Sixty-Four–Section Cardiac Computed Tomography in Mechanical Prosthetic Heart Valve Dysfunction: Thrombus or Pannus

Hypoattenuated Leaflet Thickening: A Comprehensive Review of Contemporary Data

Nearly one-third of patients who undergo surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) develop hypoattenuated leaflet thickening (HALT) within a year. HALT typically represents subclinical leaflet thrombosis in asymptomatic patients, and as a result it often is detected incidentally. However, HALT also may worsen in severity, resulting in leaflet immobility and/or valve deterioration. The clinical significance of HALT is a topic of ongoing debate, and currently there is no consensus on the screening and management of HALT in patients following TAVR or SAVR. This review provides a comprehensive evaluation of the available evidence on risk factors, preventative measures, treatment, and prognosis for this growing patient cohort.

Evaluation and Management of Mechanical Heart Valve Dysfunction and Thrombosis

PURPOSE OF REVIEW

Dysfunction and thrombosis of mechanical heart valves, although uncommon, represents a challenge that requires multidisciplinary expertise for diagnosis and management. The aim of this review is to summarize strengths and weaknesses of diagnostic methods and therapeutic strategies for this uncommon but potentially life-threatening pathology.

RECENT FINDINGS

Expeditious diagnosis of mechanical valve thrombosis and exclusion of other diagnostic considerations, often with incorporation of multimodality imaging, can inform the best treatment strategy. Presentation of mechanical valve thrombosis can be asymptomatic or can include heart failure, life-threatening embolic events, or cardiogenic shock. Echocardiography, fluoroscopy and computed tomography are important in the evaluation of mechanical valve dysfunction. Therapeutic strategies for thrombosis include anticoagulation, systemic thrombolysis, and surgery. Choice of treatment depends on multiple factors including thrombus size, degree of valve dysfunction, clinical presentation, and available surgical expertise.

Management of prosthetic valve thrombosis with unfractionated heparin

BACKGROUND

Prosthetic valve thrombosis (PVT) is a severe and life-threatening complication. Surgery and thrombolytic therapy (TT) carry a high risk, and in several circumstances, optimal anticoagulation with unfractionated heparin (UFH) infusion may be an alternative treatment. This study aimed to assess the results of UFH in patients diagnosed with both obstructive and non-obstructive PVT.

METHODS

This observational retrospective study enrolled patients who had contraindications for TT and surgery underwent UFH therapy.

RESULTS

A total of 136 patients were enrolled [male: 55 (40.4%), mean age: 50.3 ± 14.6 years] in the study. In the successful group, 66 patients (48,5%) showed >75% regression in the thrombus burden without facing death or major non-fatal complications.In the unsuccessful group, 56 had less than a 50% reduction in thrombus load and 14 (10.3%) suffered major complications. The presence of obstruction (27.1% vs. 12.1%; p = 0.028), thrombus area 1.1 cm2 vs. 0.8 cm2; p = 0.005] and the duration of UFH treatment (15.1 vs. 11.8 (days); p = 0.005) were significantly higher in the unsuccessful UFH group.In multivariate regression analyses the presence of obstruction (RR: 3.088, p = 0.020), increased thrombus area (RR: 2.400; p = 0.015), and increased duration of UFH therapy (RR: 1.073 95%, p = 0.012) were identified as independent predictive parameters for a failed UFH therapy.

CONCLUSIONS

This study suggests that UFH therapy may be considered a relatively beneficial treatment strategy for some patients with PVT. The most significant factors affecting success are the obstructive nature and area of the thrombus.

Multimodality Imaging of Infective Endocarditis

Infective endocarditis (IE) is a complex multisystemic disease resulting from infection of the endocardium, the prosthetic valves, or an implantable cardiac electronic device. The clinical presentation of patients with IE varies, ranging from acute and rapidly progressive symptoms to a more chronic disease onset. Because of its severe morbidity and mortality rates, it is necessary for radiologists to maintain a high degree of suspicion in evaluation of patients for IE. Modified Duke criteria are used to classify cases as "definite IE," "possible IE," or "rejected IE." However, these criteria are limited in characterizing definite IE in clinical practice. The use of advanced imaging techniques such as cardiac CT and nuclear imaging has increased the accuracy of these criteria and has allowed possible IE to be reclassified as definite IE in up to 90% of cases. Cardiac CT may be the best choice when there is high clinical suspicion for IE that has not been confirmed with other imaging techniques, in cases of IE and perivalvular involvement, and for preoperative treatment planning or excluding concomitant coronary artery disease. Nuclear imaging may have a complementary role in prosthetic IE. The main imaging findings in IE are classified according to the site of involvement as valvular (eg, abnormal growths [ie, "vegetations"], leaflet perforations, or pseudoaneurysms), perivalvular (eg, pseudoaneurysms, abscesses, fistulas, or prosthetic dehiscence), or extracardiac embolic phenomena. The differential diagnosis of IE includes evaluation for thrombus, pannus, nonbacterial thrombotic endocarditis, Lambl excrescences, papillary fibroelastoma, and caseous necrosis of the mitral valve. The location of the lesion relative to the surface of the valve, the presence of a stalk, and calcification or enhancement at contrast-enhanced imaging may offer useful clues for their differentiation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging: A Report From the American Society of Echocardiography Developed in Collaboration With the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography

In patients with significant cardiac valvular disease, intervention with either valve repair or valve replacement may be inevitable. Although valve repair is frequently performed, especially for mitral and tricuspid regurgitation, valve replacement remains common, particularly in adults. Diagnostic methods are often needed to assess the function of the prosthesis. Echocardiography is the first-line method for noninvasive evaluation of prosthetic valve function. The transthoracic approach is complemented with two-dimensional and three-dimensional transesophageal echocardiography for further refinement of valve morphology and function when needed. More recently, advances in computed tomography and cardiac magnetic resonance have enhanced their roles in evaluating valvular heart disease. This document offers a review of the echocardiographic techniques used and provides recommendations and general guidelines for evaluation of prosthetic valve function on the basis of the scientific literature and consensus of a panel of experts. This guideline discusses the role of advanced imaging with transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance in evaluating prosthetic valve structure, function, and regurgitation. It replaces the 2009 American Society of Echocardiography guideline on prosthetic valves and complements the 2019 guideline on the evaluation of valvular regurgitation after percutaneous valve repair or replacement.

Dysfunctioning mechanical mitral valve prosthesis: When thrombus over pannus makes hinders diagnosis

Prosthetic valve obstruction is a rare but potentially lethal complication. The most frequent causes are thrombus and pannus formation, in the absence of infectious data. Diagnosis is not always easy using cardiac CT scanning and in 46%-85% of cases thrombus and pannus coexist, complicating the diagnosis. A rapid diagnosis is essential to avoid a fatal outcome of this pathology whose mortality, despite correct treatment, is high.

Early Biological Valve Failure: Structural Valve Degeneration, Thrombosis, or Endocarditis?

Biological valve failure (BVF) is an inevitable condition that compromises the durability of biological heart valves (BHVs). It stems from various causes, including rejection, thrombosis, and endocarditis, leading to a critical state of valve dysfunction. Echocardiography, cardiac computed tomography, cardiac magnetic resonance, and nuclear imaging play pivotal roles in the diagnostic multimodality workup of BVF. By providing a comprehensive overview of the pathophysiology of BVF and the diagnostic approaches in different clinical scenarios, this review aims to aid clinicians in their decision-making process. The significance of early detection and appropriate management of BVF cannot be overstated, as these directly impact patients' prognosis and their overall quality of life. Ensuring timely intervention and tailored treatments will not only improve outcomes but also alleviate the burden of this condition on patients' life. By prioritizing comprehensive assessments and adopting the latest advancements in diagnostic technology, medical professionals can significantly enhance their ability to manage BVF effectively.

Mechanical prosthetic mitral valve obstruction: Pannus or thrombus? A case report

Substitution of a defective heart valve with a prosthetic heart valve turns the native disease for prosthesis-related complications. One of the most serious and dreaded complications is prosthetic valve obstruction. It is either the result of a thrombus or pannus formation. For the evaluation of prosthetic valve obstruction, transthoracic echography and fluoroscopy provide functional information but may not provide information about the etiology of the obstruction, unlike multidetector computed tomography (MDCT) which allows a more precise etiological diagnosis to guide the therapeutic attitude. Here, we report a case of a mechanical prosthetic mitral valve obstruction in a 45-year-old patient in whom the diagnosis of pannus was retained on the basis of clinical, biological, and imaging data. The differentiation between thrombus and pannus is crucial because it conditions the therapeutic attitude. Advanced imaging specially MDCT options should be considered whenever mechanical prosthesis valve obstruction is suspected.

Diagnosis of Left-Sided Mechanical Prosthetic Valve Thrombosis: A Pictorial Review

Although transcatheter valve therapy is rapidly evolving, surgical valve replacement is still required in many patients with severe left-side valve stenosis or regurgitation, the mechanical bi-leaflet heart valve being the standard prosthesis type in younger patients. Moreover, the prevalence of valvular heart disease is steadily increasing, especially in industrialized countries, and the problem of lifelong efficient anticoagulation of these patients remains fundamental, especially in the context where vitamin K antagonists continue to be the current standard of anticoagulation despite a level of oscillating anticoagulation. In this setting, avoiding prosthetic valve thrombosis after surgery is the number one objective for both the patient and the responsible physicians. Although rare, this complication is life threatening, with the sudden onset of acute cardiac failure such as acute pulmonary edema, cardiogenic shock, or sudden cardiac death and inadequate anticoagulation remaining the leading cause of prosthesis thrombosis, along with other risk factors. The availability of multimodal imaging techniques enables and encompasses to a full extent the diagnosis of mechanical valve thrombosis. The gold-standard diagnostic methods are transthoracic and transesophageal echocardiography. Moreover, 3D ultrasound has undoubted value in giving a more accurate description of the thrombus's extension. When transthoracic and transesophageal echocardiography are uncertain, the multidetector computer tomography examination is an important complementary imaging method. Fluoroscopy is also an excellent tool for evaluating the mobility of prosthetic discs. Each method complements the other to differentiate an acute mechanical valve thrombosis from other prosthetic valve pathologies such as pannus formation or infective endocarditis and aids the physician in accurately establishing the treatment method (surgical or pharmaceutical) and its optimal timing. The aim of this pictorial review was to discuss from an imagistic perspective the mechanical prosthetic aortic and mitral valve thrombosis and to provide an overview of the essential role of non-invasive exploration in the treatment of this severe complication.

Management of Mechanical Prosthetic Heart Valve Thrombosis: JACC Review Topic of the Week

Mechanical prosthetic heart valves, though more durable than bioprostheses, are more thrombogenic and require lifelong anticoagulation. Mechanical valve dysfunction can be caused by 4 main phenomena: 1) thrombosis; 2) fibrotic pannus ingrowth; 3) degeneration; and 4) endocarditis. Mechanical valve thrombosis (MVT) is a known complication with clinical presentation ranging from incidental imaging finding to cardiogenic shock. Thus, a high index of suspicion and expedited evaluation are essential. Multimodality imaging, including echocardiography, cine-fluoroscopy, and computed tomography, is commonly used to diagnose MVT and follow treatment response. Although surgery is oftentimes required for obstructive MVT, other guideline-recommended therapies include parenteral anticoagulation and thrombolysis. Transcatheter manipulation of stuck mechanical valve leaflet is another treatment option for those with contraindications to thrombolytic therapy or prohibitive surgical risk or as a bridge to surgery. The optimal strategy depends on degree of valve obstruction and the patient's comorbidities and hemodynamic status on presentation.

Evaluation of causal heart diseases in cardioembolic stroke by cardiac computed tomography

Cardioembolic stroke is a potentially devastating condition and tends to have a poor prognosis compared with other ischemic stroke subtypes. Therefore, it is important for proper therapeutic management to identify a cardiac source of embolism in stroke patients. Cardiac computed tomography (CCT) can detect the detailed visualization of various cardiac pathologies in the cardiac chambers, interatrial and interventricular septum, valves, and myocardium with few motion artifacts and few dead angles. Multiphase reconstruction images of the entire cardiac cycle make it possible to demonstrate cardiac structures in a dynamic manner. Consequently, CCT has the ability to provide high-quality information about causal heart disease in cardioembolic stroke. In addition, CCT can simultaneously evaluate obstructive coronary artery disease, which may be helpful in surgical planning in patients who need urgent surgery, such as cardiac tumors or infective endocarditis. This review will introduce the potential clinical applications of CCT in an ischemic stroke population, with a focus on diagnosing cardioembolic sources using CCT.

Usefulness of cardiac computed tomography in prosthetic heart valve dysfunction

BACKGROUND

Prosthetic heart valve (PHV) dysfunction is a serious complication. Echocardiography remains the first-line imaging investigation to assess PHV dysfunction. However, the role of Computed Tomography (CT) scanning in this type of case has not been thoroughly studied yet. The objective of our study was to determine if cardiac Computed Tomography (CT) had a potentially complementary role to play alongside echocardiography in diagnosing the mechanism of prosthetic valve dysfunction.

METHODS AND RESULTS

This prospective cohort study was conducted on 54 patients with suspected PHV dysfunction. All patients underwent routine diagnosis work-up (transthoracic and transesophageal echocardiography) and additional cardiac CT. Cardiac CT showed findings that were not detected by echocardiography in seven patients (12%) namely aortic pannus (5) and pseudoaneurysm (2). An underlying thrombus was detected by echocardiography and missed by cardiac CT in 15 patients (27%). However, in these thrombotic cases, cardiac CT contributed to the functional evaluation of leaflets.

CONCLUSION

This study demonstrates that an integrated approach including transthoracic, transesophageal echocardiography and computed tomography is useful in patients with suspected PHV dysfunction. While computed tomography is more accurate in the diagnosis of pannus formation and periannular complications, echocardiography is superior at detecting thrombus.

Cardiac gated multidetector computed tomography (MDCT) to determine valvular leaflet thrombosis and leaflet restriction

The evaluation of patients following aortic valve replacement has evolved, with multiple imaging modalities available that complement each other and permit better and prompt delineation of specific structural or functional valve complications. Multidetector computed tomography (MDCT) is one of the diagnostic modalities with significant technologic advancements that have made possible to evaluate high detail of the moving heart. The ability to deliver three-dimensional and multiplanar dynamic imaging with fine detail has demonstrated the technique is well suited to investigate valve complications. In this review article, we focus on some of the most contributing roles of MDCT in the diagnosis of complications associated with valvular pathology.

Deep learning-based reconstruction on cardiac CT yields distinct radiomic features compared to iterative and filtered back projection reconstructions

We aimed to determine the effects of deep learning-based reconstruction (DLR) on radiomic features obtained from cardiac computed tomography (CT) by comparing with iterative reconstruction (IR), and filtered back projection (FBP). A total of 284 consecutive patients with 285 cardiac CT scans that were reconstructed with DLR, IR, and FBP, were retrospectively enrolled. Radiomic features were extracted from the left ventricular (LV) myocardium, and from the periprosthetic mass if patients had cardiac valve replacement. Radiomic features of LV myocardium from each reconstruction were compared using a fitting linear mixed model. Radiomics models were developed to diagnose periprosthetic abnormality, and the performance was evaluated using the area under the receiver characteristics curve (AUC). Most radiomic features of LV myocardium (73 of 88) were significantly different in pairwise comparisons between all three reconstruction methods (P < 0.05). The radiomics model on IR exhibited the best diagnostic performance (AUC 0.948, 95% CI 0.880-1), relative to DLR (AUC 0.873, 95% CI 0.735-1) and FBP (AUC 0.875, 95% CI 0.731-1), but these differences did not reach significance (P > 0.05). In conclusion, applying DLR to cardiac CT scans yields radiomic features distinct from those obtained with IR and FBP, implying that feature robustness is not guaranteed when applying DLR.

Cardiovascular Imaging in Pregnancy: Valvulopathy, Hypertrophic Cardiomyopathy, and Aortopathy

Pregnancy is associated with profound hemodynamic changes that are particularly impactful in patients with underlying cardiovascular disease. Management of pregnant women with cardiovascular disease requires careful evaluation that considers the well-being of both the woman and the developing fetus. Clinical assessment begins before pregnancy and continues throughout gestation into the post-partum period and is supplemented by cardiac imaging. This review discusses the role of imaging, specifically echocardiography, cardiac MRI, and cardiac CT, in pregnant women with valvular diseases, hypertrophic cardiomyopathy, and aortic pathology.

Quality assessment of radiomics research in cardiac CT: a systematic review

OBJECTIVES

To assess the quality of current radiomics research on cardiac CT using radiomics quality score (RQS) and Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) systems.

METHODS

Systematic searches of PubMed and EMBASE were performed to identify all potentially relevant original research articles about cardiac CT radiomics. Fifteen original research articles were selected. Two cardiac radiologists assessed the quality of the methodology adopted in those studies according to the RQS and TRIPOD guidelines. Basic adherence rates for the following six key domains were evaluated: image protocol and reproducibility, feature reduction and validation, biologic/clinical utility, performance index, high level of evidence, and open science.

RESULTS

Among the 15 included articles, six (40%) were about coronary artery disease and six (40%) were about myocardial infarction. The mean RQS was 9.9 ± 7.3 (27.4% of the ideal score of 36), and the basic adherence rate was 44.6%. Fourteen (93.3%) and nine (60%) studies performed feature selection and validation, but only two (13.3%) of them performed external validation. Two studies (13.3%) were prospective, and only one study (6.7%) conducted calibration analysis and stated the potential clinical utility. None of the studies conducted phantom study and cost-effective analysis. The overall adherence rate for TRIPOD was 63%.

CONCLUSION

The quality of radiomics studies in cardiac CT is currently insufficient. A higher level of evidence is required, and analysis of clinical utility and calibration of model performance need to be improved.

KEY POINTS

• The quality of science of radiomics studies in cardiac CT is currently insufficient. • No study conducted a phantom study or cost-effective analysis, with further limitations being demonstrated in a high level of evidence for radiomics studies. • Analysis of clinical utility and calibration of model performance need to be improved, and a higher level of evidence is required.

A Challenging Case of Mechanical Mitral Valve Obstruction

Prosthetic valve thrombosis (PVT) is a frequent complication with a mechanical valve that presents with symptoms of heart failure or thromboembolic episodes. A 45-year-old lady with antiphospholipid syndrome (APS) complicated by a previous history of native mitral valve thrombus and mechanical mitral valve replacement maintained on warfarin presented with complaints of chest pain and shortness of breath (NYHA class 2). The initial lab showed a subtherapeutic international normalized ratio (INR) of 1.8. Transthoracic echo (TTE) showed severe mitral stenosis with a normal ejection fraction of 65%, elevated peak gradient of 34.5 mmHg, mean gradient of 23.7 mmHg, and pressure half time of 214 ms. Cine-fluoroscopic images revealed an immobile posterior mitral valve leaflet. She failed two trials of low-dose alteplase therapy during the hospitalization. Hence cardiac CT with contrast was done, which showed a small degree of pannus formation on the ventricular surface of the mitral valve ring and a small thrombus. Due to persistent immobility of the post mitral valve after two doses of alteplase and a cardiac CT scan concerning pannus formation, a multi-departmental decision was made to proceed with mechanical mitral valve replacement, following which she had a good recovery. Our case report depicts the importance of imaging study, like cardiac CT scan that can help distinguish thrombus (which has a lower Hounsfield unit, HU of <90) vs. pannus (higher HU of more than 145).

Thrombolysis or Surgery in Patients With Obstructive Mechanical Valve Thrombosis: The Multicenter HATTUSHA Study

BACKGROUND

Prosthetic valve thrombosis (PVT) is one of the life-threatening complications of prosthetic heart valve replacement. Due to the lack of randomized controlled trials, the optimal treatment of PVT remains controversial between thrombolytic therapy (TT) and surgery.

OBJECTIVES

This study aimed to prospectively evaluate the outcomes of TT and surgery as the first-line treatment strategy in patients with obstructive PVT.

METHODS

A total of 158 obstructive PVT patients (women: 103 [65.2%]; median age 49 years [IQR: 39-60 years]) were enrolled in this multicenter observational prospective study. TT was performed using slow (6 hours) and/or ultraslow (25 hours) infusion of low-dose tissue plasminogen activator (t-PA) (25 mg) mostly in repeated sessions. The primary endpoint of the study was 3-month mortality following TT or surgery.

RESULTS

The initial management strategy was TT in 83 (52.5%) patients and surgery in 75 (47.5%) cases. The success rate of TT was 90.4% with a median t-PA dose of 59 mg (IQR: 37.5-100 mg). The incidences of outcomes in surgery and TT groups were as follows: minor complications (29 [38.7%] and 7 [8.4%], respectively), major complications (31 [41.3%] and 5 [6%], respectively), and the 3-month mortality rate (14 [18.7%] and 2 [2.4%], respectively).

CONCLUSIONS

Low-dose and slow/ultraslow infusion of t-PA were associated with low complications and mortality and high success rates and should be considered as a viable treatment in patients with obstructive PVT.

Complementary role of cardiac CT in the diagnosis and management of mechanical aortic valve thrombosis with a novel low-dose, ultraslow thrombolysis treatment strategy

A 31-year-old man presented to our emergency department with a 3-day history of progressive breathlessness, fatigue and exertional angina. His history included a mechanical aortic valve replacement (mAVR) for rheumatic heart disease at age 19 years. He could no longer afford medication prescription costs and consequently had not taken oral anticoagulation for 2 months. Transthoracic echocardiography (TTE) demonstrated mechanical prosthetic valve obstruction (PVO) and severe left ventricular (LV) systolic dysfunction; however, valve visualisation was limited by mAVR-related artefact. The patient declined transoesophageal echocardiography. Valve haemodynamics failed to improve despite a prolonged course of parenteral anticoagulation. Multidetector cardiac CT scan was performed which confirmed prosthetic valve thrombosis. A novel low-dose, ultraslow thrombolysis regimen was administered to mitigate the associated bleeding and embolic stroke risk. The patient made an excellent recovery and was discharged on day 30, with repeat cardiac CT scan showing complete resolution of mechanical PVO and normalisation of valve and LV function on TTE.

Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Prognostic impact of identifying etiology of prosthetic valve dysfunction with CT

BACKGROUND

In patients with prosthetic heart valves (PHV), there are distinct treatment implications based on prosthetic valve dysfunction (PVD) etiology. We investigated whether evaluation for PVD etiology on computed tomography (CT) has prognostic value for adverse clinical outcomes.

METHODS

Consecutive patients with suspected PVD that had a clinically indicated contrast chest CT and echocardiogram done within 1 year of each other were identified retrospectively from the Prosthetic Heart Valve CT Registry at the University of Minnesota. CTs and echocardiograms were assessed for potential PVD etiologies of pannus, structural valve degeneration (SVD) and thrombus, as per standard guidelines. Kaplan-Meier and Cox regression analyses were performed to assess association with a composite outcome of reoperation and all-cause mortality.

RESULTS

132 patients (51.5% male, mean age 62.1 ​± ​19.3 years) with suspected PVD were included. There were 97 tissue valves, 31 mechanical valves and 4 transcatheter valves. The location of the valve was as follows: 72 aortic, 45 mitral, 8 tricuspid, and 7 pulmonic. A PVD etiology was diagnosed on CT in 80 (60.6%) patients, and on echocardiography in 45 (34.1%) patients, largely driven by a diagnosis of SVD on both modalities. Significant univariate predictors of the composite outcome included CT diagnosis of SVD (P ​< ​0.001), echocardiography diagnosis of SVD (P ​< ​0.001), degree of prosthetic stenosis (P ​< ​0.001) and degree of prosthetic regurgitation (P ​< ​0.001). On multivariable analyses adjusted for age, sex, left ventricular function, degree of prosthetic stenosis and degree of prosthetic regurgitation, CT diagnosis of SVD was significantly associated with the composite outcome (HR: 1.79, 1.09-2.95) whereas echocardiography diagnosis of SVD was not (HR: 1.56, 0.98-2.46).

CONCLUSION

In patients with suspected PVD, CT assessment of SVD had prognostic significance for hard outcomes. CT should be considered in the diagnostic evaluation of patients with suspected PVD.

Imaging Spectrum of Valvular and Paravalvular Complications of Prosthetic Heart Valve at CT Angiography

Prosthetic heart valve (PHV) dysfunction is an uncommon but potentially life-threatening condition. In routine practice, transthoracic echocardiography and cinefluoroscopy comprise first-line imaging for the diagnostic evaluation of PHV dysfunction. In cases in which the findings of echocardiography and cinefluoroscopy remain inconclusive or are contradictory, CT angiography can resolve these conflicts. CT angiography also provides incremental diagnostic information about patients with suspected PHV obstruction and endocarditis, in which case it can demonstrate the anatomic substrate and extent of involvement. Additionally, information regarding the coronary arteries, cardiac dimensions, and retrosternal space may be obtained in cases in which repeat surgery is planned. This imaging essay describes the imaging spectrum of valvular and paravalvular complications of PHV at CT angiography and how the knowledge regarding the spectrum of complications can be incorporated into multimodality imaging for guiding clinical management. Keywords: Prosthetic Heart Valve Dysfunction, Prosthetic Heart Valve Thrombosis, Pannus, Paravalvular Leak, CT Angiography, Cardiac, Valves Supplemental material is available for this article. © RSNA, 2021.

Which One to Treat When Pannus and Thrombus Coexist in a Mechanical Aortic Valve?: An Equivocal Case

The coexistence of pannus and thrombus is not uncommon. Accurate diagnosis of the etiology of prosthetic valve dysfunction (PVD) is of utmost importance in guiding adequate and rational therapy. We present a case of PVD in which computed tomography played a decisive role in guiding treatment. (Level of Difficulty: Intermediate.)

Multimodality Cardiac Imaging for Procedural Planning and Guidance of Transcatheter Mitral Valve Replacement and Mitral Paravalvular Leak Closure

Transcatheter mitral valve interventions are an evolving and growing field in which multimodality cardiac imaging is essential for diagnosis, procedural planning, and intraprocedural guidance. Currently, transcatheter mitral valve-in-valve with a balloon-expandable valve is the only form of transcatheter mitral valve replacement (TMVR) approved by the FDA, but valve-in-ring and valve-in-mitral annular calcification interventions are increasingly being performed. Additionally, there are several devices under investigation for implantation in a native annulus. Paravalvular leak (PVL) is a known complication of surgical or transcatheter valve implantation, where regurgitant flow occurs between the prosthetic sewing ring and the native mitral annulus. We sought to describe the role and applications of multimodality cardiac imaging for TMVR, and PVL closure, including the use of Cardiovascular Computed Tomography Angiography and 3-Dimensional Transesophageal Echocardiography for diagnosis, prosthetic valve evaluation, pre-procedural planning, and intraprocedural guidance, as well as evolving technologies such as fusion imaging and 3D printing.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

A comprehensive review of the diagnosis and management of mitral paravalvular leakage

Mitral paravalvular leaks (PVLs) commonly occur in patients with prosthetic valves. Paravalvular defects may be clinically inconsequential and may aggravate hemolysis or cause heart failure through regurgitation. Accordingly, patients may eventually require intervention such as redo surgery or a transcatheter closure of the defects. The introduction of purpose-specific closure devices and new steerable catheters has opened a new frontier for the transcatheter PVL closure. This mode of treatment is an initial therapy in most centers with experienced structural heart team. However, head-to-head data comparing two treatment modalities (surgery and transcatheter closure) are limited, and the world-wide experience is based on nonrandomized studies. Multimodality imaging, including three-dimensional transesophageal echocardiography, facilitates the delineation of mitral PVLs and provides essential data that aids the communication between the members of the structural heart team. In the near future, the success of interventional therapies will most probably increase in patients with mitral PVLs with the introduction of hybrid imaging modalities (echocardiography, cardiac computed tomography, and fluoroscopy). In conclusion, this paper summarizes the etiopathogenesis, clinical characteristics, diagnosis, and treatment of mitral PVLs. (Anatol J Cardiol 2020; 24: 350-60)

Normal reference values for mechanical mitral prosthetic valve inner diameters and areas assessed by two-dimensional and real-time three-dimensional transesophageal echocardiography

It was previously observed that two dimensional (2D) Doppler derived and real-time three-dimensional (RT-3D) directly measured valve areas were smaller than reported manufacturer sizes. It may be helpful to obtain the ranges of inner diameters (IDs) and the geometric orifice area (GOA) during evaluation of prosthetic mitral valves. In this study, we aimed to provide reference dimensional parameters of bileflet mitral mechanical prosthetic valves. Patients with recent mitral valve replacement were examined by 2D and RT-3D transesophageal echocardiography (TEE) in the early postoperative period when the presence of pannus overgrowth was unlikely. Measurements of 2D IDs, 3D hinge to hinge (HHD) and edge to edge diameters (EED) and 3D GOA were obtained and compared with reported manufacturer sizes and areas. This study enrolled 126 patients with mitral prosthetic valves (38 ATS, 42 Carbomedics, 46 St. Jude Medical, all bileaflet). The measured 2D and 3D IDs and GOA were significantly smaller than reported manufacturer sizes in the majority of the valve sizes. This RT-3D TEE-guided study provides ranges of reference values for directly measured IDs and GOA of the three most commonly used mechanical mitral prosthetic valve types for the first time in a relatively large series.

Imaging evaluation using computed tomography after ascending aortic graft repair

Prosthetic aortic graft repair is employed in the management of various conditions such as annuloaortic ectasia, ascending aortic aneurysm, type A aortic dissection, and aortic root abscess. Correct interpretation of post-surgical prosthetic graft complications requires familiarity with the expected normal cross-sectional imaging appearance as well knowledge of additional surgical materials used in the repair, which could influence the imaging appearance. Multiple life-threatening complications of a prosthetic ascending aortic graft can be seen in the aorta and vicinity of the operative field. Complications can arise from involvement of the prosthetic aortic graft per se or secondary involvement of the coronary arteries, mediastinum, and sternotomy site. The optimal imaging protocol using multidetector computed tomography allows accurate interpretation of the expected benign postoperative changes as well as complications associated with the prosthetic graft, and differentiation of true complications from their mimickers. This review focuses on the normal imaging appearance of a prosthetic aortic graft on multidetector computed tomography, and imaging evaluation of multiple post-surgical complications that could arise after repair of the ascending aorta and the aortic valve.

The value of brain natriuretic peptide in the prosthetic valve thrombosis

: We aimed to investigate how prosthetic valve thrombosis (PVT) affects brain natriuretic peptide (BNP) levels and how BNP changes following thrombolytic therapy. The study included 70 consecutive patients with left-sided mechanical PVT who received thrombolytic therapy. The patients were divided into two groups, namely obstructive thrombus (n = 42) and nonobstructive thrombus (NOT, n = 28). BNP levels of patients were assessed before and after thrombolytic therapy. BNP levels were higher in obstructive thrombus group than NOT group in whole study population, in patients with mitral PVT and in patients with aortic PVT [325.0 (189.5-496.0) vs. 84.0 (44.5-140.0), P < 0.001, 323.0 (193-449.0) vs. 59.0 (37.0-131.0), P < 0.001 and 321.0 (132.0-525.0) vs. 99.0 (60.5-173.0), P < 0.001]. BNP levels were positively correlated with transmitral and transaortic mean gradients, and negatively correlated with mitral valve area (r: 0.374, P = 0.013; r: 0.432, P = 0.035 and; r: -0.642, P < 0.001, respectively). BNP values above 165 pg/ml may predict the presence of obstructive thrombus with a sensitivity of 88.0%, and a specificity of 79.0% (AUC = 0.928, 95% confidence interval: 0.871-0.986, P < 0.001). Following thrombolytic therapy, BNP levels (pg/ml) significantly decreased from 325.0 (189.5-496.0) to 137.0 (101.7-224.5), P < 0.001, in all patients with obstructive thrombus, from 323.0 (193.0-449.0) to 129.0 (98.0-223.0), P < 0.001, in patients with only mitral obstructive thrombus and from 321.0 (132.0-525.0) to 181.0 (99.0-217.5), P < 0.001, in patients with only aortic obstructive thrombus. BNP levels are significantly higher in prosthetic valve patients with obstructive thrombus than in those with NOT and decrease in patients with obstructive thrombus after thrombolytic therapy. A cut off value of BNP of at least 165.0 pg/ml was found to discriminate obstructive thrombus from NOT.

Utility of CT in the diagnosis of prosthetic valve abnormalities

BACKGROUND

Patients with prosthetic heart valves (PHV) are at an increased risk of endocarditis and dysfunction. Knowledge about the etiology of dysfunction and extent of endocarditis can have distinct treatment implications. Echocardiography has limitations due to PHV-related artifacts. We hypothesized that computed tomography (CT) will have incremental value over echocardiography for evaluation of PHV abnormalities with surgical findings as the reference standard.

METHODS

Consecutive patients with PHV that had a reoperation for valve replacement, had a contrast chest CT and echocardiogram within 1 year of the reoperation, between 2010 and 2018 at a single academic center formed the study cohort. CTs and echocardiograms were assessed for potential etiologies of dysfunction (valve degeneration, pannus and thrombus); and for extent of endocarditis (vegetation, abscess, and pseudoaneurysm).

RESULTS

Seventy-three patients (65.8% male, mean age 62.1 ± 16.5 years) formed the study cohort. The indication for reoperation was PHV dysfunction in 51 and PHV endocarditis in 22. Compared to echocardiography, CT diagnosed the etiology of PHV dysfunction in 17 (33.3%) more patients (9 valve degeneration, 8 pannus). In the PHV endocarditis cohort, CT failed to detect one vegetation and one abscess, whereas echocardiography failed to detect 1 abscess. In combination, CT and echocardiography demonstrated all the vegetations and abscesses.

CONCLUSION

CT may provide superior characterization in comparison to echocardiography for the identification of the cause of prosthetic valve dysfunction, and complementary information to echocardiography for the evaluation of prosthetic valve endocarditis.

Cardiac Computed Tomography for Structural Heart Disease Assessment and Therapeutic Planning: Focus on Prosthetic Valve Dysfunction

Of the 100,000-plus valve surgeries performed each year in the United States, up to 6% of those develop complications from prosthetic valve dysfunction. Prosthetic valve dysfunction (PVD) can be life threatening and often challenging to diagnose. In this review, we discuss the prevalence and incidence of PVD, explore its different etiologies, and assess the role of multimodality imaging with an emphasis on cardiac multidetector computed tomography (MDCT) for evaluating patients with PVD. We also investigate the utility of MDCT in preprocedural planning for transcatheter devices and redo surgical planning and discuss management strategies for patients with PVD.

Obstructive bioprosthetic mitral valve thrombosis

Bioprosthetic valve thrombosis (BPVT) is not uncommon but can be under diagnosed due to the lack of awareness and technical limitations of echocardiography. When suspecting BPVT, it is imperative to consider multimodality imaging to establish the diagnosis as early treatment can alter the clinical course. Here we present a case series of two patients with a history of rheumatic heart disease status post bioprosthetic mitral valve replacement who presented with acute heart failure symptoms. In both cases, supplemental imaging with real-time 3D echocardiography was critical in establishing a diagnosis of BPVT, resulting in timely treatment. These cases support updating current guidelines for the management of patients with bioprosthetic valve replacement to include more frequent surveillance imaging even if patients are asymptomatic.

Mechanical Mitral Valve Thrombosis in a Patient With Prior Nonbacterial Thrombotic Endocarditis

A 54-year-old woman with a mechanical mitral valve replacement presented with recurrent admissions for pneumonia and pulmonary edema. Multimodality imaging revealed mobile masses on the prosthesis and discrepant point of care and inpatient international normalized ratio levels owing to antiphospholipid antibody cross-reactivity on the outpatient assay. The prosthetic valve thromboses resolved with therapeutic anticoagulation. (Level of Difficulty: Beginner.)

Imaging of the aortic root on high-pitch non-gated and ECG-gated CT: awareness is the key!

The aortic pathologies are well recognized on imaging. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. Advances in CT technology have allowed motionless imaging of the chest and abdomen, leading to an increased visualization of cardiac and aortic root diseases on non-ECG-gated imaging. The advances are mostly driven by high pitch due to faster gantry rotation and table speed. The high-pitch scans are being increasingly used for variety of clinical indications because the images are free of motion artifact (both breathing and pulsation) as well as decreased radiation dose. Recognition of aortic root pathologies may be challenging due to lack of familiarity of radiologists with disease spectrum and their imaging appearance. It is important to recognize some of these conditions as early diagnosis and intervention is key to improving prognosis. We present a comprehensive review of proximal aortic anatomy, pathologies commonly seen at the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location.

Case report of successful low-dose, ultra-slow infusion thrombolysis of prosthetic mitral valve thrombosis in a high risk patient after redo-mitral valve replacement

Background

An increase in transvalvular pressure gradient of prosthetic valve should always raise suspicion for obstructive valve thrombosis. A multimodality diagnostic approach including transthoracic echocardiography, transoesophageal echocardiography (TOE), cinefluoroscopy, or computed tomography (CT) is necessary for a prompt diagnosis. The management of mechanical prosthetic valve thrombosis (PVT) is high risk in any therapeutic option taken. Emergency valve replacement is recommended for critically ill patients. Fibrinolysis is an alternative for patients with contraindication to surgery or if surgery is not immediately available.

Case summary

A 52-year-old woman presented with symptoms and signs of cardiac congestion. On laboratory, brain natriuretic peptide was elevated and international normalized ratio (INR) was in subtherapeutic range. She underwent a mitral valve replacement with mechanical prosthesis 7 months before, because of a significant residual regurgitation after repair on the same year. TOE revealed severe stenosis of the prosthesis with immobile anterior disc but there was no mass present. CT revealed a minor lesion at the hinge points of the prosthesis without involvement of the ring, suggestive for thrombus. The initial fruitless management with intravenous (i.v) heparin in high therapeutic range was followed by a successful 'low-dose, ultra-slow' fibrinolysis.

Discussion

CT may help differentiate thrombus vs. pannus. The acute onset of symptoms, inadequate anticoagulation, and restricted leaflet motion increased the suspicion for PVT. The current European guidelines propose normal dose fibrinolysis. We performed 'low-dose, ultra-slow' fibrinolysis due to lower bleeding risk with successful results. Low dose should be considered as alternative to normal dose fibrinolysis or urgent surgery.

Computed Tomography Features of Cuspal Thrombosis and Subvalvular Tissue Ingrowth after Transcatheter Aortic Valve Implantation

Post-transcatheter aortic valve implantation (TAVI) computed tomography (CT) findings have not been fully elucidated, except hypoattenuating leaflet thickening (HALT). The objective of this study was to describe cardiac CT findings after TAVI, and investigate factors associated with HALT. This retrospective study included patients who underwent TAVI and post-TAVI cardiac CT scans. On CT, abnormal findings such as hypoattenuating subvalvular thickening (HAST), thrombus within the sinus of Valsalva, HALT, and leaflet motion limitation were thoroughly reviewed. Clinical and CT findings were compared between patients with HALT and those without HALT. Logistic regression analysis was performed to determine factors associated with HALT. A total of 138 patients (64 male, mean 78.5 ± 5.2 years of age) with post-TAVI CT scans were included. The median duration from TAVI to CT was 17.5 days (interquartile range, 3 to 390.8 days). HAST and thrombus within the sinus of Valsalva were detected in 32 (23%) and 5 (4%) patients, respectively. HALT and leaflet motion limitations were found in 25 (18%) and 20 (14%) of patients, respectively. Pannus was diagnosed in 2 patients. TAVI device implant duration (odds ratio [OR], 1.5; p = 0.01), hypertension (OR, 0.2; p = 0.03), and HAST (OR, 4.9; p = 0.003) were associated with HALT. Implant durations were longer in patients with HAST, HALT, or leaflet motion limitation (p < 0.05, for all). In conclusion, HAST, HALT, thrombus within the sinus of Valsalva, and leaflet motion limitation are not uncommon after TAVI. Implant duration, hypertension, and HAST are associated with HALT.

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.