By Gene Emery
(Reuters Health) - Medtronic's polymer-based zotarolimus-eluting stent is not inferior to BioSensors International's polymer-free umirolimus-coated stent when used for cardiac patients at high risk of bleeding who are treated with a month of dual antiplatelet therapy, according to a head-to-head test published online by The New England Journal of Medicine.
One year after therapy, the combined rate of myocardial infarction (including periprocedural infarction), stent thrombosis and death from cardiac causes was 17.1% with the zotarolimus stent versus 16.9% with the umirolimus device (P=0.01 for safety noninferiority).
Both products scored similarly on a secondary composite outcome measuring effectiveness, which included target-lesion failure, target vessel MI, a need for target-lesion revascularization and death from cardiac causes. The rates there were 17.6% and 17.4% respectively (P=0.007 for noninferiority).
Medtronic, whose drug-eluting stent is called Resolute Onyx, financed the study, known as ONYX ONE, as a way to gauge its effectiveness when follow-up antiplatelet therapy is only going to last for one month.
Biosensors sells the polymer-free drug-coated stent under the brand name BioFreedom. It is already known to be effective when the bleeding risk limits the duration of dual antiplatelet therapy.
The results are significant because nearly 1 in 3 people who could use a stent are at high risk of bleeding. Few trials have pitted different stents against each other.
"This is the first large study to compare any drug eluting stent to the polymer-free drug-coated stent," Dr. Gregg Stone, senior author and director of academic affairs at the Icahn School of Medicine at Mount Sinai in New York City, told Reuters Health in a telephone interview.
The U.S. Food and Drug Administration still needs to approve the Medtronic product for such patients.
Although the two products had comparable scores on the safety and effectiveness composite endpoints, 40 of the 969 patients assigned to polymer-free stents crossed over to receive the zotarolimus stent versus only 2 of the 988 who were supposed to get the zotarolimus product but instead received the BioSensors device.
In both cases where the patients got the BioSensors device instead of the Medtronic, the problem was a randomization error. In the 40 instances where the opposite happened, 25 were due to the doctor thinking the lesion was too complex for the BioSensors stent; in 11 cases the proper stent size was not available or the BioSensors brand was not delivered.
"There was a trend where there may have been a safety benefit for the Resolute Onyx stent, but that's a post hoc observation" that needs further study, said Dr. Stone
The rates of death from any cause were 8.8% with the zotarolimus stent and 7.4% with conventional therapy with the umirolimus-coated stent.
Eighty four medical centers in Asia, Europe and Oceania were involved in the trial.
Antiplatelet therapy consisted of 75 mg to 100 mg of aspirin plus a P2Y-12 inhibitor for the first month, with the option of subsequent treatment with one of the two drugs, or no antiplatelet therapy at all, at the discretion of the doctor.
SOURCE: https://bit.ly/2Hah9D9 The New England Journal of Medicine, online February 12, 2020