Adaptive coronary artery rotational motion through uncaging of a drug-eluting bioadaptor aiming to reduce stress on the coronary artery

First randomised controlled trial comparing the sirolimus-eluting bioadaptor with the zotarolimus-eluting drug-eluting stent in patients with de novo coronary artery lesions: 12-month clinical and imaging data from the multi-centre, international, BIODAPTOR-RCT

Background

The DynamX™ bioadaptor is the first coronary implant technology with a unique mechanism of unlocking the bioadaptor frame after polymer resorption over 6 months, uncaging the vessel while maintaining a dynamic support to the vessel. It aims to achieve the acute performance of drug-eluting stents (DES) with the advantages of restoration of vessel function.

Methods

This international, single blinded, randomised controlled (1:1) trial compared a sirolimus-eluting bioadaptor with a contemporary zotarolimus-eluting stent (DES) in 34 hospitals in Europe, Japan and New Zealand. Patients with de novo coronary lesions and absence of acute myocardial infarction were enrolled from January 2021 to Feburary 2022. The implantation of the bioadaptor followed the standards of DES. An imaging subset of 100 patients had angiographic and intravascular ultrasound assessments, and 20 patients additionally optical coherence tomography. Data collection will continue through 5 years, we herein report 12-month data based on an intention-to-treat population. This trial is registered at ClinicalTrials.gov (NCT04192747).

Findings

445 patients were randomised between January 2021 and February 2022. Device, lesion and procedural success rates, and acute gain were similar amongst the groups. The primary endpoint, 12-month target lesion failure, was 1.8% [95% CI: 0.5; 4.6] (n = 4) versus 2.8% [95% CI: 1.0; 6.0] (n = 6), pnon-inferiority < 0.001 for the bioadaptor and the DES, respectively (Δ-1.0% [95% CI: -3.3; 1.4]). One definite or probable device thrombosis occurred in each group. The 12-month imaging endpoints showed superior effectiveness of the bioadaptor such as in-device late lumen loss (0.09 mm [SD 0.34] versus 0.25 mm [SD 0.39], p = 0.04), and restored compliance and cyclic pulsatility (%mid in-device lumen area change of 7.5% versus 2.7%, p < 0.001).

Interpretation

This is the first randomised controlled trial comparing the novel bioadaptor technology against a contemporary DES. The bioadaptor demonstrated similar acute performance and 12-month clinical outcomes, and superior imaging endpoints including restoration of vessel function.

Funding

The study was funded by Elixir Medical.

DynamX sirolimus-eluting Bioadaptor versus the zotarolimus-eluting Resolute Onyx stent in patients with de novo coronary artery lesions: Design and rationale of the multi-center, international, randomized BIODAPTOR-RCT

BACKGROUND

Conventional drug-eluting stents achieve good safety and performance outcomes, but the stents permanently cage the vessel, leading to a non-plateauing rate of clinical events. The DynamX Bioadaptor is designed to reduce these long-term events through unique design features that permit restoring vessel function and physiology through the disengagement of uncaging elements after the resorption of a biodegradable polymer over six months. Promising initial results have been obtained in the DynamX mechanistic study, with excellent safety and effectiveness, positive arterial remodeling, improved vasomotion, compliance, and cyclic pulsatility. We now aim to confirm these findings randomizing the DynamX Bioadaptor against the Resolute Onyx stent.

METHODS

This multi-center, international, randomized single-blinded study is conducted in 34 sites across Europe, Japan, and New Zealand and is divided into the European/New Zealand cohort and the Japanese cohort (which includes an imaging subset). It is designed to randomly assign 444 patients (222 per region) in a 1:1 ratio to either the DynamX Bioadaptor or the Resolute Onyx stent. Furthermore, a pharmacokinetic substudy is conducted in 9 patients enrolled in Japan to assess the pharmacokinetics of sirolimus after implantation of the DynamX Bioadaptor. Study follow-up is scheduled at one, six, and 12 months, and annually thereafter for five years; imaging follow-up includes angiographic, intravascular ultrasound, and optical coherence tomography assessments at 12 months in a subset of patients. The primary endpoint is 12-month target lesion failure.

CONCLUSIONS

This trial will provide valuable insights into the safety and efficacy of this novel bioadaptor when compared to a contemporary drug-eluting stent.

CONDENSED ABSTRACT

The DynamX Sirolimus-Eluting Bioadaptor has unique design features aiming to reduce long-term events after percutaneous coronary intervention by permitting the restoration of vessel function through the freeing of uncaging elements. Promising initial results have been obtained in the DynamX mechanistic study. This trial aims to confirm these findings in a randomized setting. The European/ New Zealand and Japanese cohorts were designed to randomly assign 444 subjects in a 1:1 ratio to either the DynamX Bioadaptor or the Resolute Onyx stent. Furthermore, a pharmacokinetic substudy is conducted in 9 patients enrolled in Japan to assess the pharmacokinetics of sirolimus.

Coronary Artery Radial Deformation and Velocity in Native and Stented Arteries

Introduction

Coronary arteries are exposed to a variety of complex biomechanical forces during a normal cardiac cycle. These forces have the potential to contribute to coronary stent failure. Recent advances in stent design allow for the transmission of native pulsatile biomechanical forces in the stented vessel. However, there is a significant lack of evidence in a human model to measure vessel motion in native coronary arteries and stent conformability. Thus, we aimed to characterize and define coronary artery radial deformation and the effect of stent implantation on arterial deformation.

Materials and Methods

Intravascular ultrasound (IVUS) pullback DICOM images were obtained from human coronary arteries using a coronary ultrasound catheter. Using two-dimensional speckle tracking, coronary artery radial deformation was defined as the inward and outward displacement (mm) and velocity (cm/s) of the arterial wall during the cardiac cycle. These deformation values were obtained in native and third-generation drug-eluting stented artery segments.

Results

A total of 20 coronary artery segments were independently analyzed pre and poststent implantation for a total of 40 IVUS runs. Stent implantation impacted the degree of radial deformation and velocity. Mean radial deformation in native coronary arteries was 0.1230 mm ± 0.0522 mm compared to 0.0775 mm ± 0.0376 mm in stented vessels (p=0.0031). Mean radial velocity in native coronary arteries was 0.1194 cm/s ± 0.0535 cm/s compared to 0.0840 cm/s ± 0.0399 cm/s in stented vessels (p=0.0228).

Conclusion

In this in vivo analysis of third-generation stents, stent implantation attenuates normal human coronary deformation during the cardiac cycle. The implications of these findings on stent failure and improved clinical outcomes require further investigation.