title: Blood stream infection in patients undergoing systematic off-pump coronary artery bypass: incidence, risk factors, outcome, and associated pathogens.
abstract: BACKGROUND
  Blood stream infection (BSI) is a major cause of mortality and morbidity for patients undergoing cardiac surgery. However, information is lacking about patients undergoing off-pump coronary artery bypass (OPCAB). The purpose of this study was to assess the incidence, risk factors, outcome and associated pathogens of BSI after OPCAB.
  
  
  METHODS
  One thousand ten consecutive patients undergoing OPCAB between 2001 and 2012 were included in a retrospective case-control study. A propensity-matched control was used for risk factor analysis.
  
  
  RESULTS
  Of the 1,010 patients, 26 patients (2.6%) had 32 episodes of BSI after surgery, which occurred at a median of 14 d after surgery. Gram-negative bacilli and gram-positive cocci were distributed equally. Methicillin-resistant Staphylococcus aureus was the pathogen identified most frequently, and the most common source of infection was a surgical site. The hospital mortality rate was 54%. By univariable analysis, diabetes mellitus, pre-operative renal impairment, pre-operative low hemoglobin, pre-operative endotracheal intubation, dialysis before or after surgery, cardiogenic shock, left ventricular ejection fraction of less than 40%, non-elective surgery, low number of distal anastomoses, atrial fibrillation after surgery, and re-operation for bleeding were significant risk factors. By multivariable analysis, the independent risk factors were left ventricular ejection fraction of less than 40%, low number of distal anastomoses, atrial fibrillation after surgery, and dialysis after surgery.
  
  
  CONCLUSIONS
  Blood stream infections remained a common complication after OPCAB, and the mortality was high. Gram-negative bacilli and gram-positive cocci were distributed equally. Methicillin-resistant S. aureus was the pathogen identified most frequently. Preventive tactics should target likely pathogens and high-risk patients undergoing OPCAB.
authors.affiliation: 1 Department of Surgery, National Taiwan University Hospital , Taipei, Taiwan .
authors.forename: Chen-Yen
authors.initials: CY
authors.lastname: Chien
authors.forename: Cheng-Hsin
authors.initials: CH
authors.lastname: Lin
authors.forename: Jeng-Wei
authors.initials: JW
authors.lastname: Chen
authors.forename: Ron-Bin
authors.initials: RB
authors.lastname: Hsu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000209:etiology* / Q000382:microbiology; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome