My Experience with the DynamX™ Bioadaptor
Stefan Verheye, Senior Interventional Cardiologist, Antwerp Cardiovascular Center, ZNA Middelheim, Antwerp, Belgium
Dr. Verheye is the principal investigator of the DynamX™ Bioadaptor Mechanistic Clinical Study, the principal investigator for Belgium in the BIOADAPTOR RCT, and has significant personal experience with the DynamX Coronary Bioadaptor System.
He shared his thoughts about treating coronary artery disease patients with stents, and how the bioadaptor is demonstrating the potential to improve patient outcomes.
Tell me about treating coronary artery disease today.
The current standard in treating coronary artery disease is drug-eluting stents (DES). DES are the standard of care for patients today, but there is an opportunity for us to do better. DES have very good acute performance and clinical results over the initial 12 months, but when you look beyond this period there is a high rate of adverse events in what we are supposed to call “good performing” DES. In fact, at five years, literature is showing an almost 15% incidence of target lesion failure (TLF), and that continues to accrue annually at 2-4% without end. This has been shown in large meta-analyses of over 25,000 patients across 19 trials.
When you put a current DES into an angulated artery or arterial segment, you will straighten that segment. This straightening will last forever, which is not natural. That will change the sheer stress and hemodynamics within the artery and can cause neoatherosclerosis and increased risk of thrombus.
When a patient comes back beyond that first year, that is not something that you are happy with because, acutely, you have done a good job in terms of the technical procedure and the stent has done its job. But you know that somehow there has been a failure, and you are disappointed and wonder what could I have done differently in order to prevent this?
How is the bioadaptor unique from current drug-eluting stents?
The DynamX Bioadaptor is a unique, drug-eluting CoCr implant characterized by the 
presence of novel “uncaging elements” that are located at low stress regions of each sinusoidal ring of the bioadaptor. These uncaging elements are held together with a bioresorbable polymer that will dissolve within the first six months after implantation. After resorption, the uncaging elements are able to disengage and allow the device to adapt to the vessel physiology and move with the vessel.
The uncaging of the bioadaptor enables the vessel to increase in diameter in response to disease progression, which we know as the Glagovian phenomenon or positive adaptive remodeling. It also allows the vessel to dilate in response to the need for more blood flow during physical activity and restores pulsatility and natural vessel dynamics. It allows the vessel to do what it was intended to do, which is something that we have not seen before with any metallic stent.
Because of the unique design and benefits of this device, I was very excited to be part of the clinical trials.
What outcomes did you see for the bioadaptor at one year?
The innovative bioadaptor design was shown to match current DES in acute performance while offering the promise to improve upon the high adverse event rates that continue beyond year one with DES. In all measures, including clinical, QCA, IVUS, OCT, the bioadaptor demonstrated excellent performance and safety in the 50 patients we studied at six centers in Europe.
Clinically, the results were excellent at 12 months. There was no target vessel revascularization and no device thrombosis.
With OCT, we saw good strut apposition and very little new intimal hyperplasia. There was in-device mean late lumen loss of only 0.12 mm, which demonstrates the ability of the device and drug coating to preserve blood flow over time and inhibit disease progression.
In addition to the excellent clinical and imaging results, we demonstrated several unique benefits. We saw positive adaptive remodeling, which is the Glagovian remodeling we saw so many years ago with balloon dilatation, but has never been described with caged, stented arteries. We saw vessel area growth of 3% and bioadaptor area growth of 5%.
| DynamX Mechanistic Clinical Study IVUS Analysis (n=38 patients)15 |
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| Post-Procedure | 9- & 12-Month Follow-Up | Change from Post-Procedure | P Value | |
| Mean Vessel Area (mm2) | 14.11 ± 2.99 | 14.54 ± 3.12 | 3% | 0.02 |
| Mean Bioadaptor Area (mm2) | 7.39 ± 1.20 | 7.74 ± 1.46 | 5% | 0.0005 |
| Mean Lumen Area (mm2) | 7.39 ± 1.20 | 7.36 ± 1.31 | 0% | 0.59 |
Cyclic pulsatility between systole and diastole that has never been seen or described with any metallic caged artery was also seen in the mechanistic study. We demonstrated vessel reactivity when you administer nitrates, which allows vessel dilatation within the stented segment, and that is an incredible benefit to have. This is also something that we have not seen before with any metallic stent.
The bioadaptor also showed a return towards vessel angulation. In current practice, when we put a straight stent into a bent artery, the artery straightens and loses the angulation. We have seen that this translates into increased event rates later on. What we have shown with the bioadaptor is that by one year the vessels go back toward the initial vessel angulation, which may reduce MACE and the stresses in the vessel.
All of these features demonstrate a fundamental change compared to contemporary DES and indicate that this may have a very promising future by reducing the clinical adverse event rates. I am confident that the bioadaptor may actually address the shortcomings that we see today with the current DES.
How does implantation of the bioadaptor compare to drug-eluting stents?
The implantation technique of the bioadaptor is not any different from the metallic DES that we use today. It has the same deliverability, trackability and radial force of a best-in-class DES, and you get a very good acute outcome. The learning curve is basically nonexistent.
How do you think the bioadaptor will improve upon outcomes we see today from drug-eluting stents?
With the fundamental design changes of this device providing the capability of addressing the needs of normal vessel physiology, this device has the potential to mitigate the problems of the annually occurring events that we see today with DES.
When I look at the performance and the outcomes of the bioadaptor seen in the IVUS and OCT imaging, and knowing that there are basically no clinical events, I feel very confident with this device. This is something that I believe every physician should be keen of using in his clinical practice.
My Experience with the DynamX Bioadaptor – PMN642 RevA
