Strong Showing for Bioabsorbable-Scaffold DES

PARIS, France—Two novel drug-eluting stents (DES) with bioresorbable scaffolds made promising debuts in separate first-in-man studies presented at EuroPCR 2012 on Wednesday, May 16. Both devices documented early evidence of safety and efficacy.

The 2 stents are next in line after the PLLA-based BVS stent (Abbott Vascular, Santa Clara, CA), currently the fully bioabsorbable DES that is farthest along in clinical studies.

DESOLVE

In the DESOLVE trial, Stefan Verheye, MD, PhD, of ZNA Middelheim (Antwerp, Belgium), and colleagues looked at a myolimus-eluting stent (3 µg/mm) employing the DESolve bioresorbable coronary scaffold (Elixir, Sunnyvale, CA).

“It's very important to understand the unique [technical features] of this device,” he said, citing its PLLA-based polymer and “excellent durability and flexibility.” The device is available in diameters ranging from 3.0 mm to 3.5 mm and in lengths of 14 mm and 18 mm. The scaffold bioresorbs between 1 to 3 years, Dr. Veheye reported, and within minutes of implantation opposes itself to the vessel wall. If necessary, the device can expand beyond its original diameter up to 4.75 mm without fracture.

DESOLVE tested the stent in 16 patients with single de novo coronary lesions (reference vessel diameter 3.0 mm, lesion length ≤ 10 mm) who were given dual antiplatelet therapy for 12 months after PCI. Acute recoil was 6.4 ± 4.6%.

At 6 months, the primary endpoint of late lumen loss was 0.19 ± 0.19 mm, with no binary restenosis. Angiographic evidence of neointimal suppression was verified by IVUS, showing a volume obstruction of 7.18 ± 3.37% at 6 months. OCT imaging, meanwhile, found that more than 98% of struts were covered by a thin neointimal layer (0.12 mm). Mean scaffold and lumen areas remained constant between 1- and 6-month follow-up.

No instances of death, target-vessel MI, or clinically indicated TLR occurred by 30 days. One patient underwent clinically indicated TVR. Between 31 and 180 days, an additional patient underwent clinically indicated TLR but no other adverse events were observed.

According to Dr. Verheye, the next step is the pivotal DESolve Nx trial, which has enrolled 120 patients at 13 sites in Europe, New Zealand, and Brazil. That study is evaluating a novolimus-eluting stent (5 µg/mm) comprising the same platform.

Session moderator Raimund Erbel, MD, of West German Heart Center Essen (Essen, Germany), asked Dr. Verheye to clarify why the scaffold could expand so dramatically beyond its original diameter.

“It's a mystery,” he replied, adding, “I think the engineers at the company will certainly be better [able] to address this.”

BIOSOLVE-I

Michael Haude, MD, of Städtische Kliniken Neuss, Lukaskrankenhaus GmbH (Neuss, Germany) provided longer-term results for a different fully bioresorbable DES. In the BIOSOLVE-I trial, Dr. Haude and colleagues evaluated the DREAMS (Drug-Eluting Absorbable Metal Scaffold) stent (Biotronik, Berlin, Germany), which not only includes a bioabsorbable magnesium-alloy scaffold but also delivers paclitaxel via a bioaresorbable PLGA polymer.

A total of 46 patients with de novo coronary lesions (reference vessel diameter 3.0-3.5 mm, lesion length ≤ 12 mm) were treated with the novel stent, which was available only with a scaffold length of 16 mm and diameters of 3.25 mm and 3.5 mm.

Device and procedure success were both 100%. At 6 months, the primary endpoint of target lesion failure (TLF; composite of cardiac death, target-vessel MI, and clinically driven TLR) was 4.3%, driven by 2 cases of TLR. There was no cardiac death, MI, or stent thrombosis. By 12 months, 1 MI occurred (2.3%) outside of the scaffolded area but within the treated vessel, bringing the TLF rate to 7.0%.

Late lumen loss, meanwhile, remained stable over time: 0.64 ± 0.50 mm at 6 months and 0.52 ± 0.39 mm at 12 months. In addition, “vasomotion and natural vessel angulation were completely restored at 6-month follow-up,” Dr. Haude concluded, noting that the device also offers superior efficacy over what had previously been seen in the PROGRESS-AMS trial with a biodegradable magnesium-scaffold stent.

Dr. Haude explained the thinking behind bioabsorbable scaffolding, noting that “during and after the absorption process, . . . the artery becomes uncaged. The natural physiology of the artery returns with features like late expansive remodeling, bending flexibility, and vasomotion.” Not only will this technology hopefully reduce thrombotic risk over time, he said, but it means that “noninvasive imaging of the scaffolded vessel lumen with CT or MRI should become possible.”

 


Sources:
1. Verheye S. DESOLVE: A myolimus-eluting bioresorbable coronary scaffold first-in-man trial. Presented at: EuroPCR. May 16, 2012. Paris, France.

2. Haude M. BIOSOLVE-I: Twelve-month clinical and angiographic results of the multicentre first-in-man study with the paclitaxel-eluting bioabsorbable magnesium scaffold. Presented at: EuroPCR. May 16, 2012.

 

 

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Disclosures
  • Dr. Verheye reports no relevant conflicts of interest.
  • Dr. Haude reports having research contracts and serving as a consultant.

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