The effect of left internal mammary artery utilization on short-term outcomes after coronary revascularization.
BACKGROUND
The purpose of this study was to determine whether use of the left internal mammary artery (LIMA) during coronary revascularization influences short-term morbidity in all patients undergoing revascularization, as well as in patients over the age of 75 years, female patients, and patients with diabetes. The study also explored variability in the utilization of LIMA grafts across an entire state.


METHODS
Using the Clinical Outcomes Assessment Program (COAP) of the state of Washington, procedural outcomes were compared for patients receiving and patients not receiving LIMA grafts as part of revascularization procedures from January 1, 1999 to December 31, 2000. Mortality and major complications were examined, both as unadjusted rates and after adjusting for baseline patient risk factors.


RESULTS
A total of 16 centers performed 8,797 nonemergent coronary artery revascularizations, including 81.7% with LIMA grafts. The use of a LIMA graft was associated with a significantly lower mortality (3.7% No LIMA vs 1.6% LIMA), as well as decreases in ventricular arrhythmias, need for postoperative dialysis, need for transfusions, ventilator dependence, and length of hospital stay. These trends were true for the population as a whole as well as for all subgroups analyzed, and they persisted after correcting for differences in comorbid conditions. In addition, there was wide variability in the use of LIMA grafts from center to center in the state.


CONCLUSIONS
The use of LIMA grafts for coronary revascularization is associated with decreased mortality and morbidity. Despite these advantages, there is great variability in its application across the state of Washington.
Dabal
Robert J
RJ
Division of Cardiothoracic Surgery, Department of Internal Medicine, University of Washington School of Medicine and Health Services Research and Development, Department of Veteran's Affairs, Seattle, 98195, USA.
Goss
J Richard
JR
Maynard
Charles
C
Aldea
Gabriel S
GS
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D015897:Comorbidity; D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality*; D003327:Coronary Disease / Q000453:epidemiology / Q000601:surgery; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000009:adverse effects / Q000379:methods; D008323:Mammary Arteries / Q000637:transplantation*; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods / Q000401:mortality; D011183:Postoperative Complications / Q000401:mortality*; D011336:Probability; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome