DynamX Bioadaptor: A Paradigm Shift in Percutaneous Coronary Intervention?

© 2025 HMP Global. All Rights Reserved.

Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of Cath Lab Digest or HMP Global, their employees, and affiliates. 

Dean J. Kereiakes, MD, FACC, MSCAI
Chairman, The Christ Hospital Heart and Vascular Institute Medical Director, The Christ Hospital Research Institute Professor of Medicine, University of Cincinnati College of Medicine Professor of Clinical Medicine, The Ohio State University Cincinnati, Ohio

Disclosures: Dr. Kereiakes reports he is a consultant for Elixir Medical, Inc, and will be the international co-principal investigator (along with Robert Yeh, MD) for the upcoming U.S. FDA IDE trial.

Dr. Dean Kereiakes can be contacted at dean.kereiakes@thechristhospital.com

Percutaneous coronary intervention (PCI) has evolved from balloon angioplasty to bare metal stents (BMS), 1st and 2nd generation drug-eluting stents (DES), and subsequently, bioresorbable scaffolds (BRS). Iterations in metallic stent prostheses including drug elution, novel metal alloy composition, reduced strut thickness and improved polymer biocompatibility and/or resorption have contributed to improved stent-related clinical outcomes to 1 year following stent implantation (target lesion failure [TLF]; composite occurrence of cardiac-related death, target vessel-related myocardial infarction, and ischemia-driven target lesion revascularization). However, beyond 1 year there appears to be a 2%-3%/year annualized rate of TLF events extending at least 10-15 years post-implantation, regardless of device type (BMS, 1st or 2nd generation DES) (Figure 1).^1,2 Importantly, these device-related adverse events are not benign, and are associated with significant long-term morbidity and mortality.^3,4  

The pathophysiologic mechanism thought to be the driver for this annualized hazard is the common presence of a metallic prosthesis caging the vessel that mechanically distorts and constrains the vessel, limiting coronary vasomotion, autoregulation, and adaptive vessel remodeling via the Glagov phenomenon.⁵ A metallic prosthesis also simultaneously serves as a persistent nidus for inflammation, neoatherosclerosis and/or strut fracture, with the consequent occurrence of myocardial infarction, thrombosis, and/or restenosis.⁵ In this context, great enthusiasm surrounded the introduction of BRS, the concept of uncaging the vessel and “leave nothing behind” with the hope of restoring more normal vessel physiology. The largest cumulative clinical experience to date involves randomized comparative trials (RCT) of the Absorb bioresorbable vascular scaffold (BVS) (Abbott) compared with the metallic Xience everolimus-eluting stent (EES) (Abbott), and demonstrates a significant increase in adverse clinical events (TLF) through 5 years following implantation of Absorb BVS versus Xience EES (Figure 2A), driven by relative event rates occurring during the first 3 years (Figure 2B).⁶  

The larger Absorb BVS device profile made procedural delivery more challenging and was associated with reduced device success rates and subsequent implantation of more unassigned devices in RCT comparisons with Xience EES. Importantly, beyond 3 years post implantation (time point for complete BVS resorption), the annualized rate of TLF remained 2%-3%/year through 5-year follow-up, and was similar following either Absorb BVS or Xience EES (Figure 2B).⁶ The continued occurrence of TLF events despite complete scaffold resorption raises concerns that either prolonged (3-year) exposure to acidic polylactic acid resorption products may adversely impact the scaffolded segment and potentially accelerate neoatherosclerosis, or that there may be an additional mechanism that is missing from the “leave nothing behind” technologies that is essential and necessary to restore durable and more normal vessel functionality. Hence, the concept of a coronary prosthesis that circumferentially separates post-implantation, freeing the vessel, and which subsequently provides the essential and necessary mechanism of dynamic support to restore more normal functionality of the diseased vessel (restoration of coronary vasomotion, pulsatility, and adaptive remodeling), became extremely attractive.

The DynamX Bioadaptor

The DynamX bioadaptor (Elixir Medical) is comprised of three separate thin (71µ) CoCr sinusoidal helical strands that are temporarily locked to provide radial strength and strut integrity upon device expansion while maintaining longitudinal continuity of the helical prosthesis (Video).^7,8 The helical strands are coated and held together by a 9 µm dual layer conformal bioresorbable polymer, with the outer 3 µm composed of PLGA that resorbs over 3 months and elutes sirolimus, while the inner 6 µm basecoat is composed of a PLLA-based polymer that resorbs over 6 months with subsequent unlocking and separation of the helical strands. 

This novel design of the DynamX bioadaptor creates a unique long-term mechanism of action to provide dynamic support of the diseased vessel, offsetting the burden of atherosclerotic disease while restoring the vessel function to a more natural state. The bioadaptor has three distinct phases:

(1)     In the locked phase, designed for delivery and implantation, the bioadaptor establishes the blood flow lumen to achieve acute benefit of the angioplasty procedure. 

(2)    Unique to the bioadaptor, the second phase occurs when the device unlocks and separates after 6 months, permitting vessel motion and adaptive remodeling to maintain the established blood flow lumen. 

(3)    After the unlocking and separation phase, the final, functional phase provides dynamic support to restore vessel hemodynamic modulation by improving pulsatility, compliance, and adaptive blood flow volume.

Bioadaptor Pre-Clinical and Clinical Trials

Pre-Clinical Study. Circumferential unlocking of the bioadaptor is associated with enhanced flexibility/conformability and adaptive vessel remodeling which has been demonstrated in the adult porcine coronary model.^9,10 In this pre-clinical model, serial intracoronary imaging using optical coherence tomography (OCT) demonstrated a significant increase in both device and vessel lumen area at 12 months following bioadaptor implantation. 

Insights From Intravascular Imaging. Subsequently, in a 50-patient, single-arm “proof of concept” trial involving clinically stable patients with non-complex coronary target lesions, intracoronary imaging with OCT and intravascular ultrasound (IVUS) performed at baseline (post procedure) and at 9- or 12-months post implantation demonstrated recovery in vessel pulsatility, as well as an increase in both device and vessel lumen area on late imaging follow-up (Figure 3A-B).^8,11 

The increase in device and lumen area appeared to offset neointimal hyperplasia ingrowth with resultant very low levels of angiographic late lumen loss by quantitative coronary angiography (QCA). Further, DynamX demonstrated restoration of coronary artery rotational motion after unlocking at 6 months and reduced geometric vessel distortion with more normal recovery in vessel angulation at late (9-12 month) QCA follow-up (Figure 3C-D).¹²  

BIOADAPTOR Randomized Clinical Trial at 12 Months. More recently, the DynamX bioadaptor was compared (1:1 randomized RCT) to the Resolute Onyx zotarolimus-eluting DES involving 445 patients. The primary endpoint was TLF powered for non-inferiority at 12 months.13 A key secondary endpoint included stationary IVUS pulsatility analysis of patient paired images obtained immediately post implant and at 12 months. Device, lesion, and procedural success rates were high and similar between devices, demonstrating excellent implantability and acute procedure success. At 12 months, the primary endpoint was met (TLF 1.8% DynamX, 2.8% Onyx; P<.001 for noninferiority), and TLF component endpoints were similar between devices (Figure 4). In the IVUS sub-study, post implantation lumen area change during the cardiac cycle was similar between devices (Figure 5A).  

However, at 12 months, significant differences were observed between devices involving the proximal, mid and distal in-device segments, consistent with a return in vessel pulsatility among DynamX-treated patients (Figure 5B). Although QCA performed at baseline demonstrated no difference in any angiographic measure between devices at 12 months, both the % diameter stenosis and the degree of late lumen loss favored DynamX (Figure 6A-B).

These QCA results were supported by paired IVUS images showing less neointimal hyperplasia volume and less % neointimal obstruction following DynamX.¹³ An unexpected additional observation was made by IVUS comparing plaque volume changes (mm3) from baseline to 12 months post-device implantation.  (Figure 7). This IVUS-derived evidence for plaque stabilization and regression following DynamX compared with plaque volume increase following Onyx treatment suggests the potential for lipid-lowering drug-device synergy with the restoration of more normal vessel physiology and function, and return of the plaque efflux mechanism. This observation should be considered hypothesis generating and requires further confirmatory evidence.  

BIOADAPTOR Randomized Clinical Trial at 2 Years. Clinical events to 2 years from the BIOADAPTOR RCT were recently presented at the annual EuroPCR 2024 meeting.¹⁴ These results demonstrated progressive divergence of the time-to-event curves for TLF for the ITT population and a statistically significant difference (for superiority) when the “per-protocol” or as treated populations were analyzed for TLF including a TLF assessment of left anterior descending (LAD) artery lesions. (Figures 8A-C). 

This reflects the fact that one of the early adverse events in the bioadaptor arm occurred in a patient who was enrolled and treated for in-stent restenosis following BRS failure, which was a protocol exclusion. Indeed, in long-term follow-up, only a single event was observed in the bioadaptor arm between 6 months and 2 years compared to 6 events in Resolute Onyx arm. This extremely low annualized rate of TLF beyond 1 year, if sustained, will represent a new “gold standard” for long-term coronary device performance.  

INFINITY-SWEDEHEART Randomized Clinical Trial. Finally, the large-scale INFINITY-SWEDEHEART RCT (NCT04562805) comparing DynamX with Onyx (1:1 randomized) in 2400 patients enrolled at 20 sites in Sweden, which includes a significant portion of acute coronary syndrome (ACS) patients, presented primary outcomes at the 2024 TransCatheter Therapeutics (TCT) meeting.¹⁵ Both procedure and device success rates were similar for DynamX and Onyx. At 1 year, the rate of TLF observed for DynamX was non-inferior (2.35 versus 2.77%; P<.001) compared with Onyx. In a pre-specified, powered secondary endpoint, landmark analysis beyond 6 months post-device implantation, DynamX reduced the rate of subsequent TLF by 81% (P=.0079) (Figure 9). 

The time-to-event curves for the powered landmark analysis of TLF in patients with ACS are shown in Figure 10. No differences in risk comparisons were observed between the study groups from 0 months to 6 months (log-rank P>.05). In the landmark analysis from 6 months to 12 months, Kaplan-Meier estimates of TLF in patients with ACS were 0.3% (events in two of 906) versus 1.8% (events in 12 of 895); hazard ratio: 0.17 [0.04–0.74]; P=.018, with P interaction = .023 demonstrating significant change in treatment effect after 6 months in the favor of the bioadaptor.

Conclusion: Potential Paradigm Shift in PCI

Collectively, follow-up from multiple RCT patients forms a substantial body of evidence to establish objectively documented recovery in target lesion/vessel function that favorably impacts the 2%-3% annualized incidence of late adverse coronary prosthesis-related events documented with all prior PCI devices. If the DynamX bioadaptor provides “best-in-class” procedural performance followed by restoration of more normal vessel physiology and consequent improvement in clinical outcomes over time, a paradigm shift in PCI will occur. 

References

1. Madhavan MV, Kirtane AJ, Redfors B, et al. Stent-related adverse events > 1 year after percutaneous coronary intervention. J Am Coll Cardiol. 2020;75:590-604.

2. Kereiakes DJ. The TWENTE trial in perspective: stents and stent trials in evolution. JAMA Cardiol. 2017:2:235-237.

3. Stone GW, Ellis SG, Colombo A, et al. Offsetting impact of thrombosis and restenosis on the occurrence of death and myocardial infarction after paclitaxel-eluting and bare metal stent implantation. Circulation. 2007 Jun 5;115(22):2842-2847.

4. Tamez H, Secemsky EA, Valsdottir LR, et al. Long-term outcomes of percutaneous coronary intervention for in-stent restenosis among Medicare beneficiaries. EuroIntervention. 2021 Aug 6;17(5):e380-e387. 

5. Kereiakes DJ, Onuma Y, Serruys PW, Stone GW. Bioresorbable vascular scaffolds for coronary revascularization. Circulation. 2016;134:168-182.

6. Powers DA, Camaj A, Kereiakes DJ, et al. Early and late outcomes with the Absorb Bioresorbable Vascular Scaffold: Final report from the ABSORB clinical trial program. JACC Cardiovasc Interv. 2025 Jan 12;18(1):1-12.

7. Kereiakes DJ, Saito S, Nef HM, et al. Technology viewpoint: Evolution in PCI: The next major advance in implant technology to restore vessel function. Cardiovasc Revasc Med. 2024;61:95-98.

8. Verheye S, Vrolix M, Montofamo M, et al. Twelve-month clinical and imaging outcomes of the uncaging coronary DynamX bioadaptor system. EuroIntervention. 2020;16:e975-e981.

9. Xu J, Yang J, Huang N, et al. Mechanical response of cardiovascular stents under vascular dynamic bending. Biomed Eng Online. 2016;15-21.

10. Ormiston JA, Webber B, Ubod B, et al. Stent longitudinal strength assessed using point compression: insights from a second-generation clinical related bench test. Cir Cardiovasc Interv. Feb 2014;7(1):62-69.

11. Verheye S, Morice MC, Zivelonghi C, et al. 24-month clinical follow-up and mechanistic insights from intravascular imaging following coronary implantation of the novel DynamX bioadaptor platform. Cardiovasc Revasc Med. 2023;46:106-112.

12. Kansal MM, Wolska B, Verheye S, Vidovich MI. Adaptive coronary artery rotational motion through uncaging of a drug-eluting bioadaptor aiming to reduce stress on the coronary artery. Cardiovasc Revasc Med. 2022;39:52-57.

13. Saito S, Bennet J, Nef HM, et al; BIOADAPTOR-RCT Collaborators. First randomised controlled trial comparing the sirolimuseluting bioadaptor with the zotarolimus-eluting drug eluting stent in patients with de novo coronary artery lesions: 12-month clinical and imaging data from the mult-centre, international, BIODAPTOR-RCT. eClinicalMedicine. 2023;65:102304.

14. Saito S, Bennett J, Nef HM, et al; BIOADAPTOR-RCT Collaborators. Percutaneous coronary treatment with bioadaptor implant vs drug-eluting stent: 2-year outcomes from BIOADAPTOR RCT. JACC Cardiovasc Interv. 2025 Feb 26: S1936-8798(25)00497-2. 

15. Erlinge D, Andersson J, Fröbert O, et al. Bioadaptor implant versus contemporary drug-eluting stent in percutaneous coronary interventions in Sweden (INFINITY-SWEDEHEART): a single-blind, non-inferiority, registry-based, randomised controlled trial. Lancet. 2024 Nov 2;404(10464):1750-1759.

Find More:

Cardiovascular Ambulatory Surgery Centers (ASCs) Topic Center

The Latest Clinical & Industry News

Case Reports

Grand Rounds With Morton Kern, MD

Peripheral Artery Disease Topic Center

Watch: Cath Lab Live Videos

Podcasts: Cath Lab Conversations

Go to Cath Lab Digest's current issue page