Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The huge opportunities for transcatheter aortic valve implantation

01.09.2009
Professor Dominique Himbert

30 August: "Today, transcatheter aortic valve implantation (TAVI) represents an effective therapeutic alternative to conventional aortic valve replacement for patients who are at high risk or with contraindications to surgery, and the combination of the transfemoral and transapical approaches further increases the number of patients who can be treated" said Prof Dominique HIMBERT from the Bichat Hospital in Paris France, at a press conference at the ESC Congress in Barcelona.

"Degenerative aortic stenosis represents a serious and growing public health problem, with regard to the demographic trends expected in the next decades. It should be addressed with appropriate resources to treat a larger number of elderly patients at high-risk or with contraindications to conventional cardiac surgery. These interventions should be less invasive than surgery, less influenced by patients' comorbidities, and allow shorter hospital stays and faster recovery" concluded Prof Himbert.

Transcatheter aortic valve implantation (TAVI) is an emerging technique offering the possibility of restoring a normal aortic valve function in patients with severe aortic stenosis, without removing the native valve, on a beating heart, without cardiopulmonary bypass and sternotomy. The prosthesis can be implanted via either a transfemoral approach, like in standard cardiac catheterization, or a transapical approach, using a direct puncture of the left ventricule. Whatever the access used, this technique allows patients who are at very high surgical risk or with contraindications to conventional surgery to benefit from an effective treatment of aortic stenosis. A strategy integrating the transfemoral and the transapical accesses increases the number of patients who can be treated. One-year results are satisfactory in terms of survival and functional improvement, in particular given the patients' risk profile. The most important predictor of late survival is the experience of the medical team, which underlines the necessity of proper training and the restriction of these procedures to high-volume centers.

Degenerative calcified aortic stenosis is the most frequent valve heart disease in Europe and Western countries. Its prevalence increases with age. Mild to severe aortic stenosis is present in 2 to 4% of adults over 65 years. After the onset of symptoms, average survival is 2 to 3 years with a high risk of sudden death. Surgical aortic valve replacement is the reference treatment, leading to 60 000 operations every year in the European Union. However, one third of candidates are denied surgery, particularly in the elderly, because of a perceived high operative risk due to comorbidities, or technical contraindications to surgery. Feasibility and short-term outcomes of TAVI techniques have been demonstrated in these high-risk subsets, but mid- and long-term results need to be evaluated.

The present single-centre study reports the short and mid-term outcomes of 120 patients consecutively treated by TAVI between October 2006 and June 2009. All of them suffered from a very severe and symptomatic aortic stenosis, and multidisciplinary medicosurgical consensus concluded that they had an unacceptably high operative risk or absolute contraindications to surgery.

An anatomical evaluation using echocardiography, angiography and computed tomography was used to define the technical feasibility of TAVI, the approach (transfemoral or transapical) and the type of prosthesis to be used (Edwards SAPIEN THV [balloon expandable] or CoreValve Revalving System [self expandable]). On average, patients were 81 years old, more than half of them had at least 2 severe extracardiac comorbidities, and their estimated operative mortality was comprised between 16% and 27%, according to the predictive risk score used. The risk profile tended to be even more severe in the transapical group than in the transfemoral.

The prosthesis was successfully implanted in 96% of the cases. The most frequent complications were vascular (10%), due to the large diameters of the femoral sheaths, and heart blocks necessitating definitive cardiac pacing (9%). Strokes were rare (3%). Overall, procedural mortality was 3%, and 30-day mortality 9%: 8% in the transfemoral group, and 11% in the transapical group. At one year, overall survival was 79%. There was no statistically significant difference between the transfemoral (83%) and the transapical group (69%). The most important predictor of late mortality was related to the learning curve, involving the patients' selection process, the procedural technique itself, and post-operative care. One-year survival was 60% in the first 25 patients, compared to 85% in the last 95, and this difference was statistically significant in uni- and multivariate analysis. Most important, 87% of the survivors returned to normal life, with no or only mild residual symptoms.

Today, TAVI represents an effective therapeutic alternative to conventional aortic valve replacement for patients who are at high risk or with contraindications to surgery, and the combination of the transfemoral and transapical approaches further increases the number of patients who can be treated. In the future, randomized controlled trials and comprehensive registries with longer follow-up will help to better define the safety and the durability, and subsequently, indications of the technique and the respective places of the transfemoral and transapical approaches.

Jacquelline Partarrieu | EurekAlert!
Further information:
http://www.escardio.org

More articles from Medical Engineering:

nachricht UCLA engineers use deep learning to reconstruct holograms and improve optical microscopy
22.11.2017 | University of California - Los Angeles

nachricht First transcatheter implant for diastolic heart failure successful
16.11.2017 | The Ohio State University Wexner Medical Center

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>