Cost-comparison of third generation transcatheter aortic valve implantation (TAVI) devices in the German Health Care System.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has a substantial impact on daily cardiovascular care delivery based on issues such as cost effectiveness and economic value within a restricted health care budget. Until now, potential financial benefits of third generation valve models have not been evaluated in a real-world setting. METHODS AND RESULTS: We identified 204 eligible patients (Jan 2014-Sep 2016) who either received the balloon-expandable Edwards Sapien 3 (ES3) or the self-expandable Medtronic Evolut R (MER). Baseline information, procedural characteristics, 30-day outcome as well as in-hospital costs and reimbursement were collected and analyzed. The major cost driver was initial valve-kit costs with a significantly higher amount in the ES3 group, which was set at 0 with the lower price (ES3/MER: +4390.0€â€¯±â€¯3.807.0 vs. 0.0€â€¯±â€¯734.1; p < 0.01). However, initial valve-kit costs were balanced by additional material costs in the MER cohort. Overall costs did not differ significantly between valve models (ES3/MER: x + 13.808.0€â€¯±â€¯5.595.0 vs. x + 10.681.0€â€¯±â€¯4.518.0; p = 0.6885) and reimbursement was moderate (ES3/MER: 1.649.7€ vs. 4776.7€). CONCLUSION: Quality, success rate, and costs were comparable between third generation devices. Initial valve-kit costs were significantly higher in the ES3 group, whereas overall costs did not significantly differ between the two valve types.

Minimalist Transcatheter Aortic Valve Replacement: The Right Pathway Forward?

Minimalist transcatheter aortic valve replacement (TAVR) can be implemented with no apparent compromise in patient outcomes. Although this approach is applicable for many patients undergoing TAVR, patient selection by the heart team is critical; one must be cognizant of factors whereby a minimalist approach is unsuitable. In the current era of TAVR, a minimalist approach should encompass the entire process of care and not just the procedure. Streamlining and homogenizing preprocedural workup has potential benefits for patients and health services. Minimalist TAVR is likely the right pathway forward for most patients, but the focus should be patient centered with no compromise to safety.

Computational Fluid Dynamics Assessment Associated with Transcatheter Heart Valve Prostheses: A Position Paper of the ISO Working Group.

The governing international standard for the development of prosthetic heart valves is International Organization for Standardization (ISO) 5840. This standard requires the assessment of the thrombus potential of transcatheter heart valve substitutes using an integrated thrombus evaluation. Besides experimental flow field assessment and ex vivo flow testing, computational fluid dynamics is a critical component of this integrated approach. This position paper is intended to provide and discuss best practices for the setup of a computational model, numerical solving, post-processing, data evaluation and reporting, as it relates to transcatheter heart valve substitutes. This paper is not intended to be a review of current computational technology; instead, it represents the position of the ISO working group consisting of experts from academia and industry with regards to considerations for computational fluid dynamic assessment of transcatheter heart valve substitutes.

Experimental Assessment of Flow Fields Associated with Heart Valve Prostheses Using Particle Image Velocimetry (PIV): Recommendations for Best Practices.

Experimental flow field characterization is a critical component of the assessment of the hemolytic and thrombogenic potential of heart valve substitutes, thus it is important to identify best practices for these experimental techniques. This paper presents a brief review of commonly used flow assessment techniques such as Particle image velocimetry (PIV), Laser doppler velocimetry, and Phase contrast magnetic resonance imaging and a comparison of these methodologies. In particular, recommendations for setting up planar PIV experiments such as recommended imaging instrumentation, acquisition and data processing are discussed in the context of heart valve flows. Multiple metrics such as residence time, local velocity and shear stress that have been identified in the literature as being relevant to hemolysis and thrombosis in heart valves are discussed. Additionally, a framework for uncertainty analysis and data reporting for PIV studies of heart valves is presented in this paper. It is anticipated that this paper will provide useful information for heart valve device manufacturers and researchers to assess heart valve flow fields for the potential for hemolysis and thrombosis.

Recomendações para Avaliação por Imagens das Próteses Valvares Cardíacas / Recommendations for the Imaging Assessment of Prosthetic Heart Valves

Disfunção de prótese valvar cardíaca (PVC) é rara, porém é uma potencial ameaça à vida. Estabelecer o exato mecanismo da disfunção da PVC é desafiador, no entanto é essencial para determinar a estratégia terapêutica apropriada. Na prática clinica, uma abordagem abrangente que integra vários parâmetros de morfologia e função avaliados pelo eco transtorácico 2D/3D e transesofágico são fundamentais para detectar e quantificar a disfunção da PVC. A cinefluoroscopia, a tomografia computadorizada com multidectetores, a ressonância magnética cardíaca, e em menor escala, a imagem nuclear, são ferramentas complementares para o diagnóstico e abordagem das complicações das PVC. Este documento apresenta recomendações para o uso de imagem em multimodalidade para avaliação das PVCs

The future of transcatheter aortic valve implantation.

Since the introduction of transcatheter aortic valve implantation (TAVI) into clinical practice, the treatment of aortic stenosis has changed dramatically. In the past, medical therapy with or without balloon aortic valvuloplasty was the only option for inoperable patients. More recently, TAVI has become the treatment of choice for these patients and the preferred alternative for high-risk operable patients. Surgical aortic valve replacement (SAVR) currently remains the gold standard for patients at low or intermediate operative risk. As randomized trials have demonstrated comparable results between TAVI and SAVR in the high-risk population, there is now a clear trend towards performing TAVI even in intermediate-risk patients while awaiting the results of randomized trials in that population. Nevertheless, there are still questions regarding TAVI involving paravalvular leak (PVL), stroke, pacemaker requirements, and durability that remain to be more definitively answered before TAVI can routinely be performed in a broader, lower risk population. Improvements in patient selection, imaging, and second and third generation devices have decreased the incidence of PVLs and vascular complications that followed the earliest TAVI procedures, but the rates of perioperative stroke and permanent pacemaker implantation must still be addressed. Furthermore, the long-term durability of TAVI devices and a role for post-procedure antithrombotic management remain unanswered. Until these questions are more clearly answered, it is the Heart Team's task to determine the optimal treatment for each patient based on risk scores, frailty metrics, comorbidities, patient preference, and potential for improvement in quality of life.

In vitro assessment of the influence of aortic annulus ovality on the hydrodynamic performance of self-expanding transcatheter heart valve prostheses.

BACKGROUND: Although CT-studies as well as intraoperative analyses have described broad anatomic variations of the aortic annulus, which is predominantly found non-circular, commercially available transcatheter aortic heart valve prostheses are circular. In this study, we hypothesize that the in vitro hydrodynamic function of a self-expanding transcatheter heart valve (Medtronic CoreValve) assessed in an oval compartment representing the aortic annulus will differ from the conventionally used circular compartment. METHODS: Medtronic CoreValve prostheses were tested in specifically designed and fabricated silicone compartments with three degrees of defined ovalities. The measurements were performed in a left heart simulator at three different flow rates. In this setting, regurgitation flow, effective orifice area, and systolic pressure gradient across the valve were determined. In addition, high speed video recordings were taken to investigate leaflet kinematics. RESULTS: The pressure difference across the prosthesis increased with rising ovality. The effective orifice areas were only slightly impacted. The analyses of the regurgitation showed minor changes and partially lower regurgitation when switching from round to slightly oval settings, followed by strong increases for further ovalization. The high speed videos show minor central leakage and impaired leaflet apposition for strong ovalities, but no leaflet/stentframe contact in any setting. CONCLUSION: This study quantifies the influence of oval expansion of transcatheter heart valve prostheses on their hydrodynamic performance. While slight ovalities were well tolerated by a self-expanding prosthesis, more significant ovality led to worsening of prosthesis function and regurgitation.

A new paradigm for obtaining marketing approval for pediatric-sized prosthetic heart valves.

OBJECTIVE: Congenital heart valve disease is one of the most common abnormalities in children. There are limited technological solutions available for treating children with congenital heart valve diseases. The aim of this study is to provide the details of the consensus reached in terms of pediatric definitions, design approach, in vitro testing, and clinical trials, which may be used as guidance for developing prosthetic heart valves for the pediatric indication. METHODS: In stark contrast to the various designs of adult-sized replacement valves available in the market, there are no Food and Drug Administration (FDA)-approved prosthetic heart valves available for use in the pediatric population. There is a pressing need for FDA-approved pediatric valve devices in the United States. The pediatric patient population has been typically excluded from replacement heart valve trials for several reasons. In January 2010, heart valve manufacturers and pediatric clinicians collaborated with academicians and FDA staff in a workshop to suggest ways to successfully evaluate pediatric prosthetic valves and conduct pediatric clinical trials to provide acceptable heart valve replacement options for this patient population. RESULTS: Recommendations, derived from ISO 5840:2005 and the 2010 FDA Draft Replacement Heart Valve Guidance, are provided for hydrodynamic, durability, and fatigue testing. CONCLUSIONS: The article specifically addresses in vitro and premarket and postmarket approval clinical studies that should be considered by a heart valve manufacturer for obtaining regulatory approval of pediatric sizes of prosthetic heart valve designs that are already approved for adult clinical use.

Medtronic Mosaic porcine bioprosthesis: assessment of 12-year performance.

BACKGROUND: The Mosaic porcine bioprosthesis (Medtronic, Inc, Minneapolis, Minn) was approved in 2000 by the US Food and Drug Administration. Clinical performance was evaluated in 6 centers. METHODS: From 1994 to 2000, 797 patients (mean age 69 years) had aortic valve replacement (AVR) and 232 (mean 67 years) had mitral valve replacement (MVR). Concomitant coronary artery bypass grafting was performed with aortic valve replacement (45.4%) and mitral valve replacement (43.5%). Mean follow-ups were 7.5 years for aortic position and 7.3 years for mitral position. RESULTS: Early mortalities were 2.8% for AVR and 3.0% for MVR. Late mortalities were 4.2%/patient-year for AVR and 5.1%/patient-year for MVR. Overall 12-year survivals were 55.8% ± 3.7% for AVR and 43.9% ± 7.4% for MVR. Twelve-year freedoms from valve-related mortality were 87.1% ± 3.1% for AVR and 82.5% ± 7.7% for MVR. Twelve-year freedoms from reoperation were 84.0% ± 3.3% for AVR and 82.5% ± 7.5% for MVR. Freedoms from structural valve deterioration (SVD) by explant reoperation at 12 years for AVR were 93.3% ± 2.6% for patients at least 60 years old and 75.9% ± 9.3% for patients younger than 60 years. Freedoms from SVD by explant reoperation at 10 years for MVR were 95.3% ± 7.8% for patients at least 70 years old and 84.0% ± 9.3% for patients younger than 70 years. Hemodynamic performance data at 1 year for AVR (sizes 21-27 mm) were mean systolic gradient range 13.7 ± 4.8 to 10.3 ± 3.2 mm Hg and effective orifice area range 1.5 ± 0.3 to 2.5 ± 0.4 cm(2). For MVR (sizes 25-31 mm), data were mean diastolic gradient range 6.7 ± 1.7 to 3.7 ± 0.9 mm Hg and effective orifice area range 1.9 ± 0.3 to 2.4 ± 0.6 cm(2). CONCLUSIONS: Overall performance of Mosaic porcine bioprosthesis to 12 years is satisfactory. Freedoms from SVD by explant reoperation were most satisfactory for aortic position in patients at least 60 years old and mitral position in patients at least 70 years old. Overall actuarial freedom from SVD by explant reoperation is encouraging for patients with MVR.

Development of a tissue engineered heart valve for pediatrics: a case study in bioengineering ethics.

The following hypothetical case study was developed for bioengineering students and is concerned with choosing between two devices used for development of a pediatric tissue engineered heart valve (TEHV). This case is intended to elicit assessment of the devices, possible future outcomes, and ramifications of the decision making. It is framed in light of two predominant ethical theories: utilitarianism and rights of persons. After the case was presented to bioengineering graduate students, they voted on which device should be released. The results revealed that these bioengineering students preferred the more reliable (and substantially more expensive) design, though this choice precludes the majority of the world from having access to this technology. This case is intended to examine and explore where the balance lies between design, cost, and adequate distribution of biomedical devices.

Clinical and echocardiographic assessment of the Medtronic Advantage aortic valve prosthesis: the Scandinavian multicentre, prospective study.

OBJECTIVE: The aim of this report is the prospective, multicentre evaluation of clinical results and haemodynamic performance of the Medtronic Advantage aortic valve prosthesis. METHODS: From April 2001 to June 2003, 166 patients (male:female 125:41; mean (SD) age 61.8 (11.8) years) received an aortic advantage valve prosthesis. Complete cumulative follow-up was 242.7 patient-years (maximum 3.2; mean 1.6 years). Postoperatively, patients underwent early (within 30 days) and 1 year transthoracic echocardiography. RESULTS: 30 day mortality was 2.4% (n = 4). Kaplan-Meier estimates of freedom from complications and linearised rates were as follows: 96.9 (1.6)% survival; 94.7 (1.3)% (2.06 patients/year) thrombo-embolism; 99.4 (0.6)% (0.4 patients/year) bleeding; 98.8 (0.9)% (0.8 patients/year) non-structural valve dysfunction; 98.8 (0.9)% (0.8 patients/year) reoperation. Valvular mean pressure gradients ranged from 16 (3) mm Hg for size 19 to 7 (2) mm Hg for size 27 and the corresponding effective orifice areas ranged from 1.2 (0.25) to 3.2 (0.66) cm(2). In all, left ventricular mass significantly decreased (p<0.001) and fractional shortening increased (p<0.001) from postoperative to 1 year echocardiography. CONCLUSIONS: Haemodynamic performance and early clinical results of Medtronic advantage in the aortic position were satisfactory and comparable with those of other bileaflet valves in current clinical use.

Hydrodyamical assessment of valve prosthesis made of expanded ultra-microporous Teflon in vitro.

OBJECTIVE: To assess the hydrodynamical performance of the valve prosthesis made of expanded ultra-microporous Teflon in vitro. METHOD: Sheets of the expanded ultra-microporous Teflon were sewn onto flexible bracket to prepare artificial valve prosthesis. The leakage and steady flow of the valve prosthesis was tested in vitro with Baxter valve prosthesis as control. RESULTS: The rate of leakage of this new valve prosthesis was similar to that of Baxter valve prosthesis (P>0.05), and the systolic pressure gradient of the former was much lower than control(P<0.05). CONCLUSION: This new artificial valve prosthesis has good in vitro hydrodynamical properties, which are superior to Baxter valve.

[Three-dimensional transesophageal echocardiographic assessment for prosthetic valves].

We evaluated three-dimensional transesophageal echocardiographic assessment of the implanted mechanical valves by rotational scanning method. Patients were 7 mitral valve replacement and one aortic valve replacement, 2 mitral and aortic valve replacement. In 2 cases of 7 mitral valve replacement, the prosthetic valve regurgitation was evaluated using by color Doppler echocardiography. In this study, multiplane transesophageal probe was used. It rotated at 2-degree intervals from 0 to 180 degrees and the three-dimensional reconstruction was performed by echo scan workstation system (TOMTEC Inc, Munich, Germany). In mitral valve replacement cases, the valve motion of bileaflet valve (St. Jude Medical valve and ATS valve) were showed very clearly. The struts was easily recognized in the St. Jude Medical valve (SJM valve) cases. In one of SJM valve cases, the pannus formation was revealed, but it did not disturb valve motion. The prosthetic valve regurgitation can be seen accurately. However, aortic valve and ball valve cases cannot be reconstructed because of artifact from prosthetic valve and ultrasonic direction. The prosthetic valve regurgitation, pannus formation which was difficult to be showed in two-dimensional echocardiography and relationship between annulus and sewing cuff can be evaluated by this three-dimensional echocardiography. In this study, this system has some problems, for example real-time evaluation is impossible, aortic valve and ball valve cases cannot be reconstructed. However, we think that this new technology is suitable for evaluating valve thrombus, valve dysfunction and paravalvular leakage. In conclusion, the three-dimensional echo-cardiography demonstrated, reliable and accurate examination, and it can evaluate various complications of prosthetic valve.

A new polymer valve for mechanical circulatory support systems.

A new low-cost artificial heart valve with easily modified dimensions according to its application was developed using segmented polyurethane (SPU). It consists of a convex frame and a concave membrane which floats in the center of the frame while working. The hydrodynamic performance of the polymer valve was compared with that of the Björk-Shiley mechanical valve using a mock circulatory testing system. The hydrodynamic performance of this valve was superior to the Björk-Shiley mechanical valve. The valve was applied to a ventricular assist device (VAD) developed in our institute. In vivo performances of these systems were tested using mongrel dogs. During the experiments, there were no complications related to malfunction of the valve. At postmortem examinations, no thrombus formation was found on the valve surface, and no embolus was detected in the kidneys. We believe this valve could prove a very useful alternative for valves of mechanical circulatory support systems (MCSS) such as VAD and TAH.

In vitro function and durability assessment of a novel polyurethane heart valve prosthesis.

While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.