When HCA, the largest for-profit hospital chain in the U.S., received a tip that one of its doctors was performing cardiac procedures on patients unnecessarily, it launched an investigation. HCA uncovered evidence that cardiologists at several of its Florida hospitals were unable to justify the procedures they conducted. A review of internal documents does not reveal how many unnecessary procedures were performed or how many patients might have been injured or died as a result. Company executives disclosed to investors via conference call that in July, the civil division of the U.S. attorney’s office in Miami requested information on necessity of cardiology services provided at 10 of its hospitals. HCA declined to provide evidence that it ever notified patients who might be entitled to compensation or evidence that it had alerted insurers of its findings or reimbursed them for procedures deemed unnecessary, which is required by law.