Tricuspid Valve Leaflets-Lead Interaction: Adjunctive Role of Functional Cardiac Computed Tomography for Clinical Decision Making.

The diagnostic approach toward the management of cardiac implantable electronic device-related tricuspid regurgitation is challenging and undefined. Functional cardiac computed tomography angiography provides a complementary role to echocardiography in the evaluation of lead-leaflet interaction which can help the clinical decision-making process, as presented in this case series.

AltaValve Atrial Fixation System for the Treatment of Severe Mitral Regurgitation and Mitral Annular Calcification.

Background: Treatment options for patients with mitral regurgitation (MR) and mitral annular calcification (MAC) are limited. The limitations of current transcatheter mitral valve replacement (TMVR) technologies include high screen failure rates, increased risk of left ventricular outflow tract obstruction, and high residual regurgitation. The aim of this study was to evaluate outcomes of TMVR with the AltaValve system (4C Medical, Maple Grove, MN), a supra-annular TMVR with atrial fixation, in patients with severe MR and moderate or severe MAC. Methods: Six patients with moderate or severe MAC who were treated with AltaValve TMVR had procedural and mid-term outcomes available. Results: Technical success was achieved in all patients. Median follow-up was 232 days. At discharge, 80% of patients had none/trace MR, and 20% had mild MR. There was no intraprocedural mortality, device malposition, embolization, or thrombosis. One patient expired 3 days postprocedure due to complications related to the transapical access. All other patients were discharged from the hospital without issues. Echocardiography assessments at 30 days showed complete resolution of MR in all patients, with 1 patient with mild MR and a mean mitral valve gradient of 3.7 ± 1.4 mmHg. All patients were in New York Heart Association Class I/II at 30-day follow-up, showing marked improvement as compared with baseline. Conclusions: In patients with severe MR and severe MAC, the AltaValve TMVR technology may represent a viable treatment option. The atrial fixation minimizes the risk of left ventricular outflow tract obstruction and potentially expands treatable patients, especially in patients with MAC.

Temporal Trends, Outcomes, and Predictors of Next-Day Discharge and Readmission Following Uncomplicated Evolut Transcatheter Aortic Valve Replacement: A Propensity Score-Matched Analysis.

BACKGROUND: Next-day discharge (NDD) outcomes following uncomplicated self-expanding transcatheter aortic valve replacement have not been studied. Here, we compare readmission rates and clinical outcomes in NDD versus non-NDD transcatheter aortic valve replacement with Evolut. METHODS AND RESULTS: Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry patients (n=29 597) undergoing elective transcatheter aortic valve replacement with self-expanding supra-annular valves (Evolut R, PRO, and PRO+) from July 2019 to June 2021 were stratified by postprocedure length of stay: ≤1 day (NDD) versus >1 day (non-NDD). Propensity score matching was used to compare risk adjusted 30-day readmission rates and 1-year outcomes in NDD versus non-NDD, and multivariable regression to determine predictors of NDD and readmission. Between the first and last calendar quarter, the rate of NDD increased from 45.4% to 62.1% and median length of stay decreased from 2 days to 1. Propensity score matching produced relatively well-matched NDD and non-NDD cohorts (n=10 549 each). After matching, NDD was associated with lower 30-day readmission rates (6.3% versus 8.4%; P<0.001) and 1-year adverse outcomes (death, 7.0% versus 9.3%; life threatening/major bleeding, 1.6% versus 3.4%; new permanent pacemaker implantation/implantable cardioverter-defibrillator, 3.6 versus 11.0%; [all P<0.001]). Predictors of NDD included non-Hispanic ethnicity, preexisting permanent pacemaker implantation/implantable cardioverter-defibrillator, and previous surgical aortic valve replacement. CONCLUSIONS: Most patients undergoing uncomplicated self-expanding Evolut transcatheter aortic valve replacement are discharged the next day. This study found that NDD can be predicted from baseline patient characteristics and was associated with favorable 30-day and 1-year outcomes, including low rates of permanent pacemaker implantation and readmission.

Left atrial to coronary sinus shunting for treatment of heart failure with mildly reduced or preserved ejection fraction: The ALT FLOW Early Feasibility Study 1-year results.

AIMS: Patients with heart failure and mildly reduced or preserved ejection fraction have limited therapeutic options. The ALT-FLOW Early Feasibility Study evaluated safety, haemodynamics and outcomes for the APTURE transcatheter shunt system, a novel left atrium to coronary sinus shunt in these patients. METHODS AND RESULTS: Safety and shunt implantation success was evaluated for all 116 enrolled patients. An analysis population of implanted patients with a left ventricular ejection fraction (LVEF) >40% (n = 95) was chosen to assess efficacy via paired comparison between baseline and follow-up haemodynamic (3 and 6 months), and echocardiographic, clinical and functional outcomes (6 months and 1 year). Health status and quality of life outcomes were assessed using the Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OSS). The primary safety endpoint, major adverse cardiac, cerebral, and renal events, and reintervention through 30 days, occurred in 3/116 patients (2.6%). All implanted shunts were patent at 1 year. In patients with LVEF >40%, the mean (95% confidence interval) reduction in exercise pulmonary capillary wedge pressure (PCWP) at 20 W was -5.7 (-8.6, -2.9) mmHg at 6 months (p < 0.001). At baseline, 8% had New York Heart Association class I-II status and improved to 68% at 1 year (p < 0.001). KCCQ-OSS at baseline was 39 (35, 43) and improved at 6 months and 1 year by 25 (20-30) and 27 (22-32) points, respectively (both p < 0.0001). No adverse changes in haemodynamic and echocardiographic indices of right heart function were observed at 1 year. Overall, the reduction in PCWP at 20 W and improvement in KCCQ-OSS in multiple subgroups were consistent with those observed for the entire population. CONCLUSIONS: In patients with heart failure and LVEF >40%, the APTURE shunt demonstrated an acceptable safety profile with significant sustained improvements in haemodynamic and patient-centred outcomes, underscoring the need for further evaluation of the APTURE shunt in a randomized trial.

Redo-TAVI with the ACURATE neo2 and Prime XL for balloon-expandable transcatheter heart valve failure.

BACKGROUND: There are limited data regarding treatment for failed balloon-expandable transcatheter heart valves (THVs) in redo-transcatheter aortic valve implantation (TAVI). AIMS: We aimed to assess THV performance, neoskirt height and expansion when performing redo-TAVI with the ACURATE platform inside a SAPIEN 3 (S3) compared to redo-TAVI with an S3 in an S3. METHODS: Redo-TAVI was performed on the bench using each available size of the S3, the ACURATE neo2 (ACn2) and the next-generation ACURATE Prime XL (AC XL) implanted at 2 different depths within 20 mm/23 mm/26 mm/29 mm S3s serving as the "failed" index THV. Hydrodynamic testing was performed to assess THV function. Multimodality assessment was performed using photography, X-ray, microcomputed tomography (micro-CT), and high-speed videos. RESULTS: The ACURATE in S3 combinations had favourable hydrodynamic performance compared to the S3 in S3 for all size combinations. In the 20 mm S3, redo-TAVI with the ACn2 had lower gradients compared to the S3 (mean gradient 16.3 mmHg for the ACn2 vs 24.7 mmHg for the 20 mm S3 in 20 mm S3). Pinwheeling was less marked for the ACURATE THVs than for the S3s. On micro-CT, the S3s used for redo-TAVI were underexpanded across all sizes. This was also observed for the ACURATE platform, but to a lesser extent. CONCLUSIONS: Redo-TAVI with an ACn2/AC XL within an S3 has favourable hydrodynamic performance and less pinwheeling compared to an S3 in S3. This comes at the price of a taller neoskirt.

Transcatheter treatment of the tricuspid valve: current status and perspectives.

Transcatheter tricuspid valve interventions (TTVI) are emerging as alternatives to surgery in high-risk patients with isolated or concomitant tricuspid regurgitation. The development of new minimally invasive solutions potentially more adapted to this largely undertreated population of patients, has fuelled the interest for the tricuspid valve. Growing evidence and new concepts have contributed to revise obsolete and misleading perceptions around the right side of the heart. New definitions, classifications, and a better understanding of the disease pathophysiology and phenotypes, as well as their associated patient journeys have profoundly and durably changed the landscape of tricuspid disease. A number of registries and a recent randomized controlled pivotal trial provide preliminary guidance for decision-making. TTVI seem to be very safe and effective in selected patients, although clinical benefits beyond improved quality of life remain to be demonstrated. Even if more efforts are needed, increased disease awareness is gaining momentum in the community and supports the establishment of dedicated expert valve centres. This review is summarizing the achievements in the field and provides perspectives for a less invasive management of a no-more-forgotten disease.

Preprocedural Computed Tomography Planning for Surgical Aortic Valve Replacement.

BACKGROUND: Selection of transcatheter valve size using preprocedural computed tomography (CT) is standardized and well established. However, valve sizing for surgical aortic valve replacement (SAVR) is currently performed intraoperatively by using sizers, which may result in variation among operators and risk for prosthesis-patient mismatch. This study evaluated the usefulness of CT annulus measurement for SAVR valve sizing. METHODS: This study included patients who underwent SAVR using Inspiris or Magna Ease and received preoperative electrocardiogram-gated CT imaging. Starting from June 2022, study investigators applied a CT sizing algorithm using CT-derived annulus size to guide minimum SAVR label size. The final decision of valve selection was left to the operating surgeon during SAVR. The study compared the appropriateness of valve selection (comparing implanted size with CT-predicted size) and prosthesis-patient mismatch rates without aortic root enlargement between 2 cohorts: 102 cases since June 2022 (CT sizing cohort) and 180 cases from 2020 to 2021 (conventional sizing cohort). RESULTS: Implanted size smaller than CT predicted size and severe prosthesis-patient mismatch were significantly lower by CT sizing than by conventional sizing (12% vs 31% [P = .001] and 0% vs 6% [P = .039], respectively). Interoperator variability was a factor associated with implanted size smaller than CT predicted with conventional sizing, whereas it became nonsignificant with CT sizing. CONCLUSIONS: Applying CT sizing to SAVR led to improved valve size selection, less prosthesis-patient mismatch, and less interoperator variability. CT sizing for SAVR could also be used to predict prosthesis-patient mismatch before SAVR and identify patients who need aortic root enlargement.

Transcatheter Edge-to-Edge Repair in COAPT-Ineligible Patients With Functional Mitral Regurgitation.

BACKGROUND: Mitral valve transcatheter edge-to-edge repair (MTEER) was approved in the United States for treatment of functional mitral regurgitation (FMR) based on results from the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial. OBJECTIVES: The authors sought to analyze outcomes of MTEER in FMR patients who would have been excluded from COAPT. METHODS: MTEER procedures performed for FMR in the TVT (Transcatheter Valve Therapy) Registry between January 1, 2013, and April 30, 2020, were categorized as "trial-ineligible" if any of the following were present: cardiogenic shock, inotropic support, left ventricular ejection fraction <20%, left ventricular end-systolic dimension >7 cm, home oxygen use, or severe tricuspid regurgitation. Trial-ineligible and trial-eligible groups were compared through 1 year using multivariable models. The primary endpoint was 1-year death or heart failure hospitalization (HFH). RESULTS: Of 6,675 patients who underwent MTEER for FMR, 3,721 (55.7%) were trial-eligible and 2,954 (44.3%) were trial-ineligible. Trial-ineligible patients had lower rates of technical procedural success (86.9% vs 92.6%; P < 0.001) and more frequent in-hospital complications (11.8% vs 5.7%; P < 0.001) compared with trial-eligible patients. A clinically meaningful improvement in health status at 30 days was observed in 78.9% and 77.0% of patients in the trial-ineligible and trial-eligible groups, respectively. There was a higher risk of 1-year death or HFH (HR: 1.73; 95% CI: 1.57-1.91; P < 0.001) in trial-ineligible patients. CONCLUSIONS: Among patients who underwent MTEER for FMR in the TVT Registry, nearly one-half would have been ineligible for the COAPT trial. Health status improvement at 30 days was similar in COAPT-ineligible and COAPT-eligible patients, but trial-ineligible patients had higher 1-year rates of death or HFH.

Health Status After Transcatheter Tricuspid-Valve Repair in Patients With Severe Tricuspid Regurgitation.

BACKGROUND: In the TRILUMINATE Pivotal (Trial to Evaluate Cardiovascular Outcomes in Patients Treated with the Tricuspid Valve Repair System Pivotal), tricuspid transcatheter edge-to-edge repair (T-TEER) reduced tricuspid regurgitation (TR) and improved health status compared with medical therapy alone with no benefit on heart failure hospitalizations or survival. OBJECTIVES: The purpose of this study was to better understand the health status benefits of T-TEER within the TRILUMINATE Pivotal trial. METHODS: TRILUMINATE randomized patients with severe TR to T-TEER (n = 175) or medical therapy (n = 175). Health status was assessed at baseline and at 1, 6, and 12 months with the Kansas City Cardiomyopathy Questionnaire (KCCQ) (range 0-100; higher = better), which was compared between treatment groups using mixed effects linear regression. Alive and well was defined as KCCQ overall summary score ≥60 and no decline from baseline of >10 points at 1 year. RESULTS: Compared with medical therapy, T-TEER significantly improved health status at 1 month (mean between-group difference in KCCQ overall summary score 9.4 points; 95% CI: 5.3-13.4 points), with a small additional improvement at 1 year (mean between-group difference 10.4 points; 95% CI: 6.3-14.6 points). T-TEER patients were more likely to be alive and well at 1 year (T-TEER vs medical therapy: 74.8% vs 45.9%; P < 0.001), with a number needed to treat of 3.5. Interaction analyses demonstrated that the benefit of T-TEER diminished as baseline KCCQ overall summary score increased (Pint < 0.001). Exploratory analyses suggested that much of the health status benefit of T-TEER could be explained by TR reduction and that improvement in health status after T-TEER was strongly correlated with reduced 1-year mortality and heart failure hospitalization. CONCLUSIONS: T-TEER with the TriClip system resulted in substantial and sustained health status improvement in patients with severe TR compared with medical therapy alone.

Tricuspid Regurgitation: From Imaging to Clinical Trials to Resolving the Unmet Need for Treatment.

Tricuspid regurgitation (TR) is a highly prevalent and heterogeneous valvular disease, independently associated with excess mortality and high morbidity in all clinical contexts. TR is profoundly undertreated by surgery and is often discovered late in patients presenting with right-sided heart failure. To address the issue of undertreatment and poor clinical outcomes without intervention, numerous structural tricuspid interventional devices have been and are in development, a challenging process due to the unique anatomic and physiological characteristics of the tricuspid valve, and warranting well-designed clinical trials. The path from routine practice TR detection to appropriate TR evaluation, to conduction of clinical trials, to enriched therapeutic possibilities for improving TR access to treatment and outcomes in routine practice is complex. Therefore, this paper summarizes the key points and methods crucial to TR detection, quantitation, categorization, risk-scoring, intervention-monitoring, and outcomes evaluation, particularly of right-sided function, and to clinical trial development and conduct, for both interventional and surgical groups.

Comprehensive Myocardial Assessment by Computed Tomography: Impact on Short-Term Outcomes After Transcatheter Aortic Valve Replacement.

BACKGROUND: Quantification of myocardial changes in severe aortic stenosis (AS) is prognostically important. The potential for comprehensive myocardial assessment pre-transcatheter aortic valve replacement (TAVR) by computed tomography angiography (CTA) is unknown. OBJECTIVES: This study sought to evaluate whether quantification of left ventricular (LV) extracellular volume-a marker of myocardial fibrosis-and global longitudinal strain-a marker of myocardial deformation-at baseline CTA associate with post-TAVR outcomes. METHODS: Consecutive patients with symptomatic severe AS between January 2021 and June 2022 who underwent pre-TAVR CTA were included. Computed tomography extracellular volume (CT-ECV) was derived from septum tracing after generating the 3-dimensional CT-ECV map. Computed tomography global longitudinal strain (CT-GLS) used semi-automated feature tracking analysis. The clinical endpoint was the composite outcome of all-cause mortality and heart failure hospitalization. RESULTS: Among the 300 patients (80.0 ± 9.4 years of age, 45% female, median Society of Thoracic Surgeons Predicted Risk of Mortality score 2.80%), the left ventricular ejection fraction (LVEF) was 58% ± 12%, the median CT-ECV was 28.5% (IQR: 26.2%-32.1%), and the median CT-GLS was -20.1% (IQR: -23.8% to -16.3%). Over a median follow-up of 16 months (IQR: 12-22 months), 38 deaths and 70 composite outcomes occurred. Multivariable Cox proportional hazards model, accounting for clinical and echocardiographic variables, demonstrated that CT-ECV (HR: 1.09 [95% CI: 1.02-1.16]; P = 0.008) and CT-GLS (HR: 1.07 [95% CI: 1.01-1.13]; P = 0.017) associated with the composite outcome. In combination, elevated CT-ECV and CT-GLS (above median for each) showed a stronger association with the outcome (HR: 7.14 [95% CI: 2.63-19.36]; P < 0.001). CONCLUSIONS: Comprehensive myocardial quantification of CT-ECV and CT-GLS associated with post-TAVR outcomes in a contemporary low-risk cohort with mostly preserved LVEF. Whether these imaging biomarkers can be potentially used for the decision making including timing of AS intervention and post-TAVR follow-up will require integration into future clinical trials.

Mortality Associated With Proportionality of Secondary Mitral Regurgitation After Transcatheter Mitral Valve Repair: North American Mitraclip for Functional Mitral Regurgitation Registry.

The association, if any, between the effective regurgitant orifice area (EROA) to left ventricular end-diastolic volume (LVEDV) ratio and 1-year mortality is controversial in patients who undergo mitral transcatheter edge-to-edge repair (m-TEER) with the MitraClip system (Abbott Vascular, Santa Clara, CA). This study's objective was to determine the association between EROA/LVEDV and 1-year mortality in patients who undergo m-TEER with MitraClip. In patients with severe secondary (functional) mitral regurgitation (MR), we analyzed registry data from 11 centers using generalized linear models with the generalized estimating equations approach. We studied 525 patients with secondary MR who underwent m-TEER. Most patients were male (63%) and were New York Heart Association class III (61%) or IV (21%). Mitral regurgitation was caused by ischemic cardiomyopathy in 51% of patients. EROA/LVEDV values varied widely, with median = 0.19 mm2/ml, interquartile range [0.12,0.28] mm2/ml, and 187 patients (36%) had values <0.15 mm2/ml. Postprocedural mitral regurgitation severity was substantially alleviated, being 1+ or less in 74%, 2+ in 20%, 3+ in 4%, and 4+ in 2%; 1-year mortality was 22%. After adjustment for confounders, the logarithmic transformation (Ln) of EROA/LVEDV was associated with 1-year mortality (odds ratio 0.600, 95% confidence interval 0.386 to 0.933, p = 0.023). A higher Society of Thoracic Surgeons risk score was also associated with increased mortality. In conclusion, lower values of Ln(EROA/LVEDV) were associated with increased 1-year mortality in this multicenter registry. The slope of the association is steep at low values but gradually flattens as Ln(EROA/LVEDV) increases.

Mitral Valve Transcatheter Edge-to-Edge Repair Volumes and Trends.

Background: Despite an association between operator volumes and procedural success, there remains an incomplete understanding of the contemporary utilization and procedural volumes for mitral valve transcatheter edge-to-edge repair (MTEER). We aimed to identify annual operator procedural volumes, temporal trends, and geographic variability for MTEER among Medicare patients in the United States (US). Methods: We queried the National Medicare Provider Utilization and Payment Database for a CPT code (33418) specific for MitraClip device from 2015 through 2019. We analyzed annual operator procedural volumes and incidence and identified longitudinal and geographic trends in MTEER utilization. Results: From 2015 through 2019, a total of 27,034 MTEER procedures were performed among Medicare patients in the US. The nationwide incidence increased from 6.2 per 100,000 patients in 2015 to 23.8 per 100,000 patients in 2019, a 283% increase over the study period (Ptrend < 0.001). The incidence of MTEER by state varied by nearly 900% (range 5.5 to 54.9 per 100,000 person-years). In 2019, the mean annual MTEER operator annual volume was 9.1 MTEER procedures and had grown from 6.2 per year in 2015. Conclusions: In this nationwide study of Medicare beneficiaries in the United States, we identified a significant and sustained increase in the utilization of MTEER devices and operators and growth in annual procedural volumes from 2015 through 2019 with considerable variability in utilization by state. Further studies are needed to understand the clinical impact of variability in utilization and the optimal procedural volumes to ensure high efficacy outcomes and maintain critical access to MTEER therapies.

Transcatheter mitral valve implantation for native valve disease.

Mitral regurgitation is the second most frequent heart valve disease in Europe and the most frequent in the US. Although surgery is the therapy of choice when intervention is indicated, transcatheter mitral valve repair or replacement are alternatives for patients who are not eligible for surgery. However, the development of transcatheter mitral valves is slower than expected. Although several transcatheter heart valves have been developed, only one has been commercialised. Indeed, most of these devices are being evaluated in clinical studies, with promising initial results. In this review, we propose an overview on transcatheter mitral valve replacement for the treatment of native mitral valve disease, from indication to results, including patients with severe annular calcification, and we provide you with a glimpse into the future of these therapies.

Feasibility of Redo-Transcatheter Aortic Valve Replacement in Sapien Valves Based on In Vivo Computed Tomography Assessment.

BACKGROUND: Our aim was to assess the feasibility of repeat transcatheter aortic valve (TAV) replacement for degenerated Sapien3 (S3) prostheses by simulating subsequent implantation of S3 or Evolut, using in vivo computed tomography-based sizing and the impact on coronary and patient-prosthesis mismatch risks. METHODS: Computed tomography scans from 356 patients with prior S3 TAV replacement implantation were analyzed. The in vivo sizing for second TAV based on averaged area of 3 levels of outflow, mid (narrowest) and inflow, was compared with in vitro recommendations, that is, same size as index S3 for second S3 and 1 size larger for Evolut. Risks of coronary obstruction and patient-prosthesis mismatch were determined by valve-to-aorta distance and estimated effective orifice area, respectively. RESULTS: Overall, the majority of patients (n=328; 92.1%) had underexpanded index S3 with an expansion area of 94% (91%-97%), leading to significant differences in size selection of the second TAV between in vivo and in vitro sizing strategies. Expansion area <89% served as a threshold, resulting in 1 size smaller than the in vitro recommendations were selected in 45 patients (13%) for S3-in-S3 and 13 (4%) for Evolut-in-S3, while the remaining patients followed in vitro recommendations (P<0.01, in vivo versus in vitro sizing). Overall, 57% of total patients for S3-in-S3 simulation and 60% for Evolut-in-S3 were considered low risk for coronary complications. Deep index S3 implantation (odds ratio, 0.76 [interquartile range, 0.67-0.87]; P<0.001) and selecting Evolut as the second TAV (11% risk reduction in intermediate- or high-risk patients) reduced coronary risk. Estimated moderate or severe patient-prosthesis mismatch risk was 21% for S3-in-S3 and 1% for Evolut-in-S3, assuming optimal expansion of the second TAV. CONCLUSIONS: Redo-TAV replacement with S3-in-S3 and Evolut-in-S3 could be feasible with low risk to coronaries in ≈60% of patients, while the remaining 40% will be at intermediate or high risk. The feasibility of redo-TAV replacement is influenced by sizing strategy, type of second TAV, native annular anatomy, and implant depth.

3-Dimensional Multiplanar Reconstruction With Transesophageal Echocardiography for Alcohol Septal Ablation.

This study described the first experience with 3-dimensional multiplanar reconstruction transesophageal echocardiography to guide percutaneous alcohol septal ablation. This study demonstrated that 3-dimensional transesophageal echocardiography multiplanar reconstruction allowed for simultaneous assessment of the targeted myocardial area from left ventricular base to apex, akin to imaging seen with spatial imaging with cardiac magnetic resonance. (Level of Difficulty: Intermediate.).

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

BACKGROUND: 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. AIMS: The objective of this study was to assess the extent and predictors of THV deformation in MViV procedures. METHODS: 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. RESULTS: 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 (ß=-0.634; p<0.001; ß=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. CONCLUSIONS: 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.