EVERBIO II Published: BVS Matches Leading DES for Midterm Outcomes

In an all-comers population with significant ACS and complex lesions, bioresorbable vascular scaffolds (BVS) perform as well as best-in-class DES at 9 months, according to a small randomized trial published in the March 3, 2015, issue of the Journal of the American College of Cardiology.

The findings were originally presented at the Transcatheter Cardiovascular Therapeutics scientific session in Washington, DC, in September 2014.

“The BVS matched the in-stent [late lumen loss] and clinical outcomes of the safest DES on the market,” write Stéphane Cook, MD, and colleagues from Fribourg University and Hospital (Fribourg, Switzerland).

For the all-comers EVERBIO II trial, patients were randomly assigned to an everolimus-eluting BVS (Absorb; Abbott Vascular; n = 80), a durable polymer EES (Promus Element; Boston Scientific; n = 80), or a biodegradable polymer BES (Biomatrix Flex; Biosensors; n = 80), at the investigators’ institution between November 2012 and November 2013.

Mean age was 65 years and 79% were men. The clinical presentation was ACS in 39%. Baseline angiographic and procedural characteristics were generally well balanced between groups except for a larger preprocedural reference vessel diameter in the BVS group compared with the other 2 groups (P < .01). The BVS group also had less direct stenting, higher incidence of hybrid PCI (implantation of 1 study and 1 nonstudy stent in the same lesion), and a trend toward longer scaffold.

Similar Angiographic, Clinical Outcomes

At 9 months, in-stent late lumen loss on QCA (primary angiographic endpoint) was similar between the BVS and the combined EES/BES group. However, in-segment late lumen loss was higher for BVS. No differences were observed between groups for device-oriented MACE (cardiac death, MI, or TLR) or patient-oriented MACE (death, MI, or any revascularization; table 1). 

Clinically driven TLR and TVR were also similar between the groups.

One death occurred in the BVS group at approximately 8 months and was considered cardiac, possibly due to stent thrombosis. However, there were no ARC-defined definite or probable stent thromboses at follow-up.   

Analyses of in-stent late lumen loss found no interaction of treatment effects with diabetes, ACS, or lesion complexity. 

According to Dr. Cook and colleagues, the findings, which show a good safety profile for Absorb in an all-comer population, are “reassuring.”  

“This is of paramount importance given other published data in all-comer patients and the continuous increase in BVS implantation worldwide,” they write. 

Raising concern were recent data from the GHOST-EU registry, which reported a rate of definite/probable scaffold thrombosis with the Absorb BVS that exceeded the stent thrombosis rates in contemporary all-comers trials and registries of second-generation DES. 

As for the slight increase in in-segment late lumen loss, Dr. Cook and colleagues hypothesize that this may have been due to a “modest and transient constrictive effect found at scaffold edges,” a phenomenon that also was observed in cohort B of the ABSORB trial. However, they maintain that accumulated evidence to date suggests that in-segment loss has “low clinical impact.”

Really Ready for All Comers??

In an accompanying editorial, Alexandre Abizaid, MD, PhD, of the Instituto Dante Pazzanese de Cardiologia (São Paolo, Brazil), and colleagues, observe that while Absorb provided “reasonable acute performance” and “reassuring” safety, some issues deserve scrutiny. In addition to the modest sample size, they question why Dr. Cook and colleagues used 2 comparator groups of DES since the primary endpoint was based on 9-month angiographic parameters and there was no evidence of any differences between the DES at that time point.

Additionally, they say that while the study population “reflects the daily practice and patient composition of Switzerland’s Fribourg University Hospital, it may not represent patients in routine clinical practice elsewhere.” For example, although patient characteristics, including vessel size and lesion length, are comparable to other published all-comer studies, the mean number of stents/scaffolds per patient was low, “suggesting that only 1 lesion may have been treated in most patients,” they observe, adding that the investigators also did not report the percentage of treated bifurcation, ostial, and calcified lesions or procedure and device success rates.

“Differences in lesion complexity might confound angiographic and clinical outcomes and are therefore important to fully understand this novel device’s performance and limitations,” Dr. Abizaid and colleagues add.

Furthermore, they suggest that there may be other reasons for the greater observed in-segment late loss in the BVS group, including geographic miss, core laboratory difficulties in accurately ascertaining the in-scaffold and in-segment regions, and play of chance.

Also of importance, the editorialists say, is the different way in which DES and BVS are deployed. They emphasize that “careful vessel sizing, ‘aggressive’ predilation, and particular attention to the balloon used for postdilation help minimize risk of scaffold damage.”

1. Puricel S, Arroyo D, Corpataux N, et al. Comparison of everolimus- and biolimus-eluting coronary stents with everolimus-eluting bioresorbable vascular scaffolds. J Am Coll Cardiol. 2015;65:791-801.

2. Abizaid A, Costa JR, Gibson CM. Bioresorbable vascular scaffolds in daily clinical practice: is the essential really invisible to the eyes [editorial]? J Am Coll Cardiol. 2015;65:802-804.

Disclosures:

• Dr. Cook reports receiving speaker fees/honoraria from Abbott Vascular, Biosensors International, and Boston Scientific; and support from the Swiss National Science Foundation.
• Dr. Abizaid reports research grants from Abbott Vascular and Elixir Medical.

Related Stories:

• EVERBIO II: Angiographic Outcomes Similar for BVS, EES, BES
• ABSORB EXTEND: BVS Safe Out to 3 Years
• Bioresorbable Scaffold Performs Well, But Thrombosis Raises Concerns