In 2015, Dr. Anversa was forced out at Harvard. He moved to research posts in Switzerland and Italy, but was fired from both, he said, as the controversy followed him overseas.

Last year, the Department of Justice announced that Brigham and Women’s Hospital and Partners Healthcare, a health care system founded by the Brigham and another Harvard-affiliated hospital, would pay $10 million to settle allegations that Dr. Anversa, Dr. Leri and Dr. Kajstura knew, or should have known, that their work included “improper protocols, invalid and inaccurately characterized cardiac stem cells, reckless or deliberately misleading record-keeping, and discrepancies and/or fabrications of data and images.”

Despite the setbacks, the National Heart, Lung and Blood Institute, part of the National Institutes of Health, has been conducting a $7.9 million clinical trial of cardiac stem cells that began in 2015. Denis Buxton, associate director of the division of cardiovascular sciences at the institute, said Dr. Anversa’s work was a “catalyst” for the study, although the institute does not believe that heart stem cells can turn into heart muscle. Still, some research indicates that heart stem cells and certain bone marrow cells may help form new blood vessels and heart cells, Dr. Buxton said.

But the institute announced on Monday that it is pausing the trial to review its “scientific foundations.”

A final verdict

This month, Dr. Anversa got Harvard’s conclusive findings on his life’s work. In an Oct. 3 letter that Dr. Anversa provided to The Times, officials at Harvard and its teaching hospital told him that he had “committed research misconduct” in eight papers, some published and others submitted for publication, as well as in a grant application. Although he was the lead author on many of the other papers that Harvard said must be retracted, the university said the evidence did not support his being responsible for the malfeasance in those cases. Harvard did not name the culprit or culprits in its letter to Dr. Anversa.

But the university said 31 scientific papers produced by Dr. Anversa’s laboratories, going back to 2001, should be retracted. University and hospital officials notified each journal of their conclusions as well as the Office of Research Integrity at the Department of Health and Human Services, which can recommend that the federal government ban researchers from receiving federal funds. Anyone associated with Harvard or the hospital who gives Dr. Anversa a reference must also describe his misconduct.

Dr. Anversa insists that he is being unfairly punished for what he says were Dr. Kajstura’s deceptions. “How could I be so stupid as not to realize that he was cheating?” Dr. Anversa said.