Study: Polymer-Free Stents Don't Deliver Long Term

Stents were never the solution, they do nothing to address the inflammation in your arteries that creates plaque. And why would you want to put inflexible stents in flexible arteries? 

Study: Polymer-Free Stents Don't Deliver Long Term

— 10-year ISAR-TEST-5 results suggest the future isn't about coatings

by Nicole Lou, Staff Writer, MedPage Today July 6, 2020

Long-term adverse outcomes were similar for polymer-free and durable-polymer drug-eluting stents (DES) in the ISAR-TEST-5 study, suggesting that stent innovations might have reached their limit for improving coronary artery disease treatment.
Patients who were randomized to the polymer-free, sirolimus- and probucol-eluting Isar DES fared similarly over 10 years compared to peers who got durable-polymer, zotarolimus-eluting Endeavor Resolute DES, reported Sebastian Kufner, MD, of Deutsches Herzzentrum München, Germany, and colleagues in the July 14 issue of the Journal of the American College of Cardiology. That was true for the following endpoints:

• The device-oriented composite of cardiac death, target vessel-related MI, or target lesion revascularization (43.8% vs 43.0%, HR 1.01, 95% CI 0.89-1.14)
• The patient-oriented composite of all-cause death, any MI, or any revascularization (66.2% vs 67.7%, HR 0.94, 95% CI 0.86-1.04)
• Individual components of those composite measures
• Stent thrombosis (1.6% vs 1.9%, HR 0.85, 95% CI 0.46-1.54)

Notably, on landmark analysis of stent thrombosis events occurring more than a year after stent implantation, such late events were similarly low between groups (0.5% vs 0.7%, HR 0.69, 95% CI 0.22-2.16) -- suggesting that dual antiplatelet therapy duration may not have to depend on the presence or absence of polymer, according to the researchers.
"The benefit of stents without polymer is expected to accrue with time. However, in many respects, the failure to detect a late advantage with the polymer-free stent -- despite following a large number of patients out to 10 years -- calls this hypothesis into question," the group concluded.
On face value, that lack of long-term advantage may be the main lesson, commented Ori Ben-Yehuda, MD, of the Cardiovascular Research Foundation in New York City and the University of California San Diego, "There are, however, additional, perhaps more important takeaways."
"The most important is the linear and relentless accumulation of events over the 10 years of the trial, including a high mortality, 35.0% versus 37.3% in the polymer-free and durable polymer stents, respectively, with 60% of the deaths deemed cardiovascular," Ben-Yehuda pointed out in his editorial accompanying the paper.
In the future, choice of stent will be less important in the holistic approach to long-term care for coronary artery disease, he predicted.
"Stent technology has undoubtedly improved and will continue to evolve, but coronary atherosclerosis, the underlying process which drives coronary events, is a diffuse disease. Short of a full metal jacket (with its own set of issues!), stenting, as currently practiced, only addresses ischemia-producing lesions, leaving behind potentially vulnerable plaques as well as lesions that may progress over time," he said.
ISAR-TEST-5 was a trial in which 3,002 patients were randomized 2:1 to polymer-free Isar Vivo stents or durable-polymer Endeavor Resolute stents. A total of 4,391 lesions were treated in 2008-2009.
Median age was 67.8 years, and women comprised less than 24% of the cohort. More than 40% of patients had presented with an acute coronary syndrome.
One limitation of the trial was that 14.9% of patients were missing 10-year data. Device assignment was also not blinded to patients or physicians, and the two stents differed in various aspects (not just the presence or absence of polymer coating), Kufner and colleagues noted.
Moreover, LDL cholesterol levels were not reported in ISAR-TEST-5, so one could only speculate whether better secondary prevention efforts might have improved outcomes for these patients, Ben-Yehuda noted.

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  Nicole Lou is a reporter for MedPage Today, where she covers cardiology news and other developments in medicine. Follow

Disclosures

The study was funded in part by the Bavarian Research Foundation and the European Union under the Seventh Frame Work Programme.
Kufner disclosed receiving speaker fees from AstraZeneca and Bristol-Myers Squibb.
Ben-Yehuda reported institutional grants from Medinol, Abbott Vascular, Medtronic, SMT, Concept Medical, Biosensors International, and OrbusNeich.

Primary Source

Journal of the American College of Cardiology

Source Reference: Kufner S, et al "10-year outcomes from a randomized Trial of polymer-free versus durable polymer drug-eluting coronary stents" J Am Coll Cardiol 2020; DOI: 10.1016/j.jacc.2020.05.026.

Secondary Source

Journal of the American College of Cardiology

Source Reference: Ben-Yehuda O "Long-term outcomes with drug-eluting stents: beyond stent choice" J Am Coll Cardiol 2020; DOI: 10.1016/j.jacc.2020.05.050.