WEDNESDAY, Sept. 1, 2004 (HealthDayNews) -- Between 1996 and 2000, the annual number of Medicare patients who had renal artery interventional procedures, where angioplasty or a stent clears arteries connected to the kidneys, more than doubled.
That finding appears in a study in the September issue of the American Journal of Roentgenology.
The researchers found that much of the increase could be attributed to more cardiologists starting to do these kinds of procedures which, historically, have been done by interventional radiologists.
Renal artery interventional procedures are often done to treat hypertension, although randomized clinical trials have not proven these procedures actually help control blood pressure, the study said.
The review of Medicare claims data found that in 1996, radiologists performed 4,700 renal artery interventional procedures and cardiologists performed 2,380 such procedures. By 2000, cardiologists did 9,220 of these procedures and radiologists did 7,660 of these procedures.
"It is important to note that cardiologists self-refer, and that could be one of the reasons why there is such a large increase in the number of procedures they are doing," lead author Dr. Timothy Murphy, an associate professor of radiology at Brown University Medical School, said in a prepared statement.
The greatest increase in the use of these procedures was in southern states (Alabama, Kentucky, Mississippi, North Carolina, South Carolina and Tennessee), where use increased from 22 per 100,000 Medicare patients in 1996 to 86 per 100,000 in 2000.
In these states, there was a more than 15-fold increase in the annual volume of renal artery interventions done by cardiologists.
"If this growth rate by cardiologists in the southeast region continues, at the end of 10 years, every man, woman and child in these states will have had a renal artery stent," Murphy said.
States in the northeast had the lowest rate of increase, from 18 per 100,000 Medicare patients in 1996 to 26 per 100,000 in 2000.
These regional differences "prove there is no consensus on how these patients should be treated. Somebody is wrong. Patients are either being over- or under-treated," Murphy said.
The Society of Interventional Radiology has more about treatments for blocked blood vessels.