乌鸦传媒

PARIS -- A novel bioabsorbable polymer stent that sustains drug release after the polymer is gone stood toe-to-toe with the Xience at 1 year, according to the DESSOLVE III randomized trial.

The MiStent drug-eluting stent (DES) met non-inferiority for the combined endpoint of cardiac death, target vessel MI, and clinically-indicated target lesion revascularization at 12 months on intention-to-treat analysis (5.8% versus 6.5% for Xience, non-inferiority P<0.001).

Individual endpoints were no different between either DES, reported Robbert de Winter, MD, PhD, of Academic Medical Center in the Netherlands, at the :

• Cardiac death: 2.0% versus 1.6% (log-rank P=0.552)
• Target vessel MI: 2.2% versus 1.9% (log-rank P=0.716)
• Clinically indicated target lesion revascularization: 2.6% versus 3.8% (log-rank P=0.222)
• Stent thrombosis 0.4% versus 0.7% (log-rank P=0.480)

"The data supports the hypothesis that long-term cytostatic inhibition of early neointima could prevent the late neointimal growth seen at medium and long term with a conventional DES," de Winter told the audience.

The polymer coat on the MiStent embeds microcrystalline sirolimus into the vessel wall and disappears within 60 days of implantation. The drug stays, eluting over 9 months to suppress neointimal hyperplasia.

"It's another good stent on the shelf," said Chaim Lotan, MD, of Israel's Hadassah-Hebrew University Medical Center and a session discussant at the late-breaking trial session. It is increasingly hard to improve upon current-generation DES for major adverse cardiac event rates, he suggested, so it made sense that the authors went for non-inferiority.

So could that small numerical reduction in stent thrombosis be MiStent's advantage in the long term?

Calling the results "certainly believable," Ajay J. Kirtane, MD, SM, of New York-Presbyterian/Columbia University Medical Center in New York City, told 乌鸦传媒: "As with all head-to-head stent studies, longer term follow-up is paramount to ensure that the device is performing appropriately, but given its mechanism of action, we would expect it to. As a result, if subsequent data are supportive and consistent, this stent does appear to be a useful addition to the field."

The MiStent gained in 2013 but remains investigational in the U.S.

For the device to find a place in Kirtane's lab, he said, "I'd need to see U.S. data and a U.S. pivotal trial, but the concept of bioabsorbable polymer with the addition of a crystalline depot of sirolimus does make pathophysiologic sense in terms of an ability to combat restenosis. I think, as a result, there will be a good deal of anticipation for this stent."

In DESSOLVE III, all-comers were randomized at 20 European sites to the MiStent (n=703) or the Xience stent (n=695). The investigators have up to 3 years of follow-up planned.

Among trial participants, there were no significant baseline differences except for the MiStent group having more long lesions. Non-inferiority of the MiStent held up across patient subgroups.

The generalizability of the data is "likely to be high," commented panelist Robert Byrne, MBBCh, PhD, of Munich's German Heart Center. He cited the 25% rate of diabetes and 60% rate of acute coronary syndrome in the study population, as well as treatment of 1.5 lesions per patient.

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