Impact of three-dimensional transesophageal echocardiography on prosthesis sizing for transcatheter aortic valve implantation

A discrepancy between CT angiography and transesophageal echocardiographic measurements of the annular size affect long-term survival following trans-catheter aortic valve replacement

Introduction: Accurate measurement of the aortic valve annulus is critical for proper valve sizing for the transcatheter aortic valve replacement (TAVR) procedure. While computed tomography angiography (CTA) is the widely-accepted standard, two-dimensional (2D) and three-dimensional(3D) transesophageal echocardiography (TEE) is commonly performed to measure the size of the aortic valve and to verify appropriate seating of prostheses.

Methods: Patients undergoing TAVR between 2013-2015 were examined. 2D- and 3D-TEEmeasurements were compared to CTA taken as standard. Patients were followed for at least one year. The presence and effect of discrepancy (defined as a difference of more than 10%) between CTA and TEE measurements on survival were examined.

Results: One hundred eighty-five patients (70 men) were included. 2D- and 3D-TEE measurements underestimated the annulus size by -1.49 and -1.32 mm, respectively. Discrepancies > 10% between TEE and CTA methods in estimating the aortic annulus size were associated with a decrease in post implant survival. The peak pressure gradient across the aortic prosthesis measured one year after the implant was higher in patients with an initial discrepancy between 3D-TEE and CTA measurements. In a multivariate cox-regression model, the discrepancy between CTA and 2D-TEE readings and the smaller size of the aortic annular area were the predictors of long-term survival.

Conclusion: Both 2D and 3D-TEE underestimate the aortic annulus measurements compared to CTA, with 2D-TEE being relatively more precise than 3D-TEE technology. The presence of a discrepancy between echocardiographic and CTA measurements of the aortic annulus is associated with a lower survival rate.

Comparison of the effective orifice area of prosthetic mitral valves using two-dimensional versus three-dimensional transesophageal echocardiography

Objective

This study compared the continuity equation-based effective orifice area (EOA) of prosthetic mitral valves between two-dimensional (2D) and 3D transesophageal echocardiography (TEE).

Methods

Thirty-four patients without major aortic valve abnormalities underwent mitral valve replacement surgery. The EOAs of prosthetic mitral valves were calculated using the continuity equation with 2D and 3D TEE. For 18/34 patients using a biological valve prosthesis, the EOA of the prosthesis was obtained from commercial records.

Results

The EOA of prosthetic mitral valves significantly varied between the 2D and 3D methods (2.22 ± 0.71 vs 2.35 ± 0.70 cm², n = 34). The area of the diameter of the left ventricular outflow tract as determined by the 3D method was significantly higher than that by the 2D method (mean difference: −0.14 ± 0.20 cm²), with 95% coherence boundaries of −0.53 and 0.25 cm². The regression equation for the EOA by 3D and 2D TEE was y = 0.27 + 0.94x, with a good correlation.

Conclusions

The EOA of prosthetic mitral valves is underestimated using the 2D TEE method compared with the 3D TEE method. The 3D-TEE method has the advantage of higher precision over the 2D TEE method, and it may be helpful for better assessment of prosthetic mitral valves intraoperatively.

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.

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.

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.

Accuracy of Aortic Annulus Diameter Measurement: Comparison of Multi-Detector CT, Two- and Three-Dimensional Echocardiography

OBJECTIVE

Accurate preprocedural quantification of the aortic annulus diameter is crucial for the operative success of the aortic valve surgery and especially transcatheter aortic valve replacement (TAVR). We conducted a prospective study to compare the accuracy of preoperative aortic annulus measurements using different imaging methods and direct measurements for aortic valve surgery.

METHODS

We enrolled 52 patients who underwent open aortic valve surgery between March 2012 and March 2014. Aortic annulus diameter was prospectively measured by transthoracic two-dimensional echocardiography (2D-TTE), transesophageal three-dimensional echocardiography (3D-TEE), and multi-detector computed tomography (MDCT). Imaging measurements were performed blindly by lab technicians. At surgery, the aortic annulus diameter was directly measured.

RESULTS

Of the three methods, MDCT provided the smallest error in determining aortic annulus size as compared with the measurements at surgery. The limit of agreement of the aortic diameter by MDCT was smallest in the present study.

CONCLUSIONS

The MDCT provided the most accurate measurement of aortic annulus diameter compared with 2D-TTE and 3D-TEE.

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.

Accuracy and reproducibility of novel echocardiographic three-dimensional automated software for the assessment of the aortic root in candidates for thanscatheter aortic valve replacement

AIMS

A specialized three-dimensional transoesophageal echocardiography (3D-TOE) reconstruction tool has recently been introduced; the system automatically configures a geometric model of the aortic root from the images obtained by 3D-TOE and performs quantitative analysis of these structures. The aim of this study was to compare the measurements of the aortic annulus (AA) obtained by the new model to that obtained by 3D-TOE and multidetector computed tomography (MDCT) in candidates to transcatheter aortic valve implantation (TAVI) and to assess the reproducibility of this new method.

METHODS AND RESULTS

We included 31 patients who underwent TAVI. The AA diameters and area were evaluated by the manual 3D-TOE method and by the automatic software. We showed an excellent correlation between the measurements obtained by both methods: intra-class correlation coefficient (ICC): 0.731 (0.508-0.862), r: 0.742 for AA diameter and ICC: 0.723 (0.662-0.923), r: 0.723 for the AA area, with no significant differences regardless of the method used. The interobserver variability was superior for the automatic measurements than for the manual ones. In a subgroup of 10 patients, we also found an excellent correlation between the automatic measurements and those obtained by MDCT, ICC: 0.941 (0.761-0.985), r: 0.901 for AA diameter and ICC: 0.853 (0.409-0.964), r: 0.744 for the AA area.

CONCLUSION

The new automatic 3D-TOE software allows modelling and quantifying the aortic root from 3D-TOE data with high reproducibility. There is good correlation between the automated measurements and other 3D validated techniques. Our results support its use in clinical practice as an alternative to MDCT previous to TAVI.

Prosthesis-patient mismatch after transcatheter aortic valve implantation: impact of 2D-transthoracic echocardiography versus 3D-transesophageal echocardiography

To investigate the role of 2D-transthoracic echocardiography (2D-TTE) and 3D-transesophageal echocardiography (3D-TEE) in the determination of aortic annulus size prior transcatheter aortic valve implantation (TAVI) and its' impact on the prevalence of patient prosthesis mismatch (PPM). Echocardiography plays an important role in measuring aortic annulus dimension in patients undergoing TAVI. This has great importance since it determines both eligibility for TAVI and selection of prosthesis type and size, and can be potentially important in preventing an inadequate ratio between the prosthetic valvular orifice and the patient's body surface area, concept known as prosthesis-patient mismatch (PPM). A total of 45 patients were studied pre-TAVI: 20 underwent 3D-TEE (men/women 12/8, age 84.8 ± 5.6) and 25 2D-TTE (men/women 9/16, age 84.4 ± 5.4) in order to measure aortic annulus diameter. The presence of PPM was assessed before hospital discharge and after a mean period of 3 months. Moderate PPM was defined as indexed aortic valve area (AVAi) ≤ 0.85 cm(2)/m(2) and severe PPM as AVAi < 0.65 cm(2)/m(2). Immediately post-TAVI, moderate PPM was present in 25 and 28 % of patients worked up using 3D-TEE and 2D-TTE respectively p value = n.s) and severe PPM occurred in 10 % of the patients who underwent 3D-TEE and in 20 % in those with 2D-TTE (p value = n.s). The echocardiographic evaluation 3 months post-TAVI showed 25 % moderate PPM in the 3D-TEE group compared with 24 % in the 2D-TTE group (p value = n.s) and no cases of severe PPM in the 3DTEE group comparing to 20 % in the 2D-TTE group (p = 0.032). Our results indicate a higher incidence of severe PPM in patients who performed 2DTTE compared to those performing 3DTEE prior TAVI. This suggests that the 3D technique should replace the 2DTTE analysis when investigating the aortic annulus diameter in patients undergoing TAVI.

Early outcomes of transcatheter aortic valve replacement in patients with severe aortic stenosis: single center experience

INTRODUCTION

Transcatheter aortic valve implantation is a promising alternative to high risk surgical aortic valve replacement. The procedure is mainly indicated in patients with severe symptomatic aortic stenosis who cannot undergo surgery or who are at very high surgical risk.

AIM

Description early results of our single-center experience with balloon expandable aortic valve implantation.

MATERIAL AND METHODS

Between July 2011 and August 2012, we screened in total 75 consecutive patients with severe aortic stenosis and high risk for surgery. Twenty-one of them were found ineligible for transcatheter aortic valve implantation (TAVI) because of various reasons, and finally we treated a total of 54 patients with symptomatic severe aortic stenosis (AS) who could not be treated by open heart surgery (inoperable) because of high-risk criteria. The average age of the patients was 77.4 ±7.1; 27.8% were male and 72.2% were female. The number of patients in NYHA class II was 7 while the number of patients in class III and class IV was 47.

RESULTS

The average mortality score of patients according to the STS scoring system was 8.5%. Pre-implantation mean and maximal aortic valve gradients were measured as 53.2 ±14.1 mm Hg and 85.5 ±18.9 mm Hg, respectively. Post-implantation mean and maximal aortic valve gradients were 9.0 ±3.0 and 18.2 ±5.6, respectively (p < 0.0001). The left ventricular ejection fraction was calculated as 54.7 ±14.4% before the operation and 58.0 ±11.1% after the operation (p < 0.0001). The duration of discharge after the operation was 5.29 days, and a statistically significant correlation between the duration of discharge after the operation and STS was found (r = 0385, p = 0.004).

CONCLUSIONS

We consider that with decreasing cost and increasing treatment experience, TAVI will be used more frequently in broader indications. Our experience with TAVI using the Edwards-Sapien XT (Edwards Lifesciences, Irvine, CA) devices suggests that this is an effective and relatively safe procedure for the treatment of severe aortic stenosis in suitable patients.

Percutaneous heart valves; past, present and future

Percutaneous heart valves provide a promising future for patients refused surgery on the grounds of significant technical challenges or high risk for complications. Since the first human intervention more than 10 years ago, over 50 different types of valves have been developed. The CoreValve and Edwards SAPIEN valves have both experienced clinical trials and the latter has gained FDA approval for implantation in patients considered inoperable. Current complications, such as major vascular bleeding and stroke, prevent these valves from being commonly deployed in patients considered operable in conventional surgery. This review focuses on the past and present achievements of these valves and highlights the design considerations required to progress development further. It is envisaged that, with continued improvement in valve design and with increased clinical and engineering experience, percutaneous heart valve replacement may one day be a viable option for lower-risk operable patients.

Imaging in Transcatheter Aortic Valve Replacement (TAVR): role of the radiologist

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a novel technique developed in the last decade to treat severe aortic stenosis in patients who are non-surgical candidates because of multiple comorbidities.

METHODS

Since the technique is performed using a transvascular approach, pre-procedural assessment of the aortic valve apparatus, ascending aorta and vascular access is of paramount importance for both appropriate patient selection and correct device selection. This assessment is performed by a multi-disciplinary team with radiology being an integral and important part.

RESULTS

Among imaging modalities, there is growing scientific evidence supporting the crucial role of MDCT in the assessment of the aortic valve apparatus, suitability of the iliofemoral or alternative pathway, and determination of appropriate coaxial angles. MDCT also plays an important role in post-procedure imaging in the assessment of valve integrity and position.

CONCLUSION

This review outlines the principal aspects of TAVR, the multidisciplinary approach and utilisation of different imaging modalities, as well as a step-by-step approach to MDCT acquisition protocols, reconstruction techniques, pre-procedure measurements and post-procedure assessment.

TEACHING POINTS

• TAVR is a new technique to treat severe aortic stenosis in high-risk and nonsurgical candidates. • MDCT assessment of the aortic annulus is important for appropriate patient and device selection. • Multidisciplinary approach is required for patient selection, procedure planning and performance. • MDCT is required for assessment of the aortic root, iliofemoral or alternative vascular pathway.

Aortic annular sizing using a novel 3-dimensional echocardiographic method: use and comparison with cardiac computed tomography

BACKGROUND

Previous studies have shown cross-sectional 3-dimensional (3D) transesophageal echocardiographic (TEE) measurements to severely underestimate multidetector row computed tomographic (MDCT) measurements for the assessment of aortic annulus before transcatheter aortic valve replacement. This study compares annulus measurements from 3D-TEE using off-label use of commercially available software with MDCT measurements and assesses their ability to predict paravalvular regurgitation.

METHODS AND RESULTS

One hundred patients with severe, symptomatic aortic stenosis who had both contrast MDCT and 3D-TEE for annulus assessment before balloon-expandable transcatheter aortic valve replacement were analyzed. Annulus area, perimeter, and orthogonal maximum and minimum diameters were measured. Receiver operating characteristic analysis was performed with mild or greater paravalvular regurgitation as the classification variable. Three-dimensional TEE and MDCT cross-sectional perimeter and area measurements were strongly correlated (r=0.93-0.94; P<0.0001); however, the small differences (≤1%) were statistically significant (P=0.0002 and 0.0074, respectively). Discriminatory ability for ≥ mild paravalvular regurgitation was good for both MDCT (area under the curve for perimeter and area cover index=0.715 and 0.709, respectively) and 3D-TEE (area under the curve for perimeter and area cover index=0.709 and 0.694, respectively). Differences in receiver operating characteristic analysis between MDCT and 3D-TEE perimeter and area cover indexes were not statistically significant (P=0.15 and 0.35, respectively).

CONCLUSIONS

Annulus measurements using a new method for analyzing 3D-TEE images closely approximate those of MDCT. Annulus measurements from both modalities predict mild or greater paravalvular regurgitation with equivalent accuracy.

Patient selection for transcatheter aortic valve implantation: An interventional cardiology perspective

Transcatheter aortic valve implantation (TAVI) has emerged as a highly effective minimally invasive treatment symptomatic for severe calcific aortic stenosis in patients at high or prohibitive surgical risk. The success of TAVI has been determined by a number of factors, but in particular by appropriate patient selection. Appropriate patient selection involves identifying patients with the potential to benefit most from TAVI and individualizing the bioprosthesis type and size, and the vascular access site for each case. We present herein, our critical appraisal on patient selection for TAVI: an interventional cardiology perspective.

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

BACKGROUND

The complex anatomy of the aortic annulus warrants the use of three dimensional (3D) modalities for prosthesis sizing in transcatheter aortic valve implantation (TAVI). Multislice computed tomography (MSCT) has been used for this purpose, but its use may be restricted because of contrast administration. 3D transesophageal echocardiography (3D-TEE) lacks this limitation and data on comparison with MSCT is scarce. We compared 3D-TEE with MSCT for prosthesis sizing in TAVI.

METHODS

Aortic annulus diameters in the sagittal and coronal plane and annulus areas in 3D-TEE and MSCT were compared in 57 patients undergoing TAVI. Final prosthesis size was left at the operator's discretion and the agreement with 3D-TEE and MSCT was calculated.

RESULTS

Sagittal diameters on 3D-TEE and MSCT correlated well (r=.754, p<.0001) and means were comparable (22.3±2.1 vs. 22.5±2.3 mm; p=0.2; mean difference: -0.3 mm [-3.3-2.8]). On 3D-TEE, coronal diameter and annulus area were significantly smaller (p<.0001 for both) with moderate correlation (r=0.454 and r=0.592). Interobserver variability was comparable for both modalities. TAVI was successful in all patients with no severe post-procedural insufficiency. Final prosthesis size was best predicted by sagittal annulus diameters in 84% and 79% by 3D-TEE and MSCT, respectively. Agreement between both modalities was 77%.

CONCLUSIONS

Annulus diameters and areas for pre-procedural TAVI assessment by 3D-TEE are significantly smaller than MSCT with exception of sagittal diameters. Using sagittal diameters, both modalities predicted well final prosthesis size and excellent procedural results were obtained. 3D-TEE can thus be a useful alternative in patients with contraindications to MSCT.

Future perspectives in transcatheter aortic valve implantation

Transcatheter aortic valve replacement (TAVR) constitutes a relatively new treatment option for the patients with severe symptomatic aortic stenosis. Evidence from registries and randomized control trials has underscored the value of this treatment in inoperable and high risk populations, while new developments in valve technology and TAVR enabling devices have reduced the risk of complications, simplified the procedure, and broadened the applications of this therapy. The initial promising clinical results and the potential of an effective less invasive treatment of aortic stenosis has not only created high expectations but also the need to address the pitfalls of TAVR technology. The evolving knowledge concerning the groups of patients who would benefit from this treatment, the limited long term follow-up data, the concerns about devices' long term durability, and the severity of complications remain important caveats which restrict the widespread clinical adoption of TAVR. The aim of this review article is to present the recent advances, highlight the limitations of TAVR technology, and discuss the future perspectives in this rapidly evolving field.

Transesophageal echocardiography measurements of aortic annulus diameter using biplane mode in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Aortic stenosis (AS) is a relevant common valve disorder. Severe AS and symptoms and/or left ventricular dysfunction (EF <50%) have the indication for aortic valve replacement (AVR). Majority of the patients with AS are elderly often with co-morbidities and generally have high preoperative risk. Transcatheter aortic valve implantation (TAVI) is offered in this group. Four different sizes of Corevalve prosthesis are available. Correct measurement of aortic size prior to TAVI is of great important to choose the right prosthesis size to avoid among others paravalvular leak or prosthesis patient mismatch.Aim of the study is to assess the aortic annulus diameter in patients undergoing TAVI by biplane (BP) mode using transesophageal echocardiography (TEE) and compare it to two-dimensional (2D) transthoracic echocardiography (TTE) and 2DTEE using three-dimensional (3D) TEE as reference method.

METHODS

The study population consisted of 50 patients retrospectively (24 men and 26 women, mean age 85±8 years of age) who all had undergone echocardiography examination prior to TAVI.

RESULTS

The mean aortic annulus diameter was 20.4±2.2 mm with TTE, 22.3±2.5 mm with 2DTEE, 22.9±1.9 mm with BP-mode and 23.1±1.9 mm with 3DTEE. TTE underestimated the mean aortic annulus diameter in comparison to transesophageal imaging modalities (p<0.001). Using 3DTEE, 2% of patients were unsuitable for TAVI due to a too-small AoA (n=1). This figure was similar with BP (4%, n=2; p=1.00) but considerably larger with 2DTTE (36%, n=18; p < 0.001) and 2DTEE (12%, n=6; p=0.06). There was a strong correlation between BP-mode and 3DTEE for assessment of aortic annulus diameter (r-value 0.88) with small mean difference (-0.2±0.9 mm) whereas the other modalities showed larger 95% confidence interval and modest correlation (2DTTE vs. 3DTEE, -6.3 to 0.9 mm, r=0.64 and 2DTEE vs. 3DTEE, -4.8 to 3.2 mm, r=0.61).

CONCLUSION

A multi-dimensional method is preferred to assess aortic annulus diameter in TAVI patients since there is risk of underestimation using single plane. Biplane mode is the method of choice in view of speedy post-processing with no need for expensive dedicated software. Lastly, single plane methods lead to misclassification of patients as unsuitable for TAVI. This may be of major clinical importance.