Anemia before coronary artery bypass surgery as additional risk factor increases the perioperative risk.

Background: A negative relationship between anemia before coronary artery bypass graft (CABG) surgery and the perioperative mortality has been shown. We tried to clarify whether anemia only expresses an increased perioperative risk or is a risk factor per se in a two-institution database.

Methods: In the years 2005 and 2006, 185 of 3,311 patients undergoing isolated first-time CABG surgery had anemia defined as hematocrit less than 33% or Hb≤11 g/dL.