title: Monocyte activation in on-pump versus off-pump coronary artery bypass surgery.
abstract: OBJECTIVE
  Monocyte activation plays a key role in amplifying both inflammatory and coagulopathic sequelae in patients undergoing on-pump coronary artery bypass graft (CABG) surgery. Off-pump CABG diminishes, but does not eliminate, the systemic inflammatory response and its influence on monocyte activation remains unclear. This study was performed to determine if off-pump CABG suppresses all features of monocyte activation.
  
  
  METHODS
  Prospective, controlled, clinical study.
  
  
  METHODS
  University-affiliated veterans affairs hospital and laboratory.
  
  
  METHODS
  Twenty-two patients scheduled to undergo primary CABG surgery (11 on-pump and 11 off-pump).
  
  
  METHODS
  On-pump and off-pump CABG surgery was performed via median sternotomy. Anticoagulation and heparin reversal were identical. Moderate hypothermia (28 degrees-30 degrees C) was used for on-pump CABG surgery, whereas temperature was maintained above 35.5 degrees C for off-pump CABG. No antifibrinolytic agents were used.
  
  
  RESULTS
  Perioperative monocyte changes were assessed by using cellular (CD11b, monocyte-platelet conjugates) and secreted markers (plasma IL-6, IL-8, and IL-10) measured at 6 time points before, during, and after CABG surgery. Off-pump CABG surgery completely blocked the increases in monocyte CD11b expression (p < 0.001) and monocyte-platelet conjugate formation (p < 0.001) observed in the on-pump group. In contrast, plasma interleukin levels were significantly elevated in both groups, although off-pump CABG surgery resulted in lower levels (p < 0.001) and a delayed time course.
  
  
  CONCLUSIONS
  Off-pump CABG surgery attenuates monocyte secreted cytokines and completely suppresses activation-dependent monocyte cell-surface changes (CD11b, monocyte-platelet conjugate formation). Whether these pathophysiologic differences in monocyte activation translate into a reduction in adverse events after CABG surgery warrants a larger, randomized, outcomes study.
authors.affiliation: Department of Anesthesiology and Pain Management, UT Southwestern Medical Center, Dallas, TX 75390-9202, USA. philip.greilich@utsouthwestern.edu
authors.forename: Philip E
authors.initials: PE
authors.lastname: Greilich
authors.forename: Chad F
authors.initials: CF
authors.lastname: Brouse
authors.forename: Henry M
authors.initials: HM
authors.lastname: Rinder
authors.forename: Michael E
authors.initials: ME
authors.lastname: Jessen
authors.forename: Christine S
authors.initials: CS
authors.lastname: Rinder
authors.forename: Robert C
authors.initials: RC
authors.lastname: Eberhart
authors.forename: Charles W
authors.initials: CW
authors.lastname: Whitten
authors.forename: Brian R
authors.initials: BR
authors.lastname: Smith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000379:methods; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D019990:Perioperative Care / Q000379:methods; D011446:Prospective Studies