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

Abstract

Background: The DynamX Novolimus-Eluting Coronary Bioadaptor System (DynamX® Bioadaptor) has uncaging elements that disengage after the resorption of the polymer coating, aiming to restore vessel function in the treated segment and to avoid long-term adverse outcomes associated with the permanent caging of the coronary artery seen with conventional stenting. Methods: This prospective, multicenter, single-arm first-in-human study enrolled 50 patients in Belgium and Italy who were treated with the DynamX Bioadaptor. Eligible patients had de novo lesions in coronary arteries measuring between 2.5 and 3.5 mm in diameter and ≤24 mm in length. Clinical follow-up was performed up to 36 months. This analysis includes the intention-to-treat population and is based on data available. The preclinical studies include optical coherence tomography (OCT) analyses of 5 DynamX Bioadaptors implanted in 3 mini Yucatan pigs (at 3, 12 and 24 months), and assessment of smooth muscle cell gene expression profile in 8 pigs of which each was implanted with the DynamX Bioadaptor and the Xience drug-eluting stent. To assess the gene expression profile by quantitative real-time polymerase chain reaction, animals were sacrificed at 3, 6, 9 and 12 months. Results: Target lesion failure at 36 months was 8.7% (4/46), consisting of one clinically-driven target lesion revascularization and 3 cardiac deaths (all site-reported to be unrelated to the device or procedure). There were no additional target vessel revascularization and no definite or probable scaffold thrombosis. Preclinical data confirmed late lumen enlargement (from 7.02 ± 1.31 mm2 at baseline to 8.46 ± 1.31 mm2 at 24 months) and identified an increased expression of contractile genes around 9 months compared to a conventional drug-eluting stent. Conclusions: The DynamX Bioadaptor demonstrated very good 36-month clinical outcomes, highlighted by the absence of target-vessel myocardial infarction and definite or probable device thrombosis, and only one target lesion revascularization up to 36 months. These data are supported by preclinical studies that showed late lumen enlargement by OCT and an increased expression of contractile genes around 9 months compared to conventional drug-eluting stents, indicating faster vessel healing. Larger clinical studies are necessary to compare outcomes against contemporary drug-eluting stents. Clinical Trial Registration: https://clinicaltrials.gov/: NCT03429894.

Keywords

• coronary artery disease
• bioadaptor
• drug-eluting stent
• novolimus
• target lesion failure
• vessel motion
• pulsatility
• vasomotion
• thrombosis