A method to determine suitable fluoroscopic projections for transcatheter aortic valve implantation by computed tomography

Evaluation of the second-generation whole-heart motion correction algorithm (SSF2) used to demonstrate the aortic annulus on cardiac CT

The main purpose of pre-transcatheter aortic valve implantation (TAVI) cardiac computed tomography (CT) for patients with severe aortic stenosis is aortic annulus measurements. However, motion artifacts present a technical challenge because they can reduce the measurement accuracy of the aortic annulus. Therefore, we applied the recently developed second-generation whole-heart motion correction algorithm (SnapShot Freeze 2.0, SSF2) to pre-TAVI cardiac CT and investigated its clinical utility by stratified analysis of the patient's heart rate during scanning. We found that SSF2 reconstruction significantly reduced aortic annulus motion artifacts and improved the image quality and measurement accuracy compared to standard reconstruction, especially in patients with high heart rate or a 40% R-R interval (systolic phase). SSF2 may contribute to improving the measurement accuracy of the aortic annulus.

A CT-based technique to predict optimal projection for self-expanding TAVI in patients with different aortic valve anatomies

Background

Optimal projection is essential for valve deployment during transcatheter aortic valve implantation (TAVI). The purpose of this study was to propose an approach to predict optimal projection in TAVI candidates with different aortic valve anatomies.

Methods

331 patients undergoing self-expanding TAVI were included and the so-called non-coronary cusp (NCC)-parallel technique was utilized, which generated the predicted projection by connecting NCC commissures on the transverse plane on the pre-procedural computed tomography images.

Results

37.8% of the study cohort were bicuspid aortic valve (BAV) patients. Around 80% of both NCC-parallel views and final views were in the right anterior oblique (RAO) and caudal (CAU) quadrant. There was less than 5° change required from the NCC-parallel view to the final implanted view in 79% of tricuspid aortic valve (TAV) patients but only in 27% (13/48) of type 0 BAV patients with coronary arteries originated from the different cusps. After excluding the above mentioned BAV patients, 62.3% (48/77) of BAV patients needed less than 5° change to achieve optimal projection and only in 8 patients, the angular change was larger than 10° in either left/right anterior oblique or cranial/caudal direction.

Conclusions

The NCC-parallel technique provides reliable prediction for optimal projection in self-expanding TAVI in all TAV and most BAV patients, with a vast majority of views in the RAO and CAU quadrant.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02387-7.

Cusp Overlap Technique: Should It Become the Standard Implantation Technique for Self-expanding Valves?

PURPOSE OF REVIEW

Accurate imaging of the aortic root during valve implantation is crucial for proper prosthesis positioning during TAVR. The purpose of this review was to determine if routine use of the cusp-overlap view should be adopted for self-expanding valves.

RECENT FINDINGS

The use of the cusp-overlap view with the Evolut, Portico, ACURATE neo/neo2, and JenaValve systems is associated with lower post-procedural new permanent pacemaker implantation rates when compared with the standard 3-cusp view, presumably due to more precise valve implantation relative to the conduction system by the non-coronary cusp. By elongating the left ventricular outflow tract and accentuating the right-non commissure in the center of the fluoroscopic view, the cusp-overlap technique allows operators to more precisely control the prosthesis implant depth during self-expanding valve deployment. While the early experience with this approach in Evolut TAVR has been promising, the results of larger studies with longer follow-up across multiple self-expanding systems are warranted.

Double S-Curve Versus Cusp-Overlap Technique: Defining the Optimal Fluoroscopic Projection for TAVR With a Self-Expanding Device

OBJECTIVES

The purpose of this study was to assess the concordance between transcatheter aortic valve implantation angles generated by the "double S-curve" and "cusp-overlap" techniques.

BACKGROUND

The "double S-curve" and "cusp-overlap" methods aim to define optimal fluoroscopic projections for transcatheter aortic valve replacement (TAVR) with a self-expandable device.

METHODS

The study included 100 consecutive patients undergoing TAVR with self-expanding device planned by multidetector computed tomography. TAVR was performed using the double S-curve model, as a view in which both the aortic valve annulus and delivery catheter planes are displayed perpendicularly on fluoroscopy. Optimal projection according to the cusp-overlap technique was retrospectively generated by overlapping the right and left cups on the multidetector computed tomography annular plane. The angular difference between methods was assessed in spherical 3 dimensions and on the left and right anterior oblique (RAO) and cranial and caudal (CAU) axes.

RESULTS

The double S-curve and cusp-overlap methods provided views located in the same quadrant, mostly the RAO and CAU, in 92% of patients with a median 3-dimensional angular difference of 10.0° (interquartile range: 5.5° to 17.9°). The 3-dimensional deviation between the average angulation obtained by each method was not statistically significant (1.49°; p = 0.349). No significant differences in average coordinates were noted between the double S-curve and cusp-overlap methods (RAO: 14.7 ± 15.2 vs. 12.9 ± 12.5; p = 0.36; and CAU: 27.0 ± 9.4 vs. 26.9 ± 10.4; p = 0.90). TAVR using the double S-curve was associated with 98% device success, low complication rate, and absence of moderate-to-severe paravalvular leak.

CONCLUSIONS

The double S-curve and cusp-overlap methods provide comparable TAVR projections, mostly RAO and CAU. TAVR using the double S-curve model is associated with a high rate of device success and low rate of procedural complications.

Determination of optimal fluoroscopic angulations for aorto-coronary ostial interventions from coronary computed tomography angiography

BACKGROUND

An optimal aorto-coronary angiographic projection, characterized by an orthogonal visualization of the proximal coronary artery, is crucial for interventional success. We determined the distribution of optimal C-arm positions and assessed their feasibility by invasive coronary angiography.

METHODS

Orthogonal aorto-coronary ostial angulations were determined in 310 CT data sets. In 100 patients undergoing subsequent invasive angiography, we assessed if the CT-predicted angulations were achievable by the C-arm system. If the predicted projection was not achievable due to mechanical constraints of the C-arm system, the most close, achievable angulation was determined. Patient characteristics were analyzed regarding the distribution of optimal angulations and its feasibility by the C-arm system.

RESULTS

For the left ostium, CT revealed a mean angulation of LAO 23 ​± ​21°/cranial 25 ​± ​23° (90% of patients with a LAO/cranial angulation, 3% LAO/caudal, 4% RAO/cranial, 3% RAO/caudal) and were achievable by the C-arm system in 87% of patients. For the right ostium, the mean CT-predicted orthogonal angulation was LAO 36 ​± ​37°/cranial 36 ​± ​51° (84% LAO/cranial, 2% LAO/caudal, 14% RAO/caudal) and achievable by the C-arm system in 45% of patients. For the left ostium, a higher body weight was associated with a steeper LAO/cranial angulation being less feasible by the C-arm system due to mechanical constraints.

CONCLUSIONS

Orthogonal aorto-left coronary angulations show a relative narrow distribution predominately in LAO/cranial position whereas a wider range of angulations was found for the right coronary ostium. The feasibility of CT-predicted angulations by the C-arm system is more restricted for the right than the left coronary ostium.

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

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

Personalized Fluoroscopic Angles in Watchman™ Left Atrial Appendage Closure Landing Zone Assessment: A Three-Dimensional Printed Simulation Study

Background

Atrial fibrillation causes ischemic stroke when thrombi dislodge from a cardiac outpouching, the left atrial appendage (LAA), and embolize to the brain. LAA occlusion with the Watchman™ device (Boston Scientific Corporation, MA, USA), which prevents stroke, requires accurate LAA measurements for device sizing. We explore whether standard fluoroscopic LAA measurements improve when obtained at CT-derived viewing angles personalized to LAA anatomy while concurrently referring to three-dimensional (3D) CT.

Methods

Left atrial 3D reconstructions created from contrast CT (n=28) were analysed to identify personalized viewing angles wherein LAA dimensions (LAA maximum landing zone diameter and LAA length) were best observed. The 3D-CT reconstructions were then 3D printed with stands. Fluoroscopy of anatomically oriented models in the catheter lab simulated LAA angiography. Fluoroscopic images were acquired at standard (caudal 20˚/right anterior oblique 30˚) and personalized viewing angles. Repeated measurements of LAA dimensions were taken from CT (Control), fluoroscopy at standard angles (Standard), personalized angles (Blinded), and personalized angles while concurrently referring to 3D CT (Referred).

Results

Control measurements correlated and agreed better with Referred and Blinded measurements than with Standard measurements (diameter correlation and agreement: Control/Standard r=.554, limits of agreement [LOAs]=6.83/-5.91; Control/Blinded r=.641, LOA =5.67/-5.54; Control/Referred r=.741, LOA=4.69/-4.14; length correlation and agreement: Control/Standard r_s=.829, LOA=9.61/-3.02; Control/Blinded r_s=0.789, LOA=7.13/-4.94; Control/Referred r_s=.907, LOA=4.84/-4.13). Personalized angles resulted in hypothetical device size predictions more consistent with Control (device size correlation: Control/Standard r_s=.698, Control/Blinded r_s=.731, Control/Referred r_s=.893, P<0.001). False ineligibility rates were Standard=6/28, Blinded=6/28, and Referred=2/28.

Conclusion

This simulation suggests that personalized fluoroscopic viewing angles with in-procedural reference to 3D CT may improve the accuracy of LAA maximum landing zone diameter and length measurements at the Watchman landing zone. This improvement may result in more consistent device size selection and procedural eligibility assessment. Further clinical research on these interventions is merited.

MDCT planning of trans catheter aortic valve implantation (TAVI): determination of optimal c-arm angulation

A fluoroscopic view perpendicular to the aortic valve annulus is required during transcatheter aortic valve implantation (TAVI) for obtaining an optimal deployment of the bioprosthesis. By predicting c-arm angulation, pre-procedural MDCT could decrease the number of aortograms, shorten the time of the procedure and reduce the amount of intra-arterial contrast agent. The aim of our study was to assess the accuracy of MDCT in predicting c-arm angulation at the cath. lab. In this single center study, we investigated MDCT prediction of c-arm angulation in patients having undergone a TAVI procedure using SAPIEN 3® (Edwards Lifesciences, USA). Prior to the procedure, an experienced radiologist had reported the angulation using dedicated software (CT_report). After the procedure, a blinded experienced radiologist retrospectively measured the angles using the same method (CT_study). Interobserver variability was drawn from the comparison between CT_report and CT_study. Then, the mean angular difference between the predicted MDCT angles (CT_study) was compared to the working view recorded at the cath. lab. Seventy-nine patients (M/F = 0.65; mean age: 85.2 years ± 5.3) were included. Interobserver variability was 5.9 ± 6.1°. The mean absolute difference between MDCT and fluoroscopy was 8.8 ± 7.1°. The present study showed that MDCT could predict the coplanar fluoroscopic angles prior to TAVI using a balloon-expandable bioprosthesis Sapien 3® placed via a transfemoral approach with a mean angular difference of 8.8 ± 7.1°. Reproducibility was considered good as the mean difference between two independent measures was 5.9 ± 6.1°.

CT in planning transcatheter aortic valve implantation procedures and risk assessment

For surgical aortic valve replacement, the Society of Thoracic Surgeons score (STSS) is the reference standard for the prediction of operative risk. In transcatheter aortic valve implantation (TAVI) though, where the procedure itself is minimally invasive, the traditional risk assessment is supplemented by CTA. Through a consistent approach to the acquisition of high-quality images and the standardised reporting of annular measurements and adverse root and vascular features, patients at risk of complications can be identified. In turn, this may allow for a personalised procedural approach and treatment strategies devised to potentially reduce or mitigate this risk. This article provides a systematic and standardised approach to pre-procedural work-up with computed tomography angiography (CTA) and explores the current state of evidence and future areas of development in this rapidly developing field.

CT support of cardiac structural interventions

Due to its high temporal and isotropic spatial resolution, CT has become firmly established for pre-procedural imaging in the context of structural heart disease interventions. CT allows to very exactly measure dimensions of the target structure, CT can provide information regarding the access route and, as a very valuable addition, volumetric CT data sets can be used to identify fluoroscopic projection angulations to optimally visualize the target structure and place devices. This review provides an overview of current methods and applications of pre-interventional CT to support adult cardiac interventions including transcatheter aortic valve implantation, percutaneous mitral valve intervention, left atrial appendage occlusion and paravalvular leak closure.

Prediction of fluoroscopic angulations for transcatheter aortic valve implantation by CT angiography: influence on procedural parameters

Aims

Repeated angiograms to achieve an exactly orthogonal visualization of the aortic valve plane can substantially contribute to the total contrast amount required for transcatheter aortic valve implantation (TAVI). We investigated whether pre-procedural identification of an optimal fluoroscopic projection by cardiac computed tomography (CT) can significantly reduce the amount of a procedure-related contrast agent compared with angiographic determination of suitable angulations.

Methods and results

Eighty consecutive patients (81 ± 5 years, 55% male) with symptomatic severe aortic valve stenosis and normal renal function who underwent cardiac CT prior to TAVI were prospectively randomized. In 40 patients, a CT-predicted suitable angulation was used for the first aortic angiogram (CT cohort); in the other 40 patients, the first aortogram was acquired at LAO 10°/cranial 10 (angiography cohort). Additional aortograms were performed if no satisfactory view of the aortic valve plane was obtained. The number of aortograms needed to achieve a satisfactory fluoroscopic projection (1.2 ± 0.6 vs. 3.2 ± 1.7; P < 0.001) and the total amount of contrast agent per TAVI procedure were significantly lower in the CT cohort (95 ± 21 vs. 125 ± 36 mL; P < 0.001). Incidence of acute kidney injury was not significantly different. There was no significant difference regarding radiation dose, time of procedure, degree of post-procedural aortic regurgitation, complications and 30-day mortality between the cohorts.

Conclusion

Pre-procedural identification of a suitable fluoroscopic projection by cardiac CT significantly reduces a procedural contrast agent volume required for TAVI.

Imaging for planning of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has proven to be the standard of care for patients with prohibitive and high operative risk; today, it is considered a reasonable alternative to surgical aortic valve replacement in intermediate-risk patients. As indications for TAVI move toward patients at lower risk, safety aspects are becoming even more important. Furthermore, adequate patient selection is key for predictable procedural success with minimal complications, translating into an optimal clinical outcome. Decisions on valve type and size as well as on the access route are based on multimodality imaging including echocardiography, multislice computed tomography, and cardiac catheterization with peripheral angiography. This combination of multiple imaging modalities provides the best picture of a patient's anatomical and physiological suitability for the TAVI procedure. Yet, the reliability of preprocedural imaging is influenced by the quality of the images, which should be as high as possible, and both image acquisition and interpretation should be performed in a standardized manner. This article provides a concise overview of standardized multimodality imaging for the preprocedural planning and assessment of patients undergoing TAVI.

Role of Cardiac CT Before Transcatheter Aortic Valve Implantation (TAVI)

Catheter-based aortic valve implantation is increasingly being performed in high-risk patients with symptomatic aortic valve stenosis. For successful planning of the procedure, CT has been shown to provide crucial information concerning the aortic root as well as the peripheral access vessels. This article illustrates the increasing role of CT before transcatheter aortic valve implantation.

[Imaging in structural heart disease : Impact on interventional therapy]

For the treatment of structural heart disease, current options in the catheterization laboratory include MitraClip® implantation for treating severe mitral regurgitation, transcatheter aortic valve implantation (TAVI), closure of a patent foramen ovale (PFO) and occlusion of the left atrial appendage (LAA). These treatment options are based on a precise diagnosis provided by modern cardiac imaging, which is indispensable for treatment recommendations. Its importance for supporting the invasive procedures in the catheterization laboratory is less well known. Due to enhanced soft tissue characterization, it complements fluoroscopy and invasive angiography and thus enormously improves the safety of the procedures. In addition, it allows individualized follow-up care. The current article gives an overview of the clinically most frequently used procedures.

Comparison of Manual and Automated Preprocedural Segmentation Tools to Predict the Annulus Plane Angulation and C-Arm Positioning for Transcatheter Aortic Valve Replacement

Background

Preprocedural manual multi-slice-CT-segmentation tools (MSCT-ST) define the gold standard for planning transcatheter aortic valve replacement (TAVR). They are able to predict the perpendicular line of the aortic annulus (PPL) and to indicate the corresponding C-arm angulation (CAA). Fully automated planning-tools and their clinical relevance have not been systematically evaluated in a real world setting so far.

Methods and Results

The study population consists of an all-comers cohort of 160 consecutive TAVR patients with a drop out of 35 patients for technical and anatomical reasons. 125 TAVR patients underwent preprocedural analysis by manual (M-MSCT) and fully automated MSCT-ST (A-MSCT). Method-comparison was performed for 105 patients (Cohort A). In Cohort A, CAA was defined for each patient, and accordance within 10° between M-MSCT and A-MSCT was considered adequate for concept-proof (95% in LAO/RAO; 94% in CRAN/CAUD). Intraprocedural CAA was defined by repetitive angiograms without utilizing the preprocedural measurements. In Cohort B, intraprocedural CAA was established with the use of A-MSCT (20 patients). Using preprocedural A-MSCT to indicate the corresponding CAA, the levels of contrast medium (ml) and radiation exposure (cine runs) were reduced in Cohort B compared to Cohort A significantly (23.3±10.3 vs. 35.3 ±21.1 ml, p = 0.02; 1.6±0.7 vs. 2.4±1.4 cine runs; p = 0.02) and trends towards more safety in valve-positioning could be demonstrated.

Conclusions

A-MSCT-analysis provides precise preprocedural information on CAA for optimal visualization of the aortic annulus compared to the M-MSCT gold standard. Intraprocedural application of this information during TAVR significantly reduces the levels of contrast and radiation exposure.

Trial Registration

ClinicalTrials.gov NCT01805739

The Changing Paradigm in the Treatment of Structural Heart Disease and the Need for the Interventional Imaging Specialist

Percutaneous interventions in structural heart diseases are emerging rapidly. The variety of novel percutaneous treatment approaches and the increasing complexity of interventional procedures are associated with new challenges and demands on the imaging specialist. Standard catheterisation laboratory imaging modalities such as fluoroscopy and contrast ventriculography provide inadequate visualisation of the soft tissue or three-dimensional delineation of the heart. Consequently, additional advanced imaging technology is needed to diagnose and precisely identify structural heart diseases, to properly select patients for specific interventions and to support fluoroscopy in guiding procedures. As imaging expertise constitutes a key factor in the decision-making process and in the management of patients with structural heart disease, the sub-speciality of interventional imaging will likely develop out of an increased need for high-quality imaging.

Optimal fluoroscopic viewing angles of left-sided heart structures in patients with aortic stenosis and mitral regurgitation based on multislice computed tomography

BACKGROUND

Transcatheter interventions are currently undertaken using "generic" fluoroscopic viewing angles. However, the position and orientation of heart structures may vary across patients and disease-specific remodeling processes.

OBJECTIVE

This study uses multislice computed tomography to determine optimal fluoroscopic viewing angles of the aortic and mitral annuli, the left atrial appendage and the atrial septum. We explored differences between patients with severe aortic stenosis (AS) and severe mitral regurgitation (MR).

METHODS AND RESULTS

The multislice computed tomographies of 28 patients with severe aortic stenosis (AS) and 32 patients with severe functional mitral regurgitation (MR) were analyzed. For each patient, we evaluated the optimal fluoroscopic viewing angles of the aortic and mitral annuli (en face, maximal and minimal diameters, aortic root with right, left and non coronary sinus in center), left atrial appendage orifice (en face, maximal and minimal diameters), and atrial septum (fossa ovalis) en face. The TAVR implantation view with right coronary sinus in center was LAO 9 - CRA 0 in the AS group and LAO 6 - CAU 5 in the MR group (p = NS). AS and MR patients differed significantly with respect to the fluoroscopic angulation of the aortic annulus en face (8.3°), the aortic annulus maximal (17.7°) and minimal (18.5°) diameters, the mitral annulus aorto-mural diameter (11.3°), and the left atrial appendage orifice en face (11.1°) (all p-values<0.05).

CONCLUSION

Optimal fluoroscopic viewing angles of left-sided structures vary considerably between patients. Multislice computed tomography is a valuable tool to determine the most procedurally relevant angulations, with the potential to optimize procedural safety, efficacy and duration.

[Aortic valve stenosis: computed tomography prior to transcatheter aortic valve implantation (TAVI). How can the outcome be improved?]

Computed tomography (CT) plays an important role in the preinterventional work-up of patients referred for transcatheter aortic valve implantation (TAVI). Contrast-enhanced CT allows a comprehensive examination with evaluation of both the vascular access route as well as aortic valve and aortic root geometry. Analysis of the minimum luminal vessel diameter, tortuosity and vascular calcification are important to determine the ability to perform the procedure via a transfemoral access. The size of the aortic annulus can be accurately measured by CT to aid selection of the appropriate prosthesis and the use of CT for prosthesis sizing has been associated with a decreased incidence of paravalvular leakage as compared to 2-dimensional echocardiography. In addition CT permits accurate assessment of aortic root anatomy, distance between coronary ostia and the annulus plane as well as the dimensions of the ascending aorta. Furthermore, suitable fluoroscopic projections that permit an exact orthogonal visualization of the aortic annulus plane by fluoroscopy during the procedure can be extracted from the CT data set. In summary, CT permits comprehensive imaging in TAVI candidates and optimizes procedural outcome.

[Usefulness of multidetector computed tomography in transcatheter aortic valve implantation. Advantage of a tridimentional imaging modality]

Aortic stenosis is the most common valvular disorder in the United States and Europe. Nowadays, surgical aortic valve replacement remains the standard treatment for patients with severe aortic stenosis; however, transcatheter aortic valve implantation represents a less invasive treatment option for aortic stenosis patients considered as high-risk or not suitable for surgical management. Because of the lack of direct visualization of the operative field in transcatheter aortic valve implantation, there is an increased need for precise pre-operative assessment of vascular anatomy. Therefore, in order to improve outcome and avoid complications, multidetector tomography is part of the routine evaluation of patients considered for this treatment. The data obtained covering the aorta and iliac arteries, allows the physician a precise planning prior to the intervention. In this review, we described basic aspects of the procedure, and the clinical relevance of the multidetector tomography.

Computed Tomography for Structural Heart Disease and Interventions

Transcatheter cardiac interventions are a fast evolving field. The past decade has seen the development of transcatheter aortic valve replacement, transcatheter mitral valve repair and replacement, septal defect closure devices and left atrial appendage closure devices for thromboprophylaxis. More than ever, medical imaging is taking a central role in the care of patients with structural heart disease. In this review article we outline the use of MSCT as a tool for diagnosis of structural heart interventions, as well as patient selection, pre-procedural planning, device sizing and post-procedural assessment. We focus on procedures targeting the aortic valve, the mitral valve, the inter-atrial septum and the left atrial appendage.

Reproducibility of aortic annulus measurements by computed tomography

OBJECTIVES

To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography.

METHODS

CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers.

RESULTS

Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (ĸ = 0.86 for mean, ĸ = 0.84 for area-derived and ĸ = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10° for fluoroscopic projection angle was achieved in 84.3% of patients.

CONCLUSIONS

A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification.

KEY POINTS

• Systematic approach to generate a double oblique imaging plane for TAVI evaluation. • This method is straightforward and software independent. • An approach with high reproducibility, not influenced by aortic root calcification.

Local versus general anesthesia for transcatheter aortic valve implantation (TAVR)--systematic review and meta-analysis

BACKGROUND

The hypothesis of this study was that local anesthesia with monitored anesthesia care (MAC) is not harmful in comparison to general anesthesia (GA) for patients undergoing Transcatheter Aortic Valve Implantation (TAVR).TAVR is a rapidly spreading treatment option for severe aortic valve stenosis. Traditionally, in most centers, this procedure is done under GA, but more recently procedures with MAC have been reported.

METHODS

This is a systematic review and meta-analysis comparing MAC versus GA in patients undergoing transfemoral TAVR. Trials were identified through a literature search covering publications from 1 January 2005 through 31 January 2013. The main outcomes of interest of this literature meta-analysis were 30-day overall mortality, cardiac-/procedure-related mortality, stroke, myocardial infarction, sepsis, acute kidney injury, procedure time and duration of hospital stay. A random effects model was used to calculate the pooled relative risks (RR) with 95% confidence intervals.

RESULTS

Seven observational studies and a total of 1,542 patients were included in this analysis. None of the studies were randomized. Compared to GA, MAC was associated with a shorter hospital stay (-3.0 days (-5.0 to -1.0); P = 0.004) and a shorter procedure time (MD -36.3 minutes (-58.0 to -15.0 minutes); P <0.001). Overall 30-day mortality was not significantly different between MAC and GA (RR 0.77 (0.38 to 1.56); P = 0.460), also cardiac- and procedure-related mortality was similar between both groups (RR 0.90 (0.34 to 2.39); P = 0.830).

CONCLUSION

These data did not show a significant difference in short-term outcomes for MAC or GA in TAVR. MAC may be associated with reduced procedural time and shorter hospital stay. Now randomized trials are needed for further evaluation of MAC in the setting of TAVR.

CV imaging: what was new in 2012?

Echocardiography, single-photon emission computed tomography (SPECT), positron emission tomography (PET), cardiac magnetic resonance, and cardiac computed tomography can be used for anatomic and functional imaging of the heart. All 4 methods are subject to continuous improvement. Echocardiography benefits from the more widespread availability of 3-dimensional imaging, strain and strain rate analysis, and contrast applications. SPECT imaging continues to provide very valuable prognostic data, and PET imaging, on the one hand, permits quantification of coronary flow reserve, a strong prognostic predictor, and, on the other hand, can be used for molecular imaging, allowing the analysis of extremely small-scale functional alterations in the heart. Magnetic resonance is gaining increasing importance as a stress test, mainly through perfusion imaging, and continues to provide very valuable prognostic information based on late gadolinium enhancement. Magnetic resonance coronary angiography does not substantially contribute to clinical cardiology at this point in time. Computed tomography imaging of the heart mainly concentrates on the imaging of coronary artery lumen and plaque and has made substantial progress regarding outcome data. In this review, the current status of the 5 imaging techniques is illustrated by reviewing pertinent publications of the year 2012.

Imaging of cardiac valves by computed tomography

This paper describes "how to" examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, "how to" perform and optimize a multislice CT scan and "how to" interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide "how to" use CT for planning of transcatheter aortic valve implantation (TAVI), an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

Transcatheter aortic valve insertion (TAVI): a review

The introduction of transcatheter aortic valve insertion (TAVI) has transformed the care provided for patients with severe aortic stenosis. The uptake of this procedure is increasing rapidly, and clinicians from all disciplines are likely to increasingly encounter patients being assessed for or having undergone this intervention. Successful TAVI heavily relies on careful and comprehensive imaging assessment, before, during and after the procedure, using a range of modalities. This review outlines the background and development of TAVI, describes the nature of the procedure and considers the contribution of imaging techniques, both to successful intervention and to potential complications.

DNA transposons in vertebrate functional genomics

Genome sequences of many model organisms of developmental or agricultural importance are becoming available. The tremendous amount of sequence data is fuelling the next phases of challenging research: annotating all genes with functional information, and devising new ways for the experimental manipulation of vertebrate genomes. Transposable elements are known to be efficient carriers of foreign DNA into cells. Notably, members of the Tc1/mariner and the hAT transposon families retain their high transpositional activities in species other than their hosts. Indeed, several of these elements have been successfully used for transgenesis and insertional mutagenesis, expanding our abilities in genome manipulations in vertebrate model organisms. Transposon-based genetic tools can help scientists to understand mechanisms of embryonic development and pathogenesis, and will likely contribute to successful human gene therapy. We discuss the possibilities of transposon-based techniques in functional genomics, and review the latest results achieved by the most active DNA transposons in vertebrates. We put emphasis on the evolution and regulation of members of the best-characterized and most widely used Tc1/mariner family.