Impact on Kidney Function and Medium-Term Outcomes of Transcatheter Aortic Valve Replacement in Patients With Chronic Kidney Disease

Transcatheter aortic valve replacement (TAVR) is now widely approved for the treatment of aortic stenosis, regardless of the patients' surgical risk. However, the outcomes of TAVR and their determinants in patients with chronic kidney disease (CKD) beyond 1 year of follow-up are unknown. We aimed to assess the medium-term outcomes of TAVR in CKD, develop a risk score to estimate the 2-year mortality in patients with CKD, and evaluate the changes in kidney function at discharge after TAVR. Adults who underwent TAVR were retrospectively identified. The CKD stage was determined using the Chronic Kidney Disease Epidemiology 2021 creatinine formula. Improved kidney function was defined as post-TAVR creatinine ≤50% of pre-TAVR creatinine or decrease in creatinine of ≥0.3 mg/100 ml compared with pre-TAVR creatinine. Overall, 1,523 patients (median age 82 years; 59% men; 735 with CKD stage II or less, 661 with CKD III, 83 with CKD IV, and 44 with CKD V [of whom 40 were on dialysis]) were included. The all-cause mortality was higher in CKD stages IV and V on the multivariable analysis (p <0.001) at median follow-up of 2.9 (interquartile range 2.0 to 4.2) years. Moderate or severe tricuspid regurgitation, anemia, right ventricular systolic pressure >40 mm Hg and CKD stages IV and V were independent predictors of 2-year mortality and were used to develop a risk score. At hospital discharge, persisting acute kidney injury after TAVR occurred in 88 of 1,466 patients (6%), whereas improved kidney function occurred in 170 of 1,466 patients (12%). In conclusion, CKD stage was an independent determinant of mortality beyond 2 years after TAVR. Kidney function was more likely to improve than worsen at the time of hospital discharge after TAVR.

The Allegra transcatheter heart valve: Long-term clinical and echocardiographic outcomes

OBJECTIVES

The Allegra-THV is a novel, self-expanding THV with supra-annular bovine leaflets. The valve is available in 3 different sizes and is delivered through an 18 French sheath. To determine the safety and efficacy of the Allegra transcatheter heart valve (THV; Biosensors) for the treatment of severe aortic valve stenosis under real-world conditions.

METHODS

Consecutive patients undergoing transcatheter aortic valve replacement (TAVR) at the Heart-Centre Lucerne with the Allegra-THV were included. Echocardiographic data were collected at baseline, before discharge, and at 1-year follow-up; clinical outcomes were recorded for up to 3 years. Clinical endpoints were defined according to the definitions of the Valve-Academic-Research-Consortium.

RESULTS

One hundred-three patients (age 81 ± 7 years, 63% women) were enrolled. Median European System for Cardiac Operative Risk Evaluation II score was 4.1% (IQR 1.8%-4.2%). Mean aortic valve gradient was 6.9 ± 3.3 mm Hg and 7.7 ± 3.3 mm Hg, and an effective orifice area was 2.1 ± 0.5 cm2 and 2.0 ± 0.5 cm2 at 30 days and 1-year follow-up, respectively. More than mild paravalvular leak was observed in 2.0% of patients at 30 days and 3.3% at 1 year. At 1-year follow-up, 14.7% of patients required implantation of a new permanent pacemaker, 1 patient had endocarditis with an uneventful clinical course and good THV-function after antibiotic therapy, and no thrombosis, structural-valve-detoriation (SVD), or non-SVD had occurred. At 3-year follow-up, rates of all-cause and cardiovascular mortality were 31.4% and 18.8%, respectively.

CONCLUSIONS

Transfemoral implantation of the Allegra-THV resulted in favorable clinical and echocardiographic outcomes at up to 3-year follow-up. Head-to-head randomized clinical trials are necessary to determine if the Allegra-THV valve performs as well as current generation valves.

Coronary Artery Disease Risk Prediction in Patients With Severe Aortic Stenosis: Development and Validation of the Aortic Stenosis-Coronary Artery Disease (AS-CAD) Score

Patients at a low risk of coronary artery disease (CAD) could be triaged to noninvasive coronary computed tomography angiogram instead of invasive coronary angiography, reducing health care costs and patient morbidity. Therefore, we aimed to develop a CAD risk prediction score to identify those who underwent transcatheter aortic valve implantation (TAVI) at a low risk of CAD. We enrolled 1,782 patients who underwent TAVI and randomized the patients to the derivation or validation cohort 2:1. The aortic stenosis-CAD (AS-CAD) score was developed using logistic regression, followed by separation into low- (score 0 to 5), intermediate- (6 to 10), or high-risk (>11) categories. The AS-CAD was validated initially through the k-fold cross-validation, followed by a separately held validation cohort. The average age of the cohort was 82 ± 7 years, and 41% (730 of 1,782) were female; 35% (630) had CAD. The male sex, previous percutaneous coronary intervention, stroke, peripheral arterial disease, diabetes, smoking status, left ventricular ejection fraction <50%, and right ventricular systolic pressure >35 mm Hg were all associated with an increased risk of CAD and were included in the final AS-CAD model (all p <0.03). Within the validation cohort, the AS-CAD score stratified those into low, intermediate, and high risk of CAD (p <0.001). Discrimination was good within the internal validation cohort, with a c-statistic of 0.79 (95% confidence interval 0.74 to 0.84), with similar power obtained using k-fold cross-validation (c-statistic 0.74 [95% confidence interval 0.70 to 0.77]). In conclusion, The AS-CAD score robustly identified those at a low risk of CAD in patients with severe AS. The use of AS-CAD in practice could avoid potential complications of invasive coronary angiogram by triaging low-risk patients to noninvasive coronary assessment using existing computed tomography data.

Antithrombotic therapy with Transcatheter aortic valve replacement

Aortic valve replacement is a necessary management strategy for patients with severe aortic stenosis. The use of transaortic valve replacement (TAVR) has increased significantly over the last decade and now exceeds traditional surgical aortic valve replacement. Since the valve systems used in TAVR consist of bioprosthetic valve tissue encased in a metal stent frame, antithrombotic therapy recommendations cannot be extrapolated from prior data with differently constructed surgical bioprosthetic or mechanical valves. Data on the use of antithrombotic therapy with TAVR are a rapidly developing area of medicine. Choice of agents depends on several patient factors. Patients undergoing TAVR also have a relatively high incidence of subclinical valve thrombosis. The clinical impact of this phenomenon and the implications for antithrombotic therapy continue to evolve. It is critical for clinicians who treat patients undergoing TAVR to have a firm understanding of practice guidelines, the evolving evidence, and its implications for the use of antithrombotic therapy in these patients.

Transcatheter Aortic Valve Replacement in Degenerated Perceval Bioprosthesis: Clinical and Technical Aspects in 32 Cases

BACKGROUND

Sutureless aortic bioprostheses are increasingly being used to provide shorter cross-clamp time and facilitate minimally invasive aortic valve replacement. As the use of sutureless valves has increased over the past decade, we begin to encounter their degeneration. We describe clinical outcomes and technical aspects in patients with degenerated sutureless Perceval (CorCym, Italy) aortic bioprosthesis treated with valve-in-valve transcatheter aortic valve replacement (VIV-TAVR).

METHODS

Between March 2011 and March 2023, 1310 patients underwent aortic valve replacement (AVR) with Perceval bioprosthesis implantation. Severe bioprosthesis degeneration treated with VIV-TAVR occurred in 32 patients with a mean of 6.4 ± 1.9 years (range: 2-10 years) after first implantation. Mean EuroSCORE II was 9.5 ± 6.4% (range: 1.9-35.1%).

RESULTS

Thirty of thirty-two (94%) VIV-TAVR were performed via transfemoral and two (6%) via transapical approach. Vascular complications occurred in two patients (6%), and mean hospital stay was 4.6 ± 2.4 days. At mean follow-up of 16.7 ± 15.2 months (range: 1-50 months), survival was 100%, and mean transvalvular pressure gradient was 18.7 ± 5.3 mmHg.

CONCLUSION

VIV-TAVR is a useful option for degenerated Perceval and appears safe and effective. This procedure is associated with good clinical results and excellent hemodynamic performance in our largest single-center experience.

Cerebral embolic protection during transcatheter aortic valve replacement: Insights from a consecutive series with the Sentinel cerebral protection device

BACKGROUND

Growing interest in neuroprotection in transcatheter aortic valve replacement (TAVR) has catalyzed the development of cerebral protection systems (CPS).

OBJECTIVES

Report insights from consecutive real-world patients undergoing TAVR with the Sentinel-CPS.

METHODS

Patients with severe aortic stenosis undergoing TAVR from April 2019 to May 2022 were enrolled in a prospective registry. The reason for unsuccessful Sentinel-CPS deployment and the amount of debris captured by the filters were prospectively recorded.

RESULTS

The Sentinal CPS was successfully deployed in 330 patients (85%, Group 1). Deployment was not attempted, unsuccessful or only partially successful in 59 patients (15%, Group 2), caused by anatomical factors such as tortuosity, heavy calcification or small dimensions of radial or brachial artery in 46, technical aspects such as puncture failure or dissection in 5 or use of right radial access for the pigtail in 6. Debris was captured in 98% of patients in Group 1. In 40%, the amount of debris was graded moderate or extensive. Predictors for moderate/extensive debris were moderate/severe aortic calcification (OR 1.50, CI 1.05-2.15, p = 0.03), pre- and postdilatation (OR 1.97, CI 1.02-3.79, p = 0.04 and OR 1.71, CI 1.01-2.89, p = 0.048). The risk of stroke was numerically lower in patients who underwent TAVR with the Sentinel CPS (2.1 vs. 5.1%, respectively, p = 0.15). There was no stroke during CPS deployment, but one patient had a stroke immediately after device retrieval.

CONCLUSIONS

The Sentinel-CPS was successfully deployed in 85% of patients. Predictors for moderate/extensive debris captured were moderate/severe aortic calcification, pre- and postdilatation.

Transcatheter aortic valve durability: a contemporary clinical review

Encouraged by randomized controlled trials demonstrating non-inferiority of transfemoral transcatheter aortic valve implantation (TAVI) compared to surgical aortic valve replacement (SAVR) across all surgical risk categories, there has been a dramatic increase in the use of TAVI in a younger patient cohort with severe aortic stenosis, endorsed by both European and American Cardiac Societies. However, the standard use of TAVI in younger, less co-morbid patients with a longer life expectancy can only be supported if there is sound data demonstrating long-term durability of transcatheter aortic valves (TAVs). In this article, we have reviewed available randomized and observational registry clinical data pertaining to TAV long-term durability, placing emphasis on trials and registries using the new standardized definitions of bioprosthetic valve dysfunction (BVD) and bioprosthetic valve failure (BVF). Despite inherent difficulties in interpreting the available data, the determination reached is that the risk of structural valve deterioration (SVD) is potentially lower after TAVI than SAVR at 5 to 10 years, and that the two treatment modalities have a similar risk of BVF. This supports the adoption of TAVI in younger patients evident in current practice. However, the routine use of TAVI in younger patients with bicuspid aortic valve stenosis should be cautioned due to insufficient long-term TAV durability data in this particular patient population. Finally, we highlight the importance of future research into the unique potential mechanisms that can potentially contribute to TAV degeneration.

The Accelerated Transcatheter Heart Valve Testing Environment: Loading, Motion, and Fluid Dynamics

Transcatheter aortic valve replacements (TAVRs) are an increasingly common treatment for aortic valve disease due to their minimally invasive delivery. As TAVR designs require thinner leaflets to facilitate catheter-based delivery, they experience greater leaflet operational stresses and potentially greater durability issues than conventional surgical valves. Yet, our understanding of TAVR durability remains largely unexplored. Currently, preclinical TAVR durability is evaluated within an ISO:5840 compliant accelerated wear tester (AWT) up to a required 200 × 106 cycles, corresponding to approximately five years in vivo. While AWTs use high cycle frequencies (10-20 Hz) to achieve realistic timeframes, the resulting valve loading behaviors and fluid dynamics are not representative of the in vivo environment and thus may not accurately predict failure mechanisms. Despite the importance of fatigue and failure predictions for replacement heart valves, surprisingly, little quantitative information exists on the dynamic AWT environment. To better understand this environment, we examined frequency and diastolic period effects for the first time using high-speed enface imaging and particle image velocimetry to quantify valve motion and flow, respectively, using a Durapulse™ AWT at frequencies of 10, 15, and 20 Hz. Regardless of operating condition, no waveform achieved a physiologically relevant transvalvular loading pressure, despite having an ISO compliant geometric orifice area (GOA) and waveform. General fluid mechanics were consistent with in vivo but the AWT geometry developed secondary flow structures, which could impact mechanical loading. Therefore, the nonphysiologic loading and variability induced by changes in operating condition must be carefully regulated to ensure physiologically relevant fatigue.

Treatment of Severe Aortic Valve Stenosis: Impact of Patient Sex and Life Expectancy on Treatment Choice

In adults with severe aortic stenosis, sex and age differences in symptoms and diagnosis may lead to delays in intervention. Choice of intervention partly depends on expected longevity because bioprosthetic valves have limited durability, particularly in younger patients. Current guidelines recommend the following: a mechanical valve in younger adults (aged <50 years) if lifelong anticoagulation is possible and acceptable and a valve-sparing procedure is not possible; surgical mechanical or bioprosthetic aortic valve replacement (SAVR) in adults aged 50-65 years; and transcatheter aortic valve implantation (TAVI) for those aged >80 years based on lower mortality and morbidity compared to SAVR and adequate valve durability. For patients aged 65-80 years, the choice between TAVI and a bioprosthetic SAVR depends on expected longevity, which is greater in women than men, as well as associated cardiac and noncardiac conditions, valvular and vascular anatomy, estimated risk of SAVR versus TAVI and expected complications and patient preferences.

[How to select the best device using pre-TAVR CT scan]

Transcatheter aortic valve replacement or TAVR has become the gold standard for the treatment of symptomatic and severe aortic valve stenosis in elderly patients. Although the role of computed tomography imaging was initially limited to the determination of the optimal vascular approach, it has progressively matured to become the pilar of TAVR work-up while being standardized by consensus conferences. The list of evaluated elements includes aortic annulus diameter, the optimal projection curve, the number of aortic leaflets, the severity and localization of calcifications, coronary ostial height, membranous septum length and aortic angulation. The proper and cautious evaluation of these elements may help evaluating the risk for the main periprocedural complications such as coronary obstruction, annular rupture, permanent pacemaker implantation or procedural failure and selecting the optimal transcatheter heart valve and its size, according to the patient's specific anatomy. In this review, we detail how the evaluation of these parameters may impact the selection of the transcatheter heart valve.

Real-World Multiple Comparison of Transcatheter Aortic Valves: Insights From the Multicenter OBSERVANT II Study

BACKGROUND

Head-to-head comparisons of devices for transcatheter aortic valve implantation (TAVI) are mostly limited to 2-arm studies so far. The aim of this study was to compare simultaneously outcomes of the most used, second- and third-generation transcatheter aortic valves in a real-world population.

METHODS

A total of 2728 patients undergoing TAVI with different second- and third-generation devices, and enrolled in the multicenter, prospective OBSERVANT II study (Observational Study of Effectiveness of TAVI With New Generation Devices for Severe Aortic Stenosis Treatment) from December 2016 to September 2018 were compared according to the transcatheter aortic valve received. Outcomes were adjudicated through a linkage with administrative databases, and adjusted using inverse propensity of treatment weighting. The primary end point was the composite of all-cause death, stroke and rehospitalization for heart failure at 1-year. Rates were reported consecutively for Evolut R, Evolut PRO, SAPIEN 3, ACURATE neo, and Portico groups.

RESULTS

The primary end point did not differ among groups (23.9% versus 24.7% versus 21.5% versus 23.7% versus 27.4%, respectively, P=0.56). Permanent pacemaker implantation was significantly lower for patients receiving SAPIEN 3 (19.9% versus 19.3% versus 12.5% versus 14.7% versus 22.1%, respectively, P<0.01) at 1 year. The SAPIEN 3 had lower rates of paravalvular regurgitation (moderate-to-severe grade 10.1% versus 5.0% versus 2.1% versus 13.1% versus 10.8%, respectively, P<0.01) but higher transprosthetic gradients (median mean gradients 7.0 versus 6.0 versus 10.0 versus 7.0 versus 8.0 mm Hg, respectively, P<0.01) after TAVI.

CONCLUSIONS

Data from real-world practice showed low and comparable rates of complications after TAVI considering all the available devices. Patients receiving SAPIEN 3 valve had lower rates of paravalvular regurgitation and permanent pacemaker implantation, but higher transprosthetic gradients.

Early- and mid-term outcomes of reinterventions for aortic bioprosthesis failure

BACKGROUND

The aim of this study was to evaluate early- and mid-term results of our actual practice embedding redo aortic valve replacement and transcatheter procedures for aortic bioprosthetic failure.

METHODS

Data for aortic valve reinterventions (redo surgical aortic valve replacement, isolated redo aortic valve replacement, and valve-in-valve transcatheter aortic valve implantation, transcatheter valve-in-valve procedure) were collected (2010-2019). Logistic regression analysis was performed to identify predictors favouring the choice of transcatheter against redo surgery. Cox analysis was used to study the association of preoperative variables with survival. Survival probabilities were calculated with Kaplan-Meier analysis and compared using a log-rank test.

RESULTS

A total of 125 patients were included (redo surgical aortic valve replacement: 84 patients, valve-in-valve transcatheter aortic valve implantation: 41 patients). Median age was 74 [63-80] years, 58% of the patients were male and the median logistic EuroSCORE was 15 [8-26] %. There was no early mortality. Eighteen patients (redo surgical aortic valve replacement: 15, valve-in-valve transcatheter aortic valve implantation: 3) sustained at least one postoperative complication. At pre-discharge transthoracic echocardiogram, valve-in-valve transcatheter aortic valve implantation had significantly higher trans-prosthetic gradients (mean gradient: valve-in-valve transcatheter aortic valve implantation 18 mmHg vs. redo surgical aortic valve replacement 14 mmHg, p < 0.001). Overall survival probabilities were 94% and 73% at 1 year and 5 years, respectively. Previous coronary artery bypass surgery operation and age were independently associated with lower survival probabilities during the follow-up.

CONCLUSIONS

Redo surgical aortic valve replacement and valve-in-valve transcatheter aortic valve implantation are both safe and effective for aortic bioprosthetic failure. Further valve-in-valve data are needed to determine the haemodynamic performance of transcatheter prostheses and its impact on long-term outcomes.

The use of balloon-expandable Sapien-3 valve in redo aortic valve replacement and the potential risk of left main stem occlusion

Redo aortic valve surgery for the failure of a previously implanted valve is always challenging. In case of small‐sized implanted valves, the use of a balloon‐expanding Sapien‐3 valve can enhance the final effective orifice area, avoid annulus enlargement complex techniques, and can reduce operative time and morbidities. We describe a case where after explanting a failed 19 mm St. Jude mechanical aortic valve and further deployment of a 23 mm Sapien‐3 valve, the left coronary ostia was obstructed by the skirt of the transcatheter prosthesis. After careful removal of a little part of the skirt, we were able to restore the coronary flow and the patient had a favorable outcome.

Early and long-term outcomes of re-sternotomy for aortic valve replacement with patent coronary artery grafts

OBJECTIVE

The aim was to evaluate early and long-term outcomes of re-sternotomy for aortic valve replacement (AVR) with previous patent coronary artery grafts.

METHODS

Data for re-sternotomy for AVRs (group 1 isolated AVR, group 2 AVR with concomitant procedure) were collected (2000-2019). Logistic regression analysis was performed to identify predictors of in-hospital mortality and postoperative composite outcome (in-hospital death, transient ischemic attack/stroke, renal failure requiring new hemofiltration, deep sternal wound infection, re-exploration for bleeding/tamponade and length of stay >30 days). Survival curves were compared using log-rank test Cox proportion hazards model was used for predictors of long-term survival.

RESULTS

Total 178 patients were included (groups 1-90 patients, group 2-88 patients). Mean age was 75 ± 4 years and mean log EuroSCORE was 17 ± 12% (15 ± 8% - group 1 vs. 19 ± 14% - group 2, p = 0.06). Mean follow-up was 6.3 ± 4.4 years. Cardiovascular injury occurred in 12%. Left internal mammary artery was most commonly injured. In-hospital mortality was 7.8% (5% - group 1 vs. 10.2% - group 2, p = 0.247). NYHA class III-IV, perioperative intra-aortic balloon pump and cardiovascular injury were independent predictors of in-hospital mortality (hazard ratio: 13.33, 95% confidence interval: 2.04-83.33, p = 0.007). Survival was significantly worse with cardiovascular injury at re-sternotomy up to 5 years (46% vs. 67%, p = 0.025) and postoperative complications (p = 0.023). Survival was significantly lower than age-matched first-time AVR and UK population.

CONCLUSIONS

Long-term survival is significantly impaired by cardiovascular injury and perioperative complications of re-sternotomy.

Transcatheter aortic valve thrombosis: a review of potential mechanisms

Transcatheter aortic valve (TAV) thrombosis has been recognized as a significant problem that sometimes occurs as early as within 30 days after valve implantation, leading to increased concerns of stroke and long-term valve durability. In this article, a critical summary of the relevant literature on identifying potential mechanisms of TAV thrombosis from the perspective of the well-known Virchow's triad, which comprises blood flow, foreign materials and blood biochemistry, is presented. Blood flow mechanisms have been the primary focus thus far, with a general consensus on the flow mechanisms with respect to haemodynamic conditions, the influence of TAV placement and expansion and the influence of coronary flow. Less attention has been paid to the influence of blood biochemistry and foreign materials (and related endothelial damage), with little consensus among studies with regards to platelet and/or microparticle levels post-TAV implantation. Finally, we discuss the future outlook for research with unanswered scientific questions.

Bioprosthetic valve fracture: a practical guide

Valve-in-valve transcatheter aortic valve replacement (VIV TAVR) is currently indicated for the treatment of failed surgical tissue valves in patients determined to be at high surgical risk for re-operative surgical valve replacement. VIV TAVR, however, often results in suboptimal expansion of the transcatheter heart valve (THV) and can result in patient-prosthesis mismatch (PPM), particularly in small surgical valves. Bioprosthetic valve fracture (BVF) and bioprosthetic valve remodeling (BVR) can facilitate VIV TAVR by optimally expanding the THV and reducing the residual transvalvular gradient by utilizing a high-pressure inflation with a non-compliant balloon to either fracture or stretch the surgical valve ring, respectively. This article, along with the supplemental video, will provide patient selection, procedural planning and technical insights for performing BVF and BVR.

Clinical impact of left atrial appendage filling defects in patients undergoing transcatheter aortic valve implantation

AIMS

Incidental detection of left atrial appendage (LAA) filling defects is a common finding on multi-detector computed tomography in aortic stenosis patients under evaluation for transcatheter aortic valve implantation (TAVI). We aimed to investigate the incidence of LAA filling defects before TAVI and its impact on clinical outcomes.

METHODS AND RESULTS

In a prospective registry, LAA filling defects were retrospectively evaluated and categorized into one of four sub-types: thrombus-like, heterogeneous, horizontal, and Hounsfield Unit (HU)-run-off. The primary endpoint was the composite of cardiovascular death or disabling stroke up to 1-year follow-up. Among 1621 patients undergoing TAVI between August 2007 and June 2018, LAA filling defects were present in 177 patients (11%), and categorized as thrombus-like in 22 (1.4%), heterogeneous in 37 (2.3%), horizontal in 80 (4.9%), and HU-run-off in 38 (2.4%). Compared to patients with normal LAA filling, patients with LAA filling defects had greater prevalence of atrial fibrillation (84.7% vs. 26.4%, P < 0.001) and history of cerebrovascular events (16.4% vs. 10.9%, P = 0.045). The primary endpoint occurred in 131 patients (9.2%) with normal LAA filling and in 36 patients (21.2%) with LAA filling defects (P < 0.001). Subgroup analysis suggested that the risk of disabling stroke was greatest in the thrombus-like pattern (23.0%), followed by the HU-run-off (8.0%), the heterogeneous (6.2%), and the horizontal pattern (1.2%).

CONCLUSION

LAA filling defects were observed in 11% of aortic stenosis patients undergoing TAVI and associated with an increased risk of cardiovascular death and disabling stroke up to 1 year following TAVI.

TRIAL REGISTRATION

https://www.clinicaltrials.gov. NCT01368250.

The Allegra transcatheter heart valve: Short term results from a multicenter registry

OBJECTIVES

We aimed to determine the safety and efficacy of the Allegra transcatheter heart valve (THV) for the treatment of severe aortic valve stenosis in a large patient population treated under real-world conditions.

BACKGROUND

The Allegra is a novel self-expanding THV with supra-annular bovine leaflets. The valve is available in three different sizes (23, 27, and 31 mm), all are delivered through an 18F sheath.

METHODS

Consecutive patients undergoing TAVR with the Allegra THV were enrolled in a multicenter-registry. Data were collected throughout initial hospital-stay and at 30-day follow-up. Clinical endpoints were defined according to the updated definitions of the Valve-Academic-Research-Consortium.

RESULTS

This registry included 255 patients (mean age 83 ± 6 years, 48% women) from four European centers. Median European System for Cardiac Operative Risk Evaluation II score (EuroSCORE II) was 3.3% (IQR 1.9-5.8%). Acute device success was 95.7%. The remaining 11 patients had either moderate paravalvular regurgitation immediately after the procedure (7 patients) or the device could not be optimal positioned requiring implantation of a second THV (4 patients). Major vascular complications and major/life-threatening bleedings occurred in 10 (3.9%) and 12 (4.7%) patients, respectively. At 30 day follow-up, mean effective orifice area was 2.2 ± 0.5 cm² , mean gradient was 6.9 ± 3.8 mmHg, 7 (3.3%) patients had more than mild paravalvular leakage, 3 patients (1.2%) had died, 6 patients (2.4%) had a stroke and 30 (12.8%) patients had required implantation of a new permanent pacemaker.

CONCLUSIONS

Transfemoral implantation of the Allegra THV resulted in favorable clinical and echocardiographic outcomes during hospitalization and short-term follow up.

The Spanish Allegra valve-in-valve (SAVIV) registry

OBJECTIVES

The objective was to evaluate the results of valve-in-valve procedures performed with the Allegra device.

BACKGROUND

Transcatheter aortic valve implantation to treat degenerated biological aortic valves (valve-in-valve) is an established procedure in most catheterization laboratories, but the results are poorer than procedures done in native aortic stenosis. The Allegra device (Biosensors, Morges, Switzerland) has an excellent design to treat these patients.

METHODS

All patients with severely degenerated biological aortic valve treated with the Allegra device in centers from Spain until December 2020 were included (n = 29). Hemodynamic results and 30-day clinical outcomes were evaluated. The predominant hemodynamic failure was stenosis in 15, regurgitation in 11, and a combination of both in 3 cases. Time from aortic valve replacement to valve-in-valve procedure was 8.4 ± 3.9 years (range 3.3-22.1).

RESULTS

After the procedure, maximum and mean trans-valvular gradients were 17.4 ± 12.3 and 8.4 ± 6.1 mmHg, respectively. Device success was obtained in 28 patients (96.6%). In one patient with a degenerated 19 mm prosthetic valve, mean gradient after the procedure was 22 mmHg. No patients had a para-valvular leak grade >1. There were no deaths during the hospitalization or at 30 days and one patient suffered a stroke.

CONCLUSIONS

The Allegra trans-catheter aortic valve offers optimal hemodynamic results in patients with severely degenerated biological aortic valve.

Incidence, Predictors, and Outcomes of Acute Kidney Injury in Patients Undergoing Transcatheter Aortic Valve Replacement: Insights From the Society of Thoracic Surgeons/American College of Cardiology National Cardiovascular Data Registry-Transcatheter Valve Therapy Registry

[Figure: see text].

Caval Valve Implantation for Tricuspid Regurgitation: Insights From the United States Caval Valve Registry

BACKGROUND

We sought to describe the outcomes of patients who underwent caval valve implantation (CAVI) for treatment of severe tricuspid regurgitation (TR) in the United States. Previous studies on CAVI have used a variety of techniques and transcatheter valves. We present our findings from CAVI with inferior vena cava (IVC) implant only using a single valve.

METHODS

Patients who were determined to be poor candidates for tricuspid valve surgery and underwent CAVI in the United States from March 1, 2013 through March 1, 2018 were included in this study. Data during hospitalizations and interim outpatient follow-up from each individual site were collected and entered into a central password-protected database.

RESULTS

A total of 24 patients were treated. The median age was 79.5 years, 63% were women, and 96% were white. Twenty-three of 24 patients underwent valve implantation with a 29 mm Sapien 3 valve (Edwards Lifesciences). There was a 100% rate of successful valve implantation. There were no cases requiring emergency surgery. Thirty-day mortality rate was 25%. The median survival as of last follow-up of all patients was 350 days. Pre- and postprocedure New York Heart Association (NYHA) class data were available in 11 of 24 patients; of these 11 patients, 72.7% improved at least 1 NYHA class from baseline.

CONCLUSION

CAVI may be performed safely in a high surgical risk population with severe tricuspid regurgitation. Dedicated studies with longer-term follow-up are needed.

Risk-Adjusted Comparison of In-Hospital Outcomes of Transcatheter and Surgical Aortic Valve Replacement

Background

Transfemoral transcatheter aortic valve replacement (TF‐TAVR) is recommended for patients suffering from aortic valve stenosis at increased operative risk. Beyond that, patients with different comorbidities could benefit from TF‐TAVR. The present study compares real‐world in‐hospital outcomes of surgical aortic valve replacement and TF‐TAVR.

Methods and Results

For all 33 789 isolated TF‐TAVR and surgical aortic valve replacement procedures performed in Germany in 2014 and 2015, comorbidities and in‐hospital outcomes were identified by International Classification of Diseases (ICD)‐ and OPS (Operation and procedure key)‐codes. Patients undergoing TF‐TAVR were older and at increased estimated risk. Outcomes were risk‐adjusted to allow comparison. TF‐TAVR was associated with a lower risk for acute kidney injuries (odds ratio [OR] 0.62, P<0.001), for bleeding (OR 0.17, P<0.001), and for prolonged mechanical ventilation (>48 hours, OR 0.21, P<0.001). Risk for stroke was similar (OR 1.07, P=0.558). As expected, the risk for pacemaker implantations was higher after TF‐TAVR (OR 4.61, P<0.001). In all patients, none of the treatment strategies had a clear advantage on the risk for in‐hospital mortality (OR 0.83, P=0.068). However, in patients aged >80 years and at high operative risk undergoing TF‐TAVR in‐hospital mortality was lower (TF‐TAVR versus surgical aortic valve replacement 80–84, OR 0.55; P=0.002; ≥85 years, OR 0.42, P=0.006; EuroSCORE (European System for Cardiac Operative Risk Evaluation) >9: OR 0.62, P=0.001). TF‐TAVR was superior in patients with renal failure and in NYHA (New York Heart Association)‐Class III/IV. Other risk groups were not found to be factors favoring a treatment strategy.

Conclusions

The present study indicates a superiority of TF‐TAVR in clinical practice for patients at increased operative risk, aged >80 years, in NYHA‐Class III/IV, and with renal failure.

Coronary Access and Percutaneous Coronary Intervention Up to 3 Years After Transcatheter Aortic Valve Implantation With a Balloon-Expandable Valve

Background:

Coronary artery disease and aortic stenosis often coexist. Transcatheter aortic valve implantation (TAVI) has emerged as a valid therapeutic option for younger, lower-risk patients who may eventually require coronary artery disease treatment. Thus, post-TAVI coronary access (CA) and percutaneous coronary intervention are expected to increase. The purpose of this study was to retrospectively evaluate patients who were enrolled in the SOURCE 3 (SAPIEN 3 Aortic Bioprosthesis European Outcome) European registry for treatment with the balloon-expandable SAPIEN 3 transcatheter heart valve and underwent CA with or without percutaneous coronary intervention after TAVI.

Methods:

Baseline characteristics and clinical outcomes of patients with or without CA up to 3 years after TAVI were compared. A Kaplan-Meier estimate with a univariate model determined the impact of CA on cardiac mortality.

Results:

Of 1936 TAVI patients (mean age 81.6 years, 52% male), 68 (3.5%) had CA within 3 years (mean 441±332 days) after TAVI. At baseline, the logistic EuroSCORE was similar (20.2% versus 18.3%, P=0.2, CA and non-CA groups, respectively). Higher rates of coronary artery disease (76.5% versus 50.6%, P<0.001), myocardial infarction (20.6% versus 11.5%, P=0.03) and previous coronary artery bypass graft (22.1% versus 11.0%, P=0.01) were present in the CA group. In 100% of patients, CA was successfully achieved. The clinical success of percutaneous coronary intervention was 97.9%. Cardiovascular mortality was numerically higher in patients with CA than in those without CA.

Conclusions:

In the large SOURCE 3 European registry, CA was needed at 3-year follow-up after TAVI with a balloon-expandable valve in 3.5% of patients and was successful in all patients. The clinical success of percutaneous coronary intervention was 97.9%.

Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02698956.

Simplifying transfemoral ACURATE neo implantation using the TrueFlow nonocclusive balloon catheter

OBJECTIVES

This study aimed to investigate the safety and efficacy of ACURATE neo transcatheter aortic valve replacement (TAVR) facilitated by predilatation with the nonocclusive TrueFlow balloon catheter.

BACKGROUND

Now that TAVR is moving forward, physicians have attempted to simplify and streamline the procedure and the so-called minimalist approach has become more popular.

METHODS

We enrolled 142 patients (mean age: 82 ± 5 years, 61% female) in a prospective registry. Patients at low risk for intraprocedural third-degree atrioventricular block (AVB) underwent TAVR with the TrueFlow balloon without rapid pacing and without insertion of a provisional pacemaker (n = 121). The remaining 21 patients were predilated with rapid pacing using a provisional pacemaker and a standard balloon.

RESULTS

Predilatation with the TrueFlow balloon was successful in all 121 patients. Postdilatation was less frequently required after predilatation with the TrueFlow (25% vs. 57%, p = .003). Moreover, median procedural duration with the TrueFlow was significantly shorter (42 [interquartile range, IQR: 34-53] vs. 55 [IQR: 46-61] min, p = .004). In-hospital outcomes were similar. At 30 days, there was no mortality, two (1%) patients had suffered a stroke and only four (3%) had required implantation of a new pacemaker.

CONCLUSION

Among patients with a low risk for intraprocedural third-degree AVB, the TrueFlow nonocclusive balloon catheter facilitates implantation of the ACURATE neo without the necessity of rapid pacing and a provisional pacemaker.

Contemporary Trends and Outcomes of Percutaneous and Surgical Aortic Valve Replacement in Patients With Cancer

Background

Patients with cancer and severe aortic stenosis are often ineligible for surgical aortic valve replacement (SAVR). Patients with cancer may likely benefit from emerging transcatheter aortic valve replacement (TAVR), given its minimally invasive nature.

Methods and Results

The US‐based National Inpatient Sample was queried between 2012 and 2015 using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM), codes to identify all hospitalized adults (aged ≥50 years), who had a primary diagnosis of aortic stenosis. We examined the effect modification of cancer on the relative use rate, outcomes, and dispositions associated with propensity‐matched cohort TAVR versus SAVR. Overall, 47 295 TAVRs (22.6% comorbid cancer) and 113 405 SAVRs (15.2% comorbid cancer) were performed among admissions with aortic stenosis between 2012 and 2015. In the year 2015, patients with cancer saw relatively higher rates of TAVR use compared with SAVR (relative use rate_TAVR versus relative use rate_SAVR, 67.8% versus 57.2%; P<0.0001). Among patients with cancer, TAVR was associated with lower odds of acute kidney injury (odds ratio, 0.64; 95% CI, 0.54–0.75) and major bleeding (odds ratio, 0.44; 95% CI, 0.38–0.51]), with no differences in in‐hospital mortality and stroke compared with SAVR. In addition, TAVR was associated with higher odds of home discharge (odds ratio, 1.92; 95% CI, 1.68–2.19) compared with SAVR among patients with cancer. Lower risk of acute kidney injury was noted in cancer versus noncancer (P<0.001) undergoing TAVR versus SAVR in effect modification analysis.

Conclusions

TAVR use has increased irrespective of cancer status, with a greater increase in cancer versus noncancer. In patients with cancer, there was an association of TAVR with lower periprocedural complications and better disposition when compared with patients undergoing SAVR.

A Computational Study on Deformed Bioprosthetic Valve Geometries: Clinically Relevant Valve Performance Metrics

Transcatheter aortic valves (TAV) are symmetrically designed, but they are often not deployed inside cylindrical conduits with circular cross-sectional areas. Many TAV patients have heavily calcified aortic valves, which often result in deformed prosthesis geometries after deployment. We investigated the effects of deformed valve annulus configurations on a surgical bioprosthetic valve as a model for TAV. We studied valve leaflet motions, stresses and strains, and analog hydrodynamic measures (using geometric methods), via finite element (FE) modeling. Two categories of annular deformations were created to approximate clinical observations: (1) noncircular annulus with valve area conserved, and (2) under-expansion (reduced area) compared to circular annulus. We found that under-expansion had more impact on increasing stenosis (with geometric orifice area metrics) than noncircularity, and that noncircularity had more impact on increasing regurgitation (with regurgitation orifice area metrics) than under-expansion. We found durability predictors (stress/strain) to be the highest in the commissure regions of noncircular configurations such as EllipMajor (noncircular and under-expansion areas). Other clinically relevant performance aspects such as leaflet kinematics and coaptation were also investigated with the noncircular configurations. This study provides a framework for choosing the most challenging TAV deformations for acute and long-term valve performance in the design and testing phase of device development.

Does transcatheter aortic valve alignment matter?

Objective

This study investigates the effect of transcatheter aortic valve (TAV) angular alignment on the postprocedure haemodynamics. TAV implantation has emerged as an effective alternative to surgery when treating valve dysfunction. However, the benefit of avoiding surgery is paid back by the inability to remove the native diseased leaflets and accurately position the device in relation to the aortic root, and the literature has shown the root anatomy and substitute position can play an essential role on valve function.

Methods

A commercial TAV was placed in a silicone mock aortic root in vitro, including mock native leaflets, and either aligned commissure-to-commissure or in maximum misalignment. Haemodynamic performance data at various stroke volumes were measured, and Particle Image Velocimetry analysis was performed at a typical stroke volume for rest conditions. The two configurations were also studied without mock native leaflets, for comparison with previous in vitro studies.

Results

Haemodynamic performance data were similar for all configurations. However, imaging analysis indicated that valve misalignment resulted in the central jet flow not extending to the root wall in the native commissures’ vicinity, replaced by a low shear flow, and a reduction of upper sinus flow of 40%, increasing flow stagnation in the sinus.

Conclusions

TAV misalignment did not result in a significant change in valve hydrodynamic performance, but determined some change in the fluid flow patterns, which may promote pathological scenarios, such as increased thrombogenicity of blood flow within the sinuses of Valsalva, and plaque formation around the lumen of the sinotubular junction.

A Proof of Concept Study of Using Machine-Learning in Artificial Aortic Valve Design: From Leaflet Design to Stress Analysis

Artificial heart valves, used to replace diseased human heart valves, are life-saving medical devices. Currently, at the device development stage, new artificial valves are primarily assessed through time-consuming and expensive benchtop tests or animal implantation studies. Computational stress analysis using the finite element (FE) method presents an attractive alternative to physical testing. However, FE computational analysis requires a complex process of numeric modeling and simulation, as well as in-depth engineering expertise. In this proof of concept study, our objective was to develop machine learning (ML) techniques that can estimate the stress and deformation of a transcatheter aortic valve (TAV) from a given set of TAV leaflet design parameters. Two deep neural networks were developed and compared: the autoencoder-based ML-models and the direct ML-models. The ML-models were evaluated through Monte Carlo cross validation. From the results, both proposed deep neural networks could accurately estimate the deformed geometry of the TAV leaflets and the associated stress distributions within a second, with the direct ML-models (ML-model-d) having slightly larger errors. In conclusion, although this is a proof-of-concept study, the proposed ML approaches have demonstrated great potential to serve as a fast and reliable tool for future TAV design.

[Evaluation of bovine pericardium performance after liquid nitrogen freezing and thinning]

In the present study, the performance of the liquid nitrogen frozen and thinned bovine pericardium was studied and compared with the porcine pericardium. The microstructure and mechanical properties of the bovine pericardium were observed and tested by hematoxylin-eosin (HE) staining and tensile test respectively. In all conditions, porcine pericardium was selected as a control group. The results showed that there was little difference in the performance of bovine pericardium after being frozen by liquid nitrogen. The secant modulus and ultimate strength of the thinned bovine pericardium were similar to those of porcine pericardium, however, the elastic modulus was a little higher than porcine pericardium. The study suggested that the performance of the thinned bovine pericardium was similar to those of porcine pericardium. It was easy for the thinned bovine pericardium to obtain a relatively ideal thickness and expected performance, therefore, the thinned bovine pericardium can be used as the materials of transcatheter aortic valve leaflets.

Cost-effectiveness analysis of the SAPIEN 3 TAVI valve compared with surgery in intermediate-risk patients

OBJECTIVE

Transcatheter aortic valve implantation (TAVI) has become the therapy of choice for treating severe aortic stenosis in patients at high-risk for surgery or where it is considered too risky to attempt. This uptake varies across geographies however, and its cost or value has frequently been cited as the reason for this. We sought to evaluate the potential cost and clinical impact of TAVI in intermediate risk patients from a French collective perspective.

MATERIALS AND METHODS

The analysis was performed using a novel Markov model with data derived from the PARTNER II randomized controlled trial for survival, clinical event rates, and quality-of-life. The simulated time horizon was 15 years, costs were from French sources and presented in 2016 Euros. Discounting of all outcomes was at 4% annually and the effect of uncertainty in model parameters was explored by deterministic and probabilistic sensitivity analysis (PSA).

RESULTS

In comparison to surgery, TAVI resulted in improved clinical outcomes (life expectancy and quality-adjusted life expectancy) and lower costs over a lifetime time horizon. The base case results showed increases of 0.42 years and 0.41 QALYs with lifetime cost savings of €439 for TAVI compared to surgery. PSA results showed a >50% likelihood of cost-effectiveness at €0 willingness-to-pay and a 100% likelihood at ∼€15,000.

LIMITATIONS

Clinically, survival projections are based on limited follow-up data and introduce uncertainty into the outcomes from the model. Economically, procedure costs are derived from a heterogeneous mix of patient risk groups, although this is much more likely to bias against TAVI and under-estimate overall cost savings.

CONCLUSIONS

In our analyses of intermediate risk patients, TAVI is associated with superior clinical outcomes compared to surgery and is cost saving. It could be expected that cost savings are conservative and likely to increase over time.

Severe Symptomatic Aortic Stenosis? Check Troponin, Too

See Article by Akodad et al

Guideline-defined futility or patient-reported outcomes to assess treatment success after TAVI: what to use? Results from a prospective cohort study with long-term follow-up

Objective

Transcatheter aortic valve implantation (TAVI) provides a significant symptom relief and mortality reduction in most patients; however, a substantial group of patients does not experience the same beneficial results according to physician-determined outcomes.

Methods

Single-centre prospective design; the population comprises all consecutive patients undergoing TAVI in 2012-2017. TAVI futility was defined as the combined endpoint of either no symptomatic improvement or mortality at 1 year. We actively gathered telephone follow-up using a predefined questionnaire.

Results

Guideline defined TAVI futility was present in 212/741 patients. Multivariate regression showed lower albumin and non-transfemoral approach to be predictive for futility. In addition to these, chronic obstructive pulmonary disease, lower estimated glomerular filtration rate, atrial fibrillation, low-flow-low-gradient aortic stenosis and lower Body Mass Index were predictive for 1-year mortality. Patients who showed symptomatic benefit estimated the percentage in which their symptoms were remedied higher than patients who did not (80% vs 60%, p<0.001). Guideline-defined TAVI futility occurs frequently, contrasting with patient-reported outcome measures (PROMs). The vast majority in both groups would again choose for TAVI treatment.

Conclusion

Lower albumin and non-transfemoral access route were predictors for guideline-defined TAVI futility, defined as mortality within 1 year or no objective symptomatic improvement in New York Heart Association class. Futility according to this definition occurred frequently in this study, contrasting with much more positive PROMs. The majority of patients would undergo a TAVI again, underlining the patients' experienced value of TAVI and putting the definition of TAVI futility further on debate. In the near future, less-strict criteria for TAVI futility, that is, using a shorter warranted life expectancy and incorporating patients' perceived outcomes, should be used.

Incidence of Long-Term Structural Valve Dysfunction and Bioprosthetic Valve Failure After Transcatheter Aortic Valve Replacement

Background Long-term data on durability of currently available transcatheter heart valves are sparse. We sought to assess the incidence of long-term (8-year) structural valve dysfunction and bioprosthetic valve failure in a cohort of patients with transcatheter aortic valve replacement ( TAVR ) who reached at least 5-year follow-up. Methods and Results Consecutive patients with at least 5-year follow-up available undergoing TAVR from June 4, 2007 to March 30, 2012 were included. Structural valve dysfunction and bioprosthetic valve failure were defined according to newly standardized European Association of Percutaneous Cardiovascular Interventions/ European Society of Cardiology/European Association for Cardio-Thoracic Surgery criteria and reported as cumulative incidence function to account for the competing risk of death. A total of 288 consecutive patients with a mean age of 80.7±5.3 years and with a mean Society of Thoracic Surgery mortality score of 8.1±5.1% were analyzed. Survival rate at 8 years was 29.8%. Mean pressure gradients decreased from 53.3±15.9 mm Hg (pre- TAVR ) to 10.5±4.5 mm Hg (in-hospital post- TAVR ) ( P<0.001). There was a small, not significant, increase in the transaortic gradient throughout follow-up. Bioprosthetic valve failure was observed in a total of 11 patients (8-year cumulative incidence function: 4.51%; 95% confidence interval , 1.95%-8.76%). Severe and moderate structural valve dysfunctions were reported in 7 patients (8-year cumulative incidence function: 2.39%; 95% confidence interval, 0.77%-5.71%) and 13 patients (8-year cumulative incidence function: 5.87%; 95% confidence interval , 3.06%-9.96%), respectively. Aortic valve reintervention (redo TAVR ) was successfully performed in 2 patients (0.7%) presenting with symptomatic severe restenosis and intraprosthetic regurgitation subsequent to endocarditis. Conclusions In an aged population of patients with symptomatic severe aortic stenosis treated with first-generation bioprostheses, TAVR was associated with a survival rate of 30% but low rates of bioprosthetic valve failure and structural valve dysfunction at 8 years.

Impact of patient-specific morphologies on sinus flow stasis in transcatheter aortic valve replacement: An in vitro study

OBJECTIVE

The goal of this study is to evaluate how sinus flow patterns after transcatheter aortic valve replacement in realistic representative patient roots vary. Sinus flow can affect transcatheter aortic valve operation and likely leaflet thrombosis occurrence due to stasis and poor washout. How the interaction between transcatheter aortic valve and representative patient aortic roots affects sinus hemodynamics is important to establish for future individualization of transcatheter aortic valve replacement therapy.

METHODS

Two representative patient aortic roots were selected, segmented and 3-dimensional printed followed by deployment of Medtronic CoreValve (Medtronic Inc, Irvine, Calif) and Edwards SAPIEN (Edwards Lifesciences, Irvine Calif) transcatheter aortic valves. Sinus hemodynamics were assessed in vitro using high spatio-temporal resolution particle-image-velocimetry. Detailed sinus vortex tracking, shear stress probability density functions, and sinus washout were evaluated and assessed as a function of valve type and representative patient morphology as independent case studies.

RESULTS

Peak velocity in the sinus with SAPIEN valve was approximately 3 times higher than with CoreValve for both models (0.30 ± 0.02 m/s and 0.34 ± 0.041 m/s vs 0.13 ± 0.01 m/s and 0.10 ± 0.02 m/s) (P < .01). Between representative patient models, vorticity magnitudes were significantly different (75 ± 1.1 s^-1, 77 ± 3.2 s^-1, 109 ± 2.3 s^-1, and 250 ± 4.1 s^-1) (P < .01) regardless of valve type. Sinus blood washout characteristic as a function of cardiac cycles was strongly both patient related and valve specific. Fluid dynamics favored shear stresses and washout characteristics due to a smaller sinus and sinotubular junction, further amplified by the SAPIEN valve.

CONCLUSIONS

Sinus flow dynamics are highly sensitive to aortic root characteristics and transcatheter aortic valve aortic root interaction. Differences in sinus-flow washout and stasis regions between representative patient models may be reflected in different risks of leaflet thrombosis or valve degeneration.

An in vitro evaluation of turbulence after transcatheter aortic valve implantation

BACKGROUND

This study aimed at assessment of post-transcatheter aortic valve (TAV) replacement hemodynamics and turbulence when a same-size SAPIEN 3 (Edwards Lifesciences Corp, Irvine, Calif) and Medtronic Evolut (Minneapolis, Minn) were implanted in a rigid aortic root with physiological dimensions and in a representative root with calcific leaflets obtained from patient computed tomography scans.

METHODS

TAV hemodynamics were studied by placing a SAPIEN 3 26-mm and an Evolut 26-mm in rigid aortic roots and representative root with calcific leaflets under physiological conditions. Hemodynamics were assessed using high-fidelity particle image velocimetry and high-speed imaging. Transvalvular pressure gradients (PGs), pinwheeling indices, and Reynolds shear stress (RSS) were calculated.

RESULTS

(1) PGs obtained with the Evolut and the SAPIEN 3 were comparable among the different models (10.5 ± 0.15 mm Hg vs 7.76 ± 0.083 mm Hg in the rigid model along with 13.9 ± 0.19 mm Hg vs 5.0 ± 0.09 mm Hg in representative root with calcific leaflets obtained from patient computed tomography scans respectively); (2) more pinwheeling was found in the SAPIEN 3 than the Evolut (0.231 ± 0.057 vs 0.201 ± 0.05 in the representative root with calcific leaflets and 0.366 ± 0.067 vs 0.122 ± 0.045 in the rigid model); (3) higher rates of RSS were found in the Evolut (161.27 ± 3.45 vs 122.84 ± 1.76 Pa in representative root with calcific leaflets and 337.22 ± 7.05 vs 157.91 ± 1.80 Pa in rigid models). More lateral fluctuations were found in representative root with calcific leaflets.

CONCLUSIONS

(1) Comparable PGs were found among the TAVs in different models; (2) pinwheeling indices were found to be different between both TAVs; (3) turbulence patterns among both TAVs translated according to RSS were different. Rigid aortic models yield more conservative estimates of turbulence; (4) both TAVs exhibit peak maximal RSS that exceeds platelet activation 100 Pa threshold limit.

Stent and leaflet stresses in 26-mm, third-generation, balloon-expandable transcatheter aortic valve

OBJECTIVES

Transcatheter aortic valve replacement has proven successful in treating intermediate-risk, high-risk, and inoperable patients with severe aortic stenosis. Third-generation, balloon-expandable transcatheter aortic valves were developed with an outer sealing skirt to reduce paravalvular leakage. As transcatheter aortic valve replacement use expands, long-term durability questions remain. Valve design influences durability, where regions of increased leaflet stress are vulnerable to early degeneration. However, third-generation transcatheter aortic valve stresses are unknown. Our goals were to determine the stent and leaflet stresses of third-generation, balloon-expandable transcatheter aortic valves.

METHODS

The commercial 26-mm Edwards SAPIEN 3 valve (Edwards Lifesciences, Inc, Irvine, Calif) underwent high-resolution micro-computed tomography scanning to develop a precise 3-dimensional geometric mesh of the stent and valve. Leaflet material properties were obtained from surgical bioprostheses, and stent material properties were based on cobalt-chromium. Simulations of systemic pressure loading were performed, and stress was calculated using finite element analyses.

RESULTS

At diastole, maximum and minimum principal stresses on transcatheter aortic valve leaflets were 2.7 MPa and -0.47 MPa, respectively. Peak leaflet stresses were observed at upper leaflet commissures, at their connection to the stent. Maximum and minimum principal stresses for the stent were 38.2 MPa and -44.4 MPa, respectively, at 80 mm Hg and were located just below the commissural stent.

CONCLUSIONS

Stress analysis of the 26-mm SAPIEN 3 valve using exact geometry from high-resolution scans demonstrated that peak stresses for both transcatheter aortic valve stent and leaflets were present at commissural tips where leaflets were attached. These regions would be most likely to initiate degeneration. The Dacron skirt had minimal effect on stresses on leaflets and stent.

Comparison of transcatheter versus surgical aortic valve implantation in high-risk patients: A nationwide study in France

OBJECTIVE

To compare the clinical outcomes and direct costs at 5 years between transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) using real-world evidence.

METHODS

We performed a nationwide longitudinal study using data from the French Hospital Information System from 2009 to 2015. We matched, inside hospitals, 2 cohorts of adults who underwent TAVI or SAVR during 2010 on propensity score based on patient characteristics. Outcomes analysis included mortality, morbidity, and total costs and with a maximum 60-month follow-up. Clinical outcomes were compared between cohorts using hazard ratios (HRs) estimated from a Cox proportional hazards model for all-cause death, and from Fine and Gray's competing risk model for morbidity.

RESULTS

Based on a cohort of 1598 patients (799 in each group) from 27 centers, a higher risk of death was observed after 1 year with TAVI compared with SAVR (16.8% vs 12.8%, respectively; HR, 1.33; 95% confidence interval [CI], 1.02-1.72) and was sustained up to 5 years (52.4% vs 37.2%; HR, 1.56; 95% CI, 1.33-1.84). At 5 years, the risk of stroke was increased (HR, 1.64; 95% CI, 1.07-2.54) as was myocardial infarction (HR, 2.30; 95% CI, 1.12-4.69) and pacemaker implantation (HR, 2.40; 95% CI, 1.81-3.17) after TAVI. The hospitalization costs per patient at 5 years were €69,083 after TAVI and €55,687 after SAVR (P < .001).

CONCLUSIONS

In our study, high-risk patients harbored a greater risk of mortality and morbidity at 5 years after TAVI compared with those who underwent SAVR and higher hospitalizations costs. Those results should encourage caution before expanding the indications of TAVI.

Evolution of Veterans Affairs Transcatheter Aortic Valve Replacement Program: The First 100 Patients

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a widely established alternative to surgery in intermediate- and high-risk patients. TAVR program development within the Veterans Affairs (VA) system has been previously described. However, national TAVR registries do not capture VA outcomes data, and few data have been reported regarding TAVR outcomes at lower-volume federal institutions. The study aim was to demonstrate the evolution of a successful VA TAVR program.

METHODS

A retrospective analysis was performed of the first 100 TAVR patients at San Francisco VA Medical Center. Mortality and major complications were evaluated.

RESULTS

Between 25th November 2013 and 31st August 2016, a total of 100 TAVR procedures was performed at the authors' institution. The mean patient age was 79.7 ± 8.7 years. Patients underwent TAVR via percutaneous-transfemoral (n = 90), surgical cutdown-transfemoral (n = 8), or transapical (n = 2) approaches. The valve systems employed were Edwards SAPIEN (n = 16), SAPIEN XT (n = 31), SAPIEN 3 (n = 23), and Medtronic CoreValve (n = 16) and CoreValve Evolut R (n = 14). The overall device success was 96%. TAVR-in-TAVR was required in the remaining 4% of patients, and was successful. All-cause procedural mortality was 1%. Complications included tamponade (1%), stroke (2%), temporary hemodialysis (1%), vascular injuries requiring intervention (4%), and permanent pacemaker implantation (14%). There were no conversions to surgical aortic valve replacement. Twenty-two (22%) patients had mild, two (2%) had moderate, and none (0%) had severe paravalvular leakage. The post-procedure aortic valve gradient by echocardiography was 8.6 ± 4.5 mmHg. Follow up was 100% complete and survival was 99%, 93%, and 89% at one, six, and 12 months, respectively.

CONCLUSIONS

Successful outcomes were demonstrated for a VA TAVR program that compared favorably with benchmarks established by the National Transcatheter Valve Therapies Registry. These results provide a necessary transparency of TAVR outcomes at a federal institution.

Stent and leaflet stresses in a 26-mm first-generation balloon-expandable transcatheter aortic valve

OBJECTIVE

Transcatheter aortic valve replacement is established therapy for high-risk and inoperable patients with severe aortic stenosis, but questions remain regarding long-term durability. Valve design influences durability. Increased leaflet stresses in surgical bioprostheses have been correlated with degeneration; however, transcatheter valve leaflet stresses are unknown. From 2007 to 2014, a majority of US patients received first-generation balloon-expandable transcatheter valves. Our goal was to determine stent and leaflet stresses in this valve design using finite element analyses.

METHODS

A 26-mm Sapien Transcatheter Heart Valve (Edwards Lifesciences, Inc, Irvine, Calif) underwent high-resolution microcomputed tomography scanning to develop precise 3-dimensional geometry of the leaflets, the stent, and the polyethylene terephthalate elements. The stent was modeled using 3-dimensional elements and the leaflets were modeled using shell elements. Stent material properties were based on stainless steel, whereas those for leaflets were obtained from surgical bioprostheses. Noncylindrical Sapien valve geometry was also simulated. Pressure loading to 80 mm Hg and 120 mm Hg was performed using ABAQUS finite element software (Dassault Systèmes, Waltham, Mass).

RESULTS

At 80 mm Hg, maximum principal stresses on Sapien leaflets were 1.31 megaspascals (MPa). Peak leaflet stress was observed at commissural tips where leaflets connected to the stent. Maximum principal stresses for the stent were 188.91 MPa and located at stent tips where leaflet commissures were attached. Noncylindrical geometry increased peak principal leaflet stresses by 16%.

CONCLUSIONS

Using exact geometry from high-resolution scans, the 26-mm Sapien Transcatheter Heart Valve showed that peak stresses for both stent and leaflets were present at commissural tips where leaflets were attached. These regions would be prone to leaflet degeneration. Understanding stresses in first-generation transcatheter valves allows comparison to future designs for relative durability.