A novel drug-eluting scaffold was noninferior to a commercially available current-generation drug-eluting stent (DES) in terms of target lesion failure (TLF) and improved restoration of vessel motion and function at 1 year, according to new randomized trial results.
Shigeru Saito, MD, of Shonan Kamakura General Hospital, Kanagawa, Japan, presented these findings during a late-breaking trial session Tuesday at EuroPCR 2023 in Paris.
Adverse events continue beyond the first year after a patient receives a DES, and there is no difference between the first- and second-generation DES or bare metal stents. Bioresorbable scaffolds—thus far—have shown worse outcomes than DES due to poor acute performance and loss of long-term vessel dynamic support.
The DynamX Bioadaptor Scaffold contains three thin (71 µm) cobalt-chromium sinusoid strands with a poly lactic-co-glycolic acid bioresorbable top coat that contains sirolimus and is designed to elute the drug over 3 months. The base coat is poly-l-lactic acid that resorbs over 6 months to circumferentially unlock the scaffold along the three uncaging elements in each ring, Saito explained.
After neointimal formation and healing, the unlocked helical strands continue to provide dynamic scaffolding support, he added.
The BIOADAPTOR randomized trial comparedthe DynamX Bioadaptor Scaffold – manufactured by Elixir Medical Corp., the trial sponsor –with the Resolute Onyx DES (Medtronic). There were 445 patients enrolled in the study, divided into two groups (DynamX: n=223, mean age=67.1 years, 22.0% female; Resolute Onyx: n=222, mean age=66.2 years, 22.1% female) across Germany, Belgium, New Zealand and Japan. The primary endpoint of the study was TLF at 12 months, and secondary endpoints were evaluated with imaging by quantitative coronary angiography, intravascular ultrasound and optical coherence tomography.. Follow-up is planned through 5 years.
Most patients presented with stable angina (DynamX 64.6% vs. Resolute Onyx 67.6%). About half of the target lesions were in the left anterior descending artery (DynamX 50.4% vs. Resolute Onyx 45.2%). A small percentage of lesions were ostial (DynamX 5.8% vs. Resolute Onyx 3.5%, nearly one quarter were bifurcation lesions (DynamX 22.1% vs. Resolute Onyx 23.9%), about a fifth were moderately to severely calcified (DynamX 19.0% vs. Resolute Onyx 20.4%) and about a fifth to a quarter had moderate to severe tortuosity (DynamX 23.5% vs. Resolute Onyx 20.0%).
The acute success rates were high in both groups, ranging from procedural success of 98.7% in the DynamX group and 97.3% in the Resolute Onyx group to device and lesion success rates of 99.6% in both groups.
The DynamX device met the primary endpoint of noninferiority with regard to TLF (DynamX 1.8% vs. Resolute Onyx 2.8%; p for non-inferiority < 0.001).
Both groups had constrained post-implant pulsatility, but only with the DES did pulsatility remain constrained at 1 year, with larger percentage changes in lumen area during the cardiac cycle in the proximal (7.6% ± 4.3% vs. 2.1% ± 3.6%), mid (7.5% ± 4.6% vs. 2.7% ± 4.4%) and distal (7.5% ± 5.4% vs. 2.1% ± 3.7%) device segments (p<0.001 for all segments).
This was further demonstrated by the non-statistically significant difference in lumen area change percentage during the cardiac cycle between the proximal vessel (8.4%) and proximal device segments (7.6%, p=NS) and distal vessel (9.2%) and distal device segments (7.5%, p=NS) in the DynamX arm at 12 months. By comparison, the lumen area change was significantly smaller in the device segments in the Resolute Onyx group (proximal vessel 11.1% vs. proximal device 2.1%, p<0.001; distal vessel 10.0% vs. distal device 2.1%, p<0.001).At 1 year, blood flow increases were greater in the DynamX group compared with the Resolute Onyx group (16.7% versus 5.2%, p<0.001). There was an overall lower percentage of diameter stenosis (DS) in the DynamX patients (12.7% DS versus 17.3%, DS; p=0.051; [in subgroups= LAD: p=0.006, small vessels: p=0.045, long lesions: p=0.008]).
One novel piece of the research was the change in plaque volume (mm3) from baseline to 12 months: DynamX was reduced to 3±19 from 136.37±58.14, while Resolute Onyx was reduced to 12±24 from 148.57±74.08).
Overall, acute procedural performance of DynamX was similar to DES, but DynamX showed superiority across the secondary imaging endpoints at 12 months.