Computed tomography imaging for subclinical leaflet thrombosis following surgical and transcatheter aortic valve replacement.

Subclinical leaflet thrombosis (LT) may occur following surgical and transcatheter aortic valve replacement. Computed tomography (CT) has become an established imaging modality to diagnose subclinical LT following bioprosthetic aortic valve replacement. Even so, there is a limited (but growing) experience in utilizing CT imaging for this indication. This review emphasizes a systematic approach to acquiring and analysing CT imaging for subclinical LT, highlighting evidence surrounding clinical sequelae of subclinical LT and anti-thrombotic implications following diagnosis.

Conventional aortic root vs valve-sparing root replacement surgery in aortic dilatation syndromes: a comparison of mortality and postoperative complications.

INTRODUCTION: Conventional aortic root and valve-sparing root replacement surgery are two current surgical treatments for aortic dilatation syndromes. This review article aims to review the current literature surrounding these two established techniques. AREAS COVERED: This review article will address the current indications for valve-sparing root replacement surgery, technical considerations in surgical planning and a comparison of clinical outcomes between these two surgical techniques. EXPERT OPINION: Valve-sparing root replacement surgery is a safe and established treatment for aortic syndromes. Valve-sparing surgery procedure avoids the inherent risk of prosthetic valve dysfunction and prosthesis infection by preserving the native aortic valve compared to conventional aortic root surgery. This has been demonstrated in various observational studies and should be considered in clinically and anatomically appropriate patients. Other technical considerations, such as reimplantation versus remodeling technique and aortic cusp repair in select patients, may impact in short-term procedural and long-term clinical success with valve-sparing surgery.

Prosthesis Geometrical Predictors of Leaflet Thrombosis Following Transcatheter Aortic Valve Replacement With Intra-Annular Prostheses.

OBJECTIVE: To determine the association between prosthesis geometry with leaflet thrombosis (LT). BACKGROUND: Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) is a recognised entity. The association between prosthesis geometry with LT is unclear but maybe a potential modifiable factor in its prevention. METHODS: Patients who received an intra-annular TAVR prosthesis and were prospectively planned to undergo post-procedural computed tomography (CT) imaging were included. Leaflet thrombosis was defined as at least 50% restricted leaflet motion on CT. Prosthesis expansion and eccentricity was measured at prosthesis inflow, annulus and outflow levels. Prosthesis misalignment was defined as the average angle deviation between native and prosthesis leaflet commissure, greater than 30°. RESULTS: Prevalence of LT was 13.7% in 117 patients. None of the patients with LT were on anticoagulation therapy. Patients with LT had reduced prosthesis annular expansion (89.4±5.2% vs 97.0±4.4%, p<0.01), greater prosthesis misalignment (81.3% vs 48.5%, p=0.02) and deeper implants (6.3±1.7 mm vs 4.3±1.5 mm, p<0.01). Threshold for the presence of LT on ROC analysis was an implant depth of 5.7 mm (AUC [area under curve]=0.81). Independent predictors of LT were annular under-expansion (Odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.7, p=0.03) prosthesis misalignment (OR 6.8, 95%CI 1.1-45.5, p=0.04) and implant depth (OR 1.9, 95%CI 1.1-3.2, p=0.03). Anticoagulation therapy was a protective factor (OR 0.2; 95%CI 0.1-0.4, p<0.01). CONCLUSION: Geometrical predictors of LT post intra-annular TAVR were reduced prosthesis expansion at the annular level, lower implant depth and greater prosthesis misalignment. These factors may be important considerations during procedural planning for TAVR.

The impact of hypo-attenuated leaflet thickening on haemodynamic valve deterioration following transcatheter aortic valve replacement.

BACKGROUND: Hypo-attenuated leaflet thickening (HALT) may occur following transcatheter aortic valve replacement (TAVR), however, it remains unclear if HALT is a predictor of haemodynamic valve deterioration (HVD). AIM: To determine the impact of HALT on the occurrence of HVD. METHODS: We prospectively evaluated 186 patients for the presence of HALT at a median of 6 weeks following TAVR (Interquartile-range [IQR] 4-12 weeks). HALT depth and area were measured. HVD encompassed any of the following: mean gradient ≥20 â€‹mmHg with an increase in gradient ≥10 â€‹mmHg from baseline, Doppler velocity index reduction ≥0.1 or new moderate-to-severe valvular regurgitation. Routine echocardiograms at discharge, one month and annually, were assessed by echo-cardiologists that were blinded to the HALT status. RESULTS: LT prevalence was 17.7% (33/186). HVD was present in 8.6% (16/186) at a median follow-up of 2 years (IQR 1-3); two required valve re-intervention and five required anticoagulation. HALT was the only independent predictor of HVD on multivariate analysis (OR 33.3, 95%CI 7.4-125). Patients with HALT were more likely to develop HVD, require repeat valve intervention and have higher trans-valvular gradients at up to 3-year follow-up. Patients with HALT had a median cumulative thickness of 2.9 â€‹mm (IQR 1.9-4.7) and area of 64.2 â€‹mm2 (IQR 40.9-91.6). Thresholds for HALT in predicting HVD were a cumulative depth of 2.4 â€‹mm (Specificity 94.1%, Sensitivity 75.0%, AUC â€‹= â€‹0.87) and cumulative area of 28 â€‹mm2 (Specificity 92.2%, Sensitivity 81.3%, AUC â€‹= â€‹0.86). CONCLUSION: HALT is an independent predictor of HVD, which exhibits specific depth and area thresholds to predict HVD. CT following TAVR may determine patients at risk of HVD.

Patient-Specific Computer Simulation to Predict Conduction Disturbance With Current-Generation Self-Expanding Transcatheter Heart Valves.

Background: Patient-specific computer simulation may predict the development of conduction disturbance following transcatheter aortic valve replacement (TAVR). Validation of the computer simulations with current-generation devices has not been undertaken. Methods: A retrospective study was performed on patients who had undergone TAVR with a current-generation self-expanding transcatheter heart valve (THV). Preprocedural computed tomography imaging was used to create finite element models of the aortic root. Procedural contrast angiography was reviewed, and finite element analysis performed using a matching THV device size and implantation depth. A region of interest corresponding to the atrioventricular bundle and proximal left bundle branch was identified. The percentage of this area (contact pressure index [CPI]) and maximum contact pressure (CPMax) exerted by THV were recorded. Postprocedural electrocardiograms were reviewed, and major conduction disturbance was defined as the development of persistent left bundle branch block or high-degree atrioventricular block. Results: A total of 80 patients were included in the study. THVs were 23- to 29-mm Evolut PRO (n = 53) and 34-mm Evolut R (n = 27). Major conduction disturbance occurred in 27 patients (33.8%). CPI (28.3 ± 15.8 vs. 15.6 ± 11.2%; p < 0.001) and CPMax (0.51 ± 0.20 vs. 0.36 ± 0.24 MPa; p = 0.008) were higher in patients who developed major conduction disturbance. CPI (area under the receiver operating characteristic curve [AUC], 0.74; 95% CI, 0.63-0.86; p < 0.001) and CPMax (AUC, 0.69; 95% CI, 0.57-0.81; p = 0.006) demonstrated a discriminatory power to predict the development of major conduction disturbance. Conclusions: Patient-specific computer simulation may identify patients at risk for conduction disturbance after TAVR with current-generation self-expanding THVs.

Clinical predictors and sequelae of computed tomography defined leaflet thrombosis following transcatheter aortic valve replacement at medium-term follow-up.

BACKGROUND: The clinical predictors and sequelae of leaflet thrombosis (LT) following transcatheter aortic valve replacement (TAVR) is still unclear. Therefore, our aim was to determine the clinical predictors and sequelae at mid-term follow-up of computed tomography (CT)-defined LT following TAVR. METHODS AND RESULTS: We performed a prospective evaluation with a 320-multislice CT following TAVR for the presence of LT, defined as hypo-attenuated leaflet thickening (HALT). Four-dimensional CT image-rendering was performed to determine the presence of reduced leaflet motion (RELM). 172 patients [89 (51.7%) male, mean age 82.8 ± 5.7 years] treated with commercially available TAVR device (Lotus 54%, CoreValve 32% and Sapien 3 14%) were included, with median CT-scan at 6.0 weeks post-TAVR. Prevalence of HALT was 14.0% (24 cases) and RELM was 9.8% (17 cases). On multivariate analysis, patients with HALT were less prescribed oral anticoagulation (OAC) (OR 9.9), received larger TAVR prostheses (OR 5.7) and higher rates of moderate-severe para-valvular regurgitation (PVR) (OR 16.3). There was no difference in clinical outcomes at a median follow-up of 2.3 years. Patients with RELM had significantly higher transvalvular gradients after discharge when compared to those without RELM. CONCLUSIONS: Absence of OAC, large TAVR prostheses and moderate-severe PVR were predictors for LT. Transvalvular gradients were higher in patients that developed RELM but not HALT. Further studies are warranted to determine the long-term impact of LT on TAVR durability. Prevalence of different sub-types of CT-defined LT (HALT and RELM) and the clinical predictors of developing LT following TAVR. CT computed tomography, HALT hypo-attenuated leaflet thickening, LT leaflet thrombosis, RELM reduced leaflet motion, TAVR transcatheter aortic valve replacement.

Modification of the left atrial appendage and its role in stroke risk reduction with non-valvular atrial fibrillation.

Atrial fibrillation is one of the most common cardiovascular disorders encountered by clinicians in clinical practice. Patients with atrial fibrillation are at risk of cerebrovascular and systemic embolic events, which may be attenuated by commencement of anticoagulation therapy. Even so, due to extremely high bleeding risk certain patients may not be suitable for long-term anticoagulation therapy. The left atrial appendage is a common site for thrombus formation in patients with atrial fibrillation. Left atrial appendage exclusion, either surgical or percutaneous, has been performed to ostensibly reduce the risk of cerebrovascular events and potentially minimise or omit anticoagulation therapy in select patients. This review summarises the role of the left atrial appendage in cerebrovascular events, current evidence with modification of the left atrial appendage and future trials that may change practice with these procedures.

Women With Spontaneous Coronary Artery Dissection Are at Increased Risk of Iatrogenic Coronary Artery Dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic cause of acute coronary syndrome (ACS) that affects women disproportionately. Previous case series have found that patients with SCAD undergoing cardiac catheterisation have high rates of iatrogenic coronary damage. We formally compared the rate of iatrogenic coronary artery dissection in women with and without SCAD undergoing cardiac catheterisation over a 11-year period. METHODS: Women with SCAD were identified by a search of the cardiac catheterisation database 2007-2017 for the keywords 'SCAD', 'spontaneous coronary artery dissection', 'spontaneous coronary dissection', and 'spontaneous dissection'. For each identified case, the medical record and the coronary angiogram images were reviewed to confirm spontaneous coronary dissection. For cases of recurrent SCAD, duplicates were removed so that each patient was included only once in this analysis. For each identified case of SCAD, a control case was chosen from women aged <70 years, without SCAD, undergoing cardiac catheterisation for an ACS during the same 10-year period. One control case was chosen to match each SCAD patient as closely as possible for age and year of cardiac catheterisation. Iatrogenic coronary dissection was defined as new, proximal, flow limiting coronary artery dissection in a different coronary segment to the presenting spontaneous coronary dissection. RESULTS: Eighty-five (85) cases of women with SCAD were identified. Mean age was not different between SCAD and non-SCAD women (51±11 and 51±10 years, respectively). The SCAD group had lower rates of ST elevation myocardial infarction, lower rises in serum creatine kinase (CK) and troponin levels, lower rates of diabetes and smoking, and far less placement of stents during the procedure than the control group. The rate of additional iatrogenic dissection relating to the cardiac catheterisation procedure was 4 of 85 (4.7%) versus 0 of 85 (0%), p=0.04 in SCAD and control groups, respectively, despite a much lower rate of percutaneous coronary intervention in the SCAD group. No common factors could be identified regarding particular equipment or procedural factors associated with iatrogenic dissection. CONCLUSION: The rate of iatrogenic dissection in women with SCAD during cardiac catheterisation is confirmed to be high and significantly higher than a contemporaneous age-matched group of women without SCAD. This observation likely indicates generalised coronary fragility in this disease, and emphasises the importance of the utmost care in the engagement, injection and intervention involving the coronary arteries in this disease. Development of a non-invasive coronary imaging modality or biomarker able to diagnose SCAD non-invasively would be a great advance in the care of patients with this condition, because it would avoid the need for invasive coronary angiography for diagnosis.

The Natural history of Epicardial Adipose Tissue Volume and Attenuation: A long-term prospective cohort follow-up study.

Epicardial adipose tissue (EAT) is associated with cardiovascular risk. The longitudinal change in EAT volume (EATv) and density (EATd), and potential modulators of these parameters, has not been described. We prospectively recruited 90 patients with non-obstructive coronary atherosclerosis on baseline computed tomography coronary angiography (CTCA) performed for suspected coronary artery disease to undergo a repeat research CTCA. EATv in millilitres (mL) and EATd in Hounsfield units (HU) were analysed and multivariable regression analysis controlling for traditional cardiovascular risk factors (CVRF) performed to assess for any predictors of change. Secondary analysis was performed based on statin therapy. The median duration between CTCA was 4.3years. Mean EATv increased at follow-up (72 ± 33 mL to 89 ± 43 mL, p < 0.001) and mean EATd decreased (baseline -76 ± 6 HU vs. -86 ± 5 HU, p < 0.001). There were no associations between baseline variables of body mass index, age, sex, hypertension, hyperlipidaemia, diabetes or smoking on change in EATv or EATd. No difference in baseline, follow-up or delta EATv or EATd was seen in patients with (60%) or without baseline statin therapy. In this select group of patients, EATv consistently increased and EATd consistently decreased at long-term follow-up and these changes were independent of CVRF, age and statin use. Together with the knowledge of strong associations between EAT and cardiac disease, these findings may suggest that EAT is an independent parameter rather than a surrogate for cardiovascular risk.

The role of four-dimensional computed tomography in transcatheter aortic valve replacement prosthesis endocarditis with concurrent leaflet thrombosis: a case report.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is becoming increasingly utilized for the treatment of severe aortic valvular heart disease. Infective endocarditis of TAVR is rare but associated with higher mortality and morbidity. The potential for leaflet thrombosis following TAVR is also becoming increasingly recognized. Diagnosis of these conditions on echocardiography can be challenging due to prosthesis artefact. CASE SUMMARY: An 84-year-old man with a previous transcatheter aortic valve replacement presented with a febrile illness and bacteraemia. Transthoracic and transoesophageal echocardiography demonstrated high transvalvular gradients with features of prosthesis endocarditis, though leaflet morphology could not be fully assessed due to prosthesis artefact. Four-dimensional computed tomography revealed hypo-attenuated leaflet thickening with reduced leaflet motion, consistent with prosthesis leaflet thrombosis. The patient was successfully treated with antibiotics and anticoagulation, with resolution of the infection and normalization of the transvalvular gradient after 6 weeks. DISCUSSION: Echocardiography should be the first-line investigation for assessing leaflet morphology in suspected prosthetic valve endocarditis or leaflet thrombosis but its accuracy may be limited by artefact. Our case highlights that four-dimensional computed tomography provides further evaluation of prosthesis leaflet morphology/motion, providing valuable diagnostic information.

Transcatheter Aortic Valve Replacement and Atrial Fibrillation: Impact of Antithrombotic Strategy on Clinical Outcomes.

BACKGROUND: Antithrombotic recommendations following transcatheter aortic valve replacement (TAVR) are largely based on previous trial protocols. The efficacy and risk of anticoagulation has not been systematically assessed. The aim of this study was to determine the efficacy and safety of oral anticoagulation in patients with atrial fibrillation (AF) following TAVR with the Lotus Valve System (Boston Scientific, Marlborough, MA, USA). METHODS: Consecutive patients with severe aortic stenosis who underwent Lotus valve implantation were prospectively recruited (n=164). Atrial fibrillation patients prescribed oral anticoagulation (standard AF therapy) were compared to non-AF patients prescribed aspirin and clopidogrel (standard non-AF therapy). Twenty (20) of 164 patients were excluded, as they were not prescribed standard therapy. The primary endpoint was 6-month incidence of death, myocardial infarction, stroke/transient ischaemic attack (TIA) or major/life-threatening bleeding. Secondary endpoints included each component of the primary endpoint, defined according to VARC-2. RESULTS: Overall, the primary endpoint occurred in 20.8% and 17.7% of the standard AF and standard non-AF therapy groups respectively (p=0.82). There was no statistically significant difference in bleeding (12.5% versus 9.4%, p=0.77) or stroke/TIA (2.1% versus 8.3%, p=0.27) between the standard AF and standard non-AF therapy groups respectively. CONCLUSIONS: This study supports the safety of anticoagulation in AF patients, which did not result in excess risk of bleeding or stroke/TIA compared with dual antiplatelet therapy in non-AF patients.

Awareness of Familial Hypercholesterolemia Among Healthcare Providers Involved in the Management of Acute Coronary Syndrome in Victoria, Australia.

BACKGROUND: Familial hypercholesterolemia (FH) is a common underdiagnosed autosomal dominant lipid disorder carrying a significant risk of premature coronary artery disease. The aim of this study was to evaluate the awareness and knowledge of heterozygous FH of healthcare providers in coronary care units (CCUs). METHODS: Medical staff working in CCUs in 4 sizable metropolitan health networks in Melbourne, Australia, were requested to complete a structured anonymised questionnaire with regard to FH. The results were tabulated and analysed with the Statistical Package for the Social Sciences version 23 (IBM, New York, NY). RESULTS: A total of 121 participants (67% response rate) completed the survey. Some 76% claimed to be at least modestly familiar with FH, and more than half of them adequately described FH; however, only 16% and 43%, respectively, were aware of the prevalence of FH and existence of lipid guidelines. In regard to epidemiological knowledge and update in the management of FH in CCUs, knowledge was suboptimal. In regard to FH care, General Practitioners were rated by 72% of participants as the first most efficient healthcare provider in the management of FH, and cardiologists were rated by 54% of participants as the second most efficient healthcare provider in the management of FH. Some 36% of respondents advocated a form of alert system in laboratory reports to facilitate the diagnosis of FH. CONCLUSIONS: This survey identified substantial gaps in the knowledge and awareness of FH among healthcare providers involved in the management of acute coronary syndrome. Focused education and clinical training are warranted to raise awareness of FH among healthcare providers working in CCUs.

CONTEXTE: L'hypercholestérolémie familiale (HF) est un trouble lipidique autosomique dominant courant et sous-diagnostiqué, associé à un risque important de coronaropathie prématurée. Le but de cette étude consistait à évaluer la sensibilisation et les connaissances à l'égard de l'HF hétérozygote parmi les professionnels de la santé œuvrant en unité de soins coronariens (USC). MÉTHODOLOGIE: Les membres du personnel médical des USC de quatre réseaux de santé métropolitains relativement importants de Melbourne, en Australie, ont été invités à remplir un questionnaire anonyme structuré sur l'HF. Les résultats ont été mis sous forme de tableaux et analysés à l'aide de la trousse logicielle SPSS (Statistical Package for the Social Sciences, IBM, New York, NY), version 23. RÉSULTATS: Au total, 121 personnes (taux de réponse de 67 %) ont participé à l'enquête. Environ 76 % des répondants ont indiqué posséder à tout le moins quelques connaissances sur l'HF, tandis que plus de la moitié d'entre eux en ont donné une définition adéquate; en revanche, seuls 16 et 43 %, respectivement, connaissaient la prévalence de l'HF et l'existence de lignes directrices sur les lipides. Par rapport aux connaissances épidémiologiques et à l'actualisation des stratégies de prise en charge de l'HF en USC, les connaissances étaient sous-optimales. Soixante-douze pour cent des répondants ont jugé que le médecin généraliste était le professionnel de la santé le plus à même de soigner et de prendre en charge l'HF; le cardiologue a été mentionné en seconde position par 54 % des répondants. Quelque 36 % des répondants ont préconisé la mise en place d'un système d'alerte, dans les rapports de laboratoire, pour faciliter le diagnostic d'HF. CONCLUSIONS: Cette enquête a mis en évidence des lacunes considérables dans la sensibilisation et les connaissances à l'égard de l'HF parmi les professionnels de la santé intervenant dans la prise en charge du syndrome coronarien aigu. Un enseignement et une formation clinique ciblés s'imposent pour accroître la sensibilisation à l'égard de l'HF parmi les professionnels de la santé qui travaillent en USC.

The prevalence of computed tomography-defined leaflet thrombosis in intra- versus supra-annular transcatheter aortic valve prostheses.

INTRODUCTION: Leaflet thrombosis (LT) defined by computed tomography (CT) following transcatheter aortic valve replacement (TAVR) has been shown to increase cerebrovascular events. The neo-sinus plays an important role in the development of LT. Intra-annular valves (IAV) have a larger neo-sinus when compared to supra-annular valves (SAV), and has been associated with larger thrombus burden. The prevalence of LT with IAV and SAV in a larger, diverse cohort is unknown. METHODS: We performed a systematic review to assess the prevalence of LT in IAV versus SAV TAVR prostheses. Inclusion criteria were (1) reported CT-defined LT following TAVR, (2) comparison between LT and non-LT cohort, (3) separate registry/database, and (4) fully published status. A total of 2,013 citations were reviewed and 7 studies were included. RESULTS: Overall, 1,644 patients were included from 7 observational studies and the prevalence of LT following TAVR was 12.8%. The Portico valve system (IAV) had the highest prevalence of LT with 35.2%, followed by Symetis Acurate Neo (SAV) at 15.4% and the Lotus valve system (IAV) at 14.5%. LT occurred more frequently in IAV than SAV (13.5% vs. 7%, P = 0.02). Subanalysis of IAV versus SAV with the exclusion of the Portico valve was performed to ensure results were not influenced by this valve system and revealed IAV still had higher rates of LT (12.1% vs. 7%, P = 0.05). CONCLUSION: In summary, IAV prostheses appear to be associated with higher rates of LT when compared with SAV.

Subclinical Leaflet Thrombosis in Transcatheter Aortic Valve Replacement Detected by Multidetector Computed Tomography　- A Review of Current Evidence.

Subclinical leaflet thrombosis (SLT) following transcatheter aortic valve replacement (TAVR) has been increasingly recognized. SLT has the hallmark features of hypo-attenuated leaflet thickening (HALT) on multidetector computed tomography (MDCT), which may result in hypoattenuation affecting motion (HAM). The actual prevalence of this condition is uncertain, with limited observational registries. SLT has caught the attention of the cardiovascular community because of concerns regarding its clinical sequelae, specifically the potential increased incidence of cerebrovascular events. There are available, albeit sparse, data to suggest that when left untreated, SLT may lead to valve deterioration with potential hemodynamic compromise and potentially clinically overt prostheses thrombosis. Some clinicians have opted to treat patients with SLT with anticoagulation. Although anticoagulation may be a rational treatment option, little data exist on the safety and efficacy of this treatment. This is particularly important considering TAVR patients also have higher bleeding risk than the standard population. In this review, we aim to summarize the current evidence on SLT, explore its pathophysiological mechanism, discuss the current treatment options and future trials that may clarify the optimal antithrombotic strategies of SLT.