Objective— Endothelial progenitor cells (EPC) in one study group is not the same as EPC in other investigators, suggesting that EPC is not a single type of cell population. In this study, we tried to demonstrate the heterogeneity of EPC. Methods and Results— We cultured total mononuclear cells from human peripheral blood to get two types of EPC sequentially from the same donors. We called them early EPC and late EPC. Early EPC with spindle shape showed peak growth at 2 to 3 weeks and died at 4 weeks, whereas late EPC with cobblestone shape appeared late at 2 to 3 weeks, showed exponential growth at 4 to 8 weeks, and lived up to 12 weeks. Late EPC was different from early EPC in the expression of VE-cadherin, Flt-1, KDR, and CD45. Late EPC produced more nitric oxide, incorporated more readily into human umbilical vein endothelial cells monolayer, and formed capillary tube better than early EPC. Early EPC secreted angiogenic cytokines (vascular endothelial growth factor, interleukin 8) more so than late EPC during culture in vitro. Both types of EPC showed comparable in vivo vasculogenic capacity. Conclusions— We found two types of EPC from a source of adult peripheral blood that might have different roles in neovasculogenesis based on the identified differences.

Background—: The optimal duration of dual antiplatelet therapy (DAPT) after implantation of drug-eluting coronary stents remains undetermined. We aimed to test whether 6-month DAPT would be noninferior to 12-month DAPT after implantation of drug-eluting stents. Methods and Results—: We randomly assigned 1443 patients undergoing implantation of drug-eluting stents to receive 6- or 12-month DAPT (in a 1:1 ratio). The primary end point was a target vessel failure, defined as the composite of cardiac death, myocardial infarction, or ischemia-driven target vessel revascularization at 12 months. Rates of target vessel failure at 12 months were 4.8% in the 6-month DAPT group and 4.3% in the 12-month DAPT group (the upper limit of 1-sided 95% confidence interval, 2.4%; P =0.001 for noninferiority with a predefined noninferiority margin of 4.0%). Although stent thrombosis tended to occur more frequently in the 6-month DAPT group than in the 12-month group (0.9% versus 0.1%; hazard ratio, 6.02; 95% confidence interval, 0.72–49.96; P =0.10), the risk of death or myocardial infarction did not differ in the 2 groups (2.4% versus 1.9%; hazard ratio, 1.21; 95% confidence interval, 0.60–2.47; P =0.58). In the prespecified subgroup analysis, target vessel failure occurred more frequently in the 6-month DAPT group than in the 12-month group (hazard ratio, 3.16; 95% confidence interval, 1.42–7.03; P =0.005) among diabetic patients. Conclusions—: Six-month DAPT did not increase the risk of target vessel failure at 12 months after implantation of drug-eluting stents compared with 12-month DAPT. However, the noninferiority margin was wide, and the study was underpowered for death or myocardial infarction. Our results need to be confirmed in larger trials. Clinical Trial Registration—: URL: http://www.clinicaltrials.gov . Unique identifier: NCT00698607.

This study was performed to evaluate the functional outcomes of fractional flow reserve (FFR)-guided jailed side-branch (SB) intervention strategy. One hundred and ten patients treated by provisional strategy were consecutively enrolled and SB FFR was measured in 91 patients. SB intervention was allowed when FFR was <0.75. FFR measurement was repeated after SB intervention and at 6-month follow-up angiography. In 26 of 28 SB lesions with FFR <0.75, balloon angioplasty (SB balloon/artery ratio = 0.84 ± 0.14) was performed and FFR ≥0.75 was achieved in 92% of the lesions although the mean residual stenosis was 69 ± 10%. During follow-up, there were no changes in SB FFR in lesions with (0.86 ± 0.05 to 0.84 ± 0.01, P = 0.4) and without SB angioplasty (0.87 ± 0.06 to 0.89 ± 0.07, P = 0.1). Functional restenosis (FFR <0.75) rate was only 8% (5/65). When clinical outcomes of these patients were compared with 110 patients with similar bifurcation lesions treated without FFR-guidance, there was no difference in 9-month cardiac event rates (4.6 vs. 3.7%, P = 0.7) between the two groups. In conclusion, FFR-guided SB intervention strategy resulted in good functional outcomes.