Imaging provides cost-effective way to target revascularization in those at risk for stroke

Transcranial Doppler ultrasound is a cost-effective way to identify patients with carotid artery stenosis who are candidates for aggressive intervention, according to a study published online Sept. 16 in Radiology.

The approach used in the study, which measures cerebrovascular reserve (CVR), could help solve the issue of managing asymptomatic patients.

“CVR assessment can help identify patients with carotid artery stenosis who are at higher baseline risk for stroke, and thus, are better candidates for revascularization procedures,” wrote Ankur Pandya, PhD, assistant professor of healthcare policy and research and public health in radiology at Weill Cornell Medical College in New York City, and colleagues.

Carotid artery stenosis is the primary cause of one-in-five ischemic strokes. While stroke victims often undergo revascularization procedures, what’s less clear is whether these procedures should be used in asymptomatic patients.

To shed some light on the issue, Pandya and colleagues used a mathematical model to make hypothetical comparisons among three different approaches: CVR testing, immediate revascularization with carotid endarterectomy and medical therapy-based management (with subsequent revascularization only for patients whose stenosis got worse).

The models showed that the CVR-based approach appeared to have the most favorable combination of benefits and costs. About half the patients received revascularization using this approach and total costs per person were $16,583.

Total costs for a medical therapy-based strategy were lowest at $14,597, but also featured the lowest lifetime quality-adjusted years. Immediate revascularization resulted in the highest costs at $20,950, and resulted only in incremental health benefits compared with the CVR-based approach.

The incremental cost-effectiveness ratio for the CVR-based strategy compared with the medical therapy approach was $23,000 per quality adjusted life year.

The authors suggested that CVR testing could help stratify patients by risk of stroke and help with treatment decisions. Their study was sensitive to variations for revascularization costs and complication risk, among a number of other factors, though more work must be done to determine whether other imaging modalities would return similar results.

“Our findings were robust to plausible changes in the performance and cost of transcranial Doppler US, but CT could carry additional costs and risks from radiation exposure that could affect the cost-effectiveness profile of CVR testing; future studies could confirm whether other modalities also could be efficient approaches to measuring CVR,” wrote Pandya and colleagues.