title: Location of the second internal mammary artery graft does not influence outcome of coronary artery bypass grafting.
abstract: BACKGROUND
  Although the use of two internal mammary arteries (IMA) in coronary artery bypass graft surgery has been associated with improved patient survival and clinical status, the optimal use of the second IMA graft remains controversial. We, therefore, explored clinical outcomes in a large cohort of patients undergoing bilateral IMA grafting.
  
  
  METHODS
  Between February 1972 and May 1994, 2,215 consecutive patients underwent bilateral IMA grafting. The second IMA was used to revascularize the left coronary system (LCS) in 1,479 and the right coronary system (RCS) in 736 patients. Propensity score optimal matching algorithm was used to create the matched LCS group (n=730) and RCS group (n=730). Cross-sectional follow-up (6 weeks to 32.1 years; mean 12.8; 96.7% complete) was performed. Multivariable analyses were performed to determine correlates of operative mortality and late mortality. Patient clinical status and Short Form-36 scores of late survivors were compared.
  
  
  RESULTS
  There was no difference in either operative mortality or late survival between LCS and RCS patients, in either unmatched or matched groups. Operative mortality unmatched was LCS 38 of 1,479 (2.6%) versus RCS 20 of 736 (2.7%; p=0.837). For matched groups, it was LCS 13 of 730 (1.8%) versus RCS 20 of 736 (2.7%; p=0.284). Median survival in unmatched patients was LCS 15.8 years versus RCS 16.1 years (p=0.803); for matched patients, it was LCS 16.1 years versus RCS 16.1 years (p=0.671). Site of second IMA was not associated with either operative mortality or late survival on multivariable analysis. At follow-up, both groups demonstrated excellent clinical outcomes, with 98.4% of LCS patients and 96.8% of RCS patients in Canadian Cardiovascular Society class I or II, and no significant difference in either the physical (p=0.142) or mental (p=0.542) health summary scores on the Short Form-36.
  
  
  CONCLUSIONS
  Use of two IMA grafts demonstrates excellent long-term results with no demonstrable difference in outcome between RCS and LCS patients.
authors: Florida Heart Research Institute, Miami, Florida 33137, USA. doctorwu18@aol.com
authors: Paul A
authors: PA
authors: Kurlansky
authors: Ernest A
authors: EA
authors: Traad
authors: Malcolm J
authors: MJ
authors: Dorman
authors: David L
authors: DL
authors: Galbut
authors: Melinda
authors: M
authors: Zucker
authors: George
authors: G
authors: Ebra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000379:methods / Q000401:mortality; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000401:mortality; D006084:Graft Rejection; D006085:Graft Survival; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000379:methods* / Q000401:mortality*; D007431:Intraoperative Complications / Q000401:mortality; D008297:Male; D008323:Mammary Arteries / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate