Midterm stability and hemodynamic performance of a transfemorally implantable nonmetallic, retrievable, and repositionable aortic valve in patients with severe aortic stenosis. Up to 2-year follow-up of the direct-flow medical valve: a pilot study

Direct Flow Medical vs. Edwards Sapien 3 Prosthesis: A Propensity Matched Comparison on Intermediate Safety and Mortality

Aims: To compare intermediate performance and mortality rates in patients, who underwent transcatheter aortic valve implantation (TAVI) with two different types of prostheses: Edwards Sapien 3 (ES3) and Direct Flow Medical (DFM).

Methods and Results: 42 consecutive patients implanted with a DFM prosthesis for severe aortic stenosis were matched 1:1 with an equal number of patients, who received an ES3 during the same period. Primary endpoint was mortality. MACE, as a composite of all-cause death, stroke, and re-do-procedure (valve-in-valve), was defined as secondary endpoint. Moreover, we compared NYHA class, NT-proBNP-levels and the extent of restenosis. Patients were followed for 2 years. DFM patients showed echocardiographic elevated mean pressure gradients compared to ES3 patients before discharge (11.2 mmHg ± 5.3 vs. 3.5 mmHg ± 2.7; p < 0.001) and upon 6-months follow-up (20.3 mmHg ± 8.8 vs. 12.3 mmHg ± 4.4; p < 0.001). ES3 candidates showed superior NYHA class at follow-up (p = 0.001). Kaplan-Meier analysis revealed significantly worse survival in patients receiving a DFM prosthesis compared to ES3 (Breslow p = 0.020). MACE occurred more often in DFM patients compared to ES3 (Breslow p = 0.006).

Conclusions: Patients receiving DFM valve prostheses showed worse survival and higher rates in MACE compared to ES3. Prosthesis performance regarding mean pressure gradients and patients' NYHA class also favored ES3.

Transcatheter aortic valve replacement: clinical safety and performance data

Introduction: Patients with severe aortic stenosis and regurgitation who are inoperable or at high-risk for surgery can be treated with transcatheter aortic valve replacement (TAVR). The aim of this study was to provide a comprehensive overview of the literature of TAVR and reported clinical and performance outcomes. Areas covered: A total of 16 devices, described in 204 articles describing clinical and performance outcomes, were included. The most frequently observed outcome was 30-day mortality, ranging between 0-23%. Other commonly reported clinical outcomes were 30-day stroke, ranging between 0-14.3% and pacemaker implantation, ranging from 0-44.9%. The most common valve performance outcome was aortic valve regurgitation, however, mostly reported at 7 days follow-up. Next to a follow-up period of 30 days, numerous articles reported outcomes at 6 months and 1 year. The numbers of articles describing outcomes with a longer follow-up as well as including intermediate and low-risk patients were limited. Expert commentary: This literature review provided a clear overview of the reported clinical and performance outcomes of TAVR devices. Despite the frequently used VARC-2 definitions, we identified a huge variation across studies. Future studies using standardized definitions of study set-ups and outcomes are essential and might lead to better insights of TAVR.

Five-year follow-up after transcatheter aortic valve implantation for symptomatic aortic stenosis

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) has been implemented into the care of elderly patients suffering from severe symptomatic aortic stenosis. However, data on long-term follow-up are sparse and predictors of long-term mortality need to be evaluated to better select patients. Therefore, we aimed to analyse predictors of 5-year mortality after TAVI.

METHODS

We analysed data from the German Transcatheter Aortic Valve Interventions-Registry. Each of the 27 participating hospitals agreed to include all consecutive TAVI patients at their institution. Out of 1444 patients treated with TAVI, 1378 patients had a follow-up of at least 4.5 years (completeness 95.4%). Endpoint for this analysis was 5-year survival. Cox regression analysis was used to determine risk factors associated with this endpoint.

RESULTS

Patients who died were compared with survivors. The two groups showed multiple differences in patient characteristics, indications for interventions, preinterventional, as well as interventional characteristics and postinterventional events. Calculated 1-year mortality was 21.8% and 5-year mortality 59.1%. A higher logistic EuroScore was associated with a lower 5-year survival, being 45.5% in patients with a logistic EuroScore of <20%, 34.5% in those with 20% to 40% and 28.4% in patients with a logistic EuroScore >40%. Cox proportional hazard analysis revealed the following independent predictors of 5-year mortality: female gender (HR =0.66, 95% CI 0.56 to 0.77, p<0.0001), renal failure (HR=1.43, 95% CI 1.22 to 1.69, p<0.0001), prior mitral regurgitation ≥II° (HR=1.42, 95% CI 1.21 to 1.65, p<0.0001), residual aortic regurgitation ≥II° (HR=1.52, 95% CI 1.24 to 1.85, p<0.0001), atrial fibrillation (HR=1.38, 95% CI 1.18 to 1.64, p=0.0001), low gradient aortic stenosis (HR=1.48, 95% CI 1.19 to 1.84, p=0.0004), prior decompensation (HR=1.32, 95% CI 1.13 to 1.54, p=0.0006), frailty (HR=1.31, 95% CI 1.09 to 1.58, p=0.004), surgical TAVI (HR=1.42, 95% CI 1.12 to 1.80, p=0.004), age (by year) (HR=1.02, 95% CI 1.01 to 1.03, p=0.006), prior myocardial infarction (HR=1.29, 95% CI 1.07 to 1.57, p=0.009), urgent TAVI (HR=1.25, 95% CI 1.04 to 51, p=0.020) and diabetes mellitus (HR=1.20, 95% CI 1.02 to 1.40, p=0.024).

CONCLUSIONS

These data from the early TAVI experience show a 5-year mortality of 59.1%. Some of the predictors of 5-year mortality seem to be modifiable, such as residual aortic regurgitation, type of TAVI access route and concomitant mitral regurgitation.

Transcatheter aortic valve implantation: current trends and future directions

Transcatheter aortic valve implantation (TAVI) has been increasingly utilized for the treatment of severe symptomatic aortic stenosis in inoperable and high surgical risk patients. Recent advances in valve technology include repositionable scaffolds and smaller delivery systems, as well as improvement in periprocedural imaging. These advances have resulted in reduction of vascular complications, rates of paravalvular aortic regurgitation and periprocedural stroke and improved overall outcomes. Increasingly, TAVI is the preferred treatment for high-risk surgical patients with severe aortic stenosis. Consequently, there is growing interest for the use of TAVI in lower surgical risk patients. Furthermore, the role of TAVI has expanded to include valve-in-valve procedures for the treatment of degenerative bioprosthetic valves and bicuspid aortic valves. Questions remain in regard to the optimal management of concurrent coronary artery disease, strategies to minimize valve leaflet restriction and treatment of conduction abnormalities as well as identifying newer indications for its use.

Significant transaortic gradient after direct flow aortic valve implantation

A patient with severe aortic valve disease and high surgical risk underwent Direct Flow (DF) valve implantation. Anatomical assessment (Trans-esophageal echocardiography (TEE) and CT scan) revealed a 3-leaflet aortic valve (annulus diameter 23.4 mm) that was functionally bicuspid because of complete and linearly calcified fusion of noncoronary and right cusps. The valve had severe stenosis (peak/mean gradients of 70/45 mm Hg) and moderate to severe regurgitation. A balloon valvuloplasty (semicompliant 23 mm × 45 mm balloon, 2 inflations) was performed with persistence of balloon waist. A 25 DF valve was positioned in the aortic annulus, with both rings well expanded. A mild deformity in the vertical supporting tubes was observed but considered nonrelevant because valve function (peak/mean gradients of 25/12 mm Hg respectively and no aortic regurgitation) was acceptable. Then the polymer was injected and the valve released from its attachments. Postoperative course was uneventful without clinical complications; nevertheless 3 days later Doppler peak/mean transaortic gradients were 80/45 mm Hg. These high gradients were confirmed by direct invasive measurements while CT scan documented a severe geometrical deformation of the valve cuff. Since patient was in good clinical condition, a conservative strategy was adopted. Eight months later, patient functional status had improved (NYHA class II), left ventricular dimensions decreased, left ventricular ejection fraction (LVEF) increased, and valve gradients remained unchanged; therefore surgical aortic valve replacement has been deferred until clinical indication. Such a favorable course can be explained by disappearance of aortic regurgitation. Patient anatomical and procedural features that conditioned this very rare phenomenon are discussed as well as clues to prevent it.

Transcatheter aortic valve implantation

Transcatheter aortic valve implantation was developed to offer a therapeutic solution to patients with severe symptomatic aortic stenosis who are not candidates for conventional aortic valve replacement. The improvement in transcatheter aortic valve implantation outcomes is still of concern in the areas of stroke, vascular injury, heart block, paravalvular regurgitation and valve durability. Concomitantly, the progress, both technical and in terms of material advances of transcatheter valve systems, as well as in patient selection, renders transcatheter aortic valve implantation an increasingly viable treatment for more and more patients with structural heart disease.

Transcatheter aortic valve replacement: historical perspectives, current evidence, and future directions

Severe aortic stenosis (AS) results in considerable morbidity and mortality without aortic valve replacement and is expected to increase in prevalence with the aging population. Because AS primarily affects the elderly, many patients with comorbidities are poor candidates for surgical aortic valve replacement (SAVR) and may not be referred. Transcatheter aortic valve replacement (TAVR) has emerged as transformative technology for the management of AS over the past decade. Randomized trials have established the safety and efficacy of TAVR with improved mortality and quality of life compared with medical therapy in inoperable patients, while demonstrating noninferiority and even superiority to SAVR among high-risk operative candidates. However, early studies demonstrated an early penalty of stroke and vascular complications with TAVR as well as increased paravalvular leak as compared with SAVR. Two device platforms have been evaluated and approved for use in the United States: the Edwards SAPIEN and the Medtronic CoreValve. Early studies also suggest cost-effectiveness for TAVR. Ongoing studies are evaluating new iterations of the aforementioned TAVR devices, novel device designs, and applications of TAVR in expanded populations of patients including those with lower risk profiles as well as those with comorbidities that were excluded from early clinical trials. Future improvements in TAVR technology will likely reduce periprocedural and long-term complications. Further studies are needed to confirm device durability over long-term follow-up and explore the applicability of TAVR to broader AS patient populations.

Current and new-generation transcatheter aortic valve devices: an update on emerging technologies

Transcatheter aortic valve implantation (TAVI) has become an accepted treatment option for patients with symptomatic severe aortic stenosis who are at high risk for traditional surgical aortic valve replacement. In particular, TAVI has been shown to reduce mortality in a randomized comparison with medical treatment and to be non-inferior to surgical aortic valve replacement in 'high-risk operable' patients. From its early stages it became apparent that TAVI has tremendous potential and thus considerable efforts were made to design new devices and advance valve technology in order to improve outcomes and increase TAVI applications in complex anatomies and in patients with multiple co-morbidities. In this review, we present the advances in transcatheter aortic valve technology and discuss the current evidence on the new-generation TAVI devices.

Recent advances in transcatheter aortic valve implantation: novel devices and potential shortcomings

During the past years transcatheter aortic valve implantation (TAVI) has evolved to a standard technique for the treatment of high risk patients suffering from severe aortic stenosis. Worldwide the number of TAVI procedures is increasing exponentially. In this context both the transapical antegrade (TA) and the transfemoral retrograde (TF) approach are predominantly used and can be considered as safe and reproducible access sites for TAVI interventions. As a new technology TAVI is in a constant progress regarding the development of new devices. While in the first years only the Edwards SAPIEN(TM) and the Medtronic CoreValve(TM) prostheses were commercial available, recently additional devices obtained CE-mark approval and others have entered initial clinical trials. In addition to enhance the treatment options in general, the main driving factor to further develop new device iterations is to solve the drawbacks of the current TAVI systems: paravalvular leaks, occurrence of AV-blocks and the lack of full repositionability.

Percutaneous heart valves; past, present and future

Percutaneous heart valves provide a promising future for patients refused surgery on the grounds of significant technical challenges or high risk for complications. Since the first human intervention more than 10 years ago, over 50 different types of valves have been developed. The CoreValve and Edwards SAPIEN valves have both experienced clinical trials and the latter has gained FDA approval for implantation in patients considered inoperable. Current complications, such as major vascular bleeding and stroke, prevent these valves from being commonly deployed in patients considered operable in conventional surgery. This review focuses on the past and present achievements of these valves and highlights the design considerations required to progress development further. It is envisaged that, with continued improvement in valve design and with increased clinical and engineering experience, percutaneous heart valve replacement may one day be a viable option for lower-risk operable patients.

New devices for TAVI: technologies and initial clinical experiences

Treatment of aortic stenosis in high-risk surgical patients has been modified in the past 10 years owing to the introduction of transcatheter aortic valve implantation (TAVI). Several issues affecting outcomes with implantation of the first-generation TAVI devices remain unresolved, including haemorrhagic and vascular complications, neurological events, rhythm disturbances, and paravalvular leakage. Further technological improvements are, therefore, required before the indications for TAVI can be extended to young and low-risk patients with aortic stenosis. Many new-generation TAVI devices are currently in the early stages of clinical evaluation. Modifications in the new devices include the ability to reposition the valve before final deployment, features to reduce paravalvular leakage, and the introduction of low-profile delivery systems. The aim of this Review is to provide an overview of the new-generation transcatheter valvular technologies, including initial clinical reports.

Transcatheter Aortic Valve Replacement: Game-Changing Innovation for Patients with Aortic Stenosis

Transcatheter aortic valve replacement (TAVR) is an emerging technology for the management of patients with severe aortic stenosis (AS). First reported in 2002, TAVR has made remarkable progress in the past decade with completion of major randomized clinical trials, multiple observational registries, and evolution of several new devices. This article is a brief introductory overview of the TAVR procedure, devices, trials and registries, and newer developments in the field.

An update on complications associated with transcatheter aortic valve implantation: stroke, paravalvular leak, atrioventricular block and perforation

Transcatheter aortic valve implantation (TAVI) has become an alternative therapeutic option for patients with symptomatic severe aortic stenosis at high surgical risk and the standard of care in patients who are inoperable for open aortic valve replacement. With technological evolution and increasing experience, the procedure has become more predictable. Complications of TAVI, however, are not infrequent, and can range from minor to life-threatening events. Stroke, paravalvular leak, various forms of atrioventricular block, including the need for permanent pacemakers and aortic annular and ventricular perforation will be the focus of the present review. Other complications associated with TAVI (such as vascular injury, acute kidney injury, coronary obstruction, valve malpositioning or migration) are clinically important, but are beyond the scope of this article. Understanding the occurrence and pathophysiology of these complications may provide insights into the improvement of the transcatheter devices and techniques, and aid in extending the application of TAVI to a broader population.

Transcatheter aortic valve implantation (TAVI): valve design and evolution

The efficacy of transcatheter aortic valve implantation (TAVI) in high surgical risk and inoperable patients with severe aortic stenosis (AS) is rapidly gaining credibility with an ever-expanding body of supporting evidence. The potential of TAVI to be a treatment option for a significant cohort of patients with aortic stenosis has fuelled a drive for the optimum device and resulted in exponential advances in the technology with a focus on adverse event minimization and procedural simplification. Consequently, a plethora of new transcatheter valve choices are now available for clinical study or in the pipeline. The evaluation of past, current and emerging devices allows for an appreciation of the design considerations involved in this process and an insight to the future direction of the technology.

Future perspectives in transcatheter aortic valve implantation

Transcatheter aortic valve replacement (TAVR) constitutes a relatively new treatment option for the patients with severe symptomatic aortic stenosis. Evidence from registries and randomized control trials has underscored the value of this treatment in inoperable and high risk populations, while new developments in valve technology and TAVR enabling devices have reduced the risk of complications, simplified the procedure, and broadened the applications of this therapy. The initial promising clinical results and the potential of an effective less invasive treatment of aortic stenosis has not only created high expectations but also the need to address the pitfalls of TAVR technology. The evolving knowledge concerning the groups of patients who would benefit from this treatment, the limited long term follow-up data, the concerns about devices' long term durability, and the severity of complications remain important caveats which restrict the widespread clinical adoption of TAVR. The aim of this review article is to present the recent advances, highlight the limitations of TAVR technology, and discuss the future perspectives in this rapidly evolving field.

Most Important Papers in Transcatheter Aortic Valve Replacement and Transcatheter Aortic-Valve Implantation

The following are highlights from the series, Circulation: Cardiovascular Interventions Topic Review . This series summarizes the most important manuscripts, as selected by the editors, which have published in the Circulation portfolio. The studies included in this article represent the most noteworthy research in the areas of transcatheter aortic valve replacement and transcatheter aortic-valve implantation.