Computed tomography for planning transcatheter tricuspid valve therapy

CAR and CSTR Cardiac Computed Tomography (CT) Practice Guidelines: Part 2-Non-Coronary Imaging

The cardiac computed tomography (CT) practice guidelines provide an updated review of the technological improvements since the publication of the first Canadian Association of Radiologists (CAR) cardiac CT practice guidelines in 2009. An overview of the current evidence supporting the use of cardiac CT in the most common clinical scenarios, standards of practice to optimize patient preparation and safety as well as image quality are described. Coronary CT angiography (CCTA) is the focus of Part I. In Part II, an overview of cardiac CT for non-coronary indications that include valvular and pericardial imaging, tumour and mass evaluation, pulmonary vein imaging, and imaging of congenital heart disease for diagnosis and treatment monitoring are discussed. The guidelines are intended to be relevant for community hospitals and large academic centres with established cardiac CT imaging programs.

The Tricuspid Valve: A Review of Pathology, Imaging, and Current Treatment Options: A Scientific Statement From the American Heart Association

Tricuspid valve disease is an often underrecognized clinical problem that is associated with significant morbidity and mortality. Unfortunately, patients will often present late in their disease course with severe right-sided heart failure, pulmonary hypertension, and life-limiting symptoms that have few durable treatment options. Traditionally, the only treatment for tricuspid valve disease has been medical therapy or surgery; however, there have been increasing interest and success with the use of transcatheter tricuspid valve therapies over the past several years to treat patients with previously limited therapeutic options. The tricuspid valve is complex anatomically, lying adjacent to important anatomic structures such as the right coronary artery and the atrioventricular node, and is the passageway for permanent pacemaker leads into the right ventricle. In addition, the mechanism of tricuspid pathology varies widely between patients, which can be due to primary, secondary, or a combination of causes, meaning that it is not possible for 1 type of device to be suitable for treatment of all cases of tricuspid valve disease. To best visualize the pathology, several modalities of advanced cardiac imaging are often required, including transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging, to best visualize the pathology. This detailed imaging provides important information for choosing the ideal transcatheter treatment options for patients with tricuspid valve disease, taking into account the need for the lifetime management of the patient. This review highlights the important background, anatomic considerations, therapeutic options, and future directions with regard to treatment of tricuspid valve disease.

Multimodality imaging for transcatheter tricuspid valve repair and replacement

Transcatheter tricuspid intervention is a rapidly evolving field with multiple classes of therapeutic devices currently in development. Procedural success in tricuspid intervention is predicated on appropriate device selection for patient specific anatomy and satisfactory imaging for intra-procedural guidance. This review will outline protocols and methodology for multi-modality imaging assessment of the tricuspid valve and associated structures, with emphasis on anatomic and functional characteristics that determine suitability for each class of tricuspid intervention. Intra-procedural imaging requirements for each class of device, with design and procedural imaging guidance of specific devices, will also be addressed.

New therapeutic approach for tricuspid regurgitation: Transcatheter tricuspid valve replacement or repair

The tricuspid valve is a complex structure with normal function dependent on the leaflet morphology, right atrial and annular dynamics, and right ventricular and chordal support. Thus, the pathophysiology of tricuspid regurgitation (TR) is equally complex and current medical and surgical management options are limited. Transcatheter devices are currently being investigated as possible treatment options with lower morbidity and mortality than open surgical procedures. These devices can be divided by their implant location/mechanism of action: leaflet approximation devices, annuloplasty devices, orthotopic valve implants, and heterotopic valve implants. The current review will discuss each class of transcatheter device therapy, and further delve into the current understanding of who and when to treat. Finally, we will include a brief discussion of the future of device and surgical therapy trials for TR and the remaining questions to answer about this complex disease process.

The evolving role of multi-modality imaging in transcatheter tricuspid valve interventions

Tricuspid valve pathophysiology is not well-understood. Emergence of novel transcatheter tricuspid therapies has fueled the requirements for improved imaging visualization techniques and interventional imaging physician skillsets in guiding these complex transcatheter procedures. There is growing understanding on the clinical significance of tricuspid regurgitation which expanded the interest for percutaneous tricuspid valve interventions. The present review concentrates on three essential aspects of tricuspid valve pathophysiology: anatomical considerations for tricuspid interventions, optimal timing of tricuspid interventions by imaging guidance, and the role of interventional imaging physicians’ skillset and knowledge in this field.

Computed tomography angiography/magnetic resonance imaging-based preprocedural planning and guidance in the interventional treatment of structural heart disease

Preprocedural planning and periprocedural guidance based on image fusion are widely established techniques supporting the interventional treatment of structural heart disease. However, these two techniques are typically used independently. Previous works have already demonstrated the benefits of integrating planning details into image fusion but are limited to a few applications and the availability of the proprietary tools used. We propose a vendor-independent approach to integrate planning details into periprocedural image fusion facilitating guidance during interventional treatment. In this work, we demonstrate the feasibility of integrating planning details derived from computer tomography and magnetic resonance imaging into periprocedural image fusion with open-source and commercially established tools. The integration of preprocedural planning details into periprocedural image fusion has the potential to support safe and efficient interventional treatment of structural heart disease.

Reference ranges of tricuspid annulus geometry in healthy adults using a dedicated three-dimensional echocardiography software package

Background

Tricuspid annulus (TA) sizing is essential for planning percutaneous or surgical tricuspid procedures. According to current guidelines, TA linear dimension should be assessed using two-dimensional echocardiography (2DE). However, TA is a complex three-dimensional (3D) structure.

Aim

Identify the reference values for TA geometry and dynamics and its physiological determinants using a commercially available three-dimensional echocardiography (3DE) software package dedicated to the tricuspid valve (4D AutoTVQ, GE).

Methods

A total of 254 healthy volunteers (113 men, 47 ± 11 years) were evaluated using 2DE and 3DE. TA 3D area, perimeter, diameters, and sphericity index were assessed at mid-systole, early- and end-diastole. Right atrial (RA) and ventricular (RV) end-diastolic and end-systolic volumes were also measured by 3DE.

Results

The feasibility of the 3DE analysis of TA was 90%. TA 3D area, perimeter, and diameters were largest at end-diastole and smallest at mid-systole. Reference values of TA at end-diastole were 9.6 ± 2.1 cm2 for the area, 11.2 ± 1.2 cm for perimeter, and 38 ± 4 mm, 31 ± 4 mm, 33 ± 4 mm, and 34 ± 5 mm for major, minor, 4-chamber and 2-chamber diameters, respectively. TA end-diastolic sphericity index was 81 ± 11%. All TA parameters were correlated with body surface area (BSA) (r from 0.42 to 0.58, p < 0.001). TA 3D area and 4-chamber diameter were significantly larger in men than in women, independent of BSA (p < 0.0001). There was no significant relationship between TA metrics with age, except for the TA minor diameter (r = −0.17, p < 0.05). When measured by 2DE in 4-chamber (29 ± 5 mm) and RV-focused (30 ± 5 mm) views, both TA diameters resulted significantly smaller than the 4-chamber (33 ± 4 mm; p < 0.0001), and the major TA diameters (38 ± 4 mm; p < 0.0001) measured by 3DE. At multivariable linear regression analysis, RA maximal volume was independently associated with both TA 3D area at mid-systole (R2 = 0.511, p < 0.0001) and end-diastole (R2 = 0.506, p < 0.0001), whereas BSA (R2 = 0.526, p < 0.0001) was associated only to mid-systolic TA 3D area.

Conclusions

Reference values for TA metrics should be sex-specific and indexed to BSA. 2DE underestimates actual 3DE TA dimensions. RA maximum volume was the only independent echocardiographic parameter associated with TA 3D area in healthy subjects.

Percutaneous Atrio-Ventricular Valve Interventions: Contemporary Advances and Remaining Challenges

These are exciting exploratory times for structural/valvular heart interventions [...].

Current Status of Transcatheter Tricuspid Valve Therapies

Tricuspid regurgitation is a complex disease that carries a poor prognosis, and surgical repair is associated with high mortality. In light of the success of other transcatheter-based valve interventions, transcatheter tricuspid therapy has recently seen exponential use both clinically and in innovation. Given the rapid development of many tricuspid systems and multiple on-going clinical trials, the aim of this review is to highlight the current state of transcatheter tricuspid therapeutics and to provide an up-to-date view of their clinical use, outcomes and future directions.

The Role of Cardiac Computed Tomography in Heart Failure

PURPOSE OF REVIEW

Cardiac computed tomography (CT) is becoming a more widely applied tool in the diagnosis and management of a variety of cardiovascular conditions, including heart failure. The aim of this narrative review is to examine the role of cardiac CT in patients with heart failure.

RECENT FINDINGS

Coronary computed tomographic angiography has robust diagnostic accuracy for ruling out coronary artery disease. These data are reflected in updated guidelines from major cardiology organizations. New roles for cardiac CT in myocardial imaging, perfusion scanning, and periprocedural planning, execution, and monitoring are being implemented. Cardiac CT is useful in ruling out coronary artery disease its diagnostic accuracy, accessibility, and safety. It is also intricately linked to invasive cardiac procedures that patients with heart failure routinely undergo.

Clinical Impact of Computational Heart Valve Models

This paper provides a review of engineering applications and computational methods used to analyze the dynamics of heart valve closures in healthy and diseased states. Computational methods are a cost-effective tool that can be used to evaluate the flow parameters of heart valves. Valve repair and replacement have long-term stability and biocompatibility issues, highlighting the need for a more robust method for resolving valvular disease. For example, while fluid-structure interaction analyses are still scarcely utilized to study aortic valves, computational fluid dynamics is used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress, and oscillatory shear index in the thoracic aorta. It has been analyzed that computational flow dynamic analyses can be integrated with other methods to create a superior, more compatible method of understanding risk and compatibility.

Transcatheter tricuspid valve interventions: Current devices and associated evidence

Tricuspid regurgitation (TR) is a common finding in patients with chronic cardiopathy, and often a marker of an advanced disease. Being silent or with symptoms intertwined with the primitive left heart disease, TR has often been neglected, leading to the late referral of patients with advanced right-heart failure. Hence, isolated tricuspid surgery has been associated with high morbidity and mortality rates, the worse of all valve interventions, and medical management has been limited to symptomatic treatment. In this context, percutaneous therapies for severe TR have gained traction, addressing the unmet therapeutic gap for a less invasive disease-modifying management. The aim of this review is to provide an updated overview on transcatheter tricuspid valve interventions, focusing on devices' characteristics, associated evidence, and future perspectives.

Mutual Arrangements of Coronary Blood Vessels within the Right Atrial Appendage Vestibule

Background: The aim of our study was to investigate the presence and mutual relationships of coronary vessels within the right atrial appendage (RAA) vestibule. Methods: We examined 200 autopsied hearts. The RAA vestibule was cross-sectioned along its isthmuses (superior, middle, and inferior). Results: The right coronary artery (RCA) was present in 100% of the superior RAA isthmuses but absent in 2.0% of hearts within the middle isthmus and in 6.5% of hearts within the inferior RAA isthmus. Its diameter was quite uniform along the superior (2.6 ± 0.8 mm), middle (2.9 ± 1.1 mm), and inferior (2.7 ± 0.9 mm) isthmuses (p = 0.12). The location of the RCA varied significantly, and it was sometimes accompanied by other accessory coronary vessels. In all the isthmuses, the RCA ran significantly closer to the endocardial surface than to the epicardial surface (p < 0.001). At the superior RAA isthmus, the artery was furthest from the right atrial endocardial surface and this distance gradually decreased between the middle RAA isthmus and the inferior RAA. Conclusions: This study was the most complex analysis of the mutual arrangements and morphometric characteristics of coronary blood vessels within the RAA vestibule. Awareness of additional blood vessels within the vestibule can help clinicians plan and perform safe and efficacious procedures in this region.

Coronary Computer Tomography Angiography in 2021-Acquisition Protocols, Tips and Tricks and Heading beyond the Possible

Recent technological advances, together with an increasing body of evidence from randomized trials, have placed coronary computer tomography angiography (CCTA) in the center of the diagnostic workup of patients with coronary artery disease. The method was proven reliable in the diagnosis of relevant coronary artery stenosis. Furthermore, it can identify different stages of the atherosclerotic process, including early atherosclerotic changes of the coronary vessel wall, a quality not met by other non-invasive tests. In addition, newer computational software can measure the hemodynamic relevance (fractional flow reserve) of a certain stenosis. In addition, if required, information related to cardiac and valvular function can be provided with specific protocols. Importantly, recent trials have highlighted the prognostic relevance of CCTA in patients with coronary artery disease, which helped establishing CCTA as the first-line method for the diagnostic work-up of such patients in current guidelines. All this can be gathered in one relatively fast examination with minimal discomfort for the patient and, with newer machines, with very low radiation exposure. Herein, we provide an overview of the current technical aspects, indications, pitfalls, and new horizons with CCTA, providing examples from our own clinical practice.

Contemporary review in the multi-modality imaging evaluation and management of tricuspid regurgitation

The tricuspid valve has gained interest recently because of the poor outcomes with current treatments and advances in percutaneous valve interventions. A sound understanding of the anatomy and pathologies of the tricuspid valve is critical in its evaluation and management of tricuspid regurgitation (TR). A multi-modality imaging approach with transthoracic echocardiography, transesophageal echocardiography, computed tomography, magnetic resonance imaging all have their individual and collective roles in the evaluation of TR and guidance of surgical and percutaneous procedures. This combined with clinical factors will contribute to defining timing, indications, modality selection and risk stratification for tricuspid valve interventions, which currently remains controversial.

Morphology and Position of the Right Atrioventricular Valve in Relation to Right Atrial Structures

The right atrioventricular valve (RAV) is an important anatomical structure that prevents blood backflow from the right ventricle to the right atrium. The complex anatomy of the RAV has lowered the success rate of surgical and transcatheter procedures performed within the area. The aim of this study was to describe the morphology of the RAV and determine its spatial position in relation to selected structures of the right atrium. We examined 200 randomly selected human adult hearts. All leaflets and commissures were identified and measured. The position of the RAV was defined. Notably, 3-leaflet configurations were present in 67.0% of cases, whereas 4-leaflet configurations were present in 33.0%. Septal and mural leaflets were both significantly shorter and higher in 4-leaflet than in 3-leaflet RAVs. Significant domination of the muro-septal commissure in 3-leflet valves was noted. The supero-septal commissure was the most stable point within RAV circumference. In 3-leaflet valves, the muro-septal commissure was placed within the cavo-tricuspid isthmus area in 52.2% of cases, followed by the right atrial appendage vestibule region (20.9%). In 4-leaflet RAVs, the infero-septal commissure was located predominantly in the cavo-tricuspid isthmus area and infero-mural commissure was always located within the right atrial appendage vestibule region. The RAV is a highly variable structure. The supero-septal part of the RAV is the least variable component, whereas the infero-mural is the most variable. The number of detected RAV leaflets significantly influences the relative position of individual valve components in relation to right atrial structures.

Multi-Modality Imaging for Interventions in Tricuspid Valve Disease

Several studies have demonstrated that severe tricuspid regurgitation (TR) has a significant negative impact on morbidity and mortality. Nowadays, several therapeutic options to treat TR are available and patients at high surgical risk can also be treated with transcatheter procedures. For the management of patients with TR, an accurate assessment of the tricuspid valve and its surrounding structures is therefore of crucial importance and has gained significant interest in the medical community. Different imaging modalities can provide detailed information on the tricuspid valve apparatus, right ventricle, right atrium, and coronary circulation which are fundamental to define the timing and anatomic suitability of surgical and percutaneous procedures. The present review illustrates the role of 2D and 3D echocardiography, cardiac magnetic resonance, and multidetector row computed tomography for the assessment of the tricuspid valve and right heart with a particular focus on the data needed for planning and guiding interventional procedures.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

Catheter-based treatment of tricuspid regurgitation: state of the art

Tricuspid regurgitation is a highly prevalent condition, with detrimental effects on long-term survival. However, it has been historically neglected, and only surgically addressed when symptomatic diuretic agents proved insufficient to alleviate congestion. Besides, mortality rates of isolated tricuspid regurgitation surgery have been persistently high, even in contemporary series. This has led to the advent of a myriad of transcatheter tricuspid valve interventions mimicking current surgical technologies, for which a comprehensive imaging work-up holds the key for proper patient selection and intraprocedural monitoring. Although initially designed for compassionate use patients, growing experience and encouraging results of these less-invasive technologies are broadening the spectrum of beneficiaries. In this review, we will focus on the current picture of transcatheter tricuspid valve interventions, with special interest on the current understanding of pathoanatomic tricuspid regurgitation progression, preprocedural multimodality imaging and the latest experience on the different transcatheter devices.

Transcatheter therapies for severe tricuspid regurgitation. Quo vadis?

Moderate-to-severe tricuspid regurgitation (TR) is common and is associated with a poor prognosis. To date, most patients are undertreated; therefore, transcatheter options could be clinically impactful in those who are denied surgery. Several transcatheter solutions have been developed that address the problem via leaflet enhancement, annuloplasty, or heterotopic implantation of self-expandable or balloon-expandable valves in the caval veins. A comprehensive patient evaluation, based on multimodality imaging techniques for a better understanding of the valvular pathology and TR mechanism, remains paramount for an appropriate device selection. To date, several trials have shown the feasibility and safety of a multitude of devices in this setting, but data from randomized clinical trials regarding clinical benefit based on hard endpoints are still lacking. Although the optimal patient profile and timing of intervention remain under investigation, data from available studies indicate that an earlier treatment referral, before onset of irreversible right ventricular remodeling, could be beneficial. This review discusses the present landscape and future implications of transcatheter therapies for severe TR.

Imaging and Patient Selection for Transcatheter Tricuspid Valve Interventions

With the emergence of transcatheter solutions for the treatment of tricuspid regurgitation (TR) increased attention has been directed to the once neglected tricuspid valve (TV) complex. Recent studies have highlighted new aspects of valve anatomy and TR etiology. The assessment of valve morphology along with quantification of regurgitation severity and RV function pose several challenges to cardiac imagers guiding transcatheter valve procedures. This review article aims to give an overview over the role of modern imaging modalities during assessment and treatment of the TV.

Tricuspid Valve Annular Mechanics: Interactions with and Implications for Transcatheter Devices

In the interventional treatment of tricuspid valve regurgitation, the majority of prosthetic devices interact with or are implanted to the tricuspid valve annulus. For new transcatheter technologies, there exists a growing body of clinical experience, literature, and professional discourse related to the difficulties in delivering, securing, and sustaining the function of these devices within the dynamic tricuspid annulus. Many of the difficulties arise from circumstances not encountered in open-heart surgery, namely; a non-arrested heart, indirect visualization, and a reliance on non-suture-based methods. These challenges require the application of procedural techniques or system designs to account for tricuspid annular motion, forces, and underlying tissue strength. Improved knowledge in these interactions will support the goals of improving device systems, their procedures, and patient outcomes. This review aims to describe current concepts of tricuspid annular mechanics, key device and procedural implications, and highlight current knowledge gaps for future consideration.

Multi-Modality Imaging in the Evaluation and Treatment of Tricuspid Regurgitation

PURPOSE OF REVIEW

The goal of this review is to cover the epidemiology of tricuspid regurgitation (TR), anatomy of the tricuspid valve (TV), and the mechanisms and modern treatment of TR. The focus will be on the role of echocardiography, cardiac CT, and MRI to determine the mechanism, severity, and management strategies of TR.

RECENT FINDINGS

The evaluation and management of TR is a rapidly growing field with significant advances in both imaging and interventions. Important advances have been made to understand TV anatomy and physiology in 3D echo, CT, and MRI. Additional understanding of the abnormal outcomes in both primary TR and secondary TR have been appreciated. Multiple transcatheter devices have reached the stage of early trials in high surgical risk cohorts with favorable initial findings. TR is a significant cardiovascular problem and vastly undertreated in the present era. There has been tremendous growth in knowledge of mechanisms of TR, its prognostic implications, timing of intervention, and development of novel treatment strategies. Multimodality imaging plays a key role in evaluation and treatment of this condition.

Coordinating Self-Assembly of Copper Perylenetetracarboxylate Nanorods: Selectively Lighting up Normal Cells around Cancerous Ones for Better Cancer Diagnosis

Specific imaging of cancer cells has been well-accepted in cancer diagnosis although it cannot precisely mark the boundary between the normal and cancerous cells and report their mutual influence. We report a nanorod fluorescent probe of copper perylenetetracarbonate (PTC-Cu) that can specifically light up normal cells. In combination with cancer cell imaging, the cocultured normal and cancer cells can be lit up with different colors, offering a clear contrast between the normal and cancer cells when they coexist. Because cancerous cells are only 20-30% in cancer area, this provides a possibility to visibly detect the mutual influence between the cancer and normal cells during therapy. We expect this method is beneficial to better cancer diagnosis and therapy.