“Whether it's a real difference or a play of chance remains undetermined,” commented Dr. Mitchell W. Krucoff, a professor of medicine and interventional cardiologist at Duke University in Durham, N.C. “These types of differences [21 patients vs. 11 patients] are not certain at a statistical level.”
So if the ZES hopes to wrest any market share from the EES when it hits the U.S. market, it may need to have something to distinguish it, and that something may be an FDA-approved indication for treatment of coronary stenoses in patients with diabetes. At least that's what Medtronic is hoping for. The company included that application in its submission to the FDA, Jason Fontana, Ph.D., senior director for clinical communication at Medtronic, said in an interview.
“The diabetes subgroup was large enough, and the diabetes analysis was prespecified” in RESOLUTE US, Dr. Leon said in an interview. “If you include this subgroup, and the RESOLUTE All Comers diabetes subgroup, you have a robust enough population to justify consideration for approval, I think,” he said.
“The results were quite substantial,” with a 3.0% rate of target-lesion revascularization among the patients with diabetes, compared with a 2.0% rate for the entire main cohort of the study.”
But even if the diabetes indication works out, will interventionalists be swayed by that, or by the data?
“An issue is, to what extent can a single trial address a subgroup?” said Dr. Krucoff. “To what degree is there statistical guidance that in the real world [the ZES] would live up to this measure?”
“I don't think I'd put a lot of emphasis in my decision making on the [RESOLUTE US] data, because a problem with all [stenting] studies is that the rates are constantly improving, so the new device can appear to be better. … Even if [the ZES] was approved for use in patients with diabetes, I don't think in my practice I'd pick it to use in those patients. They'd need to do a randomized study in patients with diabetes to convince me” that it was better than the EES, Dr. Prasad said.
Dr. Serruys and Dr. Prasad had no relevant financial disclosures. Dr. Leon serves as an unpaid consultant to Abbott, Boston Scientific, and Medtronic. Dr. Yeung serves on the scientific advisory board of Medtronic; he is also a consultant for Abbott Vascular, Boston Scientific, and Cordis, and has received research grants from Boston Scientific, Edwards, and Medtronic. Dr. Fontana is an employee of Medtronic. Dr. Krucoff has been a consultant to or has received honoraria from Abbott, Biosensors, Cardiomind, Cordis Johnson & Johnson, Medtronic, Merck, Micelle, OrbusNeich, Prescient, Sanofi-Aventis, and Terumo.
'The results were quite substantial,' with a 3.0% rate of target-lesion revascularization among diabetes patients.
Source DR. LEON
The ZES and EES continued to show virtually identical efficacy performance through the 2 years of study.
Source DR. SERRUYS