The plaintiffs' attorney, Gerry Mitchell, said the patients were suffering long-term complications from taking medications such as Plavix, required for most patients after stents were used to open the arteries.
These were life-saving procedures for patients with existing cardiac conditions, who had been referred by their physicians, Mitchell said.
However, the medication causes some patients to experience bleeding and bruising, The Baltimore Sun reported.
The lawsuit also alleged the hospital, St. Joseph Medical Center and Catholic Health Initiative, failed to provide any oversight to Dr. Mark Midei, leaving the patients with lasting medical complications.
David J. McManus, Midei's attorney, said the risk of not fixing a blockage with the wire mesh stents to prop open their arteries outweighed taking no action.
The plaintiffs also alleged Midei sped through the heart procedures to complete as many as he could, racking up revenues because he was paid based on performance.
McManus said Midei often worked months without vacations and on weekends, which contributed to the high number of stent procedures, and doctors now evaluating Midei's former patients have the benefit of hindsight.