CABG Plus Endarterectomy Increases Post-Op Stroke and Death

January 15, 2007

KANSAS CITY, Kan. -- When carotid endarterectomies and coronary artery bypass grafts are combined, the risk of postoperative stroke or death rises by nearly 40% over CABG alone, investigators here reported.

KANSAS CITY, Kan., Jan. 15 -- It seemed like a good idea, but combining a carotid endarterectomy with a coronary artery bypass graft increased the risk of postoperative stroke and death by nearly 40% over CABG alone, investigators here reported.

In a review of records on patients nationwide who underwent CABG with or without carotid endarterectomy, the odds ratio for a combined endpoint of postoperative stroke or death was 2.25 for patients who underwent both procedures, reported Richard M. Dubinsky, M.D., M.P.H.; and Sue Min Lai, Ph.D., M.B.A., of the University of Kansas Medical Center.

After correction for co-morbidities, the odds ratio was reduced to a smaller but still significant 1.38 compared with patients who underwent CABG only, they wrote in the Jan. 15 issue of Neurology.

Their findings suggest that theoretical benefit of combining the surgeries may not outweigh the increased risks.

"The underlying rationales for combined carotid endarterectomy-CABG are to protect the carotid circulation from artery-to-artery embolic stroke during CABG and to lessen the risk by having just one operation, albeit longer, and one exposure to anesthesia," the authors wrote.

"Although there is an increased likelihood of carotid artery disease in those with coronary artery disease, the risk of asymptomatic carotid artery stenosis is low enough that perioperative mortality can be greater than the benefit of reduced risk of stroke compared with medication alone."

The investigators conducted a retrospective study of records from the Nationwide Inpatient Sample, a database that provides yearly admission and discharge data from nearly 1,000 hospitals.

They extracted data on community-wide mortality and morbidity rates in patients undergoing combined carotid-endarterectomy-CABG in the United States from 1993 through 2002.

The cohort included 657,877 patients ranging from 32 to 89 years old, 178,959 of whom underwent endarterectomy alone, 471,881 who underwent CABG alone, and 7,037 who underwent both procedures. Of the combined surgery group, 1,203 were known to have undergone the procedures on the same day; the spacing of procedures in the remaining 5,807 was unknown.

The investigators calculated the odds ratio for the combined outcomes of postoperative stroke or death for same-day endarterectomy-CABG to be 2.16 (95% confidence interval 1.78 to 2.62, P

"The frequency of combined carotid endarterectomy-CABG has increased, but the reported case series are inadequate to conclude whether there is a benefit to combining the procedures," Dr. Dubinsky and Dr. Lai wrote. "A randomized controlled clinical trial, stratified for the degree of carotid stenosis and for previous stroke, with a follow-up of at least one year, is clearly needed to determine the benefit, if any, of combined carotid endarterectomy-CABG in patients with carotid and coronary atherosclerosis."