Radiologists have captured a growing market share for a key interventional procedure while cardiologists have lost ground, according to a new analysis published Saturday.

Among Medicare beneficiaries, there was a marked drop in the delivery of percutaneous renal artery angioplasty, used to treat a narrowed artery, between 2010 and 2018. Overall utilization plummeted roughly 72% during that timeframe, falling from 15.5 cases per 10,000 beneficiaries down to 4.3, experts wrote in Clinical Imaging [1].

Cardiologists saw their slice of the procedural pie fall from 74% in 2010 to 36% by the end of the study period, while radiologists’ share grew from 12% to 28%. Researchers believe there are several reasons behind the market shift.

“[Percutaneous renal arteriography] utilization rates have continued to decline in the Medicare population, likely due to a combination of recently published clinical trial results, improvements in the medical management for renal artery stenosis and decreasing reimbursements,” Philip Lee, MD, with the Department of Radiology at Thomas Jefferson University, and co-authors wrote July 8. “The declining PTRA rates across all specialties, most prominently cardiologists, has led to a small relative growth in market share for radiologists and reflects the shift away from the procedural management of [renal artery stenosis].”

Lee et al. gathered their information from the Physician/Supplier Procedure Summary database, containing all fee-for-service Medicare Part B claims for patients in the U.S. They noted that radiologists’ market share grew during the study period, despite a minor decrease in the total case rates performed by the specialty (falling 34%, or from 1.9 to 1.2 cases per 10,000 Medicare beneficiaries).

“We initially hypothesized that PTRA performed by radiologists would increase due to changing referral patterns and declining utilization of PTRA by cardiologists. However, our findings did not support this hypothesis,” the authors noted. “While it is not possible to ascertain the exact etiology for this shift, there are some interesting trends that have been noted with regards to changes in reimbursement within these fields.”

These include a 2022 study [2], which found that interventional radiology procedures experienced disproportionately greater reductions in reimbursement and RVU valuations between 2010 to 2021. IR also is “heavily influenced” by the referral patterns of other specialties, impacting the types of procedures performed, Lee and colleagues wrote.

Read more about the results, including potential limitations, at the link below.