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

Intracardiac shunt assessment using CT coronary angiography

BACKGROUND

Detection of intracardiac shunts using CT Coronary Angiography (CTCA) is currently based on anatomical demonstration of defects. We assessed a novel technique using a standard CTCA test bolus in detecting shunts independent of anatomical assessment and to provide an estimate of Qp/Qs.

METHODS

We retrospectively reviewed 51 CTCAs: twenty-one from patients with known simple left to right intracardiac shunts with contemporaneous functional assessment (using CMR) within 6 months, 20 controls with structurally normal hearts, and 10 patients with shunt repairs. From the dynamic acquisition of a test bolus, we measured mean Hounsfield Units (HU) in various anatomical structures. We created time/density curves from the test bolus data, and calculated disappearance time (DT) from the ascending aorta (deriving a Qp/Qs), peak ascending aortic HU, and mean coefficient of variation of the arterial curves, and compared these with the Qp/Qs from the respective CMR.

RESULTS

Patients with intracardiac shunts had significantly higher test bolus derived Qp/Qs compared with both the controls, and the repaired shunt comparator group. There was a very strong agreement between the test bolus derived Qp/Qs, and Qp/Qs as measured by CMR (Intraclass correlation 0.89). Mean bias was 0.032 ​± ​0.341 (95% limits of agreement -0.64 to 0.70). Interobserver, and intraobserver agreement of the disappearance time was excellent (0.99, 0.99 (reader 1) and 1.00 (reader 2) respectively).

CONCLUSION

In this proof-of-concept study, we demonstrate a novel technique to detect, and to estimate severity of left to right intracardiac shunts on routine Cardiac CT.

ECG-Gated CCTA in the Assessment of Post-Procedural Complications

INTRODUCTION

The aim of our study was to assess the role of ECG-gated coronary CT angiography (CCTA) in the diagnosis, imaging follow-up, and treatment guidance in post-procedural/surgical interventions in the heart and thoracic aorta (PTCA, TAVI, PMK/ICD placement, CABGs).

MATERIALS AND METHODS

We retrospectively evaluated 294 ECG-gated CCTA studies performed in our center from January 2020 to January 2023. CCTA studies were acquired to detect/exclude possible complications related to the endovascular or surgical procedure.

RESULTS

There were 27 cases (9.2%) of post-procedural complications. Patients enrolled in the study were 18 males and 9 females (male/female ratio: 2), with age ranging from 47 to 86 years (mean age, 68.3 years). Among percutaneous coronary intervention (PCI) complications, coronary intimal dissection with ascending aorta involvement was found to be the most frequent complication after PTCA (22.2%). Vascular wall pseudoaneurysm formation (11.1%) and coronary stent misalignment or displacement (14.8%) were complications less frequently encountered after PTCA. Right atrial or ventricular perforation with associated hemopericardium were the most common complications (18.5%) after pacemaker implantation. Complications encountered after aortic valve interventions were loosening and dislocation of the prosthesis associated with aortic root pseudoaneurysm (7.4%), para-valvular leak (11.1%), and hemopericardium (7.4%). In one patient who underwent transcatheter repair of patent foramen ovale (3.7%), CTTA detected the dislocation of the Amplatzer septal occluder.

CONCLUSIONS

ECG-gated CCTA is a fundamental diagnostic tool for the detection of post-procedural endovascular/surgical complications to enable optimal patient management. Radiologists must be familiar with the use of cardiac synchronization in the course of CT and must be aware of all possible complications that can occur in the context of acute settings or routine follow-up studies.

CT Image Feature Diagnosis on the Basis of Deep Learning Algorithm for Preoperative Patients and Complications of Transcatheter Aortic Valve Implantation

This work was aimed to explore the role of CT angiography information provided by deep learning algorithm in the diagnosis and complications of the disease focusing on congenital aortic valve disease and severe aortic valve stenosis. 120 patients who underwent ultrasound cardiography for aortic stenosis and underwent transcatheter aortic valve implantation (TAVI) in hospital were selected as the research objects. Patients received CT examination of deep learning algorithm within one week. The measurement methods were long and short diameter method, area method, and perimeter method. The deep learning algorithm was used to measure the long and short diameter, area, and perimeter of the target area before CT image processing. The results showed that the average diameter of long and short diameter measurement was 95% CI (0.84, 0.92), the average diameter of perimeter measurement was 95% CI (0.68, 0.87), and the average diameter of area measurement was 95% CI (0.72, 0.91). Among the 52 patients, 35 cases were hypertension (67%), 13 cases were diabetes (25%), 6 cases were chronic renal insufficiency (Cr > 2 mg/dL) (11%) (2 cases were treated with hemodialysis, 3.8%), 11 patients had chronic pulmonary disease (21%), 9 patients had cerebrovascular disease (17.3%) and atrial flutter and atrial fibrillation. Deep learning can achieve excellent results in CT image processing, and it was of great significance for the diagnosis of TAVI patients, improving the success rate of treatment and the prognosis of patients.

Combined Coronary CT Angiography and Evaluation of Access Vessels for TAVR Patients in Free-Breathing with Single Contrast Medium Injection Using a 16-cm-Wide Detector CT

RATIONALE AND OBJECTIVES

To investigate the feasibility of combining coronary computed tomography (CT) angiography (CCTA) and CTA to evaluate access vessels for transcatheter aortic valve replacement (TAVR) patients in free-breathing and with single contrast medium injection using a 16-cm-wide detector CT.

MATERIALS AND METHODS

One hundred and twenty-one consecutive patients (73.33 ± 6.43 years) referred for TAVR underwent a serious CT scans in free-breathing after one contrast injection: ECG-triggered one-heartbeat axial CCTA, followed by non-ECG-gated neck, thoracic, and abdominal CTA. Patient weight-dependent contrast dose volume at 1.0 mL/kg was used. CT attenuation values of the coronary, neck, aortic, iliac, and femoral arteries were measured and their image quality was evaluated with a 4-point score method. Stenosis (≥50%) in CCTA was evaluated using invasive coronary angiography result as a reference standard. Radiation and contrast doses were assessed.

RESULTS

The total dose-length-product for the entire examination was 411.4 ± 91.2 mGy.cm, and the total contrast dose was 57.3 ± 9.9 mL. There were adequate attenuations (>400 HU) in all arteries, and the peripheral access vessels and aortic annulus were evaluable in all patients. In neck CTA, 5 patients had vascular tortuosity, 6 patients had aberrant arteries and there were 212 plaques and 13 severe stenoses among the patients. In CCTA, on the per-segment, per-vessel, and per-patient analysis, CCTA showed a sensitivity and negative predictive value of (95% and 99%), (95% and 99%), and (96% and 98%), respectively, for the entire patient cohort, and (92% and 98%), (92% and 98%), and (88% and 93%), respectively, for patients with atrial fibrillation or heart rate higher than 75 beats.

CONCLUSION

It is feasible to perform a combined CCTA and CTA for evaluating access vessels for TAVR patients in free-breathing with single contrast injection. This approach generates acceptable image quality for all vessels and a high negative predictive value in excluding coronary artery disease with relatively low radiation and contrast doses.

En Bloc AngioVac Removal of Thoracic Aortic Mass

The AngioVac system, designed for suction during extracorporeal bypass, is used to aspirate masses, thrombi, and other undesirable material from the cardiovascular system. To date, it has been used extensively in the venous system and right side of the heart; however, its use in the arterial system has been limited because of smaller vessel sizes and the requirement for a 26F sheath. We report the case of a 45-year-old woman with a history of angiosarcoma who presented with acute embolic events that affected her spleen and lower extremities. We removed a large mobile mass en bloc from her distal thoracic aorta by using the AngioVac system as an alternative to surgical resection. The patient recovered with no recurrence. We discuss the benefits and challenges of using the AngioVac within small vessels of the arterial system.

Sex differences in aortic valve calcification in severe aortic valve stenosis: association between computer tomography assessed calcification and valvular calcium concentrations

AIMS

The aims of this study were to investigate the correlation and sex differences between total valve calcium, valve calcium concentration, and aortic valve calcification (AVC) in explanted valves from patients with severe aortic valve stenosis undergoing aortic valve replacement (AVR).

METHODS AND RESULTS

Sixty-nine patients with severe aortic stenosis (AS) scheduled for elective AVR underwent echocardiography and cardiac computed tomography (CT) prior to surgery (AVCin vivo) and CT of the explanted aortic valve (AVCex vivo). Explanted valves were prepared in acid solution, sonicated, and analysed with Arsenazo III dye to estimate total valve calcium and valve calcium concentration. Median AVCex vivo was 2082 (1421-2973) AU; mean valve calcium concentration was 1.43 ± 0.42 µmol Ca2+/mg tissue; median total valve calcium 156 (111-255) mg Ca2+, and valve calcium density 52 (35-81) mg/cm2. AVC displayed a strong correlation with total valve calcium (R2 = 0.98, P < 0.001) and a moderate correlation with valve calcium concentration (R2 = 0.62, P < 0.001). Valvular calcium concentration was associated with sex, aortic valve area, and mean gradient. After adjusting for age and estimated glomerular filtration rate, sex and mean gradient remained associated with valve calcium concentrations.

CONCLUSION

AVC score provides a strong estimate for total valve calcium but to a lesser degree calcium concentration in the valve tissue of patients with severe AS. Females presented lower valvular calcium concentrations than males irrespective of AS severity, adding evidence and providing support to the important point that sex differences in valvular calcium concentration in AS does not reflect valvular size.

The Iliofemoral tortuosity score predicts access and bleeding complications during transfemoral transcatheter aortic valve replacement: DataData from the VIenna Cardio Thoracic aOrtic valve registrY (VICTORY)

BACKGROUND

Arterial tortuosity is linked to a higher risk of adverse clinical events after transfemoral transcatheter aortic valve replacement (TF-TAVR). Currently, there are no assessment tools that can quantify this variable in three-dimensional space. This study investigated the impact of novel scoring methods of iliofemoral tortuosity on access and bleeding complications after TF-TAVR.

METHODS

The main access vessel was assessed between the aortoiliacal and femoral bifurcation in preoperative multislice computed tomography scans of 240 consecutive patients undergoing TF-TAVR. Tortuosity was assessed by three methods: largest single angle, sum of all angles, and iliofemoral tortuosity (IFT) score [((true vessel length/ideal vessel length)-1)*100]. The primary study endpoint was a composite of access and bleeding complications. The secondary study endpoints were 30-day mortality and long-term survival.

RESULTS

Among 240 patients, only the IFT score demonstrated a good positive correlation with the composite primary endpoint of access and bleeding complications (P = 0.031). A higher incidence of access and bleeding complications was found in patients with a higher IFT score (56 [36.8%] vs 17 [19.3%]; P = 0.003). In a multivariate logistic regression analysis, only the IFT score was a significant predictor of the primary endpoint (OR: 2.11; 95% CI: 1.09-4.05; P = 0.026).

CONCLUSION

Vascular tortuosity is an underestimated risk factor during TF-TAVR. The IFT score is a valuable tool in risk stratification before TF-TAVR, predicting periprocedural access and bleeding complications.

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.

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.

Transcatheter aortic valve replacement with a focus on transcarotid: a review of the current literature

Valve replacement in high-risk patients with severe aortic stenosis has undergone a huge paradigm shift in the recent years in terms of procedural details and vascular access site for patients who have poor peripheral access. Carotid artery is one of the more promising access sites which has been proven to provide a good alternative site with comparable outcomes to transfemoral approach. In this manuscript, we will provide a review of the current literature on transaortic, transapical, transaxillary and transcarotid approaches to transcatheter aortic valve replacement (TAVR) while focusing on the transcarotid approach.

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

AIM

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

METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

Transcatheter aortic valve implantation operators - get involved in imaging!

Pre-procedural planning is the key element of transcatheter aortic valve implantation (TAVI). Multislice computed tomography of the chest, abdomen and pelvis with the ability to perform a 3-dimensional reconstruction has become the cornerstone of pre-procedural planning. We would like to encourage TAVI operators (interventional cardiologist and surgeons) to get involved in imaging. All TAVI operators should know how to assess the annulus, the annular root, and the iliofemoral access. We strongly believe that this will improve outcomes of this evolving procedure.

A prospective national survey of coronary CT angiography radiation doses in the United Kingdom

BACKGROUND

Little real-world radiation dose data exist for the majority of cardiovascular CT. Some data have been published for coronary CT angiography (coronary CTA) specifically, but they invariably arise from high-volume centres with access to the most recent technology.

OBJECTIVE

The aim of this study was to document real-world radiation doses for coronary CTA in the United Kingdom, and to establish their relationship to clinical protocol selection, acquisition heart rate, and scanner technology.

METHODS

A dose survey questionnaire was distributed to members of the British Society of Cardiovascular Imaging and other UK cardiac CT units. All participating centres collected data for consecutive coronary CTA cases over one month. The survey captured information about the exam conducted, patient demographics, pre-scan details such as beta-blocker administration, acquisition heart rate and scan technique, and post-scan dose indicators - series volumetric CT dose index (CTDI_vol), series dose-length product (DLP), and exam DLP.

RESULTS

Fifty centres provided data on a total of 1341 coronary CTA exams. Twenty-nine centres (58%) performed at least 20 coronary CTA scans in the collection period. The median BMI, acquisition heart rate and exam DLP were 28 kg/m², 60 bpm and 209 mGycm respectively. The corresponding effective dose was estimated as 5.9 mSv using a conversion factor of 0.028 mSv/mGycm. There was no statistically significant difference in radiation dose between low and high-volume centres. Median exam DLP increased with the acquisition heart rate due to the selection of wider temporal windows. The highest exam DLPs were obtained on the older scanner technology.

CONCLUSION

This study provides baseline data for benchmarking practice, optimizing radiation dose and improving service quality locally.

Role of Imaging in Transcatheter Aortic Valve Replacement

OPINION STATEMENT

Transcatheter aortic valve replacement (TAVR) has emerged as an effective treatment alternative in patients with severe aortic stenosis (AS) who are deemed surgically high-risk or ineligible for surgery. Pre-procedural imaging, in particular computed tomography (CT), plays an integral part in the planning and performance of TAVR and is crucial for a successful treatment. Novel technological advances in CT include high-pitch, low kV acquisitions, and iterative reconstruction resulting in high image quality at substantially reduced scan duration, contrast volume, and radiation exposure. Given the high spatial and temporal resolution of the acquisitions, CT angiography provides critical information on the eligibility for the peripheral vascular access, aortic root assessment, as well as the aortic annulus measurements, including the coronary ostia and concomitant cardiac pathology. Pre-procedural CT imaging is key for appropriate device size selection to minimize peri-procedural complications and optimize procedural success. In this article, we review the current state of imaging in the pre-interventional setting of TAVR with a special emphasis on CT.