TCT.15: Early results are promising for second-generation drug-eluting absorbable metal scaffold

Patients undergoing PCI who received a second-generation drug-eluting absorbable metal scaffold had favorable angiographic and clinical outcomes after six months, according to the first in-man study of the device.

The BIOSOLVE II trial evaluated the balloon-expandable, sirolimus-eluting DREAMS 2G device from Biotronik AG, which funded the prospective, non-randomized study. The scaffold is a metal-based absorbable scaffold made of a magnesium alloy and an alternative to polymeric scaffolds. It is not FDA-approved.

Lead author Michael Haude, MD, of Lukas Hospital in Neuss, Germany, presented the findings on Oct. 12 in a late-breaking clinical trial session at the Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium in San Francisco.

Results were simultaneously published online in The Lancet.

Between Oct. 8, 2013, and May 22, 2015, the researchers enrolled 123 patients at 13 PCI centers in Belgium, Brazil, Denmark, Germany, Singapore, Spain, Switzerland and the Netherlands. The inclusion criteria included a maximum of two de-novo lesions in two separate coronary arteries, although the study only enrolled patients with one lesion.

After six months, the mean in-segment late lumen loss was 0.27 mmm and the mean in-scaffold late lumen loss was 0.44 mm. Of the 25 patients who underwent vasomotion testing for six months, 20 had documented angiographically discernable vasomotion.

Four patients had target-lesion failure, one patient died from cardiac death, one patient had periprocedural MI and two patients needed clinically driven target revascularization. No patients had definite or probable scaffold thrombosis.

The researchers noted that 99 percent of patients had procedural success and 93 percent had device success.

The scaffold could not be implanted in two patients, while four patients received a second DREAMS 2G scaffold: three were due to dissection and one was due to an underestimation of lesion length. In addition, three patients received a non-study device.

The DREAMS 2G scaffold is more flexible and has a stronger scaffold backbone design, higher bending flexibility and higher radial force than its predecessor, according to the researchers. The scaffold has an absorption time of 12 months.

Patients are scheduled to have clinical follow-up at 12, 24 and 36 months.

“DREAMS 2G is built on continuous improvements of previous generations of absorbable metal scaffolds,” the researchers wrote. “Advantages of metal scaffolds are a good radial strength, low acute recoil, and high compliance to the vessel geometry. Furthermore, metal scaffolds can be implanted via a single-step inflation, hence providing the advantage that they can be implanted in a similar way to a permanent metal stent. Furthermore, they can be electropolished, which results in soft, rounded edges that can improve trackability and deliverability.”

The TCT conference also featured a late-breaking trial on one-year results of the investigational Absorb scaffold, which was noninferior to the Xience stent. The Absorb and DREAMS 2G devices are not yet approved in the U.S., but they may provide cardiologists with more options in the coming years.

“The question that you would have to pose to an engineer is what biomaterial is what biomaterial is going to get you closest to a durable, metal, drug-eluting stent that’s cobalt chromium that’s best in class,” said Daniel I. Simon, MD, division chief of cardiovascular medicine at UH Case Medical Center in Cleveland. “Is that a polymer perhaps down to 100 microns or is it a magnesium metal alloy stent that resorbs? I think that’s the question. I think whoever makes the most deliverable scaffold will win.”