Last month, St. Joseph agreed to pay a $22 million fine to settle charges that it paid illegal kickbacks to Dr. Midei’s medical practice, MidAtlantic Cardiovascular Associates, in exchange for patient referrals; the hospital did not admit wrongdoing. St. Joseph said in a statement Friday that it now conducts monthly random reviews of stent cases “to assure such a situation cannot occur again.”

As for Abbott Labs, a spokesman wrote in an e-mail that its affiliation with Dr. Midei ended early this year. “Dr. Midei has been a highly regarded physician in his field, with whom Abbott had consulted in the past,” said the spokesman, Jonathan Hamilton. “We have no further comment at this time.”

The case has had wide repercussions. Over the past year, St. Joseph has told hundreds of Dr. Midei’s patients that they did not need the expensive and potentially dangerous stents that the doctor inserted because their arteries were not as obstructed as he had claimed. Now, state health officials are investigating other local cardiologists who inserted a suspiciously high number of stents, which are tiny wire mesh devices inserted to prop open clogged arteries in the heart.

After reports about the Midei case and the wider state investigation, the number of stent procedures performed at St. Joseph and other area hospitals plunged, raising doubts about the appropriateness of much of the region’s cardiac care.

A landmark 2007 study published in The New England Journal of Medicine showed that many patients given stents would fare just as well without them. Dr. Christopher J. White, president-elect of the Society for Cardiovascular Angiography and Interventions, said that inappropriate stenting was a problem, but a rare one. The federal Medicare program spent $3.5 billion last year on stent procedures.

Prosecutors, malpractice lawyers and state medical boards are only now waking up to the issue. The Texas Medical Board last month accused a widely known cardiologist in Austin of inserting unnecessary stents. In September, federal prosecutors accused a cardiologist in Salisbury, Md., of performing unnecessary stent surgeries, and last year a Louisiana doctor was sentenced to 10 years in prison for inserting unneeded stents.

J. Stephen Simms, a Baltimore lawyer who successfully pursued a federal whistle-blower lawsuit involving kickbacks for coronary procedures, said such cases were “the flavor of the month right now” with federal prosecutors.