Cardiologists performing peripheral angioplasties: impact on utilization.

CONTEXT: Angioplasty and stent placement for peripheral arterial occlusive disease has traditionally been performed by radiologists and surgeons. However, cardiologists have recently begun to perform these procedures. It is unknown whether this has affected how often the procedure is done. OBJECTIVE: To assess how the proportion of peripheral angioplastics performed by cardiologists in a geographic area relates to population-based angioplasty rates. DESIGN: Cross-sectional analysis of all U.S. Medicare beneficiaries undergoing peripheral arterial (i.e., renal, iliac, or lower extremity) angioplasty in 1996 using Part B (physician) claims for cardiovascular procedures. Physician specialty was obtained from the American Medical Association's masterfile and Medicare. MEASURES: For each of the 306 U.S. hospital referral regions (HRRs), we calculated the proportion of procedures performed by cardiologists and rates of peripheral arterial angioplasty (adjusted for age, sex, and race). RESULTS: More than 37,000 peripheral arterial angioplastics were performed on Medicare beneficiaries in 1996 (50% for lower extremity, 33% iliac, and 17% renal arterial disease). Cardiologists performed 26% of these procedures overall, including 37% of the renal angioplastics. Few (12%) procedures were done as part of a cardiac catheterization; instead, most were done as a separate procedure. Use of peripheral angioplasty varied more than 14-fold across HRRs (median, 12 procedures per 10,000 beneficiaries; 10th to 90th percentile, 4.1 to 57.9). The mean angioplasty rate in HRRs where cardiologists performed 50% or more of the procedures was almost double that of regions where they performed none (21.9 vs. 12.1 procedures per 10,000 beneficiaries; P < 0.001). CONCLUSIONS: Cardiologists are performing a substantial proportion of peripheral angioplasties. Rates of these procedures are highest in regions where cardiologists do most of the angioplasties.