Leveraging Health Information Technology to Avoid Unnecessary Asymptomatic Carotid Revascularization

Carotid revascularization, via carotid endarterectomy or stenting, is commonly performed to reduce future stroke risk in patients with symptomatic, severe, extra-cranial carotid artery stenosis. For patients with asymptomatic carotid stenosis, decision making strategies must carefully weigh the near-term risks of revascularization against the long-term risk of stroke during the patient’s expected lifespan. Research suggests carotid revascularization is the best choice for low-risk patients likely to survive long enough to benefit from the procedure; however, it is difficult to define the factors that accurately identify patients at risk for poor peri-operative outcomes and long-term survival. These procedures are considered to have been “unnecessary” in asymptomatic patients who subsequently die from non-stroke related causes within 2 years of the procedure.

This project developed a decision making tool for patients with asymptomatic carotid stenosis. The team merged data from the Vascular Quality Initiative national registry and Medicare claims data to predict which patients presenting with asymptomatic carotid disease received unnecessary carotid revascularization. The data were then used to develop the Carotid Artery Risk Assessment Tool (CARAT) to identify patients who are most likely to receive an unnecessary carotid revascularization. A CARAT mobile application was created, and the tool was also integrated into the electronic health record.

The specific aims of this project were as follows:

• Identify which patients receive unnecessary carotid revascularization using a linked registry-claims dataset, and design and implement a Health IT Tool to convey this evidence to providers. 
• Determine the potential cost savings associated with avoiding unnecessary carotid revascularization in asymptomatic patients. 

The CARAT tool accurately identified patients unlikely to benefit from carotid revascularization, as well as the patients whose procedures were likely to be expensive. The risk model underlying the CARAT tool identified predictors of poor survival following revascularization as age over 80, diabetes, congestive heart failure, chronic obstructive pulmonary disease, smoking, renal failure, contralateral carotid stenosis, and absence of statin therapy. During pilot testing, CARAT was used by providers during 70 percent of eligible patient visits. Cost analysis found that the average cost of carotid revascularization was between $6,000 and $8,000 for Medicare patients; however, costs for patients with complications, some of whom did not need the procedure, could exceed $50,000.