Pooled Trial Data Show No Stent Thrombosis Reduction with Biodegradable Stent

At 1 year, rates of stent thrombosis are similar between patients who received a biodegradable polymer-coated biolimus-eluting stent (BES) and those given a durable-polymer everolimus-eluting stent (EES), according to data presented Saturday at TCT 2014.

Pieter C. Smits, MD, PhD, of Maasstad Hospital in Rotterdam, the Netherlands, and colleagues pooled data on 5,942 patients from the all-comers COMPARE II and NEXT trials to investigate the stent thrombosis rates of BES (Nobori, Terumo Medical Corporation) compared with EES (Xience, Abbott Vascular or Promus, Boston Scientific).

Clinical outcomes of BES vs. EES

sun.smits2.figure1Rates of Academic Research Consortium-defined definite stent thrombosis were equivalent between the BES and EES at 1 year both overall and when separated into early and late events (see Table). Rates of definite/probable stent thrombosis also did not differ.

In addition, clinical outcomes including mortality, MI, target lesion revascularization and target vessel revascularization were similar between the BES- and EES-treated patients (see Figure).

“Both stents showed an equivalent safety and efficacy profile up to 1 year in a large all-comers pooled population from a variety of geographic areas and clinical practice,” Smits said. On multivariate analysis, he added, use of BES vs. EES failed to predict any difference in stent thrombosis, whether definite (OR 2.52; 95% CI 0.92-6.89; P=.07) or definite/probable (OR 1.25; 95% CI 0.57-2.72; P=.58).

sun.smits2.figure2The advantage of using a biodegradable polymer-coated BES over a durable polymer EES is still unclear, Smits said. He added that a longer follow-up study is required to demonstrate the potential advantage of biodegradable polymer-coated BES in clinical practice.

COMPARE II, NEXT trials

COMPARE II and NEXT were both open label, randomized controlled studies that evaluated the safety and efficacy of BES compared with EES. Though the trials had indicated similar outcomes between the two devices, they “were not powered to detect differences in low-frequency events such as stent thrombosis,” Smits said.

Smits noted several study limitations. For example, only 26% of potential trial participants undergoing PCI were ultimately enrolled in the COMPARE II trial, so selection bias cannot be ruled out. The power of the COMPARE II and NEXT trials also was attenuated by low rates of the events used for sample-size calculation. In addition, both trials were designed as noninferiority studies at 12 months. Any further analysis of the data would be “post hoc,” he said.

 

Disclosures: 

  • Smits reports receiving consultant fees/honoraria from Abbott Vascular and institutional grants from Abbott Vascular, St. Jude Medical and Terumo Medical Corporation.  

Comments