The Effect of the Introduction of MR and CT Angiography on the Utilization of Catheter Angiography for Peripheral Arterial Disease

Abstract

To determine whether the utilization rate of diagnostic catheter angiography (DCA) for peripheral arterial disease (PAD) has been affected by the utilization in recent years of magnetic resonance angiography (MRA) and computed tomographic angiography (CTA). Medicare Part B data sets for 2000 to 2004 were reviewed to study utilization trends in the Current Procedural Terminology, 4th ed., codes for DCA, MRA, and CTA of peripheral arteries. The Medicare physician specialty codes were used to indicate procedures performed by radiologists, cardiologists, surgeons, and other physicians. Utilization rates per 100,000 Medicare beneficiaries were calculated. Between 2000 and 2004, the total utilization rate of all 3 types of angiographic procedures for PAD rose from 789 to 969 per 100,000 (+23%). The rate for DCA dropped slightly, from 767 to 761 per 100,000, whereas the rate for MRA and CTA together increased from 23 to 208 per 100,000. Almost all MRA and CTA were performed by radiologists. Among radiologists, the DCA utilization rate dropped from 486 to 334 per 100,000 (-31%); among cardiologists and surgeons together, the DCA rate increased from 228 to 387 per 100,000 (+70%). The total utilization rate of all diagnostic angiographic procedures for PAD among radiologists increased by 3%, compared with much higher rate increases among cardiologist and surgeons. Among radiologists, a substitution effect occurred, in that noninvasive procedures such as MRA and CTA progressively replaced an invasive procedure, DCA. However, the rapid increase in DCA utilization among cardiologists and surgeons led to an increase in the overall utilization rate of angiographic procedures for diagnosing PAD. Increasing self-referral for an invasive procedure such as DCA among these two specialties is of concern at a time when less expensive, noninvasive alternatives are readily available.