COMPARE II: BES, EES Show Similar Outcomes at Three Years

A biodegradable polymer-coated, biolimus-eluting stent (BES) performed as well as durable polymer-coated, everolimus-eluting stents (EES) in the first comparison of the two designs. Three-year results from the COMPARE II trial were presented Monday at TCT 2014.

Pieter C. Smits, MD, PhD, of Maasstad Hospital in Rotterdam, the Netherlands, and colleagues conducted the open-label, prospective, randomized, all-comers noninferiority trial at 12 sites in Europe. It included a total of 2,707 patients (4,025 lesions) randomized 2:1 to receive either the biodegradable Nobori BES (Terumo) or an EES, either Xience V or Xience Prime (both Abbott Vascular) or Promus (Boston Scientific). A total of 2,693 patients (99.1%) completed the three-year follow-up.

At three years, the two groups were equivalent with regard to rates of the primary endpoint, a composite of cardiac death, MI, or clinically indicated TVR (RR 1.04; 95% CI, 0.82-1.31) as well as other outcomes (see Table).

Table. Three-year outcomes

“The take-home message is that there is no difference in safety and/or efficacy outcomes between the bioresorbable polymer-coated, biolimus-eluting Nobori stent and the durable polymer-coated, everolimus-eluting Xience or Promus stents, up to 3-year follow-up,” Smits told TCT Daily News.

He noted that the LEADERS study, among other research, previously showed that biodegradable polymer stents have lower rates of very late stent thrombosis than first-generation DES. The second-generation DES tested here, however, use a more biocompatible polymer than in earlier iterations, he said, adding that stent thrombosis rarely occurred with either device type in COMPARE II.

“On the other hand, the relatively thick strut (120 µm) and stainless steel Nobori stent compared to the thin strut (81 µm) cobalt-chromium Xience/Promus stents might have diminished the biodegradable polymer effect,” Smits said. But if this were the case, there likely would have been differences in safety outcomes early on in favor of Xience/Promus, and in later phases for Nobori, he explained.

The current results call into question an advantage for biodegradable polymer stents, Smits acknowledged, but he said that 5-year findings of this and other trials should clear up the issue. A next-generation biodegradable stent is also in development by Terumo using a thinner strut, he reported, adding that in any case, the low event rates in COMPARE II are “very reassuring” for BES.

According to Smits, EES interestingly proved superior to BES in diabetic patients regarding the primary endpoint (11% vs. 18%; P=.04). Because other trials including LEADERS, NEXT and SORT-OUT V showed no association between diabetes status and outcomes at various time points, however, this difference should be regarded only as hypothesis generating, he stressed.