Comparison of Two-Year Outcomes of Acute Myocardial Infarction Caused by Coronary Artery Spasm Versus that Caused by Coronary Atherosclerosis.

The study compared the 2-year outcomes of patients diagnosed with acute myocardial infarction (AMI) triggered by coronary artery atherosclerosis and AMI caused by coronary artery spasm. A total of 36,797 patients in the Korea AMI Registry were grouped into 2 categories-(1) AMI due to coronary artery spasm without stenotic lesion (CAS-AMI, n = 484); and (2) AMI induced by coronary artery atherosclerosis (CAA-AMI, n = 36,313). The major clinical outcomes of the 2 groups were compared over a 2-year clinical follow-up period. Major adverse cardiac events (MACE) were defined as the composite of total death, nonfatal myocardial infarction, and repeat revascularization. The incidence of MACE (7.1% vs 11.1%; p = 0.007) and repeat revascularization (0.4% vs 4.2%; p <0.001) in the CAS-AMI group were significantly lower than in the CAA-AMI group at 2 years. However, the incidence of total death and nonfatal myocardial infarction was similar in both the groups. Aborted cardiac arrest was strongly associated with 2-year mortality in the CAS-AMI group (hazard ratios 13.5, 95% confidence interval 5.34 to 34.15, p <0.001) The incidence of MACE in CAS-AMI patients was significantly lower than in the CAA-AMI group of patients up to 2 years due to the relatively lower rate of repeat revascularization in CAS-AMI patients. However, the incidence of total death or nonfatal myocardial infarction in CAS-AMI patients was not different from that of patients with CAA-AMI.

Characterization of two types of endothelial progenitor cells and their different contributions to neovasculogenesis.

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.