Biodegradable polymer DES found noninferior to durable polymer EES at 2 years

CHICAGO — Two-year data from the BASKET-PROVE II trial demonstrated that biolimus-eluting biodegradable polymer stents were noninferior to durable polymer everolimus-eluting stents in a real-world population of patients with large vessels. The biodegradable stent also was superior to a thin-strut bare-metal stent in this patient population.

Christoph A. Kaiser, MD, from the University Hospital of Basel, Switzerland, presented the findings at the American Heart Association Scientific Sessions. For the trial, Kaiser and colleagues enrolled 2,291 patients with acute or stable coronary disease who required treatment with ≥3 mm stents from April 2010 to May 2012. Patients were randomly assigned to a biolimus-eluting biodegradable polymer stent (Nobori, Terumo; n=765), an everolimus-eluting durable polymer stent (EES; Xience Prime, Abbott Vascular; n=765) or a thin-strut-coated cobalt-chromium BMS (Pro-Kinetic; n=761). All patients received dual antiplatelet therapy consisting of prasugrel (Effient, Eli Lilly/Daiichi Sankyo) and aspirin.

The primary efficacy endpoint was a composite of cardiac mortality, MI and target vessel revascularization within 2 years, with the biodegradable polymer stent compared with the durable polymer EES for noninferiority and with the BMS for superiority. The secondary safety endpoint was a composite of definite or probable stent thrombosis, MI and cardiac death, with a focus on events occurring after 1 year.

The three groups did not differ significantly with regard to baseline characteristics.

The primary endpoint occurred in 7.6% of patients in the biodegradable polymer group, 6.8% of the durable polymer EES group and 12.7% of the BMS group. In an intention-to treat analysis, the biodegradable stent was noninferior to the EES (P for noninferiority=.042) and superior to the BMS (P=.0011).

The composite safety endpoint occurred in 3.7% of patients in the biodegradable polymer DES group after 2 years vs. 5% in the BMS group (P=.2). The researchers observed no difference in early or late safety between the groups. During his presentation, Kaiser noted that the observed difference in efficacy was only present within the first year after implantation and was driven mainly by a significantly lower incidence of TVR among the DES groups.

Kaiser said the BASKET-PROVE II trial was powered only for the measurement of efficacy, rather than safety, and the results apply only to patients who required large vessel stenting. That all patients were treated with prasugrel-based DAPT called the generalizability of these results into question, Kaiser added, noting that a separate analyses addressing this concern is under review.

“By intention-to-treat, the biodegradable polymer [DES] were not inferior to the everolimus-eluting durable polymer stents after 2 years in a real-world population in need of large-vessel stenting,” he said. “It may be [that] our findings challenge the concept that polymers should be the key in the perceived deficiency of durable polymer [DES] regarding very late stent thrombosis.”

For more information:

Kaiser C. LBCT.04: Ischemic Heart Disease: Drugs, Devices and Systems of Care. Presented at: American Heart Association Scientific Sessions; Nov. 15-19, 2014; Chicago.

Kaiser C. Circulation. 2014;doi:10.1161/CIRCULATIONAHA.114.013520.

Disclosure: Kaiser reports financial disclosures with Abbott Vascular, AstraZeneca, Bayer, Biotronik, Daiichi Sankyo, Eli Lilly and GE Healthcare.