Standardized Definition of Structural Valve Degeneration for Surgical and Transcatheter Bioprosthetic Aortic Valves

Ultrastructural Pathology of Atherosclerosis, Calcific Aortic Valve Disease, and Bioprosthetic Heart Valve Degeneration: Commonalities and Differences

Atherosclerosis, calcific aortic valve disease (CAVD), and bioprosthetic heart valve degeneration (alternatively termed structural valve deterioration, SVD) represent three diseases affecting distinct components of the circulatory system and their substitutes, yet sharing multiple risk factors and commonly leading to the extraskeletal calcification. Whereas the histopathology of the mentioned disorders is well-described, their ultrastructural pathology is largely obscure due to the lack of appropriate investigation techniques. Employing an original method for sample preparation and the electron microscopy visualisation of calcified cardiovascular tissues, here we revisited the ultrastructural features of lipid retention, macrophage infiltration, intraplaque/intraleaflet haemorrhage, and calcification which are common or unique for the indicated types of cardiovascular disease. Atherosclerotic plaques were notable for the massive accumulation of lipids in the extracellular matrix (ECM), abundant macrophage content, and pronounced neovascularisation associated with blood leakage and calcium deposition. In contrast, CAVD and SVD generally did not require vasculo- or angiogenesis to occur, instead relying on fatigue-induced ECM degradation and the concurrent migration of immune cells. Unlike native tissues, bioprosthetic heart valves contained numerous specialised macrophages and were not capable of the regeneration that underscores ECM integrity as a pivotal factor for SVD prevention. While atherosclerosis, CAVD, and SVD show similar pathogenesis patterns, these disorders demonstrate considerable ultrastructural differences.

Essential information on surgical heart valve characteristics for optimal valve prosthesis selection: expert consensus document from the European Association for Cardio-Thoracic Surgery (EACTS)–The Society of Thoracic Surgeons (STS)–American Association for Thoracic Surgery (AATS) Valve Labelling Task Force

Comprehensive information on the characteristics of surgical heart valves (SHVs) is essential for optimal valve selection. Such information is also important in assessing SHV function after valve replacement. Despite the existing regulatory framework for SHV sizing and labelling, this information is challenging to obtain in a uniform manner for various SHVs. To ensure that clinicians are adequately informed, the European Association for Cardio-Thoracic Surgery (EACTS), The Society of Thoracic Surgeons (STS) and American Association for Thoracic Surgery (AATS) set up a Task Force comprised of cardiac surgeons, cardiologists, engineers, regulatory bodies, representatives of the International Organization for Standardization and major valve manufacturers. Previously, the EACTS–STS–AATS Valve Labelling Task Force identified the most important problems around SHV sizing and labelling. This Expert Consensus Document formulates recommendations for providing SHV physical dimensions, intended implant position and haemodynamic performance in a transparent, uniform manner. Furthermore, the Task Force advocates for the introduction and use of a standardized chart to assess the probability of prosthesis–patient mismatch and calls valve manufacturers to provide essential information required for SHV choice on standardized Valve Charts, uniformly for all SHV models.

Late surgical explantation of a transcatheter heart valve in a patient with a porcelain aorta

Structural valve deterioration is a well-studied phenomenon in bioprosthetic heart valves. Conversely, structural valve deterioration after transcatheter aortic valve implantation is not as well-elucidated. Therefore, late surgical explantation after transcatheter aortic valve implantation is an infrequent procedure, and thus, surgical findings and management of such cases remain unclear, particularly in patients previously labelled as 'inoperable' or at 'high risk'. Herein, we report the case of a late surgical explantation of a transcatheter heart valve (THV) 7 years after its implantation in a patient with a porcelain aorta and periprosthetic regurgitation.

Subclinical Structural Valve Degeneration in Young Patients With Bioprosthetic Aortic Valves

BACKGROUND

Bioprosthetic structural valve degeneration (SVD) has previously been a clinical diagnosis, but subclinical changes have been increasingly recognized in transcatheter valves. The significance of subclinical SVD after surgical aortic valve replacement (SAVR), however, is not well understood. The purpose of this study was to characterize the incidence and outcomes of subclinical SVD in young patients after SAVR.

METHODS

Patients aged ≤65 years who underwent bioprosthetic SAVR between January 2002 and June 2018 at a single institution were included. Endocarditis cases and those with in-hospital mortality were excluded. All available longitudinal postoperative echocardiograms were reviewed. Subclinical SVD was defined as an increase in mean transvalvular gradient of at least 10 mm Hg and/or new onset of mild intraprosthetic regurgitation or increase by at least 1 grade, compared with baseline postoperative echocardiogram.

RESULTS

Overall, 822 unique SAVR cases were included. Over the study period, 356 (43.3%) patients developed subclinical SVD. Only 21.5% of those with subclinical SVD progressed to clinical SVD or to repeat aortic valve procedures. In those with progression, the first signs of SVD occurred significantly earlier than in those whose changes remained stable (11 months vs 23 months; P = .036). Anticoagulation did not impact the development or progression of subclinical SVD. There was no difference in long-term survival for those who did or did not develop subclinical SVD.

CONCLUSIONS

Subclinical SVD occurred in a large proportion of young patients undergoing bioprosthetic SAVR. Despite its high prevalence, subclinical SVD was not associated with decreased survival or repeat procedures.

Degeneration of Bioprosthetic Heart Valves: Update 2020

The implantation of bioprosthetic heart valves (BHVs) is increasingly becoming the treatment of choice in patients requiring heart valve replacement surgery. Unlike mechanical heart valves, BHVs are less thrombogenic and exhibit superior hemodynamic properties. However, BHVs are prone to structural valve degeneration (SVD), an unavoidable condition limiting graft durability. Mechanisms underlying SVD are incompletely understood, and early concepts suggesting the purely degenerative nature of this process are now considered oversimplified. Recent studies implicate the host immune response as a major modality of SVD pathogenesis, manifested by a combination of processes phenocopying the long‐term transplant rejection, atherosclerosis, and calcification of native aortic valves. In this review, we summarize and critically analyze relevant studies on (1) SVD triggers and pathogenesis, (2) current approaches to protect BHVs from calcification, (3) obtaining low immunogenic BHV tissue from genetically modified animals, and (4) potential strategies for SVD prevention in the clinical setting.

Bioprosthetic valve thrombosis and degeneration following transcatheter aortic valve implantation (TAVI)

Bioprosthetic valve thrombosis (BPVT) is a recognised complication of prosthetic aortic valves and can be found in up to 13% of patients after transcatheter implantation. The mechanism of BPVT is not well known, abnormal flow conditions in the new and native sinuses and lack of functional endothelialisation are suspected causes. BPVT may result in valve dysfunction, possibly related to degeneration, and recurrence of patient symptoms, or remain subclinical. BPVT is best diagnosed at multiphase gated computed tomography (CT) angiography as the presence of reduced leaflet motion (RELM) and hypoattenuating aortic leaflet thickening (HALT). Although CT is used to exclude BPVT in symptomatic patients and those with increased valve gradients, the value of screening and prophylactic anticoagulation is debatable.

Glycation and Serum Albumin Infiltration Contribute to the Structural Degeneration of Bioprosthetic Heart Valves

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Two novel and interacting mechanisms contributing to BHV SVD are reported: glycation and serum albumin infiltration.

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Glycation product formation and serum albumin deposition were observed in 45 clinical BHV explanted due to SVD as well as BHV tissue subcutaneously implanted in rats.

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In vitro exposure to glycation and serum albumin elicited collagen network misalignment similar to that seen in clinical and rat explant BHV tissue.

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Glycation was sufficient to impair BHV hydrodynamic function in ISO-5840-compliant pulse duplication testing and concomitant serum albumin infiltration exacerbated these effects.

Valvular heart diseases are associated with significant cardiovascular morbidity and mortality, and often require surgical and/or percutaneous repair or replacement. Valve replacement is limited to mechanical and biological prostheses, the latter of which circumvent the need for lifelong anticoagulation but are subject to structural valve degeneration (SVD) and failure. Although calcification is heavily studied, noncalcific SVD, which represent roughly 30% of BHV failures, is relatively underinvestigated. This original work establishes 2 novel and interacting mechanisms—glycation and serum albumin incorporation—that occur in clinical valves and are sufficient to induce hallmarks of structural degeneration as well as functional deterioration.

Possible Link Between the ABO Blood Group of Bioprosthesis Recipients and Specific Types of Structural Degeneration

Background Pigs/bovines share common antigens with humans: α-Gal, present in all pigs/bovines close to the human B-antigen; and AH-histo-blood-group antigen, identical to human AH-antigen and present only in some animals. We investigate the possible impact of patients' ABO blood group on bioprosthesis structural valve degeneration (SVD) through calcification/pannus/tears/perforations for patients ≤60 years at implantation. Methods and Results This was a single-center study (Paris, France) that included all degenerative bioprostheses explanted between 1985 and 1998, mostly porcine bioprostheses (Carpentier-Edwards second/third porcine bioprostheses) and some bovine bioprostheses. For the period 1998 to 2014, only porcine bioprostheses with longevity ≥13 years were included (total follow-up ≥29 years). Except for blood groups, important predictive factors for SVD were prospectively collected (age at implantation/longevity/number/site/sex/SVD types) and analyzed using logistic regression. All variables were available for 500 explanted porcine bioprostheses. By multivariate analyses, the A group was associated with an increased risk of: tears (odds ratio[OR], 1.61; P=0.026); pannus (OR, 1.5; P=0.054), pannus with tears (OR, 1.73; P=0.037), and tendency for lower risk of: calcifications (OR, 0.63; P=0.087) or isolated calcification (OR, 0.67; P=0.17). A-antigen was associated with lower risk of perforations (OR 0.56; P=0.087). B-group patients had an increased risk of: perforations (OR, 1.73; P=0.043); having a pannus that was calcified (OR, 3.0, P=0.025). B-antigen was associated with a propensity for calcifications in general (OR, 1.34; P=0.25). Conclusions Patient's ABO blood group is associated with specific SVD types. We hypothesize that carbohydrate antigens, which may or may not be common to patient and animal bioprosthetic tissue, will determine a patient's specific immunoreactivity with respect to xenograft tissue and thus bioprosthesis outcome in terms of SVD.

Midterm Degeneration of Transcatheter Heart Valve Device following Valve-in-Valve Transcatheter Aortic Valve Replacement Requiring Repeat Transcatheter Aortic Valve Replacement

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ViV-TAVR is an alternative to redo-SAVR in patients with a degenerate surgical bioprosthesis.

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Optimal TAVR device positioning is crucial in determining procedural durability.

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TAVR-in-TAVR can be performed to treat a degenerated ViV-TAVR device.

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Coronary obstruction, limited coronary access, and device thrombosis may occur.

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

Background:

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.

Methods:

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).

Results:

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.

Conclusions:

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.

Valve-in-Valve for Degenerated Transcatheter Aortic Valve Replacement Versus Valve-in-Valve for Degenerated Surgical Aortic Bioprostheses: A 3-Center Comparison of Hemodynamic and 1-Year Outcome

Background

As transcatheter aortic valve replacement (TAVR) is expected to progress into younger patient populations, valve‐in‐TAVR (ViTAVR) may become a frequent consideration. Data on ViTAVR, however, are limited. This study investigated the outcome of ViTAVR in comparison to valve in surgical aortic valve replacement (ViSAVR), because ViSAVR is an established procedure for higher‐risk patients requiring repeated aortic valve intervention.

Methods and Results

Clinical and procedural data of patients who underwent ViTAVR at 3 sites in the United States and Germany were retrospectively compared with data of patients who underwent ViSAVR at Cedars‐Sinai Medical Center, according to Valve Academic Research Consortium‐2 criteria. A total of 99 consecutive patients, 52.5% women, with a median Society of Thoracic Surgeons score of 7.2 were identified. Seventy‐four patients (74.7%) underwent ViSAVR, and 25 patients (25.3%) underwent ViTAVR. Balloon‐expandable devices were used in 72.7%. ViSAVR patients presented with smaller index devices (21.0 versus 26.0 mm median true internal diameter; P<0.001). Significantly better postprocedural hemodynamics (median prosthesis mean gradient, 12.5 [interquartile range, 8.8–16.2] versus 16.0 [interquartile range, 13.0–20.5] mm Hg; P=0.045) were observed for ViTAVR compared with the ViSAVR. Device success, however, was not different (79.2% and 66.2% for ViTAVR and ViSAVR, respectively; P=0.35), as were rates of permanent pacemaker implantation (16.7% versus 5.4%; P=0.1). One‐year‐mortality was 9.4% and 13.4% for ViTAVR and ViSAVR, respectively (log‐rank P=0.38).

Conclusions

Compared with ViSAVR, ViTAVR provides acceptable outcomes, with slightly better hemodynamics, similar device success rates, and similar 1‐year mortality.

Stentless Pericarbon Freedom Versus Stented Perimount Aortic Bioprosthesis: Propensity-Matched Long-Term Follow-Up

OBJECTIVE

Stentless aortic valves have shown superior hemodynamic performance and faster left ventricular mass regression compared to stented bioprostheses. Yet, controversies exist concerning the durability of stentless valves. This case-matched study compared short- and long-term clinical outcomes of stentless LivaNova-Sorin Pericarbon Freedom™ (SPF) and stented Carpentier-Edwards Perimount (CEP) aortic prostheses.

METHODS

From 2003 through 2006, 134 consecutive patients received aortic valve replacement with SPF at our institution. This cohort was matched, according to 20 preoperative clinical parameters, with a control group of 390 patients who received CEP prosthesis during the same time. The resulting 55 + 55 matched patients were analyzed for perioperative results and long-term clinical outcomes.

RESULTS

Early mortality was 0% for both groups. Lower transvalvular gradients were found in the SPF group (10.6 ± 2.9 versus 15.7 ± 3.1 mmHg, P < 0.001). Overall late mortality (mean follow-up: 10.03 years) was similar for both groups (50.1% versus 42.8%, P = 0.96). Freedom from structural valve degeneration (SVD) at 13 years was similar for both groups (SPF = 92.3%, CEP = 73.9%, P = 0.06). Freedom from aortic valve reinterventions did not differ (SPF = 92.3%, CEP = 93.5%, P = 0.55). Gradients at 13-year follow-up remained significantly lower in SPF group (10.0 ± 4.5 versus 16.2 ± 9.5 mmHg, P < 0.001). Incidence of acute bacterial endocarditis (ABE) and major adverse cardiovascular and cerebrovascular events (MACCE) was similar.

CONCLUSIONS

SPF and CEP demonstrated comparable long-term outcomes related to late mortality, SVD, aortic valve reinterventions, and incidence of ABE and MACCE. Superior hemodynamic performance of SPF over time can make this valve a suitable choice in patients with small aortic root and large body surface area.

Right anterior mini-thoracotomy and sutureless valves: the perfect marriage

Background

A minimally invasive approach (MIA) reduces mortality and morbidity in patients referred for aortic valve replacement (AVR). Sutureless technology facilitates a MIA. We describe our experience with the sutureless Perceval (LivaNova, Italy) aortic bioprosthesis through a right anterior mini-thoracotomy (RAMT) approach.

Methods

Between March 2011 and October 2019, 1,049 patients underwent AVR with Perceval bioprosthesis. Five hundred and three patients (48%) were operated through a RAMT approach in the second intercostal space. Considering only isolated AVR (881), 98% of patients were operated with MIA, and Perceval in RAMT approach was performed in 57% of these patients. Eight patients (1.6%) had previously undergone cardiac surgery. The prosthesis sizes implanted were: S (n=91), M (n=154), L (n=218) and XL (n=40). Concomitant procedures were mitral valve surgery (n=6), tricuspid valve repair (n=1), mitral valve repair and tricuspid valve repair (n=1) and miectomy (n=2). Mean age was 78±4 years (range, 65-89 years), 317 patients were female (63%) and EuroSCORE II was 5.9%±8.4%.

Results

The 30-day mortality was 0.8% (4/503). Cardiopulmonary bypass (CPB) and aortic cross-clamp times were 81.6±30.8 and 50.3±24.5 minutes respectively for stand-alone procedures. In two patients, early moderate paravalvular leakage appeared as a result of incomplete expansion of the sutureless valve due to oversizing of the bioprosthesis, requiring reoperations at two and nine postoperative days with sutured aortic bioprosthesis implantation. Permanent pacemaker implantation within the first thirty days was necessary in 26 (5.2%) patients. At the mean follow-up of 4.6 years (range, 1 month to 8.6 years), survival was 96%, freedom from reoperation was 99.2%, and mean transvalvular pressure gradient was 11.9±4.3 mmHg.

Conclusions

AVR with the Perceval bioprosthesis in a RAMT approach is a safe and feasible procedure associated with low mortality and excellent hemodynamic performance. Sutureless technology facilitates a RAMT approach.

Long-term outcomes after transcatheter aortic valve implantation in failed bioprosthetic valves

Aims

Due to bioprosthetic valve degeneration, aortic valve-in-valve (ViV) procedures are increasingly performed. There are no data on long-term outcomes after aortic ViV. Our aim was to perform a large-scale assessment of long-term survival and reintervention after aortic ViV.

Methods and results

A total of 1006 aortic ViV procedures performed more than 5 years ago [mean age 77.7 ± 9.7 years; 58.8% male; median STS-PROM score 7.3% (4.2–12.0)] were included in the analysis. Patients were treated with Medtronic self-expandable valves (CoreValve/Evolut, Medtronic Inc., Minneapolis, MN, USA) (n = 523, 52.0%), Edwards balloon-expandable valves (EBEV, SAPIEN/SAPIEN XT/SAPIEN 3, Edwards Lifesciences, Irvine, CA, USA) (n = 435, 43.2%), and other devices (n = 48, 4.8%). Survival was lower at 8 years in patients with small-failed bioprostheses [internal diameter (ID) ≤ 20 mm] compared with those with large-failed bioprostheses (ID &gt; 20 mm) (33.2% vs. 40.5%, P = 0.01). Independent correlates for mortality included smaller-failed bioprosthetic valves [hazard ratio (HR) 1.07 (95% confidence interval (CI) 1.02–1.13)], age [HR 1.21 (95% CI 1.01–1.45)], and non-transfemoral access [HR 1.43 (95% CI 1.11–1.84)]. There were 40 reinterventions after ViV. Independent correlates for all-cause reintervention included pre-existing severe prosthesis–patient mismatch [subhazard ratio (SHR) 4.34 (95% CI 1.31–14.39)], device malposition [SHR 3.75 (95% CI 1.36–10.35)], EBEV [SHR 3.34 (95% CI 1.26–8.85)], and age [SHR 0.59 (95% CI 0.44–0.78)].

Conclusions

The size of the original failed valve may influence long-term mortality, and the type of the transcatheter valve may influence the need for reintervention after aortic ViV.

Long-term follow-up of the Shelhigh™ superstentless bioprosthesis aortic valve and valved conduit in a monocentric experience

BACKGROUND

The Shelhigh™ SuperStentless (Shelhigh, INC., Union, NJ, USA) is a stentless aortic valve bioprosthesis and aortic root valved conduit. In 2007, this device was recalled by FDA due to malfunction, and subsequently reintegrated by BioIntegral Surgical™ Few data are available over late durability of this device. We performed a long-term follow-up of Shelhigh™ devices implanted at our center.

METHODS

Between 2002 and 2007, 44 patients underwent aortic valve replacement with a Shelhigh™ device (40 aortic valve bioprosthesis and 4 valved conduit). We performed a clinical and echocardiographic follow-up (9.2 years±4.3). Standardized definitions of valve-related events were adopted.

RESULTS

At discharge, maximum and mean aortic gradients averaged 36.1±11.3 and 21.0±6.8 mmHg, respectively. The 30-days mortality was 2.3%. Over the follow-up period, 29 patients died (65.9%); 2 deaths were valve related. Overall survival at 1, 5 and 10 years was 97.7%, 85.8% and 54% respectively. At last echocardiography, average transvalvular gradients had remained globally stable in the population (33.6±12 and 20.4±10.5 mmHg). Eight (19%) structural valve deterioration (SVD) events were reported. Two (5%) non-structural valve dysfunction (NSVD) events occurred (periprosthetic leak). Two (5%) infectious endocarditis events and two (5%) valve thromboses were also deplored. Three (7%) patients required re-operation (2 due to SVD and 1 due to endocarditis).

CONCLUSIONS

The immediate hemodynamic performance of the Shelhigh™ aortic bioprostheses was unexpectedly suboptimal. Despite this, hemodynamic performance remained stable over time. Patients survival at follow-up was satisfactory, however, continued surveillance is necessary.

Structural durability of early-generation Transcatheter aortic valve replacement valves compared with surgical aortic valve replacement valves in heart valve surgery: a systematic review and meta-analysis

Background

The current treatment for aortic stenosis includes open surgical aortic valve replacement (SAVR) as well as endovascular transcatheter aortic valve replacement (TAVR). This study aims to compare the 1-year, 2–3 year and 5-year structural durability of TAVR valves with that of SAVR valves.

Method

A systematic literature search was conducted in July 2019 on Medline (via PubMed), Embase and Cochrane electronic databases according to the PRISMA guidelines.

Results

Thirteen randomized controlled trials were included. From the meta-analysis, we observed higher rates of 1-year (OR: 7.65, CI: 4.57 to 12.79, p < 0.00001), 2–3-year (OR: 13.49, CI: 5.66 to 32.16, p < 0.00001) and 5-year paravalvular regurgitation (OR: 14.51, CI: 4.47 to 47.09, p < 0.00001) associated with the TAVR valves than the SAVR valves. There were also higher rates of 1-year (OR: 5.00, CI: 3.27 to 7.67, p < 0.00001), 2–3-year (OR: 8.14, CI: 3.58 to 18.50, p < 0.00001) and 5-year moderate or severe aortic regurgitation (MD: 14.65, CI: 4.55 to 47.19, p < 0.00001), and higher rates of 1-year (OR: 3.55, CI: 1.86 to 6.77, p = 0.0001), 2–3-year (OR: 3.55, CI: 1.86 to 6.77, p = 0.0001) and 5-year reintervention (OR: 3.55, CI: 1.22 to 10.38, p = 0.02) in the TAVR valves as compared to SAVR valves.

Conclusion

TAVR valves appear to be more susceptible to structural valve deterioration and thus potentially less structurally durable than SAVR valves, given that they may be associated with higher rates of moderate or severe aortic regurgitation, paravalvular regurgitation and reintervention in the 1-year-, 2–3 year, and 5-year period.

Stent and leaflet stresses across generations of balloon-expandable transcatheter aortic valves

OBJECTIVES

Transcatheter aortic valve replacement (TAVR) is established therapy for severe aortic stenosis patients with intermediate-, high- and prohibitive-risk for surgery. A significant challenge when expanding TAVR to low-risk and younger patients is the unknown long-term durability. High leaflet stresses have been associated with surgical bioprosthetic valve degeneration. In this study, we examined the impact of changes in valve design across 3 generations of same-sized TAVR devices on stent and leaflet stresses.

METHODS

The 26-mm Edwards SAPIEN, 23, 26 and 29 mm SAPIEN XT (XT) and 26 mm SAPIEN 3 (S3) (n = 1 each) underwent micro-computed tomography (micro-CT) scanning. Dynamic finite element computational simulations of 23-26 mm SAPIEN, 23-29 mm XT and 23-29 mm S3 were performed with physiological loading and micro-CT or scaled geometries.

RESULTS

Peak stresses were concentrated in the commissure area and along the bottom of the suture, representing areas most likely to develop structural valve degeneration across TAVR generations. Latest-generation S3 showed greatest 99th percentile principal stress on commissural leaflets for 26 and 29 mm, and increased stresses over XT for 23 mm. Percentage of higher stress areas within the leaflets steadily increased across generations, 3.8%, 3.9% and 5.7%, respectively, for 26 mm SAPIEN, XT and S3 with similar trend for 29-mm valves.

CONCLUSIONS

Using computational simulations based on high-fidelity modelling of balloon-expandable TAVRs, our study demonstrated that maximum stress areas existed in similar leaflet locations across SAPIEN generations, while the latest model S3 had the highest magnitude for both 26- and 29-mm valves. S3 also had the largest area of higher stresses than other generations, which would be prone to degeneration. Our study coupled with future long-term clinical outcomes >10 years will provide insight on biomechanics of TAVR degeneration.

Durability of bioprosthetic aortic valves in patients under the age of 60 years - rationale and design of the international INDURE registry

BACKGROUND

There is an ever-growing number of patients requiring aortic valve replacement (AVR). Limited data is available on the long-term outcomes and structural integrity of bioprosthetic valves in younger patients undergoing surgical AVR.

METHODS

The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, open-label, multicentre, international registry with a follow-up of 5 years to assess clinical outcomes of patients younger than 60 years who undergo surgical AVR using the INSPIRIS RESILIA aortic valve. INDURE will be conducted across 20-22 sites in Europe and Canada and intends to enrol minimum of 400 patients. Patients will be included if they are scheduled to undergo AVR with or without concomitant root replacement and/or coronary bypass surgery. The primary objectives are to 1) determine VARC-2 defined time-related valve safety at one-year (depicted as freedom from events) and 2) determine freedom from stage 3 structural valve degeneration (SVD) presenting as morphological abnormalities and severe haemodynamic valve degeneration at 5 years. Secondary objectives include the assessment of the haemodynamic performance of the valve, all stages of SVD, potential valve-in-valve procedures, clinical outcomes (in terms of New York Heart Association [NYHA] function class and freedom from valve-related rehospitalisation) and change in patient quality-of-life.

DISCUSSION

INDURE is a prospective, multicentre registry in Europe and Canada, which will provide much needed data on the long-term performance of bioprosthetic valves in general and the INSPIRIS RESILIA valve in particular. The data may help to gather a deeper understanding of the longevity of bioprosthetic valves and may expand the use of bioprosthetic valves in patients under the age of 60 years.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03666741 (registration received September, 12th, 2018).

Anticoagulation After Surgical or Transcatheter Bioprosthetic Aortic Valve Replacement

BACKGROUND

There is paucity of evidence on the impact of anticoagulation (AC) after bioprosthetic aortic valve replacement (AVR) on valve hemodynamics and clinical outcomes.

OBJECTIVES

The study aimed to assess the impact of AC after bioprosthetic AVR on valve hemodynamics and clinical outcomes.

METHODS

Data on antiplatelet and antithrombotic therapy were collected. Echocardiograms were performed at 30 days and 1 year post-AVR. Linear regression model and propensity-score adjusted cox proportional model were used to assess the impact of AC on valve hemodynamics and clinical outcomes, respectively.

RESULTS

A total of 4,832 patients undergoing bioprosthetic AVR (transcatheter aortic valve replacement [TAVR], n = 3,889 and surgical AVR [SAVR], n = 943) in the pooled cohort of PARTNER2 (Placement of Aortic Transcatheter Valves) randomized trials and nonrandomized registries were studied. Following adjustment for valve size, annular diameter, atrial fibrillation, and ejection fraction at the time of assessment of hemodynamics, there was no significant difference in aortic valve mean gradients or aortic valve areas between patients discharged on AC vs. those not discharged on AC, for either TAVR or SAVR cohorts. A significantly greater proportion of patients not discharged on AC had an increase in mean gradient >10 mm Hg from 30 days to 1 year, compared with those discharged on AC (2.3% vs. 1.1%, p = 0.03). There was no independent association between AC after TAVR and adverse outcomes (death, p = 0.15; rehospitalization, p = 0.16), whereas AC after SAVR was associated with significantly fewer strokes (hazard ratio [HR]: 0.17; 95% confidence interval [CI]: 0.05-0.60; p = 0.006).

CONCLUSIONS

In the short term, early AC after bioprosthetic AVR did not result in adverse clinical events, did not significantly affect aortic valve hemodynamics (aortic valve gradients or area), and was associated with decreased rates of stroke after SAVR (but not after TAVR). Whether early AC after bioprosthetic AVR has impact on long-term outcomes remains to be determined. (Placement of AoRTic TraNscathetER Valves [PARTNERII A]; NCT01314313).

Echocardiographic Results of Transcatheter Versus Surgical Aortic Valve Replacement in Low-Risk Patients

Background:

This study aimed to compare echocardiographic findings in low-risk patients with severe aortic stenosis after surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).

Methods:

The PARTNER 3 trial (Placement of Aortic Transcatheter Valves) randomized 1000 patients with severe aortic stenosis and low surgical risk to undergo either transfemoral TAVR with the balloon-expandable SAPIEN 3 valve or SAVR. Transthoracic echocardiograms obtained at baseline and at 30 days and 1 year after the procedure were analyzed by a consortium of 2 echocardiography core laboratories.

Results:

The percentage of moderate or severe aortic regurgitation (AR) was low and not statistically different between the TAVR and SAVR groups at 30 days (0.8% versus 0.2%; P =0.38). Mild AR was more frequent after TAVR than SAVR at 30 days (28.8% versus 4.2%; P <0.001). At 1 year, mean transvalvular gradient (13.7±5.6 versus 11.6±5.0 mm Hg; P =0.12) and aortic valve area (1.72±0.37 versus 1.76±0.42 cm 2 ; P =0.12) were similar in TAVR and SAVR. The percentage of severe prosthesis–patient mismatch at 30 days was low and similar between TAVR and SAVR (4.6 versus 6.3%; P =0.30). Valvulo-arterial impedance (Z va ), which reflects total left ventricular hemodynamic burden, was lower with TAVR than SAVR at 1 year (3.7±0.8 versus 3.9±0.9 mm Hg/mL/m 2 ; P <0.001). Tricuspid annulus plane systolic excursion decreased and the percentage of moderate or severe tricuspid regurgitation increased from baseline to 1 year in SAVR but remained unchanged in TAVR. Irrespective of treatment arm, high Z va and low tricuspid annulus plane systolic excursion, but not moderate to severe AR or severe prosthesis–patient mismatch, were associated with increased risk of the composite end point of mortality, stroke, and rehospitalization at 1 year.

Conclusions:

In patients with severe aortic stenosis and low surgical risk, TAVR with the SAPIEN 3 valve was associated with similar percentage of moderate or severe AR compared with SAVR but higher percentage of mild AR. Transprosthetic gradients, valve areas, percentage of severe prosthesis–patient mismatch, and left ventricular mass regression were similar in TAVR and SAVR. SAVR was associated with significant deterioration of right ventricular systolic function and greater tricuspid regurgitation, which persisted at 1 year. High Z va and low tricuspid annulus plane systolic excursion were associated with worse outcome at 1 year whereas AR and severe prosthesis–patient mismatch were not.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02675114.

Hypo-attenuated leaflet thickening in surgically-implanted mitral bioprosthesis

Background

Hypo-attenuated leaflet thickening (HALT) in bioprosthetic aortic valve has been studied, but its equivalent in bioprosthetic mitral valve (bMV) remains uncharacterized. We sought to identify the prevalence, hemodynamic characteristics, and significance of anticoagulation therapy in bMV HALT.

Methods

A single-center cross-sectional study of 53 consecutive patients who underwent mitral valve replacement (MVR) with bMV between 2007 and 2017 was conducted. Cardiac-gated contrasted CT scans were obtained. Anticoagulant and antiplatelet therapy use were ascertained at the time of hospital discharge and CT scanning. Patient characteristics, postoperative stroke, and hemodynamic profile by echocardiogram were obtained to descriptively characterize the prevalence and characteristics associated with bMV HALT.

Results

Three patients (5.7%) were found to have a HALT on bMV. The mean time from index MVR to CT scan was 3.4 ± 0.8 years in HALT cohort and 3.4 ± 2.7 years in non-HALT cohort. Fifty patients (94.3%) were discharged on warfarin, and 37 patients (69.8%) were on warfarin at the time of CT scans. One patient with HALT was on therapeutic warfarin at the time of the CT scan that identified HALT. All three patients were asymptomatic at the time of CT scan. In patients with HALT, mean transmitral pressure gradient were 8, 5, and 2.7 mmHg, all with trivial or mild mitral regurgitation.

Conclusions

In this study, the prevalence of HALT was low at 5.7%, all presenting without symptoms. One patient presented with HALT while on therapeutic oral anticoagulation, which may suggest thrombotic etiology may not adequately explain HALT.

3-Year Outcomes After Valve-in-Valve Transcatheter Aortic Valve Replacement for Degenerated Bioprostheses: The PARTNER 2 Registry

BACKGROUND

Transcatheter aortic valve replacement (TAVR) for degenerated surgical bioprosthetic aortic valves is associated with favorable early outcomes. However, little is known about the durability and longer-term outcomes associated with this therapy.

OBJECTIVES

The aim of this study was to examine late outcomes after valve-in-valve TAVR.

METHODS

Patients with symptomatic degeneration of surgical aortic bioprostheses at high risk (≥50% major morbidity or mortality) for reoperative surgery were prospectively enrolled in the multicenter PARTNER (Placement of Aortic Transcatheter Valves) 2 valve-in-valve and continued access registries. Three-year clinical and echocardiographic follow-up was obtained.

RESULTS

Valve-in-valve procedures were performed in 365 patients. The mean age was 78.9 ± 10.2 years, and the mean Society of Thoracic Surgeons score was 9.1 ± 4.7%. At 3 years, the overall Kaplan-Meier estimate of all-cause mortality was 32.7%. Aortic valve re-replacement was required in 1.9%. Mean transaortic gradient was 35.0 mm Hg at baseline, decreasing to 17.8 mm Hg at 30-day follow-up and 16.6 mm Hg at 3-year follow-up. Baseline effective orifice area was 0.93 cm², increasing to 1.13 and 1.15 cm² at 30 days and 3 years, respectively. Moderate to severe aortic regurgitation was reduced from 45.1% at pre-TAVR baseline to 2.5% at 3 years. Importantly, moderate or severe mitral and tricuspid regurgitation also decreased (33.7% vs. 8.6% [p < 0.0001] and 29.7% vs. 18.8% [p = 0.002], respectively). Baseline left ventricular ejection fraction was 50.7%, increasing to 54.7% at 3 years (p < 0.0001), while left ventricular mass index was 136.4 g/m², decreasing to 109.1 g/m² at 3 years (p < 0.0001). New York Heart Association functional class improved, with 90.4% in class III or IV at baseline and 14.1% at 3 years (p < 0.0001), and Kansas City Cardiomyopathy Questionnaire overall score increased (43.1 to 73.1; p < 0.0001).

CONCLUSIONS

At 3-year follow-up, TAVR for bioprosthetic aortic valve failure was associated with favorable survival, sustained improved hemodynamic status, and excellent functional and quality-of-life outcomes. (The PARTNER II Trial: Placement of Aortic Transcatheter Valves II - PARTNER II - Nested Registry 3/Valve-in-Valve [PII NR3/ViV]; NCT03225001).

Hemodynamic and Imaging Assessment of Transcatheter Aortic Valve Replacement with the Inovare® Proseal using Multislice Computed Tomography

Objective

To evaluate the hemodynamic performance (i.e., gradients and paravalvular leakage [PVL]) of the new and experimental Braile Inovare^® Proseal. Additionally, we aimed to assess pre and postoperatively the aortic annulus and the transcatheter prosthesis using multislice computed tomography (MSCT).

Methods

Patients were selected by a multidisciplinary heart team and referred for transcatheter aortic valve replacement (TAVR). MSCT was performed before and after surgery. Measurements of the aortic valve and prosthesis were conducted and correlated with the valve gradient and residual PVL.

Results

Twenty-one patients were selected for the protocol. Patients had a mean age of 79 years and 38% of them were of female sex. The mean EuroSCORE II value was 12.5%±10.8. Mean gradient was reduced from 45.8±11.04 mmHg to 5.59±2.61 mmHg and there were no instances of PVL worse than mild. There were no cases of coronary obstruction or procedural death. Circularity was present in all prostheses evaluated. Circularity indexes for the prostheses were: inflow 0.05±0.03, middle third 0.04±0.02, and outflow 0.04±0.02 (P=0.08). The mean distance between the prosthesis and the left and right coronary ostia were 14.8 mm±3.3 and 17.3 mm±3, respectively. Oversizing was appropriate with a mean of 22.14%±6%.

Conclusion

Braile Inovare^® Proseal transcatheter device has demonstrated low gradients with low rates of PVL. Oversizing by annular measurements was adequate. MSCT was adequate to evaluate device sizing and has demonstrated preserved expansibility and circularity in the evaluated cases.

Commissural fusion as etiology of bioprosthetic mitral stenosis in a patient with rheumatic heart disease

We report commissural fusion as a unique morphologic etiology of early bioprosthetic mitral valve failure in a woman with a history of rheumatic mitral stenosis. She had undergone mitral valve replacement with a 25-mm Edwards Magna Ease bovine pericardial bioprosthesis 3 years earlier and presented with progressive dyspnea. Transesophageal echocardiography revealed severe bioprosthetic stenosis due to commissural fusion. She underwent percutaneous valve-in-valve implantation with a 26-mm Edwards Sapien 3 prosthesis. Marked symptomatic improvement was noted postprocedurally. We speculate that commissural fusion may be a unique pathologic feature of failing bioprosthetic valves in patients with prior rheumatic mitral valve disease.

Untreatable Severe Structural Degeneration of a Transcatheter Aortic Heart Valve

We describe a patient who presented with heart failure 7 years post-transcatheter aortic valve implantation (TAVI) as a result of severe structural valve degeneration. Anatomic challenges, combined with the type of transcatheter heart valve used initially, meant that TAVI-in-TAVI risked obstructing the coronary arteries, even if preceded by bioprosthetic aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction. The patient was treated with balloon aortic valvuloplasty.

Sterilization and Cross-Linking Combined with Ultraviolet Irradiation and Low-Energy Electron Irradiation Procedure: New Perspectives for Bovine Pericardial Implants in Cardiac Surgery

BACKGROUND

 Bovine pericardium is the major natural source of patches and aortic valve substitutes in cardiac repair procedures. However, long-term tissue durability and biocompatibility issues lead to degeneration (e.g., calcification) that requires reoperation. Tissue preparation strategies, including glutaraldehyde fixation, are reasons for the deterioration of pericardial tissues. We describe a pretreatment procedure involving sterilization and cross-linking combined with ultraviolet (UV) irradiation and low-energy electron irradiation (SULEEI). This innovative, glutaraldehyde-free protocol improves the mechanical aspects and biocompatibility of porcine pericardium patches.

METHODS

 We adopted the SULEEI protocol, which combines decellularization, sterilization, and cross-linking, along with UV irradiation and low-energy electron irradiation, to pretreat bovine pericardium. Biomechanics, such as ultimate tensile strength and elasticity, were investigated by comparing SULEEI-treated tissue with glutaraldehyde-fixed analogues, clinical patch materials, and an aortic valve substitute. Histomorphological and cellular aspects were investigated by histology, DNA content analysis, and degradability.

RESULTS

 Mechanical parameters, including ultimate tensile strength, elasticity (Young's modulus), and suture retention strength, were similar for SULEEI-treated and clinically applied bovine pericardium. The SULEEI-treated tissues showed well-preserved histoarchitecture that resembled all pericardial tissues investigated. Fiber density did not differ significantly. DNA content after the SULEEI procedure was reduced to less than 10% of the original tissue material, and more than 50% of the SULEEI-treated pericardium was digested by collagenase.

CONCLUSION

 The SULEEI procedure represents a new treatment protocol for the preparation of patches and aortic valve prostheses from bovine pericardial tissue. The avoidance of glutaraldehyde fixation may lessen the tissue degeneration processes in cardiac repair patches and valve prostheses.

Durability of transcatheter aortic valve implantation: A translational review

Until recently, transcatheter aortic valve implantation was restricted to high-risk and inoperable patients. The updated 2017 European Society of Cardiology Guidelines has widened the indication to include intermediate-risk patients, based on two recently published trials (PARTNER 2 and SURTAVI). Moreover, two other recent trials (PARTNER 3 and EVOLUT LOW RISK) have demonstrated similar results with transcatheter aortic valve implantation in low-risk patients. Thus, extension of transcatheter aortic valve implantation to younger patients, who are currently treated by surgical aortic valve replacement, raises the crucial question of bioprosthesis durability. In this translational review, we propose to produce a state-of-the-art overview of the durability of transcatheter aortic valve implantation by integrating knowledge of the basic science of bioprosthesis degeneration (pathophysiology and biomarkers). After summarising the new definition of structural valve deterioration, we will present what is known about the pathophysiology of aortic stenosis and bioprosthesis degeneration. Next, we will consider how to identify a population at risk of early degeneration, and how basic science with the help of biomarkers could identify and predict structural valve deterioration. Finally, we will present data on the differences in durability of transcatheter aortic valve implantation compared with surgical aortic valve replacement.

Biomarkers of aortic bioprosthetic valve structural degeneration

PURPOSE OF REVIEW

Bioprosthetic valves are now used for the majority of surgical aortic valve replacements and for all transcatheter aortic valve replacements. However, bioprostheses are subject to structural valve deterioration (SVD) and have, therefore limited durability.

RECENT FINDINGS

Clinical, imaging, and circulating biomarkers may help to predict or indicate the presence of bioprosthetic valve SVD. The most important biomarkers of SVD includes: patient-related clinical biomarkers, such as diabetes and renal failure; valve-related biomarkers, such as absence of antimineralization process and severe prosthesis-patient mismatch; imaging biomarkers: the presence of valve leaflet mineralization on multidetector computed tomography or sodium fluoride uptake on positron emission tomography; and circulating biomarkers including: increased levels of HOMA index, ApoB/ApoA-I ratio, PCSK9, Lp-PLA2, phosphocalcic product. The assessment of these biomarkers may help to enhance risk stratification for SVD following AVR and may contribute to open novel pharmacotherapeutic avenues for the prevention of SVD.

SUMMARY

SVD may affect all bioprostheses after aortic valve replacement, and is the main cause of bioprosthetic valve failure and reintervention during the follow-up. Comprehensive assessment of clinical, imaging, and circulating biomarkers associated with earlier SVD could help strengthen the follow-up in high-risk patients and provide novel pharmacologic therapeutic strategies.

Transcatheter aortic valve replacement in low risk patients: a review of PARTNER 3 and Evolut low risk trials

Transcatheter aortic valve replacement (TAVR) has become a mainstay in treatment for patients with severe aortic stenosis who are considered high-risk surgical candidates. The use of TAVR in low-risk patients with severe aortic stenosis is being explored as an alternative to surgical aortic valve replacement (SAVR). Recent results from the Medtronic Evolut Low Risk trial and the Placement of Aortic Transcatheter Valves (PARTNER) 3 trial shed light on the use of TAVR in low-risk surgical candidates. The Evolut Low Risk trial compared TAVR with a self-expanding supra-annular bioprosthesis to SAVR in 1468 patients with severe aortic stenosis who were low surgical risk. Patients with a mean age of 74 and a mean Society of Thoracic Surgeons (STS) risk score of 1.9% were randomized to either TAVR or SAVR groups. Using the composite end point of death or disabling stroke at 24 months, the study found an incidence of 5.3% in the TAVR arm and 6.7% in the surgical arm. The Evolut Low Risk trial thus concluded that TAVR was statistically noninferior but not superior to SAVR (difference, -1.4 percentage points; 95% Bayesian credible interval for the difference, -4.9 to 2.1; posterior probability of noninferiority, >0.999). The PARTNER 3 trial assigned 1,000 patients with severe aortic stenosis and low surgical risk to either TAVR with transfemoral placement of balloon expandable valve or SAVR. Patients with a mean age of 73 and a mean STS score of 1.9% were randomized to either TAVR or SAVR groups. With respect to the primary endpoint of composite death from any cause, stroke, or rehospitalization, the study found an occurrence of 8.5% in TAVR and 15.1% in SAVR, confirming both noninferiority and superiority in the TAVR group [absolute difference, -6.6 percentage points; 95% confidence interval (CI), -10.8 to -2.5; P<0.001 for noninferiority; hazard ratio, 0.54; 95% CI, 0.37 to 0.79; P=0.001 for superiority]. Both the Evolut low risk trial and the PARTNER 3 trial provide evidence that the use of TAVR extends beyond the scope of high and intermediate risk surgical patients and is at the very least equivalent to SAVR in the treatment low-risk surgical candidates when using a transfemoral approach in patients without bicuspid aortic valves. In this article we provide an extensive review on the Evolute low risk and PARTNER 3 trials, including a discussion on clinically relevant outcomes.

Developments in transcatheter aortic bioprosthesis durability

Introduction: Valve durability represents a main concern, as the target population for transcatheter aortic valve implantation (TAVI) evolves to include lower risk and younger patients who are likely to survive for a number of years after the procedure.Areas covered: The purpose of this review article is to provide an overview of potential mechanisms and rates of structural valve deterioration (SVD) of transcatheter bioprostheses.Expert opinion: Recently the standardized definitions of SVD proposed by European Association of Percutaneous Cardiovascular Interventions (EAPCI), the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) have permitted for the first time, an objective evaluation of existing and novel TAVI prostheses, and to compare their longevity versus surgical bioprostheses. Although the results of midterm durability of the transcatheter bioprostheses are encouraging, our knowledge concerning the clinical outcomes of TAVI beyond 5 years is still limited. Evidence of longer-term durability is mandatory before replacing surgery with TAVI, particularly in younger and lower-risk patients.

Effect of stent crimping on calcification of transcatheter aortic valves

OBJECTIVES

Although many challenges related to the acute implantation of transcatheter aortic valves have been resolved, durability and early degeneration are currently the main concerns. Recent reports indicate the potential for early valve degeneration and calcification. However, only little is known about the underlying mechanisms behind the early degeneration of these valves. The goal of this study was to test whether stent crimping increases the risk for early calcification.

METHODS

Stented valves that were crimped at 18-Fr and 14-Fr catheter and uncrimped controls were exposed to a standard calcifying solution for 50 million cycles in an accelerated wear test system. Subsequently, the leaflets of the valves were imaged by microcomputed tomography (micro-CT) followed by histochemical staining and microscopic analyses to quantify calcification and other changes in the leaflets' characteristics.

RESULTS

Heavily calcified regions were found over the stent-crimped leaflets compared to uncrimped controls, particularly around the stent's struts. Micro-CT studies measured the total volume of calcification in the uncrimped valves as 77.31 ± 1.63 mm3 vs 95.32 ± 5.20 mm3 in 18-Fr and 110.01 ± 8.33 mm3 in 14-Fr stent-crimped valves, respectively. These results were congruent with the increase in leaflet thickness measured by CT scans (0.44 ± 0.07 mm in uncrimped valves vs 0.69 ± 0.15 mm and 0.75 ± 0.09 mm in 18-Fr and 14-Fr stent-crimped valves, respectively). Histological studies confirmed the micro-CT results, denoting that the percentage of calcification in uncrimped leaflets at the valve's posts was 5.34 ± 3.97 compared to 19.97 ± 6.18 and 27.64 ± 13.17 in the 18-Fr and 14-Fr stent-crimped leaflets, respectively.

CONCLUSIONS

This study concludes that stent-crimping damage is associated with a higher level of passive leaflet calcification, which may contribute to early valve degeneration.

Early detection of transcatheter heart valve dysfunction

Introduction: Transcatheter aortic valve implantation therapy is spreading rapidly, representing the standard of care in inoperable and high-risk patients, and a valid alternative in intermediate- and low-risk patients with severe symptomatic aortic stenosis. In this subset, the development and validation of noninvasive, quantitative, in vivo imaging modality, to monitor possible valve dysfunction is mandatory, in order to plan timely therapeutic interventions before the onset of symptoms.Areas covered: The implantation of transcatheter heart valves (THV) is increasing rapidly. As a consequence, THV dysfunction will become a major cause of cardiovascular morbidity after TAVI. Emergency repeat aortic valve replacement surgery is associated with a high rate of mortality compared with elective repeat surgery. In this context, early detection of THV dysfunction is therefore highly desirable. The review aims to examine the different diagnostic method to early detect THV dysfunction.Expert opinion: Most promising innovations in the diagnosis of early detection of THV dysfunction are evaluated, and the future outlook is explored. Waiting for upcoming evidence about the utility of CT, CMR, and PET on early detection of THV dysfunction, tailoring echocardiogram follow-up based on patients' characteristics is the desirable approach.

Long-Term Functional and Structural Durability of Bioprosthetic Valves Placed in the Aortic Valve Position via Percutaneous Rout in Israel

There is limited organized "real life" data regarding the long-term structural and functional durability of transcatheter aortic valve implants, a topic of major importance. We assessed the 5-year structural and functional integrity outcomes following trans-catheter aortic valve implantation (TAVI) with both self-expandable and balloon-expandable prosthetic valve devices. This study included 450 consecutive patients who underwent TAVI for severe symptomatic aortic stenosis (AS) between September 2008 and December 2011. Data were acquired from a multicenter Israeli registry and the median follow up time was 5.6 years. In 184 patients (40.9%) who survived 5 years, prostheses displayed sustained hemodynamic performance, with average peak and mean aortic valve gradients of 16.2 ± 8.9 and 9.2 ± 6.6 mm Hg, respectively. Late structural valve deterioration was found in 22 (12.3%) patients. Of these, 16 (8.9%) experienced valve deterioration and 6 (3.3%) experienced valve failure. Among the 6 patients with bioprosthetic valve failure, only 3 underwent re-interventions. Bioprosthetic valve dysfunction occurred more frequently in patients with small valves (23 mm) and high peak and mean transvalvular gradients at baseline. In conclusion, a relatively low rate of valve deterioration or failure was noted in our long-term follow-up study after TAVI procedures with both the catheter-based self-expandable and balloon-expandable prosthetic valves.