Abbott Laboratories hired a Baltimore-area cardiologist as a sales consultant after he was barred from practicing at a local hospital last year for allegedly putting heart stents in hundreds of patients who didn’t need them, say Senate investigators probing the medical-device industry.

Their report, to be released Monday, shines a light on one of the most lucrative procedures for hospitals and medical-device makers, at a time of spiraling health-care costs. Medicare paid some $25.7 billion for stent surgery in the six years through 2009, according to the report.

The investigators describe what they say was a tight relationship between Mark Midei, a onetime star doctor, and a company eager to expand its market share for stents, tiny wire-mesh scaffolds used to open blocked coronary arteries.

In 2008 Abbott paid more than $1,000 for a pig roast, complete with mobile pig pit, to fete the cardiologist the same week Dr. Midei, then head of the cardiac catheterization lab at St. Joseph Medical Center in Towson, Md., set a possible company record by implanting 30 stents in a single day, the report says.

Early this year, after the Baltimore Sun, reporting on the alleged overuse of stents at St. Joseph, questioned whether the devices were being overused in general, an Abbott executive suggested to a colleague — apparently in jest — that the company “send the Philly mob” to beat up the Sun writer, according to an internal Abbott email cited in the report.

Abbott, based in North Chicago., said Dr. Midei “has been a highly regarded physician in his field.” It said the company’s affiliation with him ended early this year, and declined to comment on the specifics of the relationship.

Abbott said its Xience stent is a top-selling product due to its “superior data and patient benefits.” Abbott, Johnson & Johnson, Boston Scientific Corp. and others are keen competitors in the market for stents, which can cost more than $1,000 apiece.

St. Joseph said it fully cooperated with the Senate investigation and took speedy action to protect patients by barring Dr. Midei last year after concluding he conducted hundreds of unnecessary procedures.

Dr. Midei denies St. Joseph’s allegations, and has sued the hospital, alleging it caused “irreparable damage” to his career.

His lawyer, Stephen Snyder, says the doctor was doing what the hospital had hired him to do. “They brought Mark in to replicate the success of his private practice in building up a heart center, and he did,” says Snyder. Dr. Midei didn’t receive extra pay from St. Joseph based on stent procedures and got “nothing extraordinary” from Abbott, the lawyer said.

After investigating complaints, St. Joseph notified 585 patients starting late last year that they might have been given coronary stents they didn’t need.

Senate Finance Committee Chairman Max Baucus (D., Mont.) requested the report on Dr. Midei. “Taxpayers shouldn’t be paying for improper surgeries and implants,” said Baucus. “This could be a sign of a larger national trend of wasteful medical-device use.”

Earlier this year, the Maryland State Board of Physicians charged Dr. Midei with unprofessional conduct, alleging that he repeatedly overestimated the blockage of patients’ arteries and put them in danger.

Snyder, his lawyer, said the state medical issues are unresolved, and that Dr. Midei is still in good standing with the board.

After St. Joseph barred Dr. Midei from practicing there in May 2009, Abbott arranged consultant work for him, according to emails released by the Senate committee.

In December 2009, an Abbott senior vice president wrote in an email that he was “very open” to having Dr. Midei do consulting “to see how it might go — either getting the word out in China/Japan, medical or safety work.”

The following month, the Sun reported on the allegations against Dr. Midei and St. Joseph. According to the Senate report, an Abbott executive subsequently said in an internal email, “We recommend that we not use Dr. Midei in the U.S. at this time (the press is just too hot).”

Charles Simonton, the medical director of Abbott’s vascular division, said in another email cited by the report that Dr. Midei should “clearly avoid” the Baltimore area, but Dr. Simonton encouraged colleagues to “please find key physicians or cath labs you’d like him to get in front of with our data.” Abbott wanted to hire Dr. Midei “because he helped us so many times over the years,” yet another Abbott executive said in an email.

Dr. Simonton didn’t return phone calls seeking comment.

Abbott sent Dr. Midei to Japan to promote the Xience stent, but bad publicity caused that trip to be cut short in late January, the report says. In total, Abbott paid the doctor $30,623 to help market the Xience, the Senate investigators found.

Around that time, an Abbott executive complained to a colleague by email about one of the Sun’s journalists. “Somebody needs to take this writer outside and kick his ass. Do I need to send in the Philly mob?” he wrote, according to the report.

St. Joseph agreed to a $22 million fine last month to end a federal investigation over its stent surgery charges to Medicare. At the time, the hospital said it wasn’t admitting liability, but was paying the fine “in order to avoid the expense and uncertainty of litigation.”

A 2007 Abbott document about a stent sales effort called “Project Victory” showed that Dr. Midei was among the top-volume stent doctors for the company in the Northeast, the Senate report says.

An Abbott executive vice president said in an email cited in the report that the doctor’s 30-stent day in 2008 “perhaps” achieved the company’s “single-day implant record.”

Two days later, Abbott hosted an “appreciation” barbecue for Dr. Midei and his colleagues at his home. The $1,407 pig roast boasted a mobile “Alabama pig pickin’ pit,” a whole pig smoked for 15 hours, Memphis-style ribs, chicken, hot dogs, cole slaw and two big peach cobblers, investigators found.

The doctor’s banishment in 2009 was a blow to St. Joseph’s cardiology revenue. The number of stent patients at the hospital that year fell to 116 from 350 in 2008, the Senate report says.

Stent use has flattened out in recent years in the U.S. in the wake of studies suggesting that many patients would be better off either with major heart surgery or with drugs alone.