International Journal of Cardiology xxx (2014) xxx–xxx

IJCA-18121; No of Pages 6

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International Journal of Cardiology

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Letter to the Editor

Three-dimensional imaging of the aortic valve geometry for prosthesissizing prior to transcatheter aortic valve replacement

Christoph Hammerstingl a,⁎,1, Robert Schueler a,1, Marcel Weber a, Alexander Ghanem a, Nikos Werner a,Mariuca Vasa Nicotera a, Daniel Thomas b, Fritz Mellert c, Wolfgang Schiller c, Hans H. Schild b, Armin Welz c,Eberhard Grube a, Georg Nickenig a, Jan-Malte Sinning a

a Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Germanyb Department of Radiology, Heart Center Bonn, University Hospital Bonn, Germanyc Department of Cardiothoracic Surgery, Heart Center Bonn, University Hospital Bonn, Germany

Abbreviations: 2DTEE, two-dimensional transesophathree-dimensional transesophageal echocardiography; Ainterval; CIx, cover index; Dmin, minimal diameter; Dmmean diameter; MSCT, multisliced computed tomograpvalve replacement; pAR, paravalvular aortic valve regurgi⁎ Corresponding author at: Medizinische Klinik und Po

Bonn, Siegmund-Freud-Strasse 25, 53105 Bonn, Germafax: +49 228 287 19010.

1 CH and RS contributed equally to this manuscript.

http://dx.doi.org/10.1016/j.ijcard.2014.04.2200167-5273/© 2014 Elsevier Ireland Ltd. All rights reserved

Please cite this article as: Hammerstingl Ctranscatheter aortic valve replacement, Int J

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Article history:

Received 14 April 2014Accepted 17 April 2014Available online xxxx

Keywords:3D echocardiographyComputed tomographyParavalvular aortic regurgitationTranscatheter aortic valve implantationTranscatheter aortic valve replacement

a precise determination of the AV geometry equal toMSCT, but prospec-tive studies comparing 3DTEE with MSCT are limited. In this study, wecompared results from 2DTEE, 3DTEE and MSCT on AV dimensions be-fore and after establishing an interdisciplinary consensus decision on astandardized TAVR imaging protocol and aimed to determine structuralpredictors for the occurrence of pAR after TAVRwith the self-expandingMedtronic CoreValve prosthesis (Medtronic, Minneapolis, MN, USA).

At study initiation, we established an interdisciplinary 3DTAVR im-aging protocol with exact definition of a stepwise approach to visualizethe anatomical landmarks determining the AV annulus (Fig. 1) (9) andtwo experienced examiners (MSCT and 3DTEE)were trained on the im-

Transcatheter aortic valve replacement (TAVR) is established as analternative treatment option in patients with symptomatic aortic valvestenosis at high risk for cardiovascular surgery and has shown superior-ity over conservative management in inoperable patients [1,2]. Nonin-vasive imaging of the aortic valve (AV) geometry plays a central rolein TAVR because accurate determination of aortic annular diameters iscrucial for appropriate prosthesis sizing [3–5]. Current guidelines definemultislice computed tomography (MSCT) with three-dimensional (3D)reconstruction of aortic root geometry as the gold standard for pre-procedural patient selection despite MSCT inherits important limita-tions [8].

geal echocardiography; 3DTEE,V, aortic valve; CI, confidence

ax, maximal diameter; Dmean,hy; TAVR, transcatheter aortictation.liklinik II, Universitätsklinikumny. Tel.: +49 228 287 16670;

.

, et al, Three-dimensional iCardiol (2014), http://dx.doi.

Theoretically, 3D transesophageal echocardiography (3DTEE) allows

aging protocol with simultaneous determination of AV diameters in 10prospective patients, who did not enter the final study group.

The final study group consisted of 138 consecutive patients under-going TAVRwith theMedtronic CoreValve® prosthesis which were pro-spectively included and underwent MSCT and 3DTEE. The clinicalefficacy of TAVR sizing was defined by the occurrence of pAR after 30days of FU [9]. As proposed by Detaint et al., we calculated the AVcover index (CIx) to estimate the degree of oversizing and to detect po-tential annulus-prosthesismismatch [10]. Furthermore,we adapted thisformula to calculate cover indices from AV and annular perimeters andareas.

138 consecutive patients (age 81.1 ± 5.9 years) at high surgical risk(logistic EuroSCORE 26.8 ± 16.1%, STS score 9.3 ± 6.4%) underwentTAVR with the self-expanding Medtronic CoreValve prosthesis(Table 1). In 135 subjects the TAVR procedure was completed success-fully with a 30-day all cause mortality of 6.5% (Table 2).

We found a significant, but still moderate, correlation between2DTEE and MSCT for Dmean (0.79, p b 0.0001) and 2DTEE was notapplicable for the determination of minimal or maximal diameters, AVannulus perimeters, and AV annulus areas.

All measurements from 3DTEE were significantly correlated withMSCT. The correlation between 3D areas and perimeters from 3DTEEand MSCT was higher than for AV annulus diameters as confirmedby statistical testing for differences between measurements (Dmin,p = 0.001; Dmax, p b 0.0001; Dmean, p = 0.025; area, p = 0.64; pe-rimeter, p= 0.14) (Tables 3 and4; Fig. 2). In 88% of casesmeasurementsmade by 3DTEE,MSCTwould have led to an identical valve size selection.

maging of the aortic valve geometry for prosthesis sizing prior toorg/10.1016/j.ijcard.2014.04.220

Fig. 1.Model of the aortic root and 3D reconstruction of the anatomical landmarks. TEE, transesophageal echocardiography;MSCT, multisliced computed tomography. Anatomical modelof the aortic root and three-dimensionalmultiplanar reconstruction of theAV annulus fromTEE andMSCTwith definition/visualization of the [1.] sinutubular junction (blue circle), [2.] thesurgical annulus (gray dotted circle), and [3.] the virtual aortic annulus (green circle). For appropriate delineation of the AV annulus the short axis [blue plane] is adjusted to a perpendic-ular sagittal [green], and a coronal [red] plane and dragged toward the LVOT along a virtual center line [orange dotted line].

Table 1Baseline characteristics of the study groups.

All patients(n = 138)

Age (years) 81.1 ± 5.9Male gender, n (%) 72 (52.2)Logistic EuroSCORE (%) 26.8 ± 16.1STS mortality score (%) 9.3 ± 6.4Coronary artery disease, n (%) 95 (68.8)Extracardiac arteriopathy, n (%) 61 (44.2)Previous MI, n (%) 19 (13.8)Previous PCI, n (%) 53 (38.4)Previous CABG, n (%) 24 (17.4)Previous stroke, n (%) 27 (19.5)Chronic renal failure, n (%) 80 (58.0)COPD, n (%) 51 (37.0)Pulmonary hypertension, n (%) 45 (32.6)Left ventricular EF (%) 50.5 ± 14.8Pmean (mmHg) 42.7 ± 16.8AVA (cm2) 0.7 ± 0.2

STS, society of thoracic surgery; MI, myocardial infarction; PCI, percutaneouscoronary intervention; CABG, coronary artery bypass grafting; COPD, chronicobstructive pulmonary disease; EF, ejection fraction; Pmean, mean pressuregradient; AVA, aortic valve area.

Table 2Procedural details, acute results and outcome data after TAVR.

All patients(n = 138)

Pre-dilatation, n (%) 62 (44.9)Access site–Trans-femoral, n (%) 131 (94.9)–Trans-subclavian, n (%) 6 (4.3)–Trans-aortic, n (%) 1 (0.7)

Procedure time (min) 73.0 (59.0/90.0)Contrast dye (mL) 180 (132/217)Post-dilatation, n (%) 48 (34.8)Acute complicationsAnnular rupture 1 (0.7)Ventricular perforation 1 (0.7)Valve embolization 1 (0.7)Valve-in-valve implantation 8 (5.8)Stroke, n (%) 3 (2.2)Myocardial infarction, n (%) 2 (1.4)Major vascular complications, n (%) 8 (5.8)Pacemaker implantation, n (%) 23 (16.7)

Outcome data30-day mortality, n (%) 9 (6.5)6 months mortality, n (%) 20 (14.5)12 months mortality, n (%) 29 [15]

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Please cite this article as: Hammerstingl C, et al, Three-dimensional imaging of the aortic valve geometry for prosthesis sizing prior totranscatheter aortic valve replacement, Int J Cardiol (2014), http://dx.doi.org/10.1016/j.ijcard.2014.04.220

Table 3Correlations and differences between similar measurements from 3D imaging modalities before and after establishing the TAVR protocol.

Variable r p Value(for correlation)

ICC (95% CI) † Paired difference[mm]

(95% CI) p Value(for difference)

Percentage difference(SD)

3DTEE versus MSCT— historic dataDmax 3DTEE-MSCT 0.52 0.0007 0.62 0.59–0.7 −2.3 −3.1 to −1.5 b0.0001 10.3 (11.7)Dmin 3DTEE-MSCT 0.57 0.0002 0.72 0.47–0.85 −0.4 −1.2 to −0.3 0.03 2.9 (11.8)Dmean 3DTEE-CT 0.87 b0.0001 0.68 0.58–0.78 −1.3 −2.1 to −0.7 b0.0001 6.7 (9.5)Area 3DTEE-MSCT 0.70 b0.0001 0.82 0.66–0.9 −24.5 −37.1 to −8.7 0.002 4.9 (16.1)Perimeter 3DTEE-MSCT 0.65 b0.0001 0.79 0.6–0.89 −2.1 −3.1 to −0.8 0.03 1.8 (8.1)

3DTEE versus MSCT— according to TAVR imaging protocolDmax 3DTEE-MSCT 0.87 b0.0001 0.91 0.83–0.95 0.39 −0.1 to −0.9 0.1 1.9 (6.2)Dmin 3DTEE-MSCT 0.76 b0.0001 0.86 0.74–0.93 0.32 −0.2 to −0.9 0.3 1.9 (8.7)Dmean 3DTEE-CT 0.90 b0.0001 0.89 0.82–0.92 0.35 0.003–0.71 0.05 1.7 (4.7)Area 3DTEE-MSCT 0.86 b0.0001 0.89 0.78–0.94 −14.1 −23.1 to −2.7 0.05 3.5 (10.9)Perimeter 3DTEE-MSCT 0.91 b0.0001 0.94 0.88–0.97 1.3 −2.4 to −0.2 0.06 1.9 (4.7)

Dmax,maximumdiameter; Dmin, minimumdiameter; Dmean,mean diameter; r, correlation coefficient; ICC, intra-class correlation coefficient for absolute agreement betweenmeasure-ments; CI, confidence interval; SD, standard deviation; Percentage difference = ([CT dimension/3D-TEE dimension]− 1] × 100).

† (95% CI), CI of ICC.

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Considering MSCT as the gold standard, 3DTEE underestimated in 7% ofthe patients the AV size and in 5% of the patients, AV dimensions wouldhave been oversized with 3DTEE.

Both imagingmodalities (MSCT and 3DTEE) had a good reproducibil-ity and we found no relevant differences between MSCT and 3DTEE, asshown by intra- and inter-class agreement with correlation coefficientsN0.8 (Table 5).

More-than-mild pAR [9] was found in 12 patients after TAVR(7.2%) and all AV geometry defining parameters derived from 3D imag-ing had a better sensitivity to predict the occurrence of pAR after TAVRthan the results from 2D imaging (Table 6 and Fig. 3).

The presence of more-than-mild pAR after TAVR was related to asignificantly increased all cause mortality after 30 days (p b 0.0001;hazard ratio [HR] 22.3, 95% confidence interval [CI] 5.7–83.4), 6 months(p b 0.0001; HR 9.5, 95% CI 3.7–24.9), and 12 months of follow-up(p b 0.0001; HR 7.2, 95% CI 3.1–17.1) (Fig. 4, Table 7).

Our study was able to demonstrate that 3DTEE is highly comparableto MSCT for the evaluation of AV geometry prior to TAVR. As stated,echocardiography may substitute MSCT in patients, which cannot un-dergo MSCT, or when MSCT is not applicable.

When TAVR has started in early 2002, 3D echocardiography wasnot widely available and the aortic annulus was initially sized by2-dimensional measurements obtained from TTE. However, TTE hasbeen shown to underestimate the annulus size considerably and 2DTEE was not able to overcome these limitations [11,12]. Since 3D imag-ingwithMSCT allows accurate determination of AV annular geometry, ithas become the gold standard for TAVR sizing [11–13]. Since MSCT

Table 4Correlations and differences between 2D and 3D measurements.

Variable r p Value(for correlation)

ICC (95% CI) † Pai[mm

Dmean 2DTEE-MSCT 0.79 b0.0001 0.87 0.89–0.92 1.Dmax 3DTEE-MSCT 0.91 b0.0001 0.94 0.92–0.95 1.Dmin 3DTEE-MSCT 0.89 b0.0001 0.92 0.9–0.94 1.Dmean 3DTEE-MSCT 0.94 b0.0001 0.93 0.91–0.94 0.Area 3DTEE-MSCT 0.95 b0.0001 0.97 0.96–0.98 24.Perimeter 3DTEE-MSCT 0.92 b0.0001 0.95 0.94–0.96 2.

Dmax,maximumdiameter; Dmin, minimumdiameter; Dmean,mean diameter; r, correlation coments; CI, confidence interval; SD, standard deviation; Percentage difference = ([CT dimensio

† (95% CI), CI of ICC.

Please cite this article as: Hammerstingl C, et al, Three-dimensional itranscatheter aortic valve replacement, Int J Cardiol (2014), http://dx.doi.

inherits potential drawbacks and is not widely available, a debate isgoing on whether modern 3D echocardiography may substitute MSCTin selected patient groups [6]. However, at the current time thepublished data do not allow for clear recommendations on pre-TAVRimaging with 3DTEE [7,14], and up to now MSCT and 3D TEE werenever compared in a prospective, standardized fashion.

Here we present a large cohort of TAVR patients, who wereanalyzed systematically with MSCT and 3DTEE following a TAVRdedicated imaging protocol. Following this imaging algorithm wefound results from 3DTEE on AV geometry highly comparable withMSCT. Clear definitions of the AV geometry based on pre-definedanatomical landmarks and an ECG-gated image acquisition signifi-cantly improve the accuracy of 3DTEE. Importantly, 3D measurementsof AV-annular perimeters and areas showed the best correlationsbetween 3DTEE and MSCT and had the best predictive values for theoccurrence of pAR.

Our study is limited by its single-center character andby the fact thatwe only included patients undergoing TAVR with the MedtronicCoreValve prosthesis. We prospectively analyzed patients undergoing3DTEE by using one specific analysis software, therefore we cannot ex-clude that the results may differ when using other dedicated softwarepackages. Comparability of the results must be proven in larger, multi-center studies.

3DTEE allows precise assessment of aortic-valve geometry, is highlycomparable to MSCT, and can be reliably used for prosthesis size selec-tion in order to prevent clinically significant pAR in TAVR patients,which are not suitable for MSCT.

red difference]

(95% CI) p Value(for difference)

Percentage difference(SD)

4 −0.48 to −0.03 0.025 −0.8 (6.1)1 0.15–0.50 b0.0001 1.3 (4.3)05 0.12–0.45 0.001 1.5 (5.1)06 0.10–0.36 0.001 1.1 (3.6)8 −4.99 to 3.11 0.64 0.1 (5.9)7 −0.73 to 0.11 0.14 −0.3 (3.6)

efficient; ICC, intra-class correlation coefficient for absolute agreement betweenmeasure-n/3D-TEE dimension]− 1] × 100).

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Fig. 2. Effects of the TAVR imaging protocol on echocardiographic assessment of AV geometry. r, correlation coefficient; Dmean,mean diameter; Dmax, maximal diameter. Comparison ofhistoric 3DTEE data on AV dimensions with MSCT [left side], and results after 3DTEE data reassessment following the TAVR imaging protocol [right side].

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Please cite this article as: Hammerstingl C, et al, Three-dimensional imaging of the aortic valve geometry for prosthesis sizing prior totranscatheter aortic valve replacement, Int J Cardiol (2014), http://dx.doi.org/10.1016/j.ijcard.2014.04.220

Table 5Intra-class correlation for intra- and inter-observer agreement of different imagingmodal-ities.

Variable Intra-class correlation p Value

Intra-observer agreement3D TEE Dmin 0.91 b0.001

Dmax 0.92 b0.001Perimeter 0.95 b0.001Area 0.96 b0.001

MSCT Dmin 0.92 b0.001Dmax 0.91 b0.001Perimeter 0.98 b0.001Area 0.97 b0.001

Inter-observer agreement3DTEE Dmin 0.89 0.004

Dmax 0.88 0.005Perimeter 0.91 0.002Area 0.92 0.003

MSCT Dmin 0.89 0.003Dmax 0.91 b0.001Perimeter 0.94 b0.001Area 0.95 b0.001

Dmin, minimum diameter; Dmax, maximum diameter; 3DTEE, three-dimensional trans-esophageal echocardiography; MSCT, multisliced computed tomography.

Table 6Predictive values of different imaging parameter for the occurrence of more than mildparavalvular aortic regurgitation.

Parameter AUC (95% CI) p Sensitivity(95% CI)

Specificity(95% CI)

MSCTΔ Area 0.82 (0.73–0.88) 0.013 80.0 (28.4–99.5) 87.2 (79.4–92.8)Δ Perimeter 0.85 (0.77–0.91) 0.002 83.3 (35.9–99.6) 91.5 (85.0–95.9)Δ Dmean 0.79 (0.71–0.86) 0.0002 100 (54.1–100) 51.7 (42.3–61.0)CIx diameter 0.84 (0.76–0.90) 0.0001 75.0 (34.9–96.8) 92.3 (86.3–96.8)CIx perimeter 0.84 (0.77–0.89) b0.0001 80.0 (34.8–97.5) 81.2 (74.0–87.1)CIx area 0.87 (0.79–0.93) 0.0001 80.0 (28.4–99.5) 93.6 (87.2–97.4)

3D TEEΔ Area 0.77 (0.69–0.83) 0.009 66.7 (29.9–92.5) 86.7 (79.6–92.1)Δ Perimeter 0.81 (0.73–0.87) 0.001 66.7 (29.9–92.5) 94.5 (89.1–97.8)Δ Dmean 0.76 (0.68–0.83) 0.009 55.6 (21.2–86.3) 90.6 (84.2–95.1)CIx diameter 0.79 (0.71–0.85) 0.003 77.8 (40.0–97.2) 75.8 (67.4–82.9)CIx perimeter 0.82 (0.75–0.88) 0.0002 66.7 (29.9–92.5) 95.3 (90.1–98.3)CIx area 0.82 (0.74–0.88) 0.0002 66.7 (29.9–92.5) 92.9 (87.1–96.7)

3DTEE, three-dimensional transesophageal echocardiography;MSCT,multisliced comput-ed tomography; AUC, area under the curve;Δ, delta = difference between prosthesis andannular size; CI, confidence interval; CIx, cover index; Dmean, mean diameter; Dmax,maximum diameter; SD, standard deviation.

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Please cite this article as: Hammerstingl C, et al, Three-dimensional itranscatheter aortic valve replacement, Int J Cardiol (2014), http://dx.doi.

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[5] Jilaihawi H, Chin D, Spyt T, et al. Prosthesis-patient mismatch after transcatheteraortic valve implantation with the Medtronic-Corevalve bioprosthesis. Eur Heart J2010;31:857–64.

[6] Kasel AM, Cassese S, Bleiziffer S, et al. Standardized imaging for aortic annular sizing:implications for transcatheter valve selection. JACC Cardiovasc Imaging 2013;6:249–62.

[7] Ng AC, Delgado V, van der Kley F, et al. Comparison of aortic root dimensions andgeometries before and after transcatheter aortic valve implantation by 2- and3-dimensional transesophageal echocardiography and multislice computed tomog-raphy. Circ Cardiovasc Imaging 2010;3:94–102.

[8] Sinning JM, Ghanem A, Steinhauser H, et al. Renal function as predictor of mortalityin patients after percutaneous transcatheter aortic valve implantation. JACCCardiovasc Interv 2010;3:1141–9.

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[11] Willson AB, Webb JG, Labounty TM, et al. 3-dimensional aortic annular assessmentby multidetector computed tomography predicts moderate or severe paravalvularregurgitation after transcatheter aortic valve replacement: a multicenter retrospec-tive analysis. J Am Coll Cardiol 2012;59:1287–94.

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Fig. 3. Receiver operating characteristics curves of anatomical variableswith identification of upper cutoff valueswith the best predictive values for pAR after TAVR. ROC, receiver operatingcharacteristics; CI, cover index; CT, computed tomography; TEE, transesophageal echocardiography. ROC curve analysis of different CI plotted with red dotted lines.

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Table 7Multivariate regression analysis of independent predictors of 1-year outcome.

Variable OR 95% CI Coefficient SE p

pAR 11.2 2.5 to 50.8 2.4 0.8 0.001Log EuroSCORE 1.04 1.0 to 1.1 0.04 0.01 0.009Major vascular complications 5.5 1.1 to 26.6 1.7 0.8 0.03

OR, odds ratio; CI, confidence interval; SE, standard error; pAR, paravalvular aortic regur-gitation; log, logistic.Only the most significant independent univariate predictors entered the multivariateregression model.

Fig. 4. Mortality rates after TAVR separated by presence of more-than-mild pAR. pAR,more-than-mild paravalvular aortic regurgitation; HR, hazard ratio; CI, confidence inter-val. Kaplan–Meier survival analysis for comparison between patientswith andwithout oc-currence of more-than-mild pAR; statistical differences between groups were calculatedby using the log-rank test, hazard ratios were calculated with univariate Cox regressionanalysis.

Please cite this article as: Hammerstingl C, et al, Three-dimensional imaging of the aortic valve geometry for prosthesis sizing prior totranscatheter aortic valve replacement, Int J Cardiol (2014), http://dx.doi.org/10.1016/j.ijcard.2014.04.220