Bart Meuris, M.D., Ph.D.
University Leuven Hospital, Belgium
Aortic stenosis continues to be a major global healthcare issue, affecting 62 million people over the age of 65 years worldwide. Driving earlier intervention is a key focus for healthcare providers and policymakers. Consequently, the market for Aortic Valve Replacement (mainly Transcatheter Heart Valves) is expected to grow substantially over the coming years, rising from US $6 billion today to an estimated $US 7 billion by 2025.
Once reserved for high-risk elderly patients, there is growing evidence that the use of Transcatheter Aortic Valve Replacement (TAVR) is also safe and effective for lower-risk younger patients. However, the replacement valves in younger patients will need to endure much longer periods of use than that offered by current first-generation devices.
Admedus, a Minnesota-based company, believes it holds the key to the issue of longer-lasting valves: a single-piece 3D aortic valve that commences first-in-human studies this month. Admedus’ valve combines an innovative design with the company’s scientifically proven ADAPT® tissue technology.
The Admedus valve could significantly alter the TAVR landscape. It is widely accepted that the Transcatheter method of valve replacement (TAVR) is less invasive and less risky than the surgical alternative (SAVR). The ADAPT® treated valve developed by Admedus, offers a viable solution by providing significant anti-calcification properties. In addition, its unique design will deliver a stronger, more durable alternative, providing assurance that patients will be less likely to undergo repeat surgery due to deterioration of the replacement valve.
ADAPT® tissue technology offers the most advanced tissue science
The demand for a durable solution to aortic stenosis has led to a search for superior tissue science and valve design.
ADAPT® treated tissue is a completely Acellular Bovine Pericardial tissue with zero DNA and zero glutaraldehyde toxicity.
The ADAPT® tissue technology that forms the basis of Admedus’ single-piece valve has been used clinically in the CardioCel® and VascuCel® bioscaffolds developed and commercialized by Admedus. Based on 10 years of clinical data, the ADAPT® bioscaffold is the only material that does not calcify nor degrade. Approved by the US FDA and CE Mark since 2013, these products have been used in more than 20,000 procedures to date.
In June 2019, the peer-reviewed journal The Annals of Thoracic Surgery published data from an independent, multi-centre study involving 501 implants in pediatric patients. The data showed that the ADAPT® tissue was durable, with no evidence of calcification. Ninety-six percent of patients were free from re-intervention at three and five years after implant.
The ADAPT® single-piece 3D valve design reduces the leaflet stress by 35-40% and increases the coaptation significantly. In laboratory tests, the Admedus valves were functional after 400 million cycles—equivalent to approximately 10 years of human use.
Pre-clinical sheep study provides confidence for the first-in-human study
The findings of Admedus’ 2019 pre-clinical study of the ADAPT® single-piece 3D valve in six juvenile sheep were presented earlier this year at PCR London Valves.
The sheep study demonstrated that the ADAPT® valve can be safely implanted and can deliver positive outcomes. The tissue on the valve was easy to handle during surgical implantation and there was no material failure or fatigue of the valve. The valve functioned normally following implantation. Echocardiography showed low gradients and no significant regurgitation across the implanted valves. Follow-up assessment six months later showed stable valve function.
It is reasonably expected that the ADAPT® single-piece 3D aortic valve will produce similar positive results in humans. Consequently, a first-in-human trial with this prosthesis has been designed and is expected to commence in March 2020.
Up to 15 patients will be enrolled in the first-in-human study. The patients will undergo follow-up assessments for up to six months after receiving implantation of the ADAPT® single-piece 3D aortic valve. The results from the study are expected to be available between the first quarter of 2021 and the third quarter of 2021.
With durability remaining a key challenge in treating aortic stenosis patients, Admedus is well-positioned to offer AS patients a viable long-term solution.