title: Soluble interleukin 6 receptor levels are associated with reduced myocardial reperfusion after percutaneous coronary intervention for acute myocardial infarction.
abstract: OBJECTIVE
  Interleukin-6 receptor (IL-6R) signalling has been suggested to play a causal role in the development and outcome of coronary heart disease (CHD). The aim of this study was to investigate the association of sIL-6R levels with myocardial reperfusion after percutaneous coronary intervention (PCI) for acute ST-elevated myocardial infarction (STEMI).
  
  
  METHODS
  Blood was sampled from 70 patients presenting with STEMI at 6 different time-points (baseline, post-PCI, t=1h, t=6h, t=24h, t=2w). Coronary angiograms post-PCI were analysed for myocardial blush grade (MBG) as indicator of myocardial reperfusion. Serum IL-6 and sIL-6R were measured using IL-6 and sIL-6R enzyme-linked immunosorbent assays (ELISA).
  
  
  RESULTS
  sIL-6R levels fluctuated biphasic during the two weeks after STEMI. Reduced MBG was associated with a larger change in sIL-6R levels between baseline and post-PCI compared to optimal MBG (-13.40; SEM 2.78ng/ml vs -1.99; SEM 2.35ng/ml, respectively; p<0.001). Patients with reduced MBG also showed a larger increase in sIL-6R levels after PCI and 1h after myocardial infarction (MI) compared to optimal MBG (respectively 11.56; SEM 2.68ng/ml vs 3.02; SEM 2.39ng/ml; p=0.018). IL-6/sIL-6R ratio was also more increased in patients with reduced MBG at 24h after myocardial infarction (0.23; SEM 0.08-0.51 vs 0.10; SEM 0.05-0.21; p=0.024). An optimal MBG was associated with a 10ng increase in sIL-6R level between baseline and post-PCI (OR 1.687, CI 1.095-2.598; p=0.018).
  
  
  CONCLUSIONS
  sIL-6R levels fluctuate biphasic during the two weeks after MI with larger changes and increased IL-6/sIL-6R ratio in patients with reduced MBG. Further research is needed to increase our understanding of the possible causality of these associations.
authors: University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands.
authors: Hilde E
authors: HE
authors: Groot
authors: University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands.
authors: Minke H T
authors: MH
authors: Hartman
authors: University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands.
authors: Youlan L
authors: YL
authors: Gu
authors: Department of Cardiology, Meander Medisch Centrum, Amersfoort, The Netherlands.
authors: Bart J G L
authors: BJ
authors: de Smet
authors: University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands.
authors: Ad F M
authors: AF
authors: van den Heuvel
authors: University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands.
authors: Erik
authors: E
authors: Lipsic
authors: University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands; Durrer Center for Cardiovascular Research, ICIN-Netherlands Heart Institute, Utrecht, The Netherlands. Electronic address: p.van.der.harst@umcg.nl.
authors: Pim
authors: P
authors: van der Harst
mesh_terms: D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000097:blood* / Q000000981:diagnostic imaging / Q000601:surgery; D015425:Myocardial Reperfusion; D062645:Percutaneous Coronary Intervention; D010976:Platelet Count; D019947:Receptors, Interleukin-6 / Q000097:blood*; D012044:Regression Analysis; D012995:Solubility; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D019947:Receptors, Interleukin-6; D002097:C-Reactive Protein
keywords: Myocardial reperfusion; Soluble interleukin-6 receptor