Final 36-Month Outcomes from the Multicenter DynamX Study Evaluating a Novel Thin-Strut Novolimus-Eluting Coronary Bioadaptor System and Supporting Preclinical Data

Physiological Scaffold Remodeling in the Coronary Artery After 30 Months of Bioadaptor Implantation

The DynamX Bioadaptor (Elixir Medical Corporation) is a novel coronary artery scaffold consisting of 3 helical strands connected by a bioabsorbable polymer. After 6 months, the polymer dissolves, restoring the physiological motion of the coronary artery as the interconnected (caged) structure of the scaffold disengages. Here we report the cases of 2 patients treated with the Bioadaptor who underwent intravascular imaging at the time of the index procedure and during follow-up periods of 30 and 36 months, respectively. The cross-sectional images of the scaffold were analyzed and compared with those obtained during the index procedure. At follow-up, the mean cross-sectional area of the scaffold was increased significantly in both cases, regardless of the degree of intimal hyperplasia. Such unique properties of the Bioadaptor make it a promising alternative to contemporary drug-eluting stents.

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

BACKGROUND

Persistent non-plateauing adverse event rates in patients who underwent percutaneous coronary intervention (PCI) remain a challenge. A bioadaptor is a novel implant that addresses this issue by restoring the haemodynamic modulation of the artery, allowing cyclic pulsatility, vasomotion, and adaptative remodelling, by unlocking and providing dynamic support to the artery. We aimed to assess outcomes with the device versus a contemporary drug-eluting stent (DES) in a representative PCI population.

METHODS

INFINITY-SWEDEHEART is a single-blind, non-inferiority, registry-based, randomised controlled study conducted in 20 hospitals in Sweden. Patients aged 18-85 years, with chronic or acute coronary syndrome ischaemic heart disease, with an indication for PCI, with up to three de novo lesions suitable for implantation with one single device per lesion, and successful pre-dilatation were identified via the Swedish Coronary Angiography and Angioplasty Registry and eligible for enrolment. Participants were randomly assigned (1:1), using block randomisation with random variation in block size and stratified by site, to either the DynamX bioadaptor (Elixir Medical, Milpitas, CA, USA) or a zotarolimus-eluting DES (Resolute Onyx and Onyx Trustar, Medtronic, Minneapolis, MN, USA). The primary endpoint was the device-oriented clinical endpoint of target lesion failure at 12 months (a composite of cardiovascular death, target vessel myocardial infarction, and ischaemia-driven target lesion revascularisation), assessed in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment, regardless of treatment received) who had either experienced an event up to 12 months or completed the trial up to 12 months. Non-inferiority was established if the upper limit of the two-sided 95% CI for the absolute risk difference was less than 4·2%. Powered secondary endpoints were landmark analyses from 6 months onwards for target lesion failure, target vessel failure (composite of cardiovascular death, target vessel myocardial infarction, and ischaemia-driven target vessel revascularisation), and target lesion failure for patients with acute coronary syndrome assessed in the ITT population). This study is registered with ClinicalTrials.gov, NCT04562805, and follow-up to 5 years is ongoing.

FINDINGS

Between Sept 30, 2020, and July 11, 2023, 2399 patients were randomly assigned to receive the bioadaptor (n=1201) or DES (n=1198; ITT population). Median age was 69·5 years (IQR 61·2-75·6), 575 (24·0%) of 2399 patients were female, and 1824 (76·0%) were male (data on race and ethnicity were not collected), and 1838 (76·6%) patients presented with acute coronary syndrome. The primary endpoint of 12-month target lesion failure occurred in 28 (2·4%) of 1189 assessable patients in the bioadaptor group versus 33 (2·8%) of 1192 assessable patients in the DES group, with a risk difference of -0·41% (95% CI -1·94 to 1·11; pnon-inferiority<0·0001). In the prespecified landmark analysis from 6 months to 12 months, the Kaplan-Meier estimates of target lesion failure were 0·3% (with events in three of 1170 patients) in the bioadaptor group versus 1·7% (with events in 16 of 1176 patients) in the DES group (hazard ratio 0·19 [95% CI 0·06 to 0·65]; p=0·0079), of target vessel failure were 0·8% (events in eight of 1167) versus 2·5% (events in 23 of 1174; 0·35 [0·16 to 0·79]; p=0·011), and of target lesion failure in patients with acute coronary syndrome were 0·3% (events in two of 906) versus 1·8% (events in 12 of 895; 0·17 [0·04 to 0·74]; p=0·018). The rate of definite or probable device thrombosis, which was recorded as a safety outcome, was low and did not differ between groups (eight [0·7%] of 1201 in the bioadaptor group vs six [0·5%] of 1198 in the DES group; difference in event rates of 0·16% [95% CI -0·50 to 0·83]).

INTERPRETATION

Among patients with coronary artery disease, including those with acute coronary syndrome, treatment with the bioadaptor was non-inferior to contemporary DES, showing potential to mitigate non-plateauing device-related events and improving outcomes in patients undergoing PCI. The additional planned follow-up will help to reinforce the clinical significance of the 1-year findings.

FUNDING

Elixir Medical.

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.