What a difference a few years, and a new generation, has meant for the fortunes of drug-eluting coronary stents.
In the late summer of 2006, at that year’s meeting of the European Society of Cardiology, the specter of stent thrombosis first rose around the drug eluting coronary stents of that era, the sirolimus- and paclitaxel-eluting devices. The concern led to an abrupt plunge in the use of drug-eluting stents, routine use of more prolonged dual antiplatelet therapy with aspirin and clopidogrel, and eventually the development and marketing of second-generation stents, which used new drugs—everolimus and zotarolimus—and new polymers to bind the drugs to the stent.
Over the past couple of years, the second generation has given drug-eluting stents a renewed, more robust profile. And now, a new meta-analysis published online in The Lancet brings the best news so far for the new generation: the cobalt-chromium everloimus-eluting stent–marketed as both Xience V and Promus—fared significantly better than bare metal stents in their rates of stent thrombosis both 1 and 2 years after placement, and the cobalt-chromium everolimus-eluting stent also significantly surpassed all of its competition, both first- and other second-generation coronary stents.
The Lancet article that described the meta-analysis, which included 49 trials with more than 50,000 patients, called the finding “a paradigm shift,” something that, if confirmed in a prospective trial, “would have profound clinical implications.” A drug-eluting coronary stent that’s actually substantially safer than a bare-metal stent for the important safety endpoint of stent thrombosis. Who would have thought it possible just a few years ago?
The editorial accompanying the new analysis, by New Zealand cardiologists John Ormiston and Mark Webster, cautions that as a meta-analysis the finding can strictly be regarded as only hypothesis generating, but they also note that a head-to-head randomized comparison of the cobalt-chromium everolimus-eluting stent and a bare-metal stent for this endpoint is unlikely to ever happen. They also said that while the new finding was “unexpected,” the cobalt-chromium everolimus-eluting stent must now be “regarded as the standard against which future design improvements [in stent technology] are compared.” The “firestorm” about stent safety, first set ablaze 5.5 years ago at the ESC “is now barely smoldering,” they concluded.
The authors of the meta-analysis said that the suggestion that this everolimus-eluting stent could actually best bare-metal stents for stent thrombosis first became plausible at last August’s ESC, in results from the EXAMINATION study, which compared the two stent types in about 1,500 acute myocardial infarction patients. The meta-analysis pooled results from two head-to-head comparisons of the cobalt-chromium everolimus-eluting stent against a bare-metal stent in a total of about 3,800 patients (including the EXAMINATION population), and found that the everolimus-eluting device cut the 1-year thrombosis rate by 86% and the 2-year rate by 65% compared with bare-metal stents. The cobalt-chromium everolimus-eluting model also significantly surpassed every other first- and second-generation drug-eluting stent for their 1-year rate of definite stent thrombosis.
Hypothesis generating or not, it’s a result that cardiologists will find hard to ignore.
—Mitchel Zoler (on Twitter @mitchelzoler)