Medtech giants Medtronic (NYSE:MDT) and Boston Scientific (NYSE:BSX) took their long-time stent rivalry to new heights in a 1st-of-its-kind head-to-head study of their next-generation drug-eluting stents, with researchers ultimately reporting little difference between their devices aside from a slight tendency for stent deformation.
Medtronic’s Resolute DES and Boston Scientific’s Promus Element performed effectively the same in terms of primary endpoints related to a composite of safety and efficacy, but the Promus Element was associated with a few cases of stent deformation that were not seen in the Resolute device.
The devices demonstrated no statistically significant difference in terms of cardiac death, target-vessel-related myocardial infarction or target vessel revascularization at 12 months following implantation, according to results from the co-funded DUTCH PEERS clinical trial.
The only difference appeared to be related to physical stent integrity, with the platinum-chromium Promus Element indicated in 9 instances of deformation (out of 905 patients treated), compared with none for the cobalt-alloy Resolute stent. The deformation was not associated with any adverse events, researchers noted.
The investigator-initiated, single-blind, multi-center, randomized, non-inferiority trial, which lists both Medtronic and Boston Scientific as funders, concluded that "both stents were similarly efficacious and safe, and provided excellent clinical outcomes, especially in view of the large number of patients who presented with acute myocardial infarctions." But that wasn’t the last word for Medtronic, which issued a statement today highlighting the difference in stent deformation between the 2 devices.
"A potential trade-off with the novel, flexible designs of 3rd-generation stent platforms was thought to be reduced longitudinal device stability," lead study author Dr. Clemens von Birgelen said in a Medtronic statement. "However, our study did not find such a trade-off with the Resolute Integrity DES."
Boston Scientific did not immediately return requests for comment.
In a commentary accompanying the study, published this month in the latest volume of The Lancet, authors Robert Byrne and Adnan Kastrati questioned the deformation results, writing that physical abnormality may simply be easier to detect in the Promus Element because of its material composition.
"Systematic quantitative analysis of angiography films for longitudinal deformation was not undertaken by the investigators, which might have resulted in selective reporting bias," Byrne and Kastrati wrote. "Stent deformation is easier to detect with platinum stents because of their higher radiopacity."
Other studies that have included "systematic quantitative analysis" haven’t found higher rates of deformation in platinum-chromium stents, they noted.
The authors further questioned the rationale of the study as a whole, suggesting that non-inferiority studies do little to further clinical innovation and instead place additional cost and opportunity burden on the healthcare landscape.
"From an industry perspective, although non-inferiority trials might be of interest in terms of competition for market share, the study of me-too devices in trials with a non-inferiority design does not best serve iterative advancement," they wrote. "As a community, perhaps it is time that we reassessed the focus of clinical trials of drug-eluting stents to promote progress."
Stent deformation gained a lot of attention in December 2011 when researchers bench-tested 7 different stents from various manufacturers, concluding that some devices made by Boston Scientific and Medtronic fared worse than competing designs. Boston Scientific’s Promus Element stent, which landed FDA clearance days before the crumpling study was released, was the 3rd-weakest tested, according to the report.
The company became a lightning rod for crumpling concerns after at least 2 studies and a case study presented at the Transcatheter Cardiovascular Therapies conference in San Francisco in November 2011 detailed incidents in which either a BSX Ion or Promus stent deformed after deployment.
The FDA soon took an interest, launching an investigation into the newer stent models. The federal watchdog agency found that, although there’s been only 1 reported incident of deformation involving a Promus stent from more than 4,600 implantations in clinical trials, "an unspecified number of significant adverse events had been reported."
The FDA ultimately required that Boston Scientific include a warning on the potential for stent "shrinkage" in the labeling for the Promus Element drug-eluting stent.
