SOLACI | Latin American Society of Interventional Cardiology

Most drug-eluting stents are coated by a polymer that is used to contain the antiproliferative drug. Once the drug is released, the polymer remains in place and its presence has been associated with inflammation, restenosis, and neoatherosclerosis. The MiStent device features a polymer that becomes bioabsorbable once the drug has been released, which could, theoretically, reduce the inflammatory response of the treated segment. MiStent was designed to meet three requirements: a thin-strut platform, a bioabsorbable polymer that disappears from the vessel in 3 months, and a drug whose effect remains for 9 months. The last characteristic is what makes this stent stand out among other bioresorbable-polymer stents in which the effect of the drug vanishes along with the polymer.

The study included 1398 patients from 20 sites and 4 countries, 60% of whom were included in a setting of acute coronary syndrome. Subjects with diabetes, left main lesions, restenosis, or lesions in vein grafts were also eligible (a typical all-comers population). Stable patients received dual antiplatelet therapy for 6 months, while acute patients received it for a year.

The primary endpoint was a composite of cardiac death, acute myocardial infarction, and target-vessel revascularization.

At 2 years, there was no statistically significant difference in the rate of clinical events driven by the device (8.6% for MiStent vs. 8.7% for Xience; p = 0.958).

There was a trend towards a lower risk for revascularization with the new device, although the difference was not significant (5.4% vs. 4.6%; p = 0.44).

In the final analysis at three years, we will see if there are new differences that can be attributed to the disappearing polymer.

Original title: A Randomised Comparison of a Sirolimus-Eluting Bioabsorbable Polymer-Coated Stent vs. an Everolimus-Eluting Durable Polymer Stent in an All-Comer Population – 24-Month Update.

Presenter: W. Wijns.