The study’s primary efficacy outcome was the same as in EVOLVE II, a combination of cardiac death, myocardial infarction, or need for target-vessel revascularization, but in this study, it was tallied after 24 months. The rates were 7.6% in patients who received stents with a bioabsorbable polymer, and 6.8% in those who got stents with a durable polymer, a difference that was not statistically significant, and which also met the study’s prespecified definition of noninferiority in the intention-to-treat analysis.
The study’s safety endpoint compared patients who received bioabsorbable-polymer stents with those who received bare-metal stents for rates of cardiac death, myocardial infarction, or definite or probable stent thrombosis, which occurred in 5.0% of patients who received bare-metal stents and in 3.7% of those who received stents with a bioabsorbable polymer, a difference that was not statistically significant. Notably, the rates of stent thrombosis during months 13-24 of follow-up were completely identical in patients who received the drug-eluting stent with a bioabsorbable polymer and in those who received bare-metal stents, reported Dr. Kaiser, a coprincipal investigator on the study. Concurrent with his report at the meeting, an article with the results appeared online (Circulation 2014 [doi:10.1161/CIRCULATIONAHA.114.013520/-/DC1]).
These findings “challenge the concept” that polymers are a key issue for any difference in the rate of late stent thrombosis, said Dr. Kaiser.
But another interventionalist, who cochaired the session where the results from both studies were reported, disagreed. “I think it is a step forward to get rid of the polymers. There is no use to having them” once the antirestenosis drug a stent carries is fully released, “so it is good to get rid of them,” said Dr. Stefan James, a cardiologist at Uppsala University in Sweden.
“In our registry [Swedish Coronary Angiography and Angioplasty Registry] we see that the [Synergy] stent has excellent results, with a very low stent thrombosis rate similar to what was shown” on the EVOLVE II trial. “So I think that the [bioabsorbable-polymer] stents are a step forward. After 20 years with drug-eluting stents, we are improving these devices step by step,” Dr. James said.
EVOLVE II was sponsored by Boston Scientific. Dr. Kereiakes is a consultant to and speaker for Boston Scientific, and a consultant to Abbott Vascular and Reva Medical. Dr. Mehran has received honoraria from and has been a consultant to Boston Scientific as well as to several other device and drug companies. Dr. Harrington had been an investigator for several trials that tested drugs patients take following stenting. The BASKET-PROVE II trial had no commercial sponsorship, but the study organizers received the prasugrel that patients took in the study following stenting for free from the manufacturers. Dr. Kaiser has received remuneration for being the advisory boards for Eli Lilly and Daiichi Sankyo. Dr. James had served on an advisory board for Medtronic and has received institutional research grants from Medtronic, Terumo, and Vascular Solutions.
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