortoventricular interface has gained increased importance with the advent of minimally invasive treatment modalities for aortic and mitral valve disease. This has included a standardised technique of identifying a plane through the nadir of each coronary cusp, the basal plane, and taking further measurements in relation to this plane. Despite this there is no published data defining normal ranges for these aortoventricular metrics in a healthy cohort. This study seeks to quantify normative ranges for MDCT derived aortoventricular dimensions and evaluate baseline demographic and anthropomorphic associates of these measurements in a normal cohort.

METHODS

250 consecutive patients undergoing MDCT coronary angiography were included. Aortoventricular dimensions at multiple levels of the aortoventricular interface were assessed and normative ranges quantified. Multivariate linear regression was performed to identify baseline predictors of each metric.

RESULTS

The mean age was 59±12 years. The basal plane was eccentric (EI=0.22±0.06) while the left ventricular outflow tract was more eccentric (EI=0.32±0.06), with no correlation to gender, age or hypertension. Male gender, height and body mass index were consistent independent predictors of larger aortoventricular dimensions at all anatomical levels, while age was predictive of supra-annular measurements.

CONCLUSIONS

Male gender, height and BMI are independent predictors of all aortoventricular dimensions while age predicts only supra-annular dimensions. Use of defined metrics such as the basal plane and formation of normative ranges for these metrics allows reference for clinical reporting and for future research studies by using a standardised measurement technique.