Heart doctors and makers of medical devices meeting for their annual convention here got a sobering piece of news on Thursday -- two senators are asking tough questions about financial ties between the doctors and the companies.
The two lawmakers, Charles E. Grassley, Republican of Iowa, and Herb Kohl, Democrat of Wisconsin, sent a letter asking the nonprofit group that sponsors the conference, the Cardiovascular Research Foundation, for information about its financial relationships with device manufacturers and drug producers.
The senators also sent a letter to Columbia University, which has an affiliation with the Cardiovascular Research Foundation. Two well-known researchers at Columbia, Dr. Martin B. Leon and Dr. Gregg W. Stone, are involved with the foundation; Dr. Leon is its former chairman and Dr. Stone its current one.
In a statement, the foundation said it would ''comply fully'' with the information request. ''C.R.F. is committed to maintaining the highest standards of integrity in all of its research and educational activities and ensuring independence, objectivity and scientific rigor in all of its programs,'' the statement said.
According to the foundation's most recent tax filing on the Web site guidestar.org, it had revenue in 2005 of $47.2 million.
Columbia University Medical Center issued a statement saying it would respond to the request for information. ''It is important to note that Columbia University and its Medical Center have conflict of interest policies and procedures in place, and we expect that they are followed by all members of the faculty,'' the statement said.
The manufacturers cited in the senators' letters are Abbott Laboratories, Medtronic, Boston Scientific, Johnson & Johnson and Medinol.
The annual conference here, known as Transcatheter Cardiovascular Therapeutics, has attracted hundreds of doctors from around the world who specialize in using devices that are placed in the body through catheters, most notably heart stents, the tiny devices that are used to prop open clogged arteries.
At the meeting, manufacturers of stents and related surgical products or drugs display their products in an exhibition hall.
The letters sent Thursday are part of a recent wave of inquiries by Senators Grassley and Kohl into potential conflicts of interests between medical researchers and drug and device companies. The lawmakers are also among those sponsoring legislation that would require the industry to more fully disclose such financial ties.
In their letter to the foundation, the lawmakers also took note of a comment in an article published last November in The New York Times. In the article, a researcher, Dr. Jeffrey W. Moses, who serves on the board of the Cardiovascular Research Foundation, said that the safety of heart stents ''is not the big issue any more.''
The senators wrote: ''As you are no doubt aware, there are divergent scientific opinions concerning such products, the safety and efficacy of which are a matter of dispute among cardiologists.''
The letter to the Cardiovascular Research Foundation asked the group to disclose all financing it had received since 2003 from the five device manufacturers named in the letter and also to provide documentation of any payments and benefits the foundation had provided to 22 researchers including Dr. Stone, Dr. Leon and Dr. Moses.
The lawmakers asked Columbia to provide information about the disclosures those researchers had made to the institution about their income from industry sources.
At the same conference on Thursday, researchers released results of a new study indicating that a drug-coated stent called Endeavor, made by Medtronic, was linked to more heart attacks and deadly blood clots than the Cypher stent made by Johnson & Johnson.
