Biodegradable-Polymer DES Still Not Better than Durable DES

WASHINGTON — Further follow-up of patients who got the Orsiro and Synergy biodegradable polymer-coated drug-eluting stents (DES) continues to show no benefit of these devices over a traditional durable DES, according to the BIO-RESORT trialists.

At 3 years, when the Orsiro should have completely lost its biodegradable coating, target vessel failure (combined cardiac death, target vessel-related MI, and clinically-driven target vessel revascularization) reached 10.0%, 8.8%, and 8.5% of those randomized to the Resolute Integrity, Synergy, and Orsiro stents, respectively, with no significant differences between groups in this primary endpoint or its components.

Orsiro was associated with reduced target lesion revascularizations compared to the durable-polymer Resolute (0.5% vs 1.5%, P=0.04) between years 1 and 2, but this was not reproduced in the period between years 2 and 3, reported Clemens von Birgelen, MD, PhD, of Thoraxcentrum Twente in Enschede, the Netherlands, at the Cardiovascular Research Technologies meeting.

Stent thrombosis rates were statistically indistinguishable between groups at about 1.0% out to 3 years, though it appeared at that point that events with the Orsiro were still accumulating, whereas they had plateaued somewhat with the durable-polymer Resolute and the Synergy.

“As far as I can judge, there is no clear signal of late catch-up [in stent thrombosis]. There was a small numerical advantage of events in favor of Orsiro in the second year followed by a small numerical excess of events in the third year. All this speaks for a random difference more than anything else,” commented Marco Valgimigli, MD, PhD, of Inselspital University Hospital in Bern, Switzerland, who was not involved with the study.

“The study was not powered for these endpoints so, to me, the only conclusion is that the study observed a similar outcome across stent types at 3 years,” he added.

BIO-RESORT is a trial of all-comers getting percutaneous coronary intervention (n=3,514) who were randomized 1:1:1 to one of the three DES. Three-year follow-up was complete in 96.6%.

The three stents differ in virtually all aspects of their design, including strut thickness, metal type, polymer, degradation time, and the drug eluted.

Von Birgelen’s group first reported that the Orsiro and Synergy were non-inferior to the durable-polymer Resolute Integrity at 1 year. Patients will be followed out to 5 years, he said.

“In my mind, in addition to longer term outcomes, i.e. 5 years, the only missing data is outcomes for Orsiro upon early discontinuation of DAPT [dual antiplatelet therapy]. Will it be safe to discontinue DAPT due to bleeding or a need for urgent surgery at 1-3 months? This data is pending,” according to Paul Teirstein, MD, of Scripps Clinic in La Jolla, California, who also was not involved in the study.

“We just got the Orsiro in our lab and in my first ‘real-world’ case with very complex anatomy, it delivered extremely well. Of course, we will need a lot more comparative experience before forming opinions about deliverability and radial strength in challenging lesion subtypes,” Teirstein told MedPage Today.