Common Reasons That Asymptomatic Patients Who Are 65 Years and Older Receive Carotid Imaging

National guidelines do not agree on the role of carotid screening in asymptomatic patients (ie, patients who have not had a stroke or transient ischemic attack). Recently, several physician organizations participating in the Choosing Wisely campaign have identified carotid imaging in selected asymptomatic populations as being of low value. However, the majority of patients who are evaluated for carotid stenosis and subsequently revascularized are asymptomatic.

To better understand why asymptomatic patients who undergo revascularization receive initial carotid imaging.

Retrospective cohort study of 4127 Veterans Health Administration patients 65 years and older undergoing carotid revascularization for asymptomatic carotid stenosis between 2005 and 2009.

Indications for carotid ultrasounds were extracted using trained abstractors. Frequency of indications and appropriateness of initial carotid ultrasound imaging for patients within each rating category after the intervention were reported.

The mean (SD) age of this cohort of 4127 patients was 73.6 (5.9) years; 4014 (98.8%) were male. Overall, there were 5226 indications for 4063 carotid ultrasounds. The most common indications listed were carotid bruit (1578 [30.2% of indications]) and follow-up for carotid disease (stenosis/history of carotid disease) in patients who had previously documented carotid stenosis (1087 [20.8% of indications]). Multiple vascular risk factors were the next most common indication listed. Rates of appropriate, uncertain, and inappropriate imaging were 5.4% (227 indications), 83.4% (3387 indications), and 11.3% (458 indications), respectively. Among the most common inappropriate indications were dizziness/vertigo and syncope. Among the 4063 patients, 3373 (83.0%) received a carotid endarterectomy. Overall, 663 procedures were performed in patients 80 years and older.

Carotid bruit and follow-up for carotid disease accounted for approximately half of all indications provided by physicians for carotid testing. Strong consideration should be given to improving the evidence base around carotid testing, especially around monitoring stenosis over long periods and evaluating carotid bruits. Targeting carotid ultrasound ordering with decision support tools may also be an important step in reducing use of low-value imaging.