title: Mid-term outcomes of off-pump versus on-pump coronary artery bypass graft surgery.
abstract: OBJECTIVE
  To evaluate survival and readmissions to hospital for cardiac events or coronary revascularization (REVASC) in patients having off-pump (OPCAB) versus conventional on-pump (CCAB) coronary artery bypass graft surgery (CABG).
  
  
  METHODS
  Of 11,368 consecutive patients undergoing isolated CABG between 1996 and 2002, 514 had OPCAB surgery. Using propensity scores, 503 CCAB patients were randomly matched to 503 OPCAB patients.
  
  
  RESULTS
  There were no clinical or statistical differences between the two groups for any prognostic variable. However, OPCAB patients received significantly fewer distal anastomoses than the CCAB group (2.6+/-1.0 versus 3.1+/-1.0; P<0.001). There was no difference in operative mortality (OPCAB 1.0%, CCAB 1.4%; P=0.6), but the OPCAB group had significantly fewer operative strokes (0.2% versus 1.8%; P=0.01). Follow-up was 99.7% complete at 2.2+/-1.2 years (range 0 to 6 years). Twice as many OPCAB patients (n=24) required REVASC compared with the CCAB (n=11) group. The following five-year actuarial outcomes are presented for CCAB and OPCAB, respectively: survival: 77+/-6%, 76+/-8%, P=0.8; freedom from REVASC: 95+/-3%, 92+/-2%, P=0.02; and cardiac event-free survival: 76+/-5%, 62+/-8%; P=0.05. Cox regression revealed that OPCAB was a significant independent predictor of poorer freedom from REVASC (RR 2.2, 95% CI 1.0 to 4.6; P=0.04) and cardiac event-free survival (RR 1.6, 95%CI 1.1 to 2.2; P=0.02).
  
  
  CONCLUSIONS
  The use of OPCAB remains controversial. These results, from this early experience, suggest that despite improved hospital outcomes, the lesser degree of REVASC raises concerns about the need for repeat revascularization in the OPCAB group.
authors.affiliation: Division of Cardiology, University Health Network-Toronto General Hospital, Toronto, Ontario. joan.ivanov@uhn.on.ca
authors.forename: Joan
authors.initials: J
authors.lastname: Ivanov
authors.forename: Michael A
authors.initials: MA
authors.lastname: Borger
authors.forename: Jack V
authors.initials: JV
authors.lastname: Tu
authors.forename: Vivek
authors.initials: V
authors.lastname: Rao
authors.forename: Tirone E
authors.initials: TE
authors.lastname: David
mesh_terms: D000368:Aged; D002170:Canada; D002315:Cardiopulmonary Bypass / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000401:mortality*; D047549:Coronary Artery Bypass, Off-Pump / Q000401:mortality*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000401:mortality*; D011446:Prospective Studies; D012044:Regression Analysis; D012189:Retrospective Studies; D020521:Stroke / Q000401:mortality; D016019:Survival Analysis