Long-term preclinical evaluation of bioabsorbable polymer-coated drug-eluting stent in a porcine model

A First-in-Man Clinical Evaluation of Sirolimus and Ascorbic Acid-Eluting Stent Systems: a Multicenter, Subject-Blinded, Randomized Study

This prospective, multi-center, randomized, comparative, and pivotal clinical study in patients with coronary artery occlusive disease was conducted to evaluate the safety and efficacy of D+Storm™ drug-eluting stent (DES), a sirolimus-eluting stent coated with polylactic acid and ascorbic acid. Our results showed that in-segment late lumen loss of D+Storm™ DES group was non-inferior to BioMatrix Flex™ DES group and the total procedural success rate of D+Storm™ DES group was 100%. In addition, the safety of the D+Storm™ DES group at 36 weeks was also demonstrated in this study.

Background and Objectives

This clinical trial was conducted to evaluate the safety and efficacy of D+Storm™ drug-eluting stent (DES) and BioMatrix Flex™ DES.

Methods

This study was a multicenter, subject-single-blind, randomized, and confirmed comparative clinical trial. According to the inclusion criteria, those diagnosed with stable angina, unstable angina, silent ischemia, or non-ST-segment myocardial infarction were selected among patients with coronary artery stenosis as subjects. Among the subjects with 50% stenosis on coronary angiography, the experiment was performed on those who had a lesion with reference vessel 2.5–4.0 mm in diameter and ≤40 mm in length. The primary endpoint was an in-segment late loss and the secondary endpoints were in-stent late lumen loss, stent malapposition, the incidence of mortality, myocardial infarction, reoperation, and stent thrombosis at 36 weeks.

Results

57 patients in the D+Storm™ DES group and 55 patients in the BioMatrix Flex™ DES group were enrolled in the study. Fifty-seven patients in the D+Storm™ DES group and Fifty-five patients in the BioMatrix Flex™ DES group were enrolled in the study. An average of in-segment late lumen loss was 0.08±0.13 mm in the D+Storm™ DES group and 0.14±0.32 mm in the BioMatrix Flex™ DES group with no significant difference between the 2 groups (p=0.879). In addition, there was no significant difference in adverse events between D+Storm™ DES and BioMatrix Flex™ DES.

Conclusions

This study demonstrated the clinical effectiveness and safety of D+Storm™ DES implantation in patients with coronary artery disease over a 36-week follow-up period.

Study of functional drug-eluting stent in promoting endothelialization and antiproliferation

Drug-eluting stents have been widely used in the clinic because of their impressive ability to reduce restenosis. However, the conventional biodegradable polymers used for drug-loaded coatings undergo bulk erosion, which can induce internal catalysis, resulting in a high local acidity during the degradation process and unfavorable side-effects. Herein, poly(1,3-trimethylene carbonate), a surface eroding biodegradable polymer, was chosen as a drug-loaded coating for cardiovascular stents. We modified both sides of the stent to simultaneously promote re-endothelialization at the inner layer and reduce restenosis at the outer layer, using a titanium oxide (Ti-O) film as the inner layer and a Ti-O film/drug coating as the outer layer. In vitro and in vivo results indicated that the Ti-O film accelerated endothelial cell growth and re-endothelialization, and the drug coating inhibited platelet adhesion, activation, and aggregation, smooth muscle cell proliferation, and significantly reduced neointimal hyperplasia. Therefore, this novel stent may have potential as a cardiovascular stent to treat patients with coronary artery stenosis.