Does radial use as a second arterial conduit for coronary artery bypass grafting improve long-term outcomes in diabetics?
OBJECTIVE
The evidence supporting the survival benefit of multiple arterial grafts in the general coronary bypass surgery (CABG) population is compelling. Alternatively, results of studies comparing 2 versus 1 internal thoracic artery (ITA) grafts in diabetics have reported conflicting survival data. The use of radial versus ITA as the second arterial conduit has not been studied.


METHODS
We obtained complete death follow-up in 1516 consecutive diabetic [64+/-10 years (mean+/-SD). Insulin/no insulin: There were 540 (36%)/976 (64%)] primary isolated CABG patients all with >or=1 ITA grafts. The series included 626 ITA/radial (41%) and 890 ITA/vein (59%) patients. Using separate radial-use propensity models, we matched one-to-one 475 (76%) ITA/radial to 475 (53%) unique ITA/vein patients; each including 166 insulin and 309 no insulin patients.


RESULTS
Unadjusted survival was markedly better for (1) ITA/radial (94.3%, 86.7% and 70.4% at 1, 5 and 10 years, respectively) versus ITA/vein (91.8%, 74.5% and 53.8%; p<0.0001) and (2) for no insulin (94.2%, 82.8% and 65.5%) versus insulin (90.4%, 73.1% and 49.2%; p<0.0001). In matched patients, 11-year Kaplan-Meier analysis showed essentially identical ITA/radial and ITA/vein survival for all diabetics combined (p=0.53; log rank) and for the no insulin (p=0.76) cohort. Lastly, a trend for better ITA/radial survival in insulin dependent diabetics after the second postoperative year did not reach significance (p=0.13).


CONCLUSIONS
Using radial as a second arterial conduit as opposed to vein grafting did not confer a survival benefit in diabetics. This unexpected result is perhaps related to relatively diminished radial graft patency and/or the augmented radial vasoreactivity characteristic of diabetics. These findings indicate that the radial survival advantage demonstrated in the general CABG population lies primarily in non-diabetics in whom this advantage may be underestimated.
Schwann
Thomas A
TA
Division of Cardiothoracic Surgery, The Regional Heart and Vascular Center at St. Vincent Mercy Medical Center, Toledo, OH 43608, USA.
Zacharias
Anoar
A
Riordan
Christopher J
CJ
Durham
Samuel J
SJ
Shah
Aamir S
AS
Habib
Robert H
RH
D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications / Q000401:mortality / Q000601:surgery*; D003331:Coronary Vessels / Q000601:surgery; D048909:Diabetes Complications / Q000401:mortality / Q000601:surgery*; D003922:Diabetes Mellitus, Type 1 / Q000401:mortality / Q000601:surgery; D003924:Diabetes Mellitus, Type 2 / Q000401:mortality / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008323:Mammary Arteries / Q000637:transplantation; D008875:Middle Aged; D016016:Proportional Hazards Models; D017534:Radial Artery / Q000637:transplantation*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014654:Vascular Patency