Twelve-month clinical and imaging outcomes of the uncaging coronary DynamX bioadaptor system

Rationale and design of INFINITY-SWEDEHEART: A registry-based randomized clinical trial comparing clinical outcomes of the sirolimus-eluting DynamX bioadaptor to the zotarolimus-eluting Resolute Onyx stent

BACKGROUND

Modern drug-eluting stents have seen significant improvements, yet still create a rigid cage within the coronary artery. There is a 2% to 4% annual incidence of target lesion failure (TLF) beyond 1 year, and half of the patients experience angina after 5 years. The DynamX bioadaptor is a sirolimus-eluting, thin (71 µm) cobalt-chromium platform with helical strands that unlock and separate after in vivo degradation of the bioresorbable polymer coating. This allows the vessel to return to normal physiological function and motion, along with compensatory adaptive remodeling, which may reduce the need for reintervention and alleviate angina following percutaneous coronary intervention (PCI).

METHODS

The INFINITY-SWEDEHEART trial is a single-blind, registry-based randomized clinical trial (R-RCT) to evaluate the safety and effectiveness of the DynamX bioadaptor compared to the Resolute Onyx stent in the treatment of patients with ischemic heart disease with de novo native coronary artery lesions. The R-RCT framework allows for recruitment, randomization, and pragmatic data collection of baseline demographics, medications, and clinical outcomes using existing national clinical registries integrated with the trial database. The primary objective is to demonstrate noninferiority in terms of freedom from TLF (cardiovascular death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization) at 1 year. Powered secondary endpoints will be tested sequentially for superiority from 6 months to the end of follow-up (5 years) for the following: 1) TLF in all subjects, 2) target vessel failure in all subjects, and 3) TLF in subjects with acute coronary syndrome (ACS). Subsequent superiority testing will be performed at a time determined depending on the number of events, ensuring sufficient statistical power. Change in angina-related symptoms, function and quality of life will be assessed using the Seattle Angina Questionnaire-short version. Predefined sub-groups will be analyzed. In total, 2400 patients have been randomized at 20 sites in Sweden. Available baseline characteristic reveal relatively old age (68 years) and a large proportion of ACS patients including 25% STEMI and 37% NSTEMI patients.

SUMMARY

The INFINITY-SWEDEHEART study is designed to evaluate the long-term safety and efficacy of the DynamX bioadaptor compared to the Resolute Onyx stent in a general PCI patient population.

Long-term outcomes following bioresorbable vascular scaffolds

INTRODUCTION

The higher scaffold thrombosis rates observed with the first-generation bioresorbable scaffolds (BRSs) compared to conventional drug-eluting stents were likely due in part to bioresorbable polymers having insufficient radial strength, necessitating larger strut profiles. Meta-analysis of the long-term outcomes from the first-generation Absorb bioresorbable vascular scaffold (BVS) showed that this period of excess risk ended at 3 years. Therefore, current attention has been focused on improving early outcomes by increasing the scaffold's tensile strength and reducing strut thickness.

AREAS COVERED

This review summaries the lessons learned from the first-generation BRS. It updates the long-term clinical outcomes of trials evaluating the ABSORB BVS and metallic alloy-based BRS. In addition, it reviews the next-generation BRSs manufactured in Asia.

EXPERT OPINION

Critical areas to improve the performance and safety of biodegradable scaffolds include further development in material science, surface modification, delivery systems, and long-term follow-up studies.

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.

24-Month Clinical Follow-Up and Mechanistic Insights From Intravascular Imaging Following Coronary Implantation of the Novel DynamX Bioadaptor Platform

BACKGROUND/PURPOSE

Conventional stents "cage" the coronary arteries, impairing vascular function and physiology. The DynamX Bioadaptor is a cobalt‑chromium platform with uncaging elements, designed to improve arterial pulsatility, vasomotion, compliance, and positive adaptive remodelling which may attenuate late clinical events associated with the caging of arteries through conventional stents. We present the first 24-month outcomes of this device.

METHODS/MATERIALS

This European multicenter study enrolled 50 patients with 50 de novo lesions treated with the DynamX Bioadaptor. Clinical follow-up is scheduled until 36 months and imaging follow-up was performed at 9-12 months.

RESULTS

24-month endpoints were target lesion failure (2 cardiac deaths), myocardial infarction (1 non-target vessel myocardial infarction), target vessel revascularisation (n = 0), and definite or probable device thrombosis (n = 0). No endpoint events occurred beyond 9 months. Paired intravascular ultrasound analysis of 18 patients from a single center revealed a 0.22 mm² increase in device cross-sectional area at 9-12 months. Pulsatility analysis showed an increase of in-device lumen area change by 46 % compared to the caged post-procedural configuration, reducing the compliance mismatch between the treated and not-treated vessel segments (segmental compliance). Likewise, vasomotion in response to nitroglycerin improved from 0.03mm² post-procedure to 0.17mm² at follow-up.

CONCLUSIONS

24-month clinical data demonstrate promising safety and efficacy of the DynamX Bioadaptor. Imaging data confirmed its unique capacity to improve arterial pulsatility, vasomotion, compliance and positive adaptive remodelling after "uncaging" which might have led to the promising clinical outcomes that need to be confirmed in larger studies.

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

BACKGROUND

Caged drug-eluting stents impede natural coronary rotational motion and increase vessel stress, which can contribute towards adverse events. The DynamX™ Drug-Eluting Bioadaptor is a cobalt‑chromium platform with a novel mechanism that uncages the vessel after the bioresorbable coating resorbs over six months. This study aimed to analyze the effects of the rotational uncaging in a finite element analysis (FEA) model, validating its effect on coronary artery rotational motion through in-vivo stationary intravascular ultrasound (IVUS).

METHODS

Maximum Von Mises stresses were measured in an FEA model and compared for caged and uncaged bioadaptors. Stationary IVUS images from 20 patients enrolled in a single center were acquired post implantation and at 9-12-month follow-up to evaluate coronary artery rotational motion.

RESULTS

The FEA model showed that rotational uncaging of the bioadaptor reduces peak stress by 70%. In-vivo, the in-bioadaptor segment was significantly distorted post-implant compared to the native distal and proximal vessel, measured by IVUS: The sum of clockwise and counterclockwise rotational motion (net-effect rotational motion) was -2.7 ± 4.3° versus 0.5 ± 5.0° (proximal vessel), p = 0.036, and versus 0.2 ± 3.8° (distal vessel), p = 0.042. At follow up, when the bioadaptor had uncaged, the vessel returned towards its equilibrium (net-effect rotational motion -0.2 ± 5.6°), with no significant difference between the vessel segments.

CONCLUSIONS

In concurrence with the FEA observation, the in-vivo IVUS-analysis demonstrates that uncaging of the bioadaptor affects coronary artery rotational motion. The effect of these findings on reducing clinical events warrants further investigation.

Advances in Clinical Cardiology 2020: A Summary of Key Clinical Trials

INTRODUCTION

Despite the challenge of a global pandemic, 2020 has been an invaluable year in cardiology research with numerous important clinical trials published or presented virtually at major international meetings. This article aims to summarise these trials and place them in clinical context.

METHODS

The authors reviewed clinical trials presented at major cardiology conferences during 2020 including the American College of Cardiology, European Association for Percutaneous Cardiovascular Interventions, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics and the American Heart Association. Trials with a broad relevance to the cardiology community and those with potential to change current practice were included.

RESULTS

A total of 87 key cardiology clinical trials were identified for inclusion. New interventional and structural cardiology data included trials evaluating bifurcation percutaneous coronary intervention (PCI) techniques, intravascular ultrasound (IVUS)-guided PCI, instantaneous wave-free (iFR) physiological assessment, new generation stents (DynamX bioadaptor), transcatheter aortic valve implantation (TAVI) in low-risk patients, and percutaneous mitral or tricuspid valve interventions. Preventative cardiology data included new data with proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors (evolocumab and alirocumab), omega-3 supplements, evinacumab and colchicine in the setting of chronic coronary artery disease. Antiplatelet data included trials evaluating both the optimal length of course following PCI and combination of antiplatelet agents and regimes including combination antithrombotic therapies for patients with atrial fibrillation (AF). Heart failure data included the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors (sotagliflozin, empagliflozin and dapagliflozin) and mavacamten in hypertrophic cardiomyopathy. Electrophysiology trials included early rhythm control in AF and screening for AF.

CONCLUSION

This article presents a summary of key clinical cardiology trials during the past year and should be of relevance to both clinicians and cardiology researchers.