Hypoattenuated Leaflet Thickening Research Articles

Thrombus attenuation predicts natural history of hypo-attenuating leaflet thickening after transcatheter aortic valve replacement

Abstract Background Hypo-attenuating leaflet thickening (HALT) after transcatheter aortic valve replacement (TAVR) occurs in up to 25% of patients and is characterized by diverse temporal dynamics. Several studies investigated the natural history of HALT in transcatheter and surgical cohorts, but little is known about the imaging features of persistent thrombus. Purpose To examine the association of quantitative HALT volume and attenuation from computed tomography angiography (CTA) with its natural history. Methods We prospectively examined patients with HALT present on CTA at 30 days after TAVR and who underwent a follow-up CTA at one year. Hypoattenuation affecting motion (HAM) was defined as the presence of HALT with at least moderately reduced (>50%) leaflet motion. HALT was quantified by segmenting the inner volume of the bioprosthetic frame at the level of the leaflets and extracting voxels between a threshold of -200 to 200 HU. Thrombus volume, mean thrombus attenuation and thrombus heterogeneity measured with standard deviation of attenuation were automatically calculated (Figure 1). Results A total of 37 patients (70% men, 71±7 years old) undergoing TAVR with balloon-expandable SAPIEN3 (86%) and self-expanding EVOLUT (14%) valves were evaluated. Hypoattenuation affecting motion (HAM) at 30 days after TAVR was present in 29 (74%) patients. Patients with HAM had higher thrombus volume than patients without reduced leaflet motion (0.40cm3 [IQR 0.16 – 0.61cm3] vs 0.14 [IQR 0.06 – 0.19 cm3], p=0.009) but comparable mean attenuation values (145HU [IQR 141-151HU] vs 123 [IQR 114 – 141HU], p=0.079). Only 3 patients were switched to oral anticoagulation following HALT detection. At one year, HALT resolution was observed in 18/37 (48%) and HAM resolution in 19/29 (65%). No difference in quantitative thrombus features was noted between patients with persistent and resolved HALT. Notably, patients with persistent HAM had higher mean thrombus attenuation (141HU [IQR 123-156HU] vs 123HU [IQR 110 – 138 HU), p=0.045; Figure 2) and thrombus heterogeneity (58HU [IQR 51-63HU] vs 48HU [IQR 41- 54HU], p=0.021) than resolved HAM. Mean thrombus attenuation (area under the curve of 0.732, p=0.044) and thrombus heterogeneity (area under the curve of 0.763, p=0.022) were predictive of HAM resolution at one year. The optimal cutoff values as determined by Youden index was 140HU for mean attenuation and 52HU for heterogeneity. There was an increase in the mean transvalvular gradients between measurements at 30 days and one year in patients with persistent HAM as compared to patients with HAM resolution (Δ3mmHg [IQR -3 – 11mmHg] vs Δ-1mmHg [IQR -4 – 0mmHg], p=0.049). The volume of thrombus at one year was associated with the magnitude of change in transvalvular gradients (β = 10.3, 95% CI 1.6- 19.0, p=0.025). Conclusion Quantitative evaluation of HALT by CTA may aid the identification of patients at risk of persistent thrombus.

A new wearable cardiac acoustic monitoring technology for the evaluation of subclinical leaflet thrombosis after transcatheter aortic valve replacement: a pilot study

Abstract Background Subclinical leaflet thrombosis characterized by hypoattenuated leaflet thickening (HALT) and reduced leaflet motion (RLM) is a common complication after transcatheter aortic valve replacement (TAVR), whether it affects hemodynamic change is still debated. Purpose We attempted to use a novel wearable heart acoustic monitoring device, and combined multi-dimensional computed tomography (MDCT) and echocardiography to diagnose SLT and analyze the changes of transvalvular hemodynamics after TAVR. Methods Patients with severe symptomatic aortic stenosis and underwent successful TAVR were consecutively enrolled. Clinical data, acoustic cardiographic parameters including the frequency, amplitude, and energy of heart sounds , and imaging results were collected and analyzed by Core laboratory at pre- and post TAVR, and follow-up at one month and six month. According to severity of SLT at one month follow-up, we divided the patients into three groups: Group1: no SLT, Group2: mild SLT, defined as existed HALT did not qualify for Group 3, and Group 3: moderate to severe SLT, defined as at least 1 leaflet with HALT of grade 3 or 4 or RLM of ≥50%, or 2 leaflets with HALT of grade 2 or RLM of ≥50%. A consistency analysis of SLT presence between MDCT findings and acoustic cardiographic variables was performed using Kappa statistics. Results The study included 116 TAVR patients. The prevalence of SLT as detected by MDCT at one-month follow-up was 25%, with moderate to severe SLT representing 11.2% of cases. A significant decrease in aortic valve orifice area (AVA) (-0.2±0.48cm2 vs. -0.1±0.33cm2, p=0.009) and an increase in mean gradient (MG) (3.5±5.85 mmHg vs. 0.1±11.34mmHg, p=0.028) were observed in moderate to severe SLT group at one-month follow-up versus post-TAVR via echocardiography. However, no significant differences were found in the mild SLT or no SLT group. Acoustic cardiographic characteristics exhibited a distinct pattern with early systolic, baseless, and high-energy murmurs in patients with moderate to severe SLT, but not in the mild SLT or no SLT group. The sensitivity, specificity, and Kappa values for acoustic cardiography in diagnosing moderate to severe SLT were 81.82%, 83.33%, and 0.41, respectively. At the 6-month follow-up, MDCT showed that 11 (85%) patients with moderate to severe SLT who received anticoagulant therapy reached complete dissolution of SLT. Conclusion Moderate to severe SLT presented notably transvalvular hemodynamic influences following TAVR. Acoustic cardiography demonstrated specific characteristics of moderate to severe SLT, providing a valuable tool for SLT diagnosis and evaluation in clinical follow-up.Figure 1.Baseline characteristicsFigure 2.SLT and acoustic cardiography

Lipoprotein(a) and High-Sensitivity C-Reactive Protein Compound the Risk of Hypoattenuating Leaflet Thickening After Transcatheter Aortic Valve Replacement.

The mechanism for hypoattenuating leaflet thickening (HALT) after transcatheter aortic valve replacement is still not well elucidated, and the role of Lp(a) (lipoprotein[a]) and hs-CRP (high-sensitivity C-reactive protein) has rarely been studied. This study sought to test the hypothesis that the risk of HALT is associated with an elevated level of Lp(a) or hs-CRP. A total of 307 consecutive individuals who underwent a transcatheter aortic valve replacement procedure were included. All patients received their first postoperative computed tomography scans within 12 months, and raw data were analyzed on 3mensio software. HALT was defined as visually identified increased leaflet thickness with typical meniscal appearance and at least 2 different multiplanar reformation projections. Associations of Lp(a) or hs-CRP with the risk of HALT were evaluated using multivariable logistic regression analysis. The incidence of HALT within 12 months after transcatheter aortic valve replacement in this study was 36.2%, and the risk of HALT was associated with higher baseline Lp(a) (the multivariable adjusted odds ratio [OR] for every 10 mg/dL change was 1.18 [95% CI, 1.09-1.29]) and hs-CRP level (the multivariable adjusted OR for every 1 mg/L change was 1.08 [95% CI, 1.00-1.27]). Compared with individuals out of the top 25th percentile for both Lp(a) and hs-CRP, the multivariable adjusted OR for HALT was 4.74 (95% CI, 1.65-14.37) for the top 25th percentile. This result remained consistent after excluding patients receiving anticoagulant therapy. The top 25th percentile of Lp(a) level (≥40 mg/dL) combined with the top 25th percentile of hs-CRP level (≥3.5 mg/L) conferred a 4.74-fold risk of HALT.

Subclinical valve leaflet thrombosis following bioprosthetic aortic valve replacement.

Subclinical leaflet thrombosis (SLT) is often an incidental finding characterized by a thin layer of thrombus involving one, two or three leaflets, with typical appearance on multi-detector computed tomography (MDCT) of hypo-attenuating defect at the aortic side of the leaflet, also called hypo-attenuating leaflet thickening (HALT). SLT may occur following both transcatheter aortic replacement (TAVR) or biological surgical aortic valve replacement (SAVR). The aim of this review is to present an overview of the current state of knowledge on the incidence, diagnosis, clinical impact, and management of SLT following TAVR or SAVR. SLT occurs in 10-20% of patients following TAVR and is somewhat more frequent than following SAVR (5-15%). SLT may regress spontaneously without treatment in about 50% of the cases but may also progress to clinically significant valve thrombosis in some cases. Oral anticoagulation with vitamin K antagonist is reasonable if SLT is detected by echocardiography and/or MDCT during follow-up and is generally efficient to reverse SLT. SLT is associated with mild increase in the risk of stroke but has no impact on survival. SLT has been linked with accelerated structural valve deterioration and may thus impact valve durability and long-term outcomes. SLT is often an incidental finding on echocardiography or MDCT that occurs in 10-20% of patients following TAVR or 5-15% following biological SAVR and is associated with a mild increase in the risk of thrombo-embolic event with no significant impact on mortality but may be associated with reduced valve durability.

Long-term prosthetic-associated subclinical thrombotic events evaluation by cardiac CTA after transcatheter aortic valve implantation: incidence and outcomes

ObjectiveTo observe prosthetic-associated subclinical thrombotic events (PASTE) after transcatheter aortic valve implantation (TAVI) by cardiac CTA, and assess their impact on long-term patient outcomes.MaterialsWe prospectively and consecutively enrolled 188 patients with severe aortic stenosis treated with TAVI from February 2014 to April 2017. At 5 years, 61 of 141 survived patients who had completed annual follow-up CTA (≥ 5 years) were included. We analyzed PASTE by CTA, including hypoattenuated leaflet thickening (HALT), sinus filling defect (SFD), and prosthesis filling defect (PFD). The primary outcome was a major adverse cardiovascular composite outcome (MACCO) of stroke, cardiac re-hospitalization, and bioprosthetic valve dysfunction (BVD); the secondary outcomes were bioprosthetic hemodynamics deterioration (PGmean) and cardiac dysfunction (LVEF).ResultsDuring a median follow-up time of 5.25 years, long-term incidence of HALT, SFD, and PFD were 54.1%, 37.7%, and 73.8%, respectively. In the primary outcome, SFD and early SFD were associated with the MACCO (SFD: p = 0.005; early SFD: p = 0.018), and SFD was a predictor of MACCO (HR: 2.870; 95% CI: 1.010 to 8.154, p = 0.048). In the secondary outcomes, HALT was associated with increased PGmean (p = 0.031), while persistent HALT was correlated with ΔPGmean (β = 0.38, p = 0.035). SFD was negatively correlated with ΔLVEF (β = −0.39, p = 0.041), and early SFD was negatively correlated with LVEF and ΔLVEF (LVEF: r = −0.50, p = 0.041; ΔLVEF: r = −0.53, p = 0.030).ConclusionsPASTE were associated with adverse long-term outcomes, bioprosthetic hemodynamics deterioration, and cardiac dysfunction. In particular, SFD was a predictor of MACCO and may be a potential target for anticoagulation after TAVI (NCT02803294).RegistrationURL: https://www.clinicaltrials.gov; Unique identifier: NCT02803294.Critical relevance statementPASTE, especially SFD, after TAVI based on cardiac CTA findings impacts the long-term outcomes of patients which is a predictor of long-term major adverse outcomes in patients and may be a potential target for anticoagulation after TAVI.Key PointsTranscatheter aortic valve implantation is being used more often; associated subclinical thromboses have not been thoroughly evaluated.Prosthetic-associated subclinical thrombotic events were associated with adverse outcomes, bioprosthetic hemodynamics deterioration, and cardiac dysfunction.Studies should be directed at these topics to determine if they should be intervened upon.Graphical

Prediction of hypoattenuating leaflet thickening in patients undergoing transcatheter aortic valves replacement based on clinical factors and 4D-computed tomography morphological characteristics: A retrospective cross-sectional study

BackgroundThe rapid increase in the number of transcatheter aortic valve replacement (TAVR) procedures in China and worldwide has led to growing attention to hypoattenuating leaflet thickening (HALT) detected during follow-up by 4D-CT. It's reported that HALT may impact the durability of prosthetic valve. Early identification of these patients and timely deployment of anticoagulant therapy are therefore particularly important. MethodsWe retrospectively recruited 234 consecutive patients who underwent TAVR procedure in Fuwai Hospital. We collected clinical information and extracted morphological characteristics parameters of the transcatheter heart valve (THV) post TAVR procedure from 4D-CT. LASSO analysis was conducted to select important features. Three models were constructed, encapsulating clinical factors (Model 1), morphological characteristics parameters (Model 2), and all together (Model 3), to identify patients with HALT. Receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were plotted to evaluate the discriminatory ability of models. A nomogram for HALT was developed and verified by bootstrap resampling. ResultsIn our study patients, Model 3 (AUC = 0.738) showed higher recognition effectiveness compared to Model 1 (AUC = 0.674, p = 0.032) and Model 2 (AUC = 0.675, p = 0.021). Internal bootstrap validation also showed that Model 3 had a statistical power similar to that of the initial stepwise model (AUC = 0.723 95%CI: 0.661–0.786). Overall, Model 3 was rated best for the identification of HALT in TAVR patients. ConclusionA comprehensive predictive model combining patient clinical factors with CT-based morphology parameters has superior efficacy in predicting the occurrence of HALT in TAVR patients.

Comparison of apixaban versus aspirin for the prevention of latent bioprosthetic aortic valve thrombosis: study protocol for a prospective randomized trial.

The optimal antithrombotic strategy early after aortic valve replacement surgery with a biological valve remains controversial due to lack of high-quality evidence. Either oral anticoagulants or acetylsalicylic acid should be considered for the first 3 months. Hypo-attenuated leaflet thickening on cardiac computed tomography has been associated with latent bioprosthetic valve thrombosis and may be prevented with anticoagulation. We hypothesize that anticoagulation with apixaban is superior to single antiplatelet therapy with acetylsalicylic acid in reducing hypo-attenuated leaflet thickening of bioprosthetic aortic valve prostheses. In this prospective, open-label, randomized trial, patients undergoing isolated aortic valve replacement surgery with rapid deployment bioprosthetic valves will be randomized. The treatment group will receive 5 mg of apixaban twice a day for the first 3 months and 100 mg of acetylsalicylic acid thereafter. The control group will be administered 100 mg of acetylsalicylic acid once a day, indefinitely. After the 3-month treatment period, a contrast-enhanced electrocardiogram-gated cardiac computed tomography will be performed to identify hypo-attenuated leaflet thickening of the bioprosthetic valve. The primary objective of the study is to assess the impact of apixaban on the prevention of hypo-attenuated leaflet thickening at 3 months. The secondary and exploratory endpoints will be clinical outcomes and safety profiles of the two strategies. Antithrombotic therapy after aortic valve replacement is used to prevent valve thrombosis and systemic thromboembolism. Latent bioprosthetic valve thrombosis is a precursor of clinically significant prosthetic valve dysfunction or thromboembolic events. The hallmark feature of latent bioprosthetic valve thrombosis is hypo-attenuated leaflet thickening on cardiac computed tomography. Subclinical leaflet thrombosis occurs frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. There is no evidence on the effect of direct oral anticoagulants on the incidence of hypo-attenuated leaflet thickening after surgical aortic valve replacement with rapid deployment bioprostheses. ClinicalTrials.gov NCT06184113. Registered on December 28, 2023.

One-year initial efficacy and safety outcomes of the premounted dry-pericardium Vienna self-expandable transcatheter aortic valve system: A first-in-human VIVA feasibility study.

The dry-pericardium Vienna transcatheter aortic valve system is repositionable and retrievable, already premounted on the delivery system, eliminating the need for assembly and crimping of the device before valve implantation. The VIVA first-in-human feasibility study, a prospective, nonrandomized, single-center trial, evaluated the Vienna aortic valve in 10 patients with severe symptomatic aortic stenosis, who were at intermediate or high surgical risk. This study, registered at ClinicalTrials.gov (NCT04861805), focused on the safety, feasibility, clinical and hemodynamic performance of the Vienna system up to 1-year follow-up. The mean patient age was 79 ± 5 years, 60% male. Valve sizes used: 26 mm (10%), 29 mm (30%), 31 mm (60%). Key hemodynamic improvements were significant: mean aortic valve pressure gradient (mmHg) decreased from 48.7 to 8.1, aortic valve area (cm2) increased from 0.75 to 1.91, and maximum jet velocity through the aortic valve (m/s) decreased from 4.41 to 1.95 (p < 0.0001). No moderate/severe paravalvular leakage was observed, and computed tomography scans revealed no evidence of hypo-attenuated leaflet thickening. The study recorded one life-threatening bleeding event, two cases requiring postprocedural pacemaker implantation, and three ischemic events, with only one causing lasting neurological impairment. Importantly, there were no cases of cardiovascular mortality and only one noncardiovascular death, which was confirmed as unrelated to the device. The study indicates the Vienna valve as a potential option for severe symptomatic aortic stenosis, designed to streamline the procedure and potentially lower healthcare costs by reducing resource and equipment needs, also procedural errors. Further research is essential to thoroughly evaluate its safety and efficacy.

Risk Factors for Early HALT after Transfemoral TAVI

Objective: To investigate the risk factors of hypoattenuated leaflet thickening (HALT) in the early stage after transfemoral transcatheter aortic valve implantation (TAVI). Methods: Patients who underwent transfemoral TAVI in the Affiliated Hospital of Qingdao University from January 2021 to June 2023 were selected. According to the results of four-dimensional computed tomography (4DCT), patients were divided into HALT group and non-HALT group. The perioperative data of the two groups were collected to find the risk factors of HALT in the early postoperative period. Results: A total of 100 patients underwent TAVI operation via femoral artery, 2 died after operation, 1 discharged due to cerebral complication, and 2 patients had incomplete 4DCT data. The data of 95 patients were completely collected, including 56 males and 39 females, with an average age of (72.0 ± 6.7) years and a body mass index of (24.0 ± 3.7) kg/m2. 10 patients had HALT, the incidence was 10.5%. 85 patients were in the non-HALT group, including 52 males (61.2%). 10 patients were in the HALT group, 4 cases were male (40%). There were no significant differences in age, sex, body mass index (BMI), hypertension, diabetes, chronic obstructive pulmonary disease (COPD), brain complications, coronary heart disease, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and operation time between the two groups. And the differences between the two groups in perioperative white blood cell, neutrophil, lymphocyte and platelet counts, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and creatinine were not significant. Compared with the non-HALT group, patients in the HALT group had a higher proportion of isolated aortic insufficiency, a lower proportion of post dilatation after valve release, and a higher proportion of valves with skirts. Conclusion: Isolated aortic insufficiency, without post dilatation after valve release, and use of valves with skirt are associated with early HALT after transfemoral TAVI.

Early thrombus formation including hypo-attenuated leaflet thrombosis after surgical bioprosthetic aortic valve replacement.

To assess the occurrence, predictors, and outcomes of hypo-attenuated leaflet thickening (HALT) and thrombus outside the prosthetic valve following surgical aortic valve replacement. A total of 118 patients underwent surgical aortic valve replacement with bioprosthetic valves between July 2020 and June 2022. Sixty-two (52.5%) patients, which is a fairly high number of patients, underwent cardiac computed tomography and transthoracic echocardiography one week after surgery. Patients were divided into two groups, those with HALT (n = 14) and those without HALT (n = 48). Of the 62 patients who underwent cardiac computed tomography, HALT was observed in 14 (22.5%) patients during the very early postoperative phase. Reduced leaflet motion was observed in two of the 14 patients. The low-attenuation areas were located outside the prosthetic valve in 10 cases (71.4%) in the HALT group and in 14 cases (29.2%) in the non-HALT group. More than 50% of patients (57.1%) with HALT and 79.2% without HALT were administered warfarin. Neither in-hospital deaths nor postoperative thromboembolic events were observed during hospitalization. No patient had a mean pressure gradient > 20mmHg in either group. HALT was observed in one-fifth of the cases after surgical aortic valve replacement during the very early postoperative phase in an institution wherein administration of continuous heparin infusion after surgery is a standard practice. HALT did not affect the early prognosis or incidence of cerebral infarction.

Incidence and impact of hypoattenuated leaflet thickening following aortic valve replacement using a glycerol-preserved bioprosthesis

Incidence and impact of hypoattenuated leaflet thickening following aortic valve replacement using a glycerol-preserved bioprosthesis

Utility of Photon Counting CT in Transcatheter Structural Heart Disease Interventions

Photon counting Computed Tomography (PCCT) is an innovative technology that utilizes a semiconductor detector and assigns x-ray photons to specific energy bins. PCCT features include ultra high-resolution, multi-energy binning, higher signal of iodine, lower artifacts, lower noise, and geometric radiation dose efficiency. These advantages may be highly beneficial in pre- and post-procedural assessment of transcatheter structural heart disease (SHD) interventions. Ultra-high resolution improves visualization of device structure and subtle findings such as hypoattenuated leaflet thickening, small vegetations and paravalvular leaks. High resolution also improves the evaluation of heavily calcified and stented coronary arteries, which are prevalent in high-risk transcatheter aortic valve replacement (TAVR) population. Visualization of heavily calcified coronary arteries and access vessels can also be improved by using multienergy calcium separation or high-energy virtual monoenergetic images (VMIs). PCCT allows use of low dose of iodinated contrast in severe renal dysfunction, due to inherent higher contrast-to-noise ratio of iodine, availability of a high-pitch helical mode and low-energy VMIs. High-energy VMIs can decrease artifacts including calcium blooming, beam hardening and metallic artifacts. Iodine maps enable quantification of extracellular volume without need for a non-contrast scan, facilitating the identification of cardiomyopathies like cardiac amyloidosis. Moreover, calcium score can be obtained from virtual non contrast (VNC) images derived from CT angiographic images. Additionally, VNC and iodine maps can characterize incidentally encountered lesions such as thrombus. In this article, we review the utility of PCCT in transcatheter SHD interventions.

Effect of Sinotubular Junction Size on TAVR Leaflet Thrombosis: A Fluid-Structure Interaction Analysis.

TAVR has emerged as a standard approach for treating severe aortic stenosis patients. However, it is associated with several clinical complications, including subclinical leaflet thrombosis characterized by Hypoattenuated Leaflet Thickening (HALT). A rigorous analysis of TAVR device thrombogenicity considering anatomical variations is essential for estimating this risk. Clinicians use the Sinotubular Junction (STJ) diameter for TAVR sizing, but there is a paucity of research on its influence on TAVR devices thrombogenicity. A Medtronic Evolut® TAVR device was deployed in three patient models with varying STJ diameters (26, 30, and 34mm) to evaluate its impact on post-deployment hemodynamics and thrombogenicity, employing a novel computational framework combining prosthesis deployment and fluid-structure interaction analysis. The 30mm STJ patient case exhibited the best hemodynamic performance: 5.94mmHg mean transvalvular pressure gradient (TPG), 2.64 cm2 mean geometric orifice area (GOA), and the lowest mean residence time (TR)-indicating a reduced thrombogenic risk; 26mm STJ exhibited a 10 % reduction in GOA and a 35% increase in mean TPG compared to the 30mm STJ; 34mm STJ depicted hemodynamics comparable to the 30mm STJ, but with a 6% increase in TR and elevated platelet stress accumulation. A smaller STJ size impairs adequate expansion of the TAVR stent, which may lead to suboptimal hemodynamic performance. Conversely, a larger STJ size marginally enhances the hemodynamic performance but increases the risk of TAVR leaflet thrombosis. Such analysis can aid pre-procedural planning and minimize the risk of TAVR leaflet thrombosis.

Deformation of transcatheter heart valves with mitral valve-in-valve.

The use of oversizing in mitral valve-in-valve (MViV) procedures can lead to non-uniform expansion of transcatheter heart valves (THV). This may have implications for THV durability. The objective of this study was to assess the extent and predictors of THV deformation in MViV procedures. We examined 33 patients who underwent MViV with SAPIEN prostheses. The extent of THV deformation (deformation index, eccentricity, neosinus volume, asymmetric leaflet expansion and vertical deformation) and hypoattenuating leaflet thickening (HALT) were assessed using cardiac computed tomography (CT), performed prospectively at 30 days post-procedure. For descriptive purposes, the THV deformation index was calculated, with values >1.00 representing a more hourglass shape. Non-uniform underexpansion of THV was common after MViV implantation, with a median expansion area of 74.0% (interquartile range 68.1-84.1) at the narrowest level and a THV deformation index of 1.21 (1.13-1.29), but circularity was maintained with eccentricity ranging from 0.24 to 0.28. The degree of oversizing was a key factor associated with greater underexpansion and a higher deformation index (β=-0.634; p<0.001; β=0.594; p<0.001, respectively). Overall, the incidence of HALT on the 30-day postprocedural CT was 27.3% (9 of 33). Most patients (32 of 33) were on anticoagulation therapy, but the prothrombin time and international normalised ratio (PT-INR) at the time of the CT scan was <2.5 in 23 of 32 patients. Among patients with a PT-INR of <2.5, HALT was predominantly observed with a high THV deformation index of ≥1.18. THV deformation, i.e., underexpansion and an hourglass shape, commonly occurs after MViV implantation and is negatively affected by excessive oversizing. Optimising THV expansion during MViV could potentially prevent HALT.

Leaflet thrombosis in transcatheter aortic valve intervention: mechanisms, prevention, and treatment options.

Transcatheter aortic valve intervention (TAVR) has emerged as a promising alternative to surgical aortic valve replacement for patients with severe aortic stenosis. However, leaflet thrombosis has raised concerns about the long-term durability and outcomes of TAVR. This study aims to provide an overview of the mechanisms, prevention strategies, and treatment options for leaflet thrombosis in TAVR. Leaflet thrombosis refers to the formation of blood clots on bioprosthetic valve leaflets, leading to impaired leaflet mobility, early valve degeneration and dysfunction, and potential clinical implications. While the mechanisms underlying thrombus formation on valve leaflets are not fully understood, several factors, such as altered blood flow patterns within valve neosinuses, prothrombotic surfaces, and patient-related causes, have been implicated. Two distinct entities have been identified, namely, hypoattenuated leaflet thickening and restricted leaflet motion. Their occurrence appears dynamic over time and is related to the valve type. Imaging, including transesophageal echocardiography and multidetector computed tomography, plays a crucial role in the diagnosis and follow-up of leaflet thrombosis. Preventing leaflet thrombosis requires a comprehensive and tailored approach involving identifying high-risk patients, close monitoring, and antithrombotic therapy. Antithrombotic therapy with dual antiplatelet agents or anticoagulation is commonly employed in TAVR patients, although the optimal regimen is yet to be defined. Novel antithrombotic agents, such as direct oral anticoagulants, are being investigated for their efficacy and safety in preventing leaflet thrombosis. When leaflet thrombosis is detected, treatment options include intensified antithrombotic therapy, valve-in-valve intervention, or balloon valvuloplasty. The long-term outcomes and impact of leaflet thrombosis on valve durability and patient prognosis are areas of ongoing research. Leaflet thrombosis in TAVR is a considerable complication affecting valve function and patient outcomes. Understanding the mechanisms underlying thrombus formation and implementing appropriate prevention strategies are essential for mitigating this risk. Treatment options aim to restore leaflet mobility and optimize valve performance. Further research is needed to establish standardized protocols for antithrombotic therapy, identify high-risk patient populations, and determine the long-term consequences of leaflet thrombosis on TAVR outcomes.

TCT-82 Implications of Prosthetic Deformation in Acute Valve-in-Valve TAVR: Hypoattenuating Leaflet Thickening at 1 Year

TCT-82 Implications of Prosthetic Deformation in Acute Valve-in-Valve TAVR: Hypoattenuating Leaflet Thickening at 1 Year

An investigator-sponsored pragmatic randomized controlled trial of AntiCoagulation vs AcetylSalicylic Acid after Transcatheter Aortic Valve Implantation: Rationale and design of ACASA-TAVI

The optimal antithrombotic therapy after transcatheter aortic valve implantation (TAVI) is unknown. Bioprosthetic valve dysfunction (BVD) is associated with adverse outcomes and may be prevented by anticoagulation therapy. A dedicated randomized trial comparing monotherapy NOAC to single antiplatelet therapy has not been performed previously. We hypothesize that therapy with any anti-factor Xa NOAC will reduce BVD compared to antiplatelet therapy, without compromising safety. ACASA-TAVI is a multicenter, prospective, randomized, open-label, blinded endpoint, all-comers trial comparing a monotherapy anti-factor Xa NOAC strategy (intervention arm) with a single antiplatelet therapy strategy (control arm) after successful TAVI. Three-hundred and sixty patients without indication for oral anticoagulation will be randomized in a 1:1 ratio to either apixaban 5 mg twice per day, edoxaban 60 mg daily, or rivaroxaban 20 mg daily for 12 months followed by acetylsalicylic acid 75 mg daily indefinitely, or to acetylsalicylic acid 75 mg daily indefinitely. The 2 co-primary outcomes are (1) incidence of Hypo-Attenuated Leaflet Thickening (HALT) on 4-dimensional cardiac CT at 12 months, and (2) a Safety Composite of VARC-3 bleeding events, thromboembolic events (myocardial infarction and stroke), and death from any cause, at 12 months. The first 100 patients had a mean age of 74 ± 3.6 years, 33% were female, the average body-mass index was 27.9 ± 4.4 kg/m2, and 15% were smokers. A balloon-expanded valve was used in 82% and a self-expandable valve in 18%. The trial is planned, initiated, funded, and conducted without industry involvement. ClinicalTrials.gov Identifier NCT05035277.

Impact of leaflet thrombosis on valve haemodynamic status after transcatheter aortic valve replacement

ObjectivesThe effect of subclinical leaflet thrombosis, characterised by hypoattenuated leaflet thickening (HALT), on the valve haemodynamic function and durability of the bioprosthetic valve, is not yet determined. We determined the...

Assessment of Hypoattenuated Leaflet Thickening Following Transcatheter Aortic Valve Replacement With the Self-Expanding Evolut Valve

Assessment of Hypoattenuated Leaflet Thickening Following Transcatheter Aortic Valve Replacement With the Self-Expanding Evolut Valve

Investigation of factors determining haemodynamic relevance of leaflet thrombosis after transcatheter aortic valve implantation.

To determine the conditions under which early hypoattenuated leaflet thickening (HALT) after transcatheter aortic valve implantation (TAVI) becomes haemodynamically relevant. The study included 100 patients (age: 81.5 ± 5.5 years; female 63%), thereof 50 patients with HALT. After anonymization and randomization, blinded readers measured maximum thrombus thickness per prosthesis (MT_pr) and movement restriction (MR_pr) on electrocardiogram (ECG)-gated whole heart cycle computed tomography angiography. These measurements were compared with echocardiographic mean pressure gradient (mPG), its increase from baseline (ΔmPG), and Doppler velocity index (DVI). Haemodynamic valve deterioration (HVD) was defined as mPG > 20 mmHg. Age, body mass index, valve type, valve size, left ventricular ejection fraction, and atrial fibrillation were considered as influencing factors. Multiple regression analysis revealed that only valve size (P = 0.001) and MT_pr (P = 0.02) had a significant influence on mPG. In an interaction model, valve size moderated the effect of MT_pr on mPG significantly (P = 0.004). Sub-group analysis stratified by valve sizes showed a strong correlation between MT_pr and echocardiographic parameters for 23 mm valves (mPG: r = 0.57, ΔmPG: r = 0.68, DVI: r = 0.55, each with P < 0.001), but neither for 26 nor 29 mm valves (r < 0.2, P > 0.2 for all correlations). Six of seven prostheses with HVD had a 23 mm valve diameter, while one had 29 mm (P = 0.02). Early HALT rarely causes significant mPG increase. Our study shows that valve size is a key factor influencing the haemodynamic impact of HALT. In small valve sizes, mPG is more likely to increase. Our study is the first to offer in vivo evidence supporting previous in vitro findings on this topic.