EVOLVE II: Novel bioabsorbable polymer-coated stent noninferior to durable polymer stent

CHICAGO — A novel bioabsorbable polymer-coated everolimus-eluting stent was noninferior to a durable polymer everolimus-eluting stent at 1 year, according to results from the EVOLVE II pivotal trial presented at the American Heart Association Scientific Sessions.

The EVOLVE II trial was designed to support FDA approval of the stent, which would be the first bioabsorbable polymer drug-eluting stent in the United States, if approved, Dean J. Kereiakes, MD, FACC, medical director of The Christ Hospital Heart and Vascular Center and The Lindner Center for Research and Education at The Christ Hospital in Cincinnati, said during a presentation.

Dean J. Kereiakes

The multicenter, international, prospective, single blind, pivotal trial included 1,684 patients (mean age, 63.7 years; 28.4% women) randomly assigned to the bioabsorbable polymer-coated everolimus-eluting stent (EES; Synergy, Boston Scientific) or a durable polymer EES (Promus Element Plus, Boston Scientific).

The Synergy EES consists of a thin-strut platform constructed of a platinum chromium metal alloy, with a thin, bioabsorbable abluminal polymer that elutes everolimus at a dose density of 100 mcg/cm².

Patients underwent PCI across 125 participating sites between November 2012 and August 2013, and had up to three target stenoses in up to two major epicardial vessels. Included lesions had a reference vessel diameter between 2.25 mm and 4 mm (mean, 2.63 mm), length of ≤34 mm (mean, 13.9 mm), and diameter stenosis between 50% and 100%. At baseline, 31% of patients had diabetes, 34.3% had unstable angina and 28% had elevated cardiac enzymes pre-PCI. Planned follow-up was 5 years.

The primary endpoint was target lesion failure, defined as a composite of cardiac death, target vessel-related MI or ischemia-driven target lesion revascularization within 12 months of stent deployment.

In an intention-to treat analysis, 6.7% of patients assigned the bioabsorbable polymer EES experienced TLR compared with 6.5% of patients assigned the durable polymer EES (P=.0005 for noninferiority). All three components of the primary endpoint occurred at similar rates between groups: cardiac death (0.5% vs. 0.9%; P=.34), target vessel-related MI (4.3% vs. 4.7%; P=.71), clinically indicated TLR (2.6% vs. 1.7%; P=.21).

In a per-protocol analysis, the primary endpoint was reported in 6.4% of patients in each stent group (P=.0003 for noninferiority). Definite and probable stent thrombosis occurred at a similar rate between the groups: 0.4% of the bioabsorbable polymer EES group vs. 0.6% of the durable polymer EES group (P=.5). No cases of definite thrombosis beyond 24 hours of stent deployment were reported in patients assigned the bioabsorbable polymer EES.

“In this pivotal, noninferiority trial … the Synergy stent proved noninferior to the Promus Element Plus stent for [target lesion failure] at 1 year,” Kereiakes said. “Despite the clinical and angiographic complexity of the study population, definite and probable stent thrombosis rates were low.”

Kereiakes added that the long-term efficacy and safety of the bioabsorbable polymer stent are currently under evaluation. – by Adam Taliercio

For more information:

Kereiakes DJ. LBCT.04: Ischemic heart disease: drugs, devices and systems of care. Presented at: American Heart Association Scientific Sessions; Nov. 15-19, 2014; Chicago.

Disclosure: Kereiakes reports consulting for Abbott Vascular, Boston Scientific and Reva Medical.