Transcatheter Aortic Valve Replacement Durability Research Articles

The Promise and Perils of Transcatheter Aortic Valve Replacement (TAVR) in Low Surgical Risk Patients with Severe Aortic Stenosis in the Current Era.

Transcatheter Aortic Valve Replacement (TAVR) has become the preferred treatment approach for many patients with symptomatic severe aortic valve stenosis (SsAS), particularly those who are deemed at high surgical risk. However, in low-risk surgical patients (LSRP) with SsAS, the choice between TAVR and surgical aortic valve replacement (SAVR) is often a matter of debate and depends on several clinical and anatomical considerations. Midterm data show similar clinical outcomes and durability of TAVR and SAVR bioprosthetic valves in LRSP. Data on long term durability and outcomes of TAVR in LRSP remains scarce. Both TAVR and SAVR are reasonable options in LRSP with SsAS. Nevertheless, many of these LRSP are expected to outlive their bioprosthetic valves and planning for the second aortic valve replacement should begin at the time of the index procedure with special consideration for coronary re-access, risk for coronary obstruction, and prothesis patient mismatch.

Effect of leaflet laceration on transcatheter aortic valve replacement fluid mechanics and comparison with surgical aortic valve replacement

BackgroundLeaflet thrombosis after surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) may be caused by blood flow stagnation in the native and neosinus regions. To date, aortic leaflet laceration has been used to mitigate coronary obstruction following TAVR; however, its influence on the fluid mechanics of the native and neosinus regions is poorly understood. This in vitro study compared the flow velocities and flow patterns in the setting of SAVR vs TAVR with and without aortic leaflet lacerations. MethodsTwo valves, (23-mm Perimount and 26-mm SAPIEN 3; Edwards Lifesciences) were studied in a validated mock flow loop under physiologic conditions. Neosinus and native sinus fluid mechanics were quantified using particle image velocimetry in the left and noncoronary cusp, with an increasing number of aortic leaflets lacerated or removed. ResultsAcross all conditions, SAVR had the highest average sinus and neosinus velocities, and this value was used as a reference to compare against the TAVR conditions. With an increasing number of leaflets lacerated or removed with TAVR, the average sinus and neosinus velocities increased from 25% to 70% of SAVR flow (100%). Diastolic velocities were substantially augmented by leaflet laceration. Also, the shorter frame of the SAVR led to higher flow velocities compared with the longer frame of the TAVR, even after complete leaflet removal. ConclusionsLeaflet laceration augmented TAVR native and neosinus flow fields, approaching that of SAVR. These findings may have potential clinical implications for the use of single or multiple leaflet lacerations to reduce leaflet thrombosis and thus potentially improve TAVR durability.

Analysis of thrombosis risk of commissural misaligned transcatheter aortic valve prostheses using particle image velocimetry

Abstract Due to excellent clinical results, transcatheter aortic valve replacement (TAVR) has evolved to a treatment option for patients with low surgical risk, resulting in an increasing demand for durable heart valve prostheses. Durability of TAVR could be limited by leaflet thrombosis. Thrombus formation in the aortic root is mainly affected by the hemodynamic situation, which is dependent on the positioning of the implant. We investigated the flow field in the aortic root after TAVR implantation by means of particle image velocimetry. To quantify the influence of the implant-position with respect to an alignment or misalignment of the leaflet commissures on the thrombogenic potential, we used a transport equation for residence time (RT) to consider washout behavior. Furthermore, we introduced a shear effect criterion (SIE) to address platelet activation as a measure for a potential thrombus formation. Misaligned implantation of a TAVR resulted in a reversed direction of rotation of the occurring recirculation area. This led to fluid flow with comparable areas of increased relative blood RT (RTaligned: 97.6%, RTmisaligned: 88.0%) and a smaller area of low shear load for the misaligned TAVR (SIEaligned: 57.7%, SIEmisaligned: 3.70%) into the sinus region, indicating a higher potential for thrombus formation.

Validation of a Fluid Structure Interaction Model for TAVR using Particle Image Velocimetry

Abstract The implantation of a transcatheter aortic valve replacement (TAVR) in patients with severe aortic stenosis improves pathologic blood flow through the aortic valve, but still alters hemodynamics in comparison to a healthy native aortic valve. The hemodynamic characteristics of TAVR are associated with hypo-attenuating leaflet thickening and prosthetic leaflet thrombosis, which may reduce the durability of TAVR. For this reason we developed a numerical model to identify pro-thrombotic regions of TAVR based on the velocity field. In silico models have already been proven to be an effective tool for device optimization in other medical device applications. However, when using an in silico model, it is important to validate the model assumptions with experimental data or analytical solutions to confirm the accuracy of the model. In this study, we present an approach to validate a complex numerical Fluid Structure Interaction (FSI) model used to simulate leaflet kinematics and flow in the vicinity of a TAVR. Based on the recommendation of ISO 5840 (2021), a combined validation of the kinematic and fluid dynamic parameters was performed for this purpose. The leaflet kinematic was investigated via high-speed recordings and evaluated based on the Geometric Orifice Area (GOA). The velocity field of the TAVR was determined experimentally using Particle Image Velocimetry (PIV). The evaluation of the GOA showed a good agreement of the in silico model with the in vitro data for the systolic duration. The occurring velocities were qualitatively compared during peak systole for three planes and showed similar flow characteristics. The maximum velocity was 1.1 m/s in the in vitro and in silico model. Based on the results, it can be assumed that the numerical FSI model of the TAVR can be used for thrombosis risk assessment.

Cost-utility and cost-benefit analysis of TAVR availability in the US severe symptomatic aortic stenosis patient population

Aims We evaluated the availability of transcatheter aortic valve replacement (TAVR) to determine its value across all severe symptomatic aortic stenosis (SSAS) patients, especially those untreated because of concerns regarding invasive surgical AVR (SAVR) and its impact on active aging. Methods We performed payer perspective cost-utility analysis (CUA) and societal perspective cost-benefit analysis (CBA). The CBA’s benefit measure is active time: salaried labor, unpaid work, and active leisure. The study population is a cohort of US elderly SSAS patients. We compared a “TAVR available” scenario in which SSAS patients distribute themselves across TAVR, SAVR, and medical management (MM); and a “TAVR not available” scenario with only SAVR and MM. We structured each scenario with a decision-tree model of SSAS patient treatment allocation. We measured the association between health and active time in the US Health and Retirement Study and used this association to impute active time to SSAS patients given their health. Results The incremental cost-effectiveness ratio (ICER) and rate of return (RoR) of TAVR availability were $8,533 and 395%, respectively. CUA net monetary benefits (NMB) were $212,199 per patient and $43.4 billion population-wide. CBA NMB were $50,530 per patient and $10.3 billion population-wide. Limitations Among study limitations were scarcity of evidence regarding key parameters and the lack of long-term survival, health utility, and treatment cost data. Our analysis did not account for TAVR durability, retreatments, and valve-in-valve treatments. Conclusion Across risk-, age-, and treatment-eligibility groups, TAVR is the economically optimal treatment choice. It represents strong value-for-money per patient and population-wide. The vast majority of TAVR value involves raising treatment uptake among the untreated.

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

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. 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 ± 5.7years] treated with commercially available TAVR device (Lotus 54%, CoreValve 32% and Sapien 3 14%) were included, with median CT-scan at 6.0weeks 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 2.3years. Patients with RELM had significantly higher transvalvular gradients after discharge when compared to those without RELM. 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.

Is this a bridge too far?

Maeda et al. present what may be the second reported case of transcatheter aortic valve replacement (TAVR) followed by staged open surgical aortic valve replacement (SAVR) in a high-risk patient. The authors propose that TAVR may serve as a bridge procedure before SAVR for aortic stenosis in selected younger patients with high surgical risk. Further experience may clarify how long to wait after TAVR to perform SAVR. Timing will be a balance between improving surgical risk versus increasing difficulty removing the prosthesis. Knowledge of TAVR durability will ultimately be needed to decide between "destination" TAVR versus bridging to SAVR with a more durable device.

Severe, Symptomatic Aortic Stenosis: an Update on the Diagnostic and Treatment Tools in Our Arsenal

We aim to provide the cardiovascular clinician with an update on the classification and diagnosis of severe AS and an evidence-based guide to the treatment options available for severe, symptomatic AS. The classification of AS is evolving with increasing recognition of hemodynamically distinct AS subtypes and the importance of transvalvular flow in both the diagnosis and management of severe AS. Transcatheter aortic valve replacement (TAVR) has continued to expand its safety and efficacy to include patients with symptomatic, severe AS at low risk for surgical AVR (SAVR). There is emerging data supporting the use of TAVR among patients with asymptomatic, severe AS, bicuspid aortic valve (BAV) anatomy, and surgical bioprosthetic failure, but additional studies are needed. As treatment options for managing patients with symptomatic, severe AS continue to grow at a rapid rate, it is essential to improve the recognition and diagnosis of the spectrum of clinical and hemodynamic presentations of severe AS. Despite the rapid expansion of TAVR, there remains a role for SAVR among a unique subset of patients. Future research should focus on optimizing the timing of valvular intervention while ensuring the acquisition of longer-term data on the durability of TAVR.

Impact of Transcatheter Aortic Valve Durability on Life Expectancy in Low-Risk Patients With Severe Aortic Stenosis.

Recent clinical trial results showed that transcatheter aortic valve replacement (TAVR) is noninferior and may be superior to surgical aortic valve replacement (SAVR) for mortality, stroke, and rehospitalization. However, the impact of transcatheter valve durability remains uncertain. Discrete event simulation was used to model hypothetical scenarios of TAVR versus SAVR durability in which TAVR failure times were varied to determine the impact of TAVR valve durability on life expectancy in a cohort of low-risk patients similar to those in recent trials. Discrete event simulation modeling was used to estimate the tradeoff between a less invasive procedure with unknown valve durability (TAVR) and that of a more invasive procedure with known durability (SAVR). Standardized differences were calculated, and a difference >0.10 was considered clinically significant. In the base-case analysis, patients with structural valve deterioration requiring reoperation were assumed to undergo a valve-in-valve TAVR procedure. A sensitivity analysis was conducted to determine the impact of TAVR valve durability on life expectancy in younger age groups (40, 50, and 60 years). Our cohort consisted of patients with aortic stenosis at low surgical risk with a mean age of 73.4±5.9 years. In the base-case scenario, the standardized difference in life expectancy was <0.10 between TAVR and SAVR until transcatheter valve prosthesis failure time was 70% shorter than that of surgical prostheses. At a transcatheter valve failure time <30% compared with surgical valves, SAVR was the preferred option. In younger patients, life expectancy was reduced when TAVR durability was 30%, 40%, and 50% shorter than that of surgical valves in 40-, 50-, and 60-year-old patients, respectively. According to our simulation models, the durability of TAVR valves must be 70% shorter than that of surgical valves to result in reduced life expectancy in patients with demographics similar to those of recent trials. However, in younger patients, this threshold for TAVR valve durability was substantially higher. These findings suggest that durability concerns should not influence the initial treatment decision concerning TAVR versus SAVR in older low-risk patients on the basis of current evidence supporting TAVR valve durability. However, in younger low-risk patients, valve durability must be weighed against other patient factors such as life expectancy.

Transcatheter Aortic Valve Replacement in Left Ventricular Assist Device Patients with Aortic Regurgitation

ABSTRACT Backgro und: Development of aortic regurgitation (AR) following left ventricular assist device (LVAD) implantation is common, and it is associated with a poor prognosis. Transcatheter aortic valve replacement (TAVR) has become a mainstay therapy for patients with severe aortic stenosis, with an off-label use for severe AR. The aim of this study was to assess the feasibility and durability of TAVR in LVAD patients with significant AR. Methods: We evaluated all LVAD patients within our database that underwent TAVR for AR. Clinical and echocardiographic data were collected before and after TAVR procedure. Aortic regurgitant fraction (RF) was calculated using outflow graft Doppler echocardiography. Results: Seven patients underwent nine attempted TAVR procedures. Median age was 69 (IQR 63–73) and 43% were female. Median time from LVAD to TAVR was 23 (IQR 17–52) months. One procedure was aborted due to vascular complications, and one patient underwent two separate procedures 22 months apart. Five patients (71%) survived over median follow-up of 9 (IQR 6–23) months. Two patients died of paravalvular complications following device deployment. Procedural success was achieved in 67% of attempts, with significant improvement in RF from 44.8% (IQR 37.6–63.6) pre-procedurally to 28.1% (IQR 0.30–29.6) at six-month follow-up. Qualitatively, mild or moderate paravalvular leak was noted on all surviving patients at one- and six-month follow-up. There was significant improvement in right ventricular function at 6-month follow-up. Conclusion: TAVR is a reasonable option for treating LVAD-induced AR. Longer follow-up and larger cohorts are needed to assess the durability and long-term efficacy of this procedure. Abbreviations: AR: Aortic regurgitation; AV: Aortic valve; LV: Left ventricle; LVAD: Left ventricular assist device; LVIDd: Left ventricular internal dimension at end-diastole; LVIDs: Left ventricular internal dimension at end-systole; PAPi: Pulmonary artery pulsatility index; RA: Right atrial; RF: Regurgitant fraction; RV: Right ventricle; RVEDA: Right ventricular end-diastolic area; RVFAC: Right ventricular fractional area change; RVSP: Right ventricular systolic pressure; TAPSE: tricuspid annular plane systolic excursion; TAVR: Transcatheter aortic valve replacement; TV: Tricuspid valve

Review of Major Registries and Clinical Trials of Late Outcomes After Transcatheter Aortic Valve Replacement.

The results of the Placement of AoRtic TraNscathetER Valves (PARTNER) 2 trial established the feasibility of transcatheter aortic valve replacement (TAVR) for intermediate surgical risk patients. The expansion of TAVR into the low-risk patient population will largely depend on its durability outcomes due to the high life expectancy in low-risk patients. Long-term follow-up results from low-risk clinical trials will take several years to be reported. Given this, we performed a systematic review of current long-term data to provide further insights into TAVR durability and long-term patient survival. We searched MEDLINE, Embase, Google Scholar, BIOSIS, and major conference abstracts for TAVR studies with follow-up of at least 4years. Abstracts were retrieved and independently reviewed for eligibility. Final studies were selected irrespective of the type of TAVR valve, route of vascular access, or surgical risk profile. A total of 12studies met the inclusion criteria. We reviewed data from these studies with emphasis on long-term survival and echocardiographic findings.

Haemodynamic Evaluation of Long-term TAVR Durability: A Single Centre Experience

Background: Transcatheter aortic valve replacement (TAVR) is now an acceptable treatment for patients at high surgical risk. Recent limited data raise some concerns on valve durability long-term. We aim to determine structural valve deterioration (SVD) in TAVR over 5-year implant durations. Methods: Patients undergoing TAVR with Edwards SAPIEN/SAPIEN XT or Medtronic CoreValve prostheses at The Prince Charles Hospital between August 2008 and November 2011 with echocardiographic follow-up of a minimum of 5 years were included. Exclusion criteria included cases with aortic endocarditis, index valve-in-valve cases, and patients lost to follow-up. Valve performance was assessed using VARC-2 criteria for SVD and analysed using JMP 13 statistical software. Results: 28 patients (average age 82.14 ± 8.68 years) met selection criteria, who underwent TAVR with either Edwards (n = 12) or Medtronic (n = 16) valves. Average STS score was 6.43 ± 2.88 and average EuroSCORE was 18.74 ± 8.53. Comparison of 30-day (30D) post-implant data with 5 year (5Y) follow up data showed a slight increase in mean aortic gradient (30D: 10.46 ± 2.92 mmHg; 5Y:12.52 ± 15.26 mmHg; p = NS). Only one patient demonstrated a mean gradient increase of over 20 mmHg. This patient required a TAVR-in-TAVR 8 years post-initial TAVR. Aortic valve area showed a slight decrease (30D: 2.03 ± 0.37 cm2; 5Y: 1.83 ± 0.54 cm2; p = NS). 2 (7.1%) patients showed moderately severe/severe valvular or circumferential aortic regurgitation (grade ≥ 3) 5 years post-implant. Conclusion: In this small observational cohort, TAVR SVD requiring reintervention was infrequently observed. Defining SVD for TAVR and longer-term follow-up will be essential for the future.

TCT-741 Leaflet Stresses of Sapien 3 Transcatheter Aortic Valve: Implications for Durability

Recently. long-term evaluation of transcatheter aortic valve replacement (TAVR) indicated that half of transcatheter aortic valves (TAV) may undergo degeneration at 8 years after implantation. Concerns for TAVR durability require investigation of better designs to prolong the lifespan of TAV. From

Year in review: transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) has been effective in prohibitive/high-risk patients. Expansion toward intermediate or even low-risk patients has been proposed. A review of recent developments will help understand current trends and issues. The 5-year results from the PARTNER I trial and 2-year results of the CoreValve US Pivotal Trial, together with national registries, confirmed the long-term efficacy and durability of TAVR. Studies including PARTNER II, ADVANCE, and The German Aortic Valve Registry showed short-to mid-term success in intermediate-risk patients. Comparison of balloon-expandable and self-expanding valves in the CHOICE trial associated specific outcome differences with specific valve types, suggesting a more customized approach in valve selection. Short-term results of newer-generation valves have demonstrated excellent safety and efficacy with improved designs. Studies on TAVR-specific complications, such as conduction block and arrhythmia, paravalvular aortic regurgitation, and stroke, have renewed ideas about their prognosis, treatment, and prevention. Conscious sedation percutaneous TAVR has become more popular, with excellent outcomes and improved cost savings. TAVR has been accepted as an effective treatment even for intermediate-risk patients. This article aims to review the most recent results and essential issues.

TCT-659 Impact of Balloon-Expandable Transcatheter Aortic Valve Size on Stent and Leaflet Stresses

As transcatheter aortic valve replacement (TAVR) is being considered for surgical patients of lower risk and younger age, concerns remain regarding TAVR durability. From a valve design perspective, durability decreases with increased stresses on the stent and leaflets. Patient annulus sizes can fall