Long-term clinical and angiographic outcomes of patients with sirolimus-eluting stent fracture.

BACKGROUND: There is limited data on the long-term outcomes of patients with sirolimus-eluting stent (SES) fracture. METHODS: After performing index percutaneous coronary intervention (PCI) with SES from Dec. 2003 to Dec. 2007, the patients with stent fracture (SF) detected by angiography at follow-up or adverse events were enrolled. SF was angiographically defined as complete or partial separation of the stent and this had been contiguous after stenting. The patients were divided into two groups as SF without in-stent restenosis (ISR) (Group 1, n=55) and SF with ISR (Group 2, n=44) and the patients were clinically and angiographically followed up after the detection of SF. The major adverse cardiovascular events (MACE), including cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), and stent thrombosis (ST) were determined. RESULTS: At SF detection, most patients were asymptomatic (92.7% in Group 1 vs. 43.2% in Group 2, p=0.001). Acute coronary syndrome developed in 18.2% of Group 2, but it developed in only 1.8% of the patients of Group 1. Clinical follow-up was done in all patients for 675 ± 375 days from SF detection. From the detection of SF, MACEs were noted in 32.3% of the patients (10.9% in Group 1 vs. 59.1% in Group 2, p=0.001), mostly from TVR (9.1% in Group 1 vs. 54.5% in Group 2, p=0.001). CONCLUSION: The long-term follow-up results of SF after SES implantation show an increased risk of adverse cardiac events, and especially for the patients with ISR.

Ex vivo organ culture of adipose tissue for in situ mobilization of adipose-derived stem cells and defining the stem cell niche.

In spite of the advances in the knowledge of adipose-derived stem cells (ASCs), in situ location of ASCs and the niche component of adipose tissue (AT) remain controversial due to the lack of an appropriate culture system. Here we describe a fibrin matrix-supported three-dimensional (3D) organ culture system for AT which sustains the ASC niche and allows for in situ mobilization and expansion of ASCs in vitro. AT fragments were completely encapsulated within the fibrin matrix and cultured under dynamic condition. The use of organ culture of AT resulted in a robust outgrowth and proliferation in the fibrin matrix. The outgrown cells were successfully recovered from fibrin by urokinase treatment. These outgrown cells fulfilled the criteria of mesenchymal stem cells, adherence to plastic, multilineage differentiation, and cell surface molecule expression. In vitro label retaining assay revealed that newly divided cells during the culture resided in interstitium between adipocytes and capillary endothelial cells. These interstitial stromal cells proliferated and outgrew into the fibrin matrix. Both in situ mobilized and outgrown cells expressed CD146 and alpha-smooth muscle actin (SMA), but no endothelial cell markers (CD31 and CD34). The structural integrity and spatial approximation of CD31(-)/CD34(-)/CD146(+)/SMA(+) interstitial stromal cells, adipocytes, and capillary endothelial cells were well preserved during in vitro culture. Our results suggest that ASCs are natively associated with the capillary wall and more specifically, belong to a subset of pericytes. Furthermore, organ culture of AT within a fibrin matrix-supported 3D environment can recapitulate the ASC niche in vitro.