Randomized evaluation of short-term dual antiplatelet therapy in patients with acute coronary syndrome treated with the COMBO dual therapy stent: rationale and design of the REDUCE trial.

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS) patients treated with drug eluting stents (DES) is still under debate. Recent meta-analyses on ≤6months versus 12months DAPT suggest that bleeding rates can be reduced, without a higher rate of thrombotic complications. In particular, the COMBO dual therapy stent, being associated with early re-endothelialization, may allow for a reduction of the duration of DAPT without increasing the thrombotic risk, while reducing the risk of bleeding complications. AIM: The aim of the REDUCE trial is to demonstrate the non-inferiority of a combined efficacy and safety endpoint of a short-term 3months DAPT strategy as compared to standard 12-month DAPT strategy in ACS patients treated with the COMBO stent. DESIGN: A prospective, multicenter, randomized study designed to enroll 1500 patients with ACS treated with the COMBO stent. Patients will be randomized before discharge in a 1:1 fashion to either 3 or 12months of DAPT. A clinical follow-up is scheduled at 3, 6, 12, and 24months. The primary endpoint is the time to event as defined by the occurrence of one of the following: all cause mortality, myocardial infarction, stent thrombosis, stroke, target vessel revascularization or bleeding (Bleeding Academic Research Council type II, III and V) within 12months. The study has recruited patients since July 2014, and the results are expected in 2017. SUMMARY: A reduction of the DAPT duration in ACS patients after PCI without affecting the thrombotic risk is an attractive option with regard to the associated bleeding risk. The REDUCE trial will be the first to investigate the efficacy and safety of a 3-month DAPT strategy compared to a 12-month DAPT strategy in an ACS only population treated with the COMBO stent.

Capture of circulatory endothelial progenitor cells and accelerated re-endothelialization of a bio-engineered stent in human ex vivo shunt and rabbit denudation model.

AIMS: The Genous™ Bio-engineered R™ stent (GS) aims to promote vascular healing by capture of circulatory endothelial progenitor cells (EPCs) to the surface of the stent struts, resulting in accelerated re-endothelialization. Here, we assessed the function of the GS in comparison to bare-metal stent (BMS), when exposed to the human and animal circulation. METHODS AND RESULTS: First, 15 patients undergoing coronary angiography received an extracorporeal femoral arteriovenous (AV) shunt containing BMS and GS. Macroscopical mural thrombi were observed in BMS, whereas GS remained visibly clean. Confocal and scanning electron microscopic (SEM) analysis of GS showed an increase in strut coverage. Quantitative polymerase chain reaction (qPCR) analysis of captured cells on the GS demonstrated increased expression of endothelial markers KDR/VEGFR2 and E-selectin, and a decrease in pro-thrombogenic markers tissue factor pathway inhibitor and plasminogen activator inhibitor-1 compared with BMS. Secondly, a similar primate AV shunt model was used to validate these findings and occlusion of BMS was observed, while GS remained patent, as demonstrated by live imaging of indium-labelled platelets. Thirdly, in an in vitro cell-capture assay, GS struts showed increased coverage by EPCs, whereas monocyte coverage remained similar to BMS. Finally, the assessment of re-endothelialization was studied in a rabbit denudation model. Twenty animals received BMS and GS in the aorta and iliac arteries for 7 days. Scanning electron microscopic analysis showed a trend towards increased strut coverage, confirmed by qPCR analysis revealing increased levels of endothelial markers (Tie2, CD34, PCD31, and P-selectin) in GS. CONCLUSION: In this proof-of-concept study, we have demonstrated that the bio-engineered EPC-capture stent, Genous™ R™ stent, is effective in EPC capture, resulting in accelerated re-endothelialization and reduced thrombogenicity.

A fibronectin-fibrinogen-tropoelastin coating reduces smooth muscle cell growth but improves endothelial cell function.

Reendothelialization of the stent surface after percutaneous coronary intervention (PCI) is known to be an important determinant of clinical outcome. We compared the effects of biological stent coatings, fibronectin, fibrinogen and tropoelastin, on human umbilical vein endothelial cell (HUVEC) and vascular smooth muscle cell (VSMC) characteristics. Umbilical cord arterial segments were cultured on coated surfaces and VSMC outgrowth (indicating proliferation and migration) was measured after 12 days. mRNA was isolated from HUVEC and VSMC cultured on these coatings and gene expression was profiled by QPCR. Procoagulant properties of HUVEC were determined by an indirect chromogenic assay which detects tissue factor activity. The varying stent coatings influence VSMC outgrowth: 31.2 ± 4.0 mm(2) on fibronectin, 1.6 ± 0.3 mm(2) on tropoelastin and 8.1 ± 1.5 mm(2) on a mixture of fibronectin/fibrinogen/tropoelastin, although HUVEC migration remains unaffected. Culturing HUVEC on tropoelastin induces increased expression of VCAM-1 (13.1 ± 4.4 pg/ml), ICAM-1 (5.1 ± 1.3 pg/ml) and IL-8 (11.6 ± 3.1 pg/ml) compared to fibronectin (0.7 ± 0.2, 0.8 ± 0.2, 2.3 ± 0.5 pg/ml, respectively), although expression levels on fibronectin/fibrinogen/tropoelastin remain unaltered. No significant differences in VCAM-1, ICAM-1 and IL-8 mRNA expression are found in VSMC. Finally, HUVEC cultured on tropoelastin display a fivefold increased tissue factor activity (511.6 ± 26.7%), compared to cells cultured on fibronectin (100 ± 3.9%) or fibronectin/fibrinogen/tropoelastin (76.3 ± 25.0%). These results indicate that tropoelastin inhibits VSMC migration but leads to increased inflammatory and procoagulant markers on endothelial cells. Fibronectin/fibrinogen/tropoelastin inhibits VSMCs while compensating the inflammatory and procoagulant effects. These data suggest that coating a mixture of fibronectin/fibrinogen/tropoelastin on a stent may promote reendothelialization, while keeping unfavourable processes such as restenosis and procoagulant activity limited.

Impact of age on the comparison between short-term vs 12-month dual antiplatelet therapy in patients with acute coronary syndrome treated with the COMBO dual therapy stent: 2-Year follow-up results of the REDUCE trial.

BACKGROUND AND AIMS: The impact of advanced age on the optimal duration of dual antiplatelet therapy (DAPT) in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary revascularization (PCI) is still greatly debated. Therefore, the aim of the present sub-analysis of the REDUCE trial was to assess the impact of age on the comparison between a short 3 months vs standard 12 months DAPT in ACS patients treated with the COMBO Dual Stent Therapy. METHODS: The REDUCE trial is a prospective, multicenter, investigator-initiated study that randomized ACS patients undergoing PCI with the COMBO drug eluting stent to either 3 or 12 months of DAPT. The study population was divided according to age (

Efficiency of statin treatment on EPC recruitment depends on baseline EPC titer and does not improve angiographic outcome in coronary artery disease patients treated with the Genous stent.

The objective of this study was to assess the effect of high-dose atorvastatin treatment on endothelial progenitor cell (EPC) recruitment and angiographic and clinical outcome in coronary artery disease (CAD) patients treated with the Genous EPC-capturing stent. The HEALING IIB study was a multicenter, open-label, prospective trial that enrolled 100 patients. Patients were started on 80 mg atorvastatin qd, at least 2 weeks before the index procedure and continued for at least 4 weeks after the index procedure. Eighty-seven patients were included in this analysis. EPC levels significantly increased as early as 2 weeks after the start of atorvastatin. Remarkably, among this group, 31 patients proved to be nonresponders to atorvastatin treatment (i.e., no increase in EPC levels), while 56 patients were responders (i.e., rise in EPC count between week -2 and 0). Compared to responders, nonresponders had a significantly higher baseline EPC count (76 ± 10 vs. 41 ± 5, p < 0.01) with a lower late luminal loss (LLL) at 6- and 18-month follow-up (FU) (0.61 ± 0.07 vs. 0.88 ± 0.08, p < 0.05, and 0.50 ± 0.08 vs. 0.82 ± 0.08, p < 0.01 respectively). Furthermore, baseline EPC count was inversely correlated with LLL at 6-month FU (R = -0.42, p < 0.001). Patients with a higher EPC count at baseline showed no increase in EPC recruitment in response to statin treatment but had favorable LLL at 6- and 18-month FU, whereas patients with lower EPC count were responsive to statin therapy, but EPCs might be less functional as they had higher LLL at 6- and 18-month FU. These data imply that although statin treatment can enhance EPC titer in patients with low baseline levels, there is no indication for a possible beneficial clinical effect with EPC capture stents.

Final results of the HEALING IIB trial to evaluate a bio-engineered CD34 antibody coated stent (Genous™Stent) designed to promote vascular healing by capture of circulating endothelial progenitor cells in CAD patients.

OBJECTIVE: To assess the safety and efficacy of the Genous™ endothelial progenitor cell (EPC) capturing stent in conjunction with HmG-CoA-reductase inhibitors (statins) to stimulate EPC recruitment, in the treatment of patients with de novo coronary artery lesions. METHODS AND RESULTS: The HEALING IIB study was a multi-center, prospective trial, including 100 patients. The primary efficacy endpoint was late luminal loss by QCA at 6-month follow-up (FU). Although statin therapy increased relative EPC levels by 5.6-fold, the angiographic outcome at 6 month FU was not improved in patients with an overall in-stent late luminal loss of 0.76±0.50 mm. The composite major adverse cardiac events (MACE) rate was 9.4%, whereas 6.3% clinically justified target lesion revascularizations (TLRs) were observed. 2 Patients died within the first 30 days after stent implantation due to angiographically verified in-stent thrombosis. At 12 month FU, MACE and TLR increased to 15.6% and 11.5% respectively and stabilized until 24 month FU. 18 Month angiographic FU showed a significant decrease in late luminal loss (0.67±0.54, 11.8% reduction or 10% by matched serial analysis, P=0.001). CONCLUSION: The HEALING IIB study suggests that statin therapy in combination with the EPC capture stent does not contribute to a reduction of in-stent restenosis formation for the treatment of de novo coronary artery disease. Although concomitant statin therapy was able to stimulate EPC recruitment, it did not improve the angiographic outcome of the bio-engineered EPC capture stent. Remarkably, angiographic late loss was significantly reduced between 6 and 18 months.