John Ormiston, Mercy Angiography Unit, Auckland, New Zealand, presented four, six and eight month data from the first-in-human DESSOLVE I trial of the MiStent Sirolimus drug-eluting coronary stent system (Micell Technologies) at the Transcatheter Cardiovascular Therapeutics Conference (TCT) 2011, in San Francisco, USA.
“These preliminary study results demonstrated excellent performance by the MiStent DES at up to eight months post-procedure—when patients typically experience the greatest increase in neointimal hyperplasia,” said Ormiston, principal investigator of the study. “MiStent DES is intended to provide enhanced patient safety and outcome by eliminating long-term exposure to DES non-erodible polymers. In addition to delivering clinical performance, MiStent DES may also enable physicians to pursue shorter duration dual anti-platelet therapy, and offer a safer choice to their non-compliant patients or patients who may be undergoing additional surgical procedures.”
Thirty patients were treated with the MiStent DES with independent subgroups of 10 patients assigned to a four-month, six-month or eight-month follow-up. The primary efficacy endpoint was in-stent late lumen loss. Safety was assessed by incidence of major adverse cardiac events and presence of tissue coverage within the treated artery at each time point.
Angiography, intravascular ultrasound and optical coherence tomography imaging results were measured by independent core laboratories. Preliminary analysis of the data demonstrated a very low median in-stent late lumen loss of 0.03 mm at four months, 0.10 mm at six months and 0.08 mm at eight months follow-up with no binary restenosis or revascularisations. The mean in-stent late lumen loss values at four, six and eight months were 0.01, 0.21 and 0.09 mm, respectively. The mean and median values were comparable except at the six month time point, in which one patient experienced a high late loss value due to treatment of a highly calcified lesion and under-expansion of the stent. When data from this patient is excluded, the six month mean late lumen loss is 0.10 mm. The median per cent of stent struts covered by tissue was 96% at eight months, 97% at six months and 90% at four months per OCT analysis.
“The MiStent DES was designed to address a need for improved patient safety while providing equivalent or better efficacy as compared to currently available drug-eluting stents,” observed Dennis Donohoe, chief medical advisor to Micell. “The excellent clinical outcomes of the DESSOLVE I trial demonstrate the value of the MiStent design in enabling elimination of drug and polymer from the stent in 45 to 60 days and providing patients the best of drug-eluting stent and bare metal stent in one solution.”