title: Circulating Microparticles Decrease After Cardiac Stress in Patients With Significant Coronary Artery Stenosis.
abstract: BACKGROUND
  Cardiac stress leads to a dynamic increase of circulating microparticles (MPs) in healthy individuals that is diminished in individuals with vascular disease. The impact of coronary ischemia on circulating MP level is unknown. This study investigates the kinetics of circulating MPs during cardiac stress in patients with coronary artery stenosis.
  
  
  OBJECTIVE
  Patients with significant coronary stenosis show altered circulating MP levels after cardiac stress.
  
  
  METHODS
  Eighty patients with stable coronary artery disease underwent dobutamine stress echocardiography (DSE) on the day before coronary angiography. Before, immediately after, at 4 hours, and at 24 hours after DSE, blood was drawn to determine CD144+endothelial microparticles (EMPs), CD14+CD16+monocyte-derived microparticles (MMPs), and CD31+CD42b+platelet microparticles. A significant stenosis was defined as stenosis diameter ≥70% in a major native epicardial coronary artery with a diameter of ≥2.5 mm.
  
  
  RESULTS
  Significant coronary artery stenoses were found in 41 patients. In these patients, CD144+-EMP and CD14+CD16+-MMP concentrations decreased immediately after DSE. Stimulation of target endothelial cells with sera from patients with significant coronary artery stenoses significantly augmented endothelial capacity to take up EMPs, but not MMPs, in vitro. Serum-induced enhancement of endothelial phosphatidylserine receptor expression was found as a potential mechanism of increased endothelial EMP uptake and subsequently reduced circulating EMP levels after cardiac stress.
  
  
  CONCLUSIONS
  Cardiac ischemia leads to reduced circulating MP levels under cardiac stress. Changes of endothelial MP uptake capacities could be one possible mechanism.
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany. jan-malte.sinning@ukb.uni-bonn.de.
authors.forename: Jan-Malte
authors.initials: JM
authors.lastname: Sinning
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Jansen
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hammerstingl
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Meier
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Losch
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Rohwer
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Schmitz
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Paul
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Sedaghat
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Schueler
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Mariuca
authors.initials: M
authors.lastname: Vasa-Nicotera
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Müller
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Nickenig
authors.affiliation: Department of Medicine II, Heart Center Bonn, University Hospital Bonn, Bonn, Germany.
authors.forename: Nikos
authors.initials: N
authors.lastname: Werner
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000097:blood; D015415:Biomarkers / Q000097:blood; D055252:Cell-Derived Microparticles / Q000378:metabolism* / Q000473:pathology; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000097:blood* / Q000000981:diagnostic imaging; D025401:Echocardiography, Stress; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011956:Receptors, Cell Surface / Q000378:metabolism; D012720:Severity of Illness Index
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D011956:Receptors, Cell Surface; C408123:phosphatidylserine receptor