National trends in catheter angiography and cerebrovascular imaging in a group of privately insured patients in the US.

Background: Despite the increasing use of non-invasive imaging, DSA remains the gold standard for cerebrovascular imaging. However, trends in DSA utilization are poorly understood. The goal of this study was to describe DSA utilization in a large claims database in the US over a 13 year period.

Methods: This retrospective cohort study assessed a nationwide database of privately insured individuals from 2005 to 2018 for patients undergoing cranial CT angiography (CTA), MR angiography (MRA), and DSA. We assessed trends in the overall use of and indications for each modality. For DSA, we examined the types of performing proceduralists.

Results: Among patients undergoing DSA in 2018, median age was 52 years, and 60% were women. MRA and DSA use decreased, from 289 to 275 claims, and from 38 to 29 claims per 100 000 enrollees, respectively, while CTA use increased from 31 to 286 claims per 100 000 enrollees. These trends differed by geographic region and indication. Nearly half of DSA procedures but <25% of non-invasive imaging were inpatient studies. DSA performed by neurosurgeons increased from 0.5 to 4.1 while those performed by radiologists decreased from 7.2 to 4.0 studies per 100 000 enrollees.

Conclusions: DSA use decreased slightly while CTA use increased by ninefold. The reasons for this change are likely complex and may reflect more aggressive imaging for stroke, increased detection of incidental findings, and increased quality of non-invasive imaging. Over time, the proportion of DSA procedures performed by neurosurgeons overtook that performed by radiologists.