Metallic bioresorbable scaffold “can be considered as an alternative” to polymeric scaffolds


Michael Haude (Medical Clinic I, Städtische Kliniken Neuss, Neuss, Germany) and others report in the European Heart Journal that a second-generation, metallic bioresorbable scaffold (Dreams 2G, Biotronik) is associated with a continuous safety profile up to 12 months. They add these results indicate that the scaffold could be used as an alternative to the current generation of polymeric bioresorbable scaffolds (such as Abbott Vascular’s Absorb).

Haude et al comment that six-month data for Dreams 2G, a sirolimus-eluting bioresorbable magnesium scaffold, have already shown that the device is associated with favourable angiographic and clinical outcomes with a low rate of target lesion failure and no definite or probable scaffold thrombosis. They add that, in this present study, “We aimed to evaluate if those results are sustained at 12 months, a time point when the magnesium scaffold is expected to be absorbed.”

In this prospective, multicentre, first-in-man study, 123 patients with a maximum of two single de novo stenosis in two separate coronary arteries were assigned to undergo percutaneous coronary intervention (PCI) with the Dreams 2G scaffold. The patients either had stable angina, unstable angina, or silent ischaemia. The primary endpoint was in-segment late lumen loss at six months and secondary endpoints were target lesion failure, scaffold thrombosis, in-scaffold and in-segment binary restenosis, diameter stenosis, and in-scaffold late-lumen loss.

A review of quantitative coronary angiography data for 42 paired patients showed no significant differences for in-segment late lumen loss or in-scaffold late lumen loss between six and 12 months. Also, Haude et al report that were no additional target lesion failure events occurring beyond six months and that there were no incidences of definite or probable scaffold thrombosis throughout the 12 months of follow-up. They add that while the late lumen loss data for the scaffold are “inferior” to those for new-generation drug-eluting stents, the clinical outcomes (ie. target lesion failure) are “comparable”.

Haude et al state that the lack of scaffold thrombosis with the device is “promising” given that a recent meta-analysis indicated that the risk of device thrombosis was significantly higher with polymeric bioresorbable scaffolds than it was with drug-eluting stents. They add that there are “several factors” that indicate that Dreams 2G might have a reduced risk for scaffold thrombosis compared with polymeric bioresorbable scaffolds. For example, they note that late acquired mal-apposition “appears to be impossible” with Dreams 2G because it is nearly fully absorbed at 12 months. “This is important since recent observations found four very late scaffold thrombosis in 171 patients treated with a polymeric bioresorbable scaffold with a longer degradation time compared with Dreams 2G. All of those were associated with scaffold discontinuity, mal-apposed, and/or uncovered scaffold struts potentially promoting thrombotic events,” Haude et al comment. Another potential benefit of the device, they say, is that it does “not require stepwise inflation as required with polymeric scaffolds, which may result in better expansion and apposition.”

Haude et al conclude: “This novel absorbable metal scaffold showed a sustained favourable safety profile up to 12 months and no increase in late lumen loss between six months and 12 months in a subgroup of 42 patients. These findings suggest that Dreams 2G can be considered as an alternative to current polymeric bioresorbable scaffolds.”

Haude told Cardiovascular News that Dreams 2G is likely to receive CE certification within the next weeks and will be called “Magmaris” when commercially available. He added: “Once CE-marked, a large world-wide registry is planned followed by head-to-head comparison trials with other scaffolds and drug-eluting stents, respectively, to further evaluate safety and efficacy of this latest generation of bioresorbable scaffold.”

He presented the study at a late-breaking trial session at EuroPCR (17–20 May, Paris, France). During the same session, Alexandre Abizaid (Instituto Dante Pazzanese, São Paulo, Brazil) presented data for the novel bioresorbable sirolimus-eluting scaffold Fantom (Reva Medical). He reported that initial clinical data for the device showed it was associated with “sustained performance and safety through six months” with low rates of major adverse cardiac events and late lumen loss.
Furthermore, Patrick Serruys (National Heart and Lung Institute, Imperial College, London, UK) presented a first-in-man study that compared a sirolimus-eluting polylactide scaffold (Mirage, Manli Cardiology) with an everolimus-eluting polylactide scaffold (Absorb). He reported that there were no significant differences, after 12 months of follow-up, in the rate of binary restenosis between the Mirage device (occurring in 19.4% of 31 patients) and Absorb device (occurring in 16.7% of 30 patients).