title: Impact of an endothelial progenitor cell capturing stent on coronary microvascular function: comparison with drug-eluting stents.
abstract: OBJECTIVE
  Although drug-eluting stents (DESs) effectively reduce restenosis following percutaneous coronary intervention (PCI), they also delay re-endothelialization and impair microvascular function, resulting in adverse clinical outcomes. Endothelial progenitor cell (EPC) capturing stents, by providing a functional endothelial layer on the stent, have beneficial effects on microvascular function. However, data on coronary microvascular function in patients with EPC stents versus DESs are lacking.
  
  
  METHODS
  Seventy-four patients who previously underwent PCI were enrolled in this study. Microvascular function was evaluated 6 months after PCI based on the index of microvascular resistance (IMR) and the coronary flow reserve (CFR). IMR was calculated as the ratio of the mean distal coronary pressure at maximal hyperemia to the inverse of the hyperemic mean transit time (hTmn). The CFR was calculated by dividing the hTmn by the baseline mean transit time.
  
  
  RESULTS
  Twenty-one patients (age, 67.2 ± 9.6 years; male:female, 15:6) with an EPC stent and 53 patients (age, 61.5 ± 14.7 years; male:female, 40:13) with second-generation DESs were included in the study. There were no significant differences in the baseline clinical and angiographic characteristics of the two groups. Angiography performed 6 months postoperatively did not show significant differences in their CFR values. However, patients with the EPC stent had a significantly lower IMR than patients with second-generation DESs (median, 25.5 [interquartile range, 12.85 to 28.18] vs. 29.0 [interquartile range, 15.42 to 39.23]; p = 0.043).
  
  
  CONCLUSIONS
  Microvascular dysfunction was significantly improved after 6 months in patients with EPC stents compared to those with DESs. The complete re-endothelialization achieved with the EPC stent may provide clinical benefits over DESs, especially in patients with microvascular dysfunction.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Konkuk University School of Medicine, Chungju, Korea.
authors.forename: Woong Gil
authors.initials: WG
authors.lastname: Choi
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Konkuk University School of Medicine, Chungju, Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Konkuk University School of Medicine, Chungju, Korea.
authors.forename: Hyung Seok
authors.initials: HS
authors.lastname: Yoon
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Konkuk University School of Medicine, Chungju, Korea.
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, Korea.
authors.forename: Dong Woon
authors.initials: DW
authors.lastname: Kim
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D054855:Drug-Eluting Stents; D066026:Endothelial Progenitor Cells / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation*; D011474:Prosthesis Design; D062326:Re-Epithelialization; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance
keywords: Coronary stent; Microvascular function