Multistate utilization, processes, and outcomes of carotid endarterectomy

The purpose of this study was to describe variation in utilization, care processes, and outcomes for carotid endarterectomy (CEA) procedures in 10 states.

We reviewed the medical records of Medicare patients who underwent 10,561 CEA procedures between June 1, 1995, and May 31, 1996, in 10 different states to determine indications, care processes, and outcomes. This study also included medical record review of hospital readmissions within 30 days of the procedure and identification of out-of-hospital deaths from the Medicare beneficiary files.

Utilization rates of CEA varied from 25.7 to 38.4 procedures per 10,000 Medicare beneficiaries among states. The overall combined event rate (30-day stroke or mortality) was 5.2% for primary CEA alone (n = 9945). The mortality rate was 1.5%, and the nonfatal stroke rate was 3.7%. Combined event rates (CEA alone) by surgical indication were 7.7% for stroke (n = 1037), 7.4% for transient ischemic attack (n = 1304), 5.3% for nonspecific symptoms (n = 3713), and 3.7% for asymptomatic patients (n = 3891). The combined event rates (CEA alone) among states ranged from 4.1% to 7.7% with the event rates in asymptomatic patients ranging from 2.3% to 6.7%. In a multivariate analysis (correcting for indication), the use of preoperative antiplatelet agents (odds ratio [OR], 0.70), intraoperative heparin (OR, 0.49), and patch angioplasty (OR, 0.73) was significantly associated with lower combined event rates. There were significant differences among states in the use of preoperative antiplatelet therapy (range, 56%-70%) and patch angioplasty (range, 11%-49%). Combined event rates for repeat procedures (n = 380) and CEA combined with coronary artery bypass grafting (n = 236) were 6.3% and 17.4%, respectively.

The striking variation among states suggests that there is room for improvement in the utilization, care processes, and outcomes of CEA. All surgeons performing CEA should participate in outcome assessment and adopt protocols that include the routine administration of antiplatelet agents preoperatively, the use of heparin intraoperatively, and patch angioplasty of the endarterectomy site.