Propensity Analysis Compares the MiStent SES and Xience V at 1 and 3 Years

May 19, 2015—Micell Technologies, Inc. announced the presentation of data from a retrospective cross-study propensity analysis comparing the company’s absorbable polymer coronary MiStent sirolimus-eluting stent (SES) system to Abbott Vascular’s durable polymer coronary Xience V everolimus-eluting stent system. Alexandra Lansky, MD, presented the data at the EuroPCR 2015 conference held May 19–22 in Paris, France. 

Dr. Lansky is Director of Interventional Cardiovascular Research at Yale University School of Medicine in New Haven, Connecticut. The analysis was conducted independently by Dr. Lansky and Robert Byrne, MD, of the German Heart Center in Munich, Germany, with funding from Micell Technologies.

The objective of the analysis was to compare the clinical outcomes of the MiStent to the cobalt chromium Xience V stent at 1- and 3-years postimplantation. Investigators performed a retrospective patient-level, propensity-matched analysis comparing data from the DESSOLVE I and DESSOLVE II studies, which evaluated the MiStent, to the Xience V arm of the ISAR-TEST-4 study using prespecified baseline and lesion characteristics. 

Micell noted that ISAR-TEST-4 used very similar event definitions as the DESSOLVE studies, with a Clinical Events Committee review process. Clinical and angiographic endpoints were compared between the two treatment groups in the matched cohort. The prespecified primary endpoint was target lesion failure (TLF) at 1 and 3 years.

The propensity-matched analysis demonstrated statistically significant reduced TLF and target lesion revascularization (TLR) rates at 1 and 3 years for the absorbable MiStent SES (n = 102) compared to the durable Xience V stent (n = 102). The TLF rates at 1 year were 2.9% versus 12.3% (P = .01), and at 3 years, they were 5% versus 16.5% (P = .006). The TLR rates at 1 year were 1% versus 8.7% (P = .009), and at 3 years, TLR rates were 2% versus 12.3% (P = .004).

Micell Technologies stated that these results are hypothesized to be due to improvements in device design, and DESSOLVE III, a 1,400 patient, all-comers randomized clinical trial, has been initiated to confirm these results. DESSOLVE III will also include an optical coherence tomography substudy evaluation of 60 patients at 6 and 24 months posttreatment to evaluate and compare for superiority of MiStent SES against Xience V in the progression of in-stent percent volume obstruction and frequency of neoatheroma formation over time.

In the company’s press release, Dr. Lansky said, “Acknowledging this is a cross-study comparison, the patient-level propensity analysis provided for the identification of well-matched populations. Our results suggest that the design of the MiStent SES may offer clinical benefit compared to Xience.”

Also at EuroPCR, Micell presented updated DESSOLVE I data which showed a long-term safety profile with 0% TLR and 0% stent thrombosis through 4 years. Previously reported imaging studies have revealed high rates of initial healing after implantation of the MiStent SES, with early stent strut coverage and normal endothelial function at 9 months combined with a minimal progression of neointimal hyperplasia through 18 months.