A Pittsburgh hospital informed 141 patients earlier this year that they may have received unneeded angioplasties and stents, the tiny mesh tubes inserted to keep arteries open.

A Towson, Md., cardiologist faces a hearing on the fate of his medical license after being accused of implanting stents unnecessarily in more than 500 patients.

And this week, a new study found that more than half of patients with stable heart disease who received angioplasty and stents didn't first receive medications, as scientific guidelines recommend.

While a host of lawsuits and research studies has raised questions about the overuse of stents, the group that represents cardiologists who implant them relies heavily on income from the makers of these devices.

The Society for Cardiac Angiography and Interventions (SCAI) received 57 percent of its revenues in 2009 from medical device and pharmaceutical makers, according to financial information on the group's website.

Industry contributions to the society's budget covered $4.7 million of the $8.2 million it received that year.

The group's biggest funders are the companies with the biggest share of the stent market: Cordis Corp. (a subsidiary of Johnson & Johnson), Boston Scientific, Abbott Laboratories and Medtronic.

Researchers who study conflicts of interest in medicine say medical societies that receive a lot of industry support are susceptible to taking positions that either promote their sponsors' products or downplay their risks.

ProPublica reported last week that the Heart Rhythm Society, which gets nearly half its revenues from drug and device makers, had sometimes left out or downplayed information about the risks and limitations of cardiac devices and procedures.

SCAI's immediate past president, Dr. Larry Dean, said industry funding has no influence on the group's medical positions or treatment guidelines and that it supports proper use of stents.

Asked about doctors accused of implanting unnecessary stents in patients, Dean said his group is not a "policing agency" but takes the issue seriously and would expel any doctor found guilty of inappropriately implanting them.

Stents are big business.

From fiscal 2004 to 2009, Medicare paid about $25.7 billion for inpatient hospital stays in which a patient received a cardiac stent. From calendar years 2005 to 2009, Medicare paid doctors approximately $1.3 billion for 248,116 procedures, government records show.

This week's study about stent use in the Journal of the American Medical Association did not look at the role SCAI or other medical societies played in treatment decisions. One of the authors, however, said such groups need to play a role in ensuring that doctors practice medicine in line with the best scientific evidence.

"Our study should be viewed as ... an important stimulus to societies, providers, physicians and health care organizations to try to optimize medical therapy," said Dr. Alvin Mushlin, chairman of the public health department at New York Presbyterian/Weill Cornell Medical Center. "I think there are plenty of opportunities to do more."

Dean said the study doesn't demonstrate the influence of industry on practice but rather "how difficult it is to educate the masses of cardiologists out there in practice." Other studies, he said, have shown that the vast majority of stents have been implanted properly, particularly for patients with acute heart problems.

"I don't think industry is driving the delivery of health care," Dean said. "The companies that make stents don't drive it either."

A report released last year by the U.S. Senate Finance Committee suggests that the field of interventional cardiology has done little to discourage overtreatment.

The committee's report cited an internal document from Abbott Laboratories describing a medical advisory board meeting in October 2007. Among the topics mentioned was a large clinical trial that recommended patients with stable heart disease be given drugs before receiving angioplasty and stents.

One of the "key takeaways" of the board meeting was that panelists "revealed candidly that they're [sic] profession has done a better job promoting PCI [percutaneous coronary intervention] than policing it and that some of these practices have alienated their fellow cardiologists," the senate report quoted the Abbott document as saying.

SCAI receives a significantly higher proportion of industry funds than the American College of Cardiology, which last year took in less than a third of its revenues from drug and device makers.

Dean said his group would like to have a similar ratio of industry funding. But without raising dues or registration fees, he said, that could be tough.

About 20 percent of SCAI's industry money is passed along to hospitals that run training programs for interventional cardiologists. Other funds are used to provide educational programs for doctors and raise awareness of heart disease among the public, he said.

Industry funding "has allowed us to do a lot of things that we would not have been able to do otherwise," Dean said.

Membership societies, representing every specialty of medicine, play a critical role because they help set treatment guidelines used by physicians across the country, lobby for Medicare coverage and research funding, and provide information about diseases and treatments to the public.

Experts said that while many societies are eager to discuss the latest advances in their fields and ways in which drugs and devices may be underused, they spend less time talking about possible overuse.

In 2008 and 2009, Sens. Charles Grassley, R-Iowa, and Herb Kohl, D-Wis., targeted another cardiac group, the Cardiovascular Research Foundation, which holds annual gatherings to show off advances in stents and heart catheters.

The senators accused the research group's leaders of failing to disclose millions of dollars they received from industry to Columbia University, with which the foundation is affiliated.

Columbia told the senators that the doctors received some of the money before they became employees and therefore did not have to disclose it. The university adopted a new policy on financial conflicts of interest in research in 2009.